A new and distinct cultivar of Browallia plant named ‘UNHBR4’, characterized by numerous single flowers that are purple pink in color with a small white center, compact and rounded plant growth, stems that do not break or separate on the center of the mature plant, and good performance in partial shade in the garden and as a hanging basket.

The present Invention relates to a new and distinct cultivar of Browallia plant, botanically known as a Browallia speciosa, and hereinafter referred to by the cultivar name 'UNHBR4'.
The new Browallia is a product of a planned breeding program conducted by the Inventor in Durham. N.H. The objective of the breeding program is to create new compact Browallia plants with attractive flowers in a range of colors, profuse flowering and reduced fruit set.
The new 'UNHBR4' originated from a manual self pollination made by the Inventor on Dec. 4, 2001 on proprietary selection UNH B010-13 resulting from hybridization between a proprietary selection of Browallia speciosa code BROW7, not patented, used as female, and a proprietary selection of Browallia speciosa BROW5-1, not patented, used as male. Seed was sown on Feb. 14, 2002. From the segregating progeny, a single plant BR2-10-1, later coded as 'UNHBR4' was selected in Durham, N.H., USA, on the basis of its profuse flowering, compact growth habit and attractive flowers.
Asexual reproduction of the new cultivar by terminal vegetative cuttings since June 2002 in Durham, N.H. has shown that the unique features of this new Browallia are stable and reproduced true to type in successive generations.


A communication device (1) includes a communication unit (60) that communicates with another communication device, a display unit (30) that displays an object corresponding to an object displayed on a display unit of the other communication device, and a control unit (10) that controls the communication unit (60) to transmit threshold information associated with the object displayed on the display unit (30) to the other communication device.

A variety of techniques are known for interactive exchange of a variety of information using devices such as, for example, mobile phones or portable game devices that communicate with each other over a wired or wireless connection.
Typical examples include participating in a game over a network. In such a game, a plurality of communication devices are connected over a network, and a variety of services that would be impossible with only one device are provided, for example allowing a plurality of users to compete or cooperate.
A communication system that uses such a network is not limited to games and is attracting attention from businesses in all fields as a possible medium for providing a variety of new services. One example of a proposed technique to allow for such services is an entertainment system that is not limited to network gaming but can also provide marketing or advertisement information (for example, see JP2002-049681A (Patent Literature 1)).

Communication device and communication system


A focusing-device for the radiation from a light source (2) is provided with a collector mirror (1, 1′) which is arranged in a mount (24) and collects the light, in virtual or real terms, from the light source (2) at the second focus (200). The collector mirror (1, 1′) is displaceably connected to the mount (24) via a bearing in such a way that its optical properties remain at least approximately the same even in the event of temperature changes.

1. Field of the Invention
The invention relates to a focusing-device for the radiation from a light source, in particular a laser plasma source, having a collector mirror according to the preamble of claim 1 of a type defined more closely.
An illuminating system having a collector mirror is described in U.S. Pat. No. 5,798,823.
2. Description of the Related Art
In semiconductor lithography, use is frequently made of a light source, for example a laser plasma source, whose light is collected, in virtual or real terms, via a collector mirror at a second focus, and then guided for beam formation into an illuminating system. The collector mirror is heated by the laser plasma source, resulting in corresponding changes in shape which have negative effects on the downstream illuminating system such as, for example, illumination defects, for example telecentring errors, uniformity defects, and this can lead to light losses.
It is known for the purpose of avoiding these disadvantages to cool the collector mirror in order to dissipate the heat produced. Irrespective of the large outlay required for this purpose, because of unavoidable tolerances problems continue to exist, nevertheless, with reference to the imaging accuracy, and these are to be ascribed, inter alia, to a change in position of the second focus. In addition, given high thermal loads, which can vary strongly with time in the case of pulsed operation, the collector mirror cannot be kept entirely at a constant temperature level, and so would necessitate a "dynamic" cooling system.

Focusing-device for the radiation from a light source


A triggering device for a safety apparatus includes a first detecting section and a second detecting section. The first detection section includes at least one first sensor located in a right-hand portion of a vehicle for detecting a deceleration acting on the vehicle in at least one of a longitudinal direction and a lateral direction of the vehicle. The second detecting section includes at least one second sensor located in a left-hand portion of the vehicle for detecting a deceleration acting on the vehicle in at least one of the longitudinal direction and the lateral direction of the vehicle. A controlling section is operative for triggering the safety apparatus in response to at least two out of detection values related to the longitudinal direction and detection values related to the lateral direction which are generated by the first and second sensors.

1. Field of the Invention
This invention relates to a triggering device for a vehicle occupant safety apparatus such as an air-bag apparatus or a vehicle safety-belt pretensioner (tightener).
2. Description of the Related Art
U.S. Pat. No. 5,107,245 discloses a control arrangement for the occupant restraint system of an automotive vehicle which includes an acceleration pickup for sensing deceleration of the vehicle and providing an acceleration signal. A trip device is in the occupant restraint system. A microcomputer processes the acceleration signal. The microcomputer supplies one or more trip signals to the trip device when the result of processing of the acceleration signal fulfills a criterion for activation of the occupant restraint system. A monitoring circuit external to the microcomputer includes an associated stable oscillator providing a reference signal. The monitoring circuit serves to monitor, as to correct frequency by comparison with the reference signal, a check signal derived from a clock signal of the microcomputer. The monitoring circuit produces an enable signal when the check signal has the correct frequency. The monitoring circuit activates an indicating means when the check signal is found to be incorrect. The monitoring circuit prevents the supply of the trip signal to the trip device in response to the disappearance of the enable signal.
U.S. Pat. No. 5,359,515 corresponding to Japanese published PCT application 4-506495 discloses a vehicle occupant safety system which includes a sensor device having at least two sensors, and a processing device having at least two processing circuits for the respective sensor signals. The vehicle occupant safety system in U.S. Pat. No. 5,359,515 further includes a computing system and a trigger circuit each having at least two stages for a safety device. For providing a high degree of safety with relatively low costs, the computing system is constructed as a single-computer system in such a way that it processes the data of the two processing circuits in two programs with staggered timing with respect to one another.
Japanese published unexamined patent application 5-69791 discloses a side-crash sensing system for automotive side air-bag devices in which an air-bag trigger component is controlled in response to the output signals of plural acceleration sensors.
Japanese published unexamined patent application 5-38998 discloses an arrangement of acceleration sensors for an automotive air-bag device. Specifically, in the sensor arrangement of Japanese application 5-38998, a crash sensor is located at a center of a front of a vehicle body outside a passenger compartment, and two crash sensors are located near front-right and front-left vehicle wheels respectively. The former crash sensor is referred to as the central crash sensor while the latter crash sensors are called the side crash sensors. As viewed from above, the three crash sensors extend at the comers of an isosceles triangle respectively. In addition, a safety sensor is disposed in the passenger compartment within the vehicle body. The three crash sensors are electrically connected in parallel. The safety sensor is electrically connected in series with the parallel combination of the crash sensors. When the safety sensor and at least one of the crash sensors simultaneously fall into ON states, the air-bag device is triggered and activated. A frontal collision can be quickly detected by the central crash sensor. Offset collisions can be detected by the side crash sensors. Collisions against front pillars of the vehicle body can also be detected by the side crash sensors.
U.S. Pat. No. 5,072,966 corresponding to Japanese published unexamined patent application 3-273959 discloses an energy absorbing structure for a vehicle body side portion which includes a pair of vehicle body members constituting two side portions of a vehicle body, and a pair of collision detection sensors for respectively detecting collisions on two side surfaces of the vehicle body. In addition, one air bag is provided in each vehicle body member. Each air bag can be unfolded toward the interior of a passenger room, and can receive at least one passenger who is moved sideways by a side collision. In the energy absorbing structure of U.S. Pat. No. 5,072,966, a timing varying unit serves to change the unfolding timings of the two air bags in accordance with a side-collision direction on the basis of detection results from the collision detection sensors. The air bags are unfolded in accordance with the unfolding timings set by the timing varying unit.
Japanese published unexamined patent application 5-270355 discloses an arrangement of G sensors for a flat floor vehicle which detects not only longitudinal gravity but also a yaw rate through easy computation without disturbing free walking of occupants in a vehicle room. In the arrangement disclosed by Japanese application 5-270355, right and left G sensors are located at laterally symmetrical positions about the central longitudinal line of a vehicle body on which the center of gravity of the vehicle is present. Both the G sensors are on a vehicle floor panel outside a walk-through region. The right G sensor extends below a right front seat while the left G sensor extends below a left front seat.
Japanese published unexamined utility model application 6-79667 discloses an air-bag apparatus for an automotive vehicle which includes a sensor for detecting a shock from the front, and two sensors for detecting shocks in transverse directions. These sensors are located in a front portion of a vehicle body. Air bags respond to the output signals of the sensors. The air bags are located in front and at side of a driver's seat and a passenger's seat respectively.


Accommodating intraocular (AIOL) assemblies for enabling post implantation in situ manual selective displacement of an AIOL along a human eye's visual axis relative to stationary anchor points. Axial displacement may be over a continuous range or alternatively at discrete axial stopping positions typically from about 100 μm to about 300 μm apart. Novels AIOLs designed to be at least partially folded for facilitating insertion into a human eye through a relatively small incision.

Commonly owned PCT International Application No. PCT/IL02/00693 entitled Accommodating Lens Assembly and published on 27 Feb. 2003 under PCT International Publication No. WO 03/015669 illustrates and describes accommodating intraocular lens (hereinafter AIOL) assemblies, the contents of which are incorporated herein by reference. The AIOL assemblies each include a haptics system adapted to be securely fixed in a human eye's annular ciliary sulcus at at least two spaced apart stationary anchor points so that it may act as a reference plane for an AIOL of continuously variable Diopter strength affected by a human eye's capsular diaphragm under control of its sphincter-like ciliary body and acting thereagainst from a posterior direction. The haptics systems include a rigid planar haptics plate with a telescoping haptics member for sliding extension. The haptics plate and the haptics member are preferably self-anchoring as illustrated and described in commonly owned PCT International Application No. PCT/IL02/00128 entitled Intraocular Lens and published on 29 Aug. 2002 under PCT International Publication No. WO 02/065951, the contents of which are incorporated herein by reference.
Commonly owned PCT International Application No. PCT/IL2005/000456 entitled Accommodating Intraocular Lens Assemblies and Accommodation Measurement Implant and published on 10 Nov. 2005 under PCT International Publication No. WO 2005/104994 illustrates and describes AIOL assemblies enabling post implantation in situ manual selective displacement of an AIOL along a human eye's visual axis relative to at least two spaced apart stationary anchor points to a desired position to ensure that an AIOL assumes a non-compressed state in a human eye's constricted ciliary body state. Such in situ manual selective displacement can be effected post implantation to correct for capsular contraction which is a natural reaction which typically develops over a few months following extraction of the contents of a human eye's natural crystalline lens, and also a subject's changing eyesight overtime with minimal clinical intervention. Such in situ manual selective displacement can be achieved as follows: First, a discrete haptics system for retaining a discrete AIOL which is manually displaceable relative thereto. And second, a haptics system with at least two haptics having radiation sensitive regions capable of undergoing plastic deformation for in situ manual displacement of an integrally formed AIOL.
Commonly owned PCT International Application No. PCT/IL2005/001069 entitled Accommodating Intraocular Lens (AIOL), and AIOL Assemblies Including Same illustrates and describes an AIOL including a biasing mechanism for elastically deforming an elastically deformable shape memory disk-like optical element for affording the AIOL a natural positive Diopter strength for near vision. The AIOL is intended to be implanted in a human eye such that relaxation of its ciliary body causes its capsular diaphragm to apply an external force for overcoming the biasing mechanism to reduce the AIOL's natural positive Diopter strength for distance vision.
Other AIOLs are illustrated and described in U.S. Pat. No. 4,254,509 to Tennant, U.S. Pat. No. 4,409,691 to Levy, U.S. Pat. No. 4,888,012 to Horn et al., U.S. Pat. No. 4,892,543 to Turley, U.S. Pat. No. 4,932,966 to Christie et al., U.S. Pat. No. 5,476,514 to Cumming, U.S. Pat. No. 5,489,302 to Skottun, U.S. Pat. No. 5,496,366 to Cumming, U.S. Pat. No. 5,522,891 to Klaas, U.S. Pat. No. 5,674,282 to Cumming, U.S. Pat. No. 6,117,171 to Skottun, U.S. Pat. No. 6,197,059 to Cumming, U.S. Pat. No. 6,299,641 to Woods, U.S. Pat. No. 6,342,073 to Cumming et al., U.S. Pat. No. 6,387,126 to Cumming, U.S. Pat. No. 6,406,494 to Laguette et al., U.S. Pat. No. 6,423,094 to Sarfarazi, U.S. Pat. No. 6,443,985 to Woods, U.S. Pat. No. 6,464,725 to Skotton, U.S. Pat. No. 6,494,911 to Cumming, U.S. Pat. No. 6,503,276 to Lang et al., U.S. Pat. No. 6,638,306 to Cumming, U.S. Pat. No. 6,645,245 to Preussner, US Patent Application Publication No. US 2004/0169816 to Esch, and EP 1 321 112.

This patent is subject to a terminal disclaimer.

Accommodating intraocular lens (AIOL) assemblies, and discrete components therefor


A perforating system having annular connectors for attachment between adjacent perforating guns and connectors. The connectors include male and female connectors with respective outer and inner contact surfaces. The connectors also include attachment for electrical detonators and/or booster charges for transferring ballistic detonations between the perforating gun and connector sub.

1. Field of Invention
The invention relates generally to the field of oil and gas production. More specifically, the present invention relates to a perforating system having signal circuit connectors on adjacent members of a perforating string that can be put into direct contact.
2. Description of Prior Art
Perforating systems are used for the purpose, among others, of making hydraulic communication passages, called perforations, in wellbores drilled through earth formations so that predetermined zones of the earth formations can be hydraulically connected to the wellbore. Perforations are needed because wellbores are typically completed by coaxially inserting a pipe or casing into the wellbore. The casing is retained in the wellbore by pumping cement into the annular space between the wellbore and the casing. The cemented casing is provided in the wellbore for the specific purpose of hydraulically isolating from each other the various earth formations penetrated by the wellbore.
Perforating systems typically comprise one or more perforating guns strung together, these strings of guns can sometimes surpass a thousand feet of perforating length. In FIG. 1 an example of a perforating system 11 is shown having a perforating gun string 4 with perforating guns 6 coupled together by connector subs 13. The gun string 4 is shown disposed within a wellbore 1 on a wireline 5. The perforating system 11 as shown also includes a service truck 7 on the surface 9, where in addition to providing a raising and lowering means, the wireline 5 also provides communication and control connectivity between the truck 7 and the perforating gun 6. The wireline 5 is threaded through pulleys 3 supported above the wellbore 1. As is known, derricks, slips and other similar systems may be used in lieu of a surface truck for inserting and retrieving the perforating system into and from a wellbore. Moreover, perforating systems may also be disposed into a wellbore via tubing, drill pipe, slick line, coiled tubing, to mention a few.
Included with the perforating gun 6 are shaped charges 8 that typically include a housing, a liner, and a quantity of high explosive inserted between the liner and the housing. When the high explosive is detonated, the force of the detonation collapses the liner and ejects it from one end of the charge 8 at very high velocity in a pattern called a "jet" 12. The jet 12 perforates the casing and the cement and creates a perforation 10 that extends into the surrounding formation 2.
FIG. 2 is a side partial sectional view of a portion of a known perforating gun string 4 depicting an example connection between a perforating gun 6 and a connector sub 13. Also shown in FIG. 2 is an example detonation system for the shaped charges 8. The detonation system illustrated includes a detonation cord 15, that when ignited imparts a shock wave to initiate shaped charge 8 detonation. The system further includes an electrical circuit 14 that delivers electrical signals from the surface to initiators 17 for selectively igniting a specific detonation cord 15. Wire connectors 16 are shown within the circuit 14 for providing electrical communication between components within the circuit 14 and external to the circuit 14.
The circuits 14 therefore can be implemented for selective detonation of shaped charges 8 in specific perforating guns. Final assembly of the circuits 14, such as making up the wire connectors 16, is performed within the body of the guns 6. Ports 18 with removable covers are shown for accessing the circuits 14 and connectors 16. The ports 18 however may leak when exposed to high pressures downhole. Moreover, wires of the circuit 14 that pass between adjacent connector subs 13 and guns 6 can become twisted or otherwise damaged during assembly.

Electric and ballistic connection through a field joint


A method for fabricating field emission cathode, a field emission cathode, and a field emission lighting source are provided. The method includes: forming a catalyst crystallite nucleus layer on the surface of cathode substrate by self-assembly of a noble metal catalyst, growing a composited nano carbon material on the cathode substrate by using a TCVD process, in which the composited nano carbon material includes coil carbon nano tubes and coil carbon nano fibers. The measured quantity of total coil carbon nano tubes and coil carbon nano fibers is higher than 40%. The field emission cathode is fabricated by the aforementioned method, and the field emission lighting source includes the aforementioned field emission cathode.

A theory of field emission was first discovered by R. H. Fowler and L. W. Nordheim in 1928; by applying a strong electric field between a field emission cathode and a field emission anode, the electrons might be able to directly tunnel through a potential barrier from the field emission cathode and to collided to the field emission anode. Based on this theory, in practice, the field emission cathode can be constituted by using outgrowing spike structures in the past, or carbon nano tubes (CNT) or nano zinc oxide materials nowadays. These structures or materials being used nowadays have better aspect ratio, thereby generating greater field emission enhancing factors for enhancing field emission.
Carbon nano tubes are single or multiple layered nano scaled graphite sheets forming a hollow cylindrical structure. Because of the small diameter and the large depth-to-width ratio of the carbon nano tube, hundreds to thousands times of locally enhanced electric field can be generated at the tip of the carbon nano tube, so that electrons can be emitted with an electric field of 1˜2 V/μm from the CNT by overcoming a work function of 4.5 eV, which offers an excellent electron-emitting effect and can be applied to field emission lighting components in the field of light emitting. When the carbon nano tube is disposed at the cathode of an electric field, electrons can be driven to emit from the tip of CNT by the driving force of the electric field. Those electrons will be collided with phosphors layer on the anode through a vacuum interval, thereby a light beam is emitted from the phosphor layer based on the field emission light theory. The field emission light theory is applied for developing field emission light (FEL), and field emission display (FED). For instance, in 2002, J.-M. Bollard, R. Gaal, S. Garaj et al. had published a paper (Field emission properties of carbon nanohorn films; Journal of applied physics 91 (12): 10107-10109), which illustrates that carbon nanostructure, multi-single-wall carbon nano tube, and carbon nano cone have great field emission properties. In addition, US Pub. No. 20030001477, U.S. Pat. No. 7,276,843, and a paper published by Pan L, Hayashida T, Nakayama Y et al. in 2002 (Fabrication of Carbon Nanocoil Field-Emitters and Their Application to Display; Japan Hardcopy Vol 2002, page 533-534, 2002) also illustrate that single-wall carbon nano tube, cylindrical graphene, graphitic nano fibers, carbon nano-coil fiber can be used as a cathode emitter.
Field emission is driven by electrical energy to emit light; nowadays, field emission lighting sources are gradually sprout in the field of lighting. Referring to FIG. 1, a field emission cathode 95 is disposed in a vacuum glass tube 92 of a field emission lighting source 91, a electric field is formed while applying a electrical potential to the field emission light source 91, so that a light can be generated by colliding an electron beam emitted from the field emission cathode 95 with a phosphor layer 941, where the luminous efficiency thereof ranges from 40 to 60 lumens per watt. By using this kind of field emission light source having simple structure and having none energy consuming during semiconductor manufacture, the luminance environment in human society may be significantly improved.
The major component in the field emission lighting source is the field emission cathode; in numerous prior arts, processes for fabricating carbon nano tubes being used in the field emission cathode have been provided, such as the chemical vapor deposition (CVD) method provided by J-Ean-Bonard and Thomas stockli et al. in 2001 (Appl. Phys. Lett. 78, 2775), in which a metal filament made of Kanthal (Fe—Al—Cr alloy) was used as a substrate and was immersed in a catalyst of Fe(No3)39H2O, and then the substrate was disposed in a reacting furnace with a temperature of 720° C. and acetylene and nitrogen gas were introduced thereinto. By using the CVD method, carbon nano tubes were then being grown on the surface of the metal filament, and forms a field emission cathode filament; while this field emission cathode filament is combined to an anode fluorescence tube, a field emission lighting source can be formed. This process for fabricating CNT directly by using CVD, however, needs to be processed in a high temperature environment, and those instruments used in this process are expensive. Additionally, using this process to mass produce the field emission lighting source is quite difficult and is not cost-effective. Moreover, the carbon nano tube is linear-shaped, electrons can only be emitted from the tip end thereof, and the emitting area is then limited accompanying with the melting of the carbon nano tube, so that the luminous quantity is low, thereby limiting the range of its applications.
Other processes each including a step of depositing a conductive layer on the substrate for growing CNT were also provided and disclosed under patents or publications, such as U.S. Pat. No. 6,948,995, TW Pat. No. I321806, or a paper published by Woo Yong Sung et al. in 2007 (Nanotechnology 18 245603) where CNT was grown on an electrical conductive thin layer on a nickel metal substrate. In addition, in 2008, Weiqi Fu, Liang Liu et al. had also provided a process (J. Vac. Sci. Technol. B, vol. 26, 1404), in which a stainless steel sphere was applied to be as a substrate, and this substrate was first coated with a silver paste. Then, a slurry containing carbon nano tube combined with organics which is like ethyl cellulose, terpineol, and diethyl ophthalate, etc. were coated on the surface of the substrate followed by a baking step. Next, the substrate was fixed on an inner center of an anode fluorescence sphere in order to form a field emission lighting bulb. Moreover, in TW Pat. No. I318963, another process was disclosed, in which a carbon nano tube array and prepolymer of polymethyl methacrylate thin layer was disposed on a substrate for fabricating materials of field emission cathode. In JP2005-166690, U.S. Pat. No. 7,960,904, an electrical conductive paste was plated on a field emission cathode lamp filament for adhering with carbon nano tube. Nevertheless, while using these processes, the requirement of an amount of organic materials like diethyl opthalate, polymethyl methacrylate is great such that organics will remain. Therefore, while fabricating the field emission lighting source, the organics will gradually leak during vacuum packaging and ion bombard, thus influencing the working life and the service luminous efficiency of the field emission lighting source.
In still another process disclosed under prior arts is to form composited plated layer by whether electroplating or chemical plating, such as in U.S. Pat. No. 6,975,063, Mao et al. disclosed an electroless plating manner, in which a carbon nano tube and a reduced metal were co-deposited on the surface of a substrate, and then the composited plated layer of carbon nano tube and metal can be obtained, and therefore the adhesion between the substrate and the carbon nano tube can be improved. However, in this manner, a traditional composited plating process was used, the plating solution thereof is easy to decompose and is hard to be storage. Plus, the emission efficiency and the luminance uniformity of the field emission lighting source merely using the carbon nano tube for field emission was too low to be used widely.
Another process as TW Pub. No. 201025415 and TW Pub. No. 201001476 were disclosed; in which zinc, zinc-plated, or aluminum substrate was roughened, afterwards, the substrate surface was immersed in a solution containing single-wall carbon nano tube, double-wall carbon nano tube, wall-less carbon nano tube, multi-wall carbon nano tube, carbon nano fiber, coil shaped carbon nano fiber, nano diamond, or other carbon nano materials, so that the surface of the substrate can be coated with a layer of nano carbon materials in order to fabricate a field emission cathode. Among these prior arts, even the carbon nano fiber had better field emission characteristics than the carbon nano tube, the fractional yield of the carbon nano fiber was low, and the aspect ratio of the carbon nano fiber was small due to the rapid growth of the carbon nano fiber triggered by metals like nickel, zinc, or aluminum, so that when the carbon nano fiber is applied to be as a field emission cathode, the overall electron beams emitted from the field emission cathode are still insufficient.
Other prior arts such as U.S. Pat. No. 6,333,016 and US Pub. No. 20020090468 have provided processes for fabricating carbon nano tubes, in which reduced metals were used to germinate carbon nano tubes, and more particularly, catalytic particles contain at least one metal from Group VIII, and at least one metal from Group VIb as assisted metal catalysts for germinating the carbon nano tubes. Furthermore, manners of chemical replacement of metals were also disclosed under TW Pat. No. I274789 and TW Pub. No. 200743677 for fabricating carbon nano tubes, where composited metal micro-particles such as nickel-cobalt, nickel-gold, nickel-platinum, cobalt-palladium or cobalt-platinum were used for growing carbon nano tubes. However, reduction reactions of these manners using metal catalysts and assisted metal catalysts were difficult to control, and the uniformity of the carbon nano tubes grown by using these manners was insufficient, such that field emission generated by these manners was poor, thereby the luminance quantity of the field emission lighting source was unlikely to be enhanced.
What is more, TW Pub, No, 201014787 and a paper published by J. X. Hung, Jun Chen et al. (J. Vac. Sci. Technol. B, vol. 26, 1700) disclosed that by using the thermal chemical vapor deposition process, where stainless steel filaments was used as a substrate, and iron, cobalt, nickel, rhodium, palladium, or platinum was used as a catalyst, carbon nano tubes can be formed with high sintering temperature for fabricating field emission cathode filaments. These field emission cathode filaments can be combined with an anode fluorescence tube to form a field emission lighting tube. According to some disclosures, including U.S. Pat. No. 7,098,112, US Pub. No. 20050023950, and JP2008-254757, nano carbon materials, majorly carbon nano tubes, can be grown on a silicon cathode carrier with cobalt catalysts. Besides, except the carbon nano tubes, other nano materials grown on the silicon carrier are also included such as carbon nano fibers, carbon nanohorns, carbon nanofilament walls, and so on. In US20060142148, US20110014368, U.S. Pat. No. 7,923,403, U.S. Pat. No. 7,396,798, and U.S. Pat. No. 7,968,489, palladium, oxidized metals, or sulfurized metals may be used as catalyst for growing carbon nano tubes, single-wall carbon nano tubes, or graphene. Moreover, TW Pub. No. 201012964 has disclosed that unsaturated vinyl monomers and hydrophilic monomer copolymer of noble metal catalysts were used to grow carbon nano tubes. However, the final yield of the coiled carbon nano tubes and coiled carbon nano fibers grown by using these processes are insufficient, and the diameters of the carbon nano tubes are about 200 nm˜300 nm as well as the aspect ratios of carbon nano tubes are too high to use in field emission. Accordingly, carbon nano tubes with relatively smaller aspect ratios were disclosed under U.S. Pat. No. 8,044,581, where the diameter and lengths of such carbon nano tubes ranges from 5˜10 nm and 20 nm˜1 μm, respectively. As above, carbon nano tubes are linear shaped, and electrons can only be emitted at the tip of the carbon nano tubes, so that the electron beams emitted therefrom are limited, even the intensity of the electron beams might be enhanced by increasing the emitting electric potential during field emission, the working life of the field emission lighting source would be significantly shortened as a side effect.
Hence, it is the major issues of field emission lighting sources to grow coiled-structured nano carbon materials applied to field emission cathodes with high fractional yields, and to be endure the consequence of applying higher driving electric potentials to provide higher luminance quantities.

Method for fabricating field emission cathode, field emission cathode thereof, and field emission lighting source using the same


A method of optical communication includes generating an amplified optical signal from at least a portion of a first optical signal having a first carrier wavelength, λ1. The amplified optical signal is applied to Brillouin media to stimulate generation of a Brillouin effect signal at a wavelength λ2. The Brillouin effect signal is modulated to produce a second optical signal having a second carrier wavelength, λ2. In one embodiment, the first optical signal is a downstream optical signal and the second optical signal is an upstream optical signal of a passive optical network.

Optical communications networks are used to transport large amounts of information attributable to voice, data, and video communications. These communications are in the form of optical signals carried by fiber optic cables.
Optical fiber might be used for long-haul transport between central office hubs of telecommunication providers. The optical fiber infrastructure has begun to encroach on traditional wireline infrastructure as optical fiber is extended closer to customer premises.
For example, fiber has been extended from the central office "to the curb", i.e., a service node near one or more customer buildings as a result of growing demand for increased bandwidth at a local level. The connection between individual buildings and the service node is completed with traditional wireline medium such as copper wires. An optical network unit (ONU) provided the optical-to-electrical and electrical-to-optical conversion required for interfacing the fiber portion of the network with the copper wire portion. The ONU communicates with an optical line terminal (OLT) at the central office.
Decreasing costs of fiber, increasing demand for bandwidth, and lower infrastructure costs have encouraged extension of the optical fiber all the way to the customer premises. An optical network terminal (ONT) terminates the fiber optic network at or near the customer premises and provides the interface between the optical network and any electrical media.
In order to appropriately direct communications between the appropriate customer premises and the OLT, each ONT may be assigned a unique communication channel. In one approach, the unique channel is realized as a specific timeslot of a time-division-multiplexed (TDM) optical signal. As the demand for greater bandwidth increases, a TDM timeslot becomes inadequate.
One approach for accommodating greater bandwidth is to provide a wavelength division multiplexed (WDM) network where each channel is distinguished by wavelength. The use of the same channel for upstream and downstream communications results in Rayleigh backscattering that impairs bi-directional communications on the same channel.

Optical network element with Brillouin effect colorless wavelength shift


An AC motor drive includes a PWM voltage inverter which is responsive to voltage commands from a synchronous current regulator to control motor armature current and rotor speed. A feedforward voltage is also applied as input to the PWM voltage inverter and it is compensated to boost the effective gain of the inverter when it is operated in the pulse dropping region. The compensation values are precalculated and stored in a table from which they are read during drive operation.

The field of the invention is AC motor drives for variable speed control of AC induction motors, and more particularly, high performance AC motor drives using pulse width modulation (PWM)techniques.
A motor drive for an AC induction motor includes a power section and a logic and control section. The power section receives power from a 3-phase AC source operating at 60 Hz frequency. The AC power is converted to DC power to provide a PWM inverter with a DC source for synthesizing voltages of different frequencies which are necessary to control the speed of an AC motor.
In high performance drives such as that described in U.S. Pat. No. 5,032,771, vector control, or field-oriented control is employed to control the speed and torque of the AC motor by developing command voltages for the PWM inverter. Such high performance drives employ motor stator current feedback which is resolved into a torque-producing or q-axis component of current, I.sub.q, and a flux-producing or d-axis component of current, I.sub.d. A motor speed feedback signal is also used for controlling the current components I.sub.q and I.sub.d to thereby control motor torque, speed and slip in accordance with the desired control strategy.
The operation of a closed loop, high performance drive is determined in part by the gain of the loops formed by the feedback from the motor. These closed loops include the PWM inverter, and their gains are, therefore, subject to variations in the gain of the PWM inverter at different motor speeds.
As disclosed in U.S. Pat. No. 5,121,043, the PWM inverter has three distinct regions of operation. At low motor speeds the inverter operates in a linear pulse width modulation mode in which the inverter chops the DC bus voltage into pulses that produce a sinusoidal current in the motor armature that is related to the input voltage command by a constant gain factor and the motor's impedance. Similarly, at high motor speeds the inverter changes to a six step inverter mode in which it produces a current, the fundamental component of which is related to the command voltage by a different gain factor and the motor's impedance. However, in the transition range between these two modes of operation the inverter gain is not constant. This transition range is referred to as the "pulse dropping region" since some of the triangular carrier pulses applied to the PWM inverter are not large enough to produce even a short voltage pulse or are nonexistent at the inverter output.
In this pulse dropping region, the inverter gain drops significantly and adversely affects the closed loop operation of the drive. For example, if a transient load is applied to a motor operating in this pulse dropping region, the drive will not respond properly to the speed or current feedback signal to correct the situation. This problem may be manifested as drops in motor speed or torque or as nuisance trips of the drive protection circuits due to current overload.

Compensated feedforward voltage for a PWM AC motor drive


A heat transfer device for sheet assembly for the heat transfer of an image on a transfer sheet to a receptor sheet for printing by inserting a sheet assembly comprising the transfer sheet on which an image has been formed and a receptor sheet for printing superimposed on an auxiliary plate into an inlet opening portion formed on a casing along an inlet stand, and passing between a pair of heat pressure rolls arranged inside the casing, includes: an exhaust fan for taking the outside air from the inlet opening portion toward the pair of the heat pressure rollers for cooling the pair of the heat pressure rollers; and aperture maintaining means for maintaining air passage for allowing the intake of the outside air between the upper edge portion of the inlet opening portion and the upper surface of the sheet assembly at the time of inserting the sheet assembly into the inlet opening portion. Accordingly, the pair of the heat pressure rollers can be securely cooled by the outside air via the air passage.

1. Field of the invention
The present invention relates to a heat transfer device for sheet assembly or a laminator, wherein the sheet assembly comprising a transfer sheet on which an image has been formed and a receptor sheet for printing superimposed on an auxiliary plate passes between a pair of heat pressure rollers so as to heat transfer the image on the transfer sheet onto the receptor sheet for printing.
2. Description of the Related Art
When an image is digitally processed and the image is transferred onto a transfer sheet with a printer based on the digital data, an image with a rich tone can be reproduced, realizing a sharp image quality. Since the tone of the image obtained a printed matter obtained by the offset printing of the image on the transfer sheet is slightly different from the tone of the image on the transfer sheet, a printing sample applied with color correction beforehand is necessary in order to grasp the finished image on the printed matter accurately.
As a device for producing the printing sample, recent attention is paid to a heat transfer device for sheet assembly (laminator). The heat transfer device for sheet assembly is constructed to transfer an image on a transfer sheet 100 onto a receptor sheet for printing by inserting a sheet assembly 108 comprising a transfer sheet 100 on which an image has been formed and a receptor sheet for printing 102 superimposed on an auxiliary plate 104 of an aluminum plate of about 0.3 mm thickness, further applied with a cover sheet 106 thereon, from an inlet opening formed on a casing along an inlet stand, and passing between a pair of heat pressure rollers. By the use of an ink ribbon applied with a thin film containing a pigment matched with the hue of a printing ink for printing an image on a transfer sheet based on digital data, a printing sample excellently exact to the actual printed matter at the time of the heat transfer of the image on the transfer sheet on the receptor sheet for printing can be provided stably.
In the heat transfer device for sheet assembly, the pair of heat pressure rolls comprise soft rollers comprising core rollers of metal pipes, of which surface covered with a soft synthetic resin such as silicone rubber, and built-inheat lamps. In order to obtain a printing sample exact to the actual printed matter, it is necessary to have the temperature of the heat pressure rollers homogeneously as much as possible at the time of the heat transfer by pressing the transfer sheet onto the receptor sheet for printing with the heat pressure rollers. If the temperature of the heat pressure rollers rises during the heat transfer process, not only inconveniences occur such as uneven transfer and generation of wrinkles in the receptor sheet for printing due to difficulty of peeling off the transfer sheet and the receptor sheet for printing, but also deterioration of the heat pressure rollers due to the temperature higher than the bearable temperature of the soft synthetic resin.
Therefore, the temperature of the heat pressure rollers is measured by a sensor for thyristor control of the power inputted to the heater lamps arranged in the heat pressure rollers. In order to prevent casting heat effect on other electric control parts in the casing, the temperature rise of the heat pressure rollers is prevented by covering the heat pressure rollers with roller covers as well as providing an exhaust fan at the bottom of the casing for taking cooling air from the inlet opening and cooling the heat pressure rollers.
Since the transfer sheet and the receptor sheet for printing adsorb moisture, the moisture may be evaporated by the heat of the heat pressure rollers so that the sheet assembly curls at the time of inputting from the inlet opening formed on the casing along the inlet stand. As to the auxiliary plate, even though it comprises an aluminum plate, in the case the thickness is about 0.3 mm, "warpage" would generate over a long term use. Accordingly, the sheet assembly may contact to the upper edge or surface of the inlet opening and choke the inlet opening due to deformation. In this case, intake of the cooling air from the inlet opening is bothered, resulting in extraordinary temperature rise of the heat pressure rollers.


There are provided a character input apparatus and a tape printing apparatus incorporating the character input apparatus as well as a character input method, which are capable of easily preparing a desired document by calling a design form having a sample text input therein in advance and then editing contents of the sample text. A plurality of design forms each having a sample text input therein in advance are stored, and one design form is selected from the plurality of stored design forms. The sample text of the selected one design form is edited. The sample text of the selected one design form or the edited sample text is displayed on a screen. At the same time, the sample text is also displayed with a cursor added to a character to be edited. In an initial state before editing, the sample text is displayed with the cursor added to a last character thereof.

1. Field of the Invention
This invention relates to a character input apparatus which is capable of calling a design form having a sample text input in advance therein and then editing contents of the sample text, and a tape printing apparatus incorporating the character input apparatus as well as to a character input method.
1. Prior Art
Recently, there has been proposed a character input apparatus (such as a word processor) that stores in advance design forms (templates) prepared assuming various uses, and enables a user to readily and easily prepare a document which meets the user's needs by calling a design form according to an intended use and inputting required data items into the same. Further, a tape printing apparatus is also widely used which stores a plurality of design forms and enables a user to produce various labels according to uses intended by users.
In the tape printing apparatus of the above-mentioned kind, e.g. in a process of making a label to be affixed to such a floppy disk as shown in FIG. 20A, a user selects a design form intended for the floppy disk and then causes an entered form illustrated e.g. in FIG. 20B to be displayed on a display screen. In this example, an upper area of the screen is allocated to a print image display section for displaying an image to be printed on a tape, and a lower area of the same is allocated to a text display section for displaying an edited state of an entered text. Text entry is started at a location immediately after a cursor K ("L" (short for letter) mark) displayed in the text display section. A numeral in white against black at the head of each line represents the line number of a character string, and a triangle mark displayed in white against black on the right side of the numeral, with one of its vertexes directed rightward, indicates that a specific format is set for the line.
In a state shown in FIG. 20B, the user operates a keyboard and the like while viewing a image displayed on the screen, to enter desired characters, such as letters and symbols (see FIG. 20C). Then, after entry of all character strings (three strings in this example) (see FIG. 20D), a printing process is executed, whereby it is possible to make a label having a predetermined size suitable for affixation to the floppy disk. In this case, the label size (tape length) is preset as shown in FIG. 20A, and hence the user can obtain a nice-looking label with ease without carrying out troublesome setting of the tape length.
However, when a design form is called for label making, no text is displayed in the print image display section at a stage of FIG. 20B before text entry, so that the user cannot obtain a print image of a character or a character string until the character or the character string is entered. In short, the user is given no idea of what text should be entered or where a text should be entered. Therefore, the user has to enter a character or a character string on a trial basis to view a print image thereof in the print image display section, and then retry character input when the result of the text input is not pleasing, or alternatively carry out character input while viewing samples of text entry to the design form e.g. by consulting an instruction manual.

Character input apparatus and tape printing apparatus incorporating the same as well as character input method


A composite elastomeric article for cushioning or mounting purposes including a mass substantially of tacky rubbery solid microspheres formed by suspension polymerization and agglomerated together in substantial contact with one another.

Solid microspheres which are tacky and rubbery and prepared by suspension polymerization are disclosed in many prior patents, including U.S. Pat. No. 3,691,140 and the several patents referred to therein and U.S. Pat. No. 5,194,329 and the several patents referred to therein. The principal uses for those prior art microspheres are as low-tack adhesives for repositionable note pads. In that application the microspheres are disposed over a substrate such as paper in a thin layer characterized in that the individual microspheres are dispersed and spaced apart and not in contact with one another. This spacing apart of the microspheres is a factor enhancing their ability to be applied, removed and reapplied to surfaces without transfer of adhesive or damage to the surface and with the low-tack adhesion needed for easy removal.
In the arts of adhesive cushioning and mounting means it is well known to use layers or slabs of elastomeric material which possess qualities of tackiness and rubberiness. In footwear, for example, U.S. Pat. No. 4,970,807 teaches the deposit in a recess within a shoe sole of small balls of resilient polyurethane or rubber. The balls are pre-coated with an adhesive such as silicone rubber so that they form a body which can be handled as a self-contained unit during assembly. U.S. Pat. No. 5,024,880 also discloses a form of tacky elastomer suitable for shock dampening. Similarly, adhesive coated foams have been widely used as mounting "dots" which typically are separated from release sheets and then pressed into adherence with a surface such as a wall to provide tacky exposed faces for releasable attachment of various objects. The 3M Corporation of St. Paul, Minn., U.S.A. has marketed one form of these prior art elastomeric products under the designation "Mounting Squares".
In none of these prior art adhesive cushioning and mounting elastomers, however, has any known use been made of solid microspheres which are tacky and rubbery and prepared by suspension polymerization as in the previously mentioned microspheres for repositionable note papers. The conventional utilization of those microspheres in very thin layers with the individual microspheres dispersed measurably apart has made them well suited for low-tack repositionable note pads but not for cushioning or mounting means.
It is a principal object of the present invention to provide improved composite elastomeric articles for adhesive cushioning and mounting purposes which utilize a specifically modified form of known solid microspheres prepared by suspension polymerization.

Composite elastomeric article for adhesive cushioning and mounting means


A vehicle information system is provided that includes an interface module configured to receive operating data from a vehicle information system. The interface module is also configured to transfer the operating data to a navigation system that is not built-in to the vehicle to facilitate vehicle position determination without using external positioning signals received or processed by the vehicle.

The invention relates generally to a system and method for transferring vehicle operating data to an external navigation system.
Certain vehicles include a spatial locating system (e.g., global positioning system (GPS)) configured to determine the position of the vehicle based on external positioning signals (e.g., signals from GPS satellites). The vehicle position may be presented to a driver and/or passenger via a graphical display located within the vehicle interior. In addition, the vehicle position may be broadcast via a vehicle communication network to an off-board vehicle navigation system positioned remote from the vehicle. The off-board navigation system is configured to monitor the position of the vehicle, thereby enabling a remote operator to provide directions toward a destination, send emergency vehicles in the event of a collision and/or identify the position of a stolen vehicle, for example. Certain off-board navigation systems may be configured to transmit navigation information back to the vehicle such that a driver may view route information on the graphical display. Unfortunately, if the vehicle passes under a bridge, through a tunnel or by a tall building, the signal from the external positioning signals may be insufficient to determine vehicle position.
Other vehicles may include an on-board spatial locating device, such as a handheld/mountable GPS receiver, or a portable device (e.g., mobile phone, personal digital assistant, notebook computer, etc.) having an integrated spatial locating device. Similar to the spatial locating system described above, the on-board spatial locating device is configured to receive external positioning signals (e.g., via an internal antenna, an antenna mounted to the roof of the vehicle, etc.), and to determine vehicle position based on the signals. Unfortunately, if the external positioning signals are at least partially blocked, the signal received by the on-board spatial locating device may be insufficient to determine vehicle position.

System and method for transferring vehicle operating data to an external navigation system


A gas turbine combustor comprises a plurality of circumferentially spaced can type combustion liners disposed between inner and outer casings of the gas turbine engine. Each combustion liner has an auxiliary set of circumferentially spaced air slots behind a set of circumferentially spaced primary air holes that introduce compressor discharge air to cool hot spots in the primary combustion zone. The air slots are set at an angle so that the compressor discharge air is admitted into the combustion liner in such a way as to induce a swirling motion in the primary combustion zone. The combustion liner also has a set of circumferentially spaced dilution air holes that are sized and located upstream far enough to maintain an acceptable exit temperature profile and acceptable low level carbon monoxide and unburned hydrocarbons emissions.

This invention relates generally to gas turbine engines and more particularly to combustors for gas turbine engines that have can type combustion liners.
Allison Gas Turbine Division of General Motors Corporation presently produces a state-of-the-art combustor that comprises six circumferentially spaced can type combustion liners located in an annulus formed by inner and outer engine casings. Cross over tubes interconnect the combustion liners and provide flame transfer for starting the engine. Each combustion liner has a fuel nozzle that is connected to a fuel manifold attached to an external surface of the outer engine casing.
While these gas turbine engines perform very well, new stricter air quality control regulations require significant reductions in emissions of oxides of nitrogen (NOx). At the same time emissions of carbon monoxide (CO) and unburned hydrocarbons (UHC) must be maintained at low levels.
A common way to reduce NOx emission is to inject water or steam into the combustor. However, water or steam injection generally results in increased emissions of carbon monoxide and unburned hydrocarbons. Moreover such system are costly from both installation and operational standpoints.

Low nox gas turbine combustor liner with elliptical apertures for air swirling


A technique for observing optical second harmonic generation effect at a surface of a material during processing thereof, particularly in the presence of a plasma, for controlling the processing of the material. A preferred form of the apparatus and method includes a combination of spectral, spatial, polarization and temporal filtering to allow observation of optical second harmonic generation and control of processing of the material with processes such as reactive ion etching to a high degree of resolution.

1. Field of the Invention
The present invention generally relates to optical measurement techniques and, more particularly, to the detection of boundaries and thicknesses with very high resolution, especially in controlling manufacturing processes of material deposition, removal, and reaction and, most particularly, in the fabrication of integrated circuits.
2. Description of the Prior Art
Modern electronic, opto-electronic devices and the like are complex structures formed by many repeated steps of material deposition, reaction, modification (e.g. annealing), and removal. These processes are common to the fabrication of individual devices, integrated circuits and magnetic recording media (such as surfaces formed by sputtering) and apparatus. While typical dimensions of lateral features in such applications are frequently in the range of one micron, the thickness of layers is often far smaller than this scale, sometimes down to the range of 100 Angstroms. A thickness of 100 Angstroms corresponds to only some 50 atomic layers. It can be easily understood that precise measurement of the dimensions during processing is crucial to device performance and to the yield of the manufacturing process.
One of the critical general issues is the detection of a boundary during the removal of material. Material removal may occur by methods such as chemical etching or by a plasma process such as reactive ion etching. It is generally necessary to determine the time at which all of the desired material has been removed, but the underlying layer has not been etched significantly. This constitutes the so-called detection of endpoints. The etched material and the underlying material are frequently made of different compositions, such as silicon dioxide on a silicon layer. They may, however, differ primarily in their crystalline structure or doping level and not in their gross chemical composition. This poses particular challenges for the problem of endpoint detection. For example, in the manufacture of bipolar transistors the step of emitter opening involves etching an area of a deposited layer of polycrystalline silicon down to an epitaxial (single crystal) layer. This operation is typically performed by reactive ion etching which does not present any obvious means for real-time control. The consequences of improper etching are, however, significant. Underetching will cause a degradation of the gain of the transistor, while overetching will result in a degraded contact between the intrinsic and extrinsic base regions.
While some etching processes may provide selective removal of the overlayer and a slow rate of removal of the underlying material, this is not always attainable in practice. A real manufacturing process has numerous constraints, such as obtaining high etch rates and using relatively safe chemicals. The step may also require a strongly anisotropic etch rate. These conditions collectively mean that a highly selective etch may not be available. In this instance, the capability of monitoring the progress of the etching process during manufacturing becomes of critical importance.
A related issue is the determination of the thickness of layers of finite dimensions. This may be of relevance either in removing material to obtain a layer of a given thickness or in depositing material until a layer of a given thickness is reached. To cite one example, consider the gate insulator in a field effect transistor. The thickness of the insulating region will affect the switching voltage and the uniformity of the thickness will affect the uniformity of performance of transistors in an integrated circuit. The thickness of a layer formed by the reaction of two materials is also a quantity of interest. Examples of this situation occur in the formation of a silicon oxide layer by a chemical reaction with gas species containing oxygen and in the formation of a metal silicide on a silicon surface, an important process for forming contacts in semiconductor devices.
It should be noted that some reactions and modifications of surfaces will occur spontaneously such as oxidation of silicon at room temperature in the presence of oxygen and the formation of silicides. However, such spontaneous reactions typically will only occur to a small depth which is trivial for purposes of fabrication of any useful device. However, such processes can be made to continue in a controllable manner by imposing appropriate conditions such as high temperature. Accordingly, by reference herein to controllable surface reactions and modifications, it is intended to exclude reactions and modifications which occur spontaneously at relatively low temperatures and are not controllable in the sense in which a manufacturing process may be controlled.
Many techniques have been developed for examining the thickness and other properties of thin layers subsequent to processing. One of the important techniques for post-processing analysis is secondary ion mass spectrometry. This process involves detection of the material by mass spectrometric means as it is sputtered by an impinging ion beam. Although providing important and precise information on chemical composition and thicknesses of layers, this technique is destructive, since it destroys the sample under investigation. It is also not suitable for in-situ measurements even if its destructive character could be tolerated. Similar considerations apply for electron microscopy and direct mechanical measurements which are other familiar approaches for post-processing analysis. Other methods appropriate for surface analysis may give very high sensitivity. These include electron diffraction techniques (LEED and RHEED), electron energy loss spectroscopy, Auger electron spectroscopy, photoelectron spectroscopy, and so forth. These latter methods are, however, all restricted to high vacuum environments and cannot be used under realistic processing conditions.
It should be noted that all techniques which are not adaptable to in-situ process monitoring and destructive testing techniques, in particular, rely on trial-and-error development of an appropriate process and the repeatability of the process itself to form the desired structures. The trial-and-error process development increases cost of the process and reliance on repeatability reduces yield, particularly in devices in which endpoints and thicknesses are critical.
Non-destructive techniques for real-time, in-situ, analysis in processing environments are far fewer than those summarized above. Non-destructive techniques are typically optical, although in some cases electrical measurements may be appropriate, depending on the processing environment.
Electrical techniques usually depend on the measurement of the electrical resistance or the voltage dependence of the electrical resistance determined by passing a current through the layer either in a direction parallel or perpendicular to the surface layer. The analysis of such measurements may be quite complex, since the observed resistance depends on a variety of factors in addition to the layer thickness, such as the width of the layer, the influence of underlying structures, and the material properties. The measurements may also be strongly affected by factors such as the contact resistance and are clearly limited in application to materials with reasonable electrical conductively. Refinements in these techniques are capable of detecting slight nonlinearities in the relation between applied voltage and the induced current, that is, a voltage-dependent effective resistance. These approaches are particularly useful for identifying material defects, but do not necessarily improve the method for detecting boundaries and determining layer thicknesses. From the processing point of view, electrical measurements are also undesirable. Electrical measurements are generally invasive, requiring a current to be passed through the material under test and requiring contacts to be made to the device or region of the material under investigation. This imposes practical difficulties such as the provision of space for such contacts, in turn limiting potential integration density, and certain processing environments. Such practical limitations may render the approach entirely impractical for some devices and impossible in typical environments such as plasmas or liquid chemical etchants.
The above-described electrical testing techniques are exemplified by Heiber et al. U.S. Pat. No. 4,562,089, which relies on resistance measurements, and DiStephano et al, U.S. Pat. No. 4,496,900, which applies an alternating voltage to a region and detects defects by observing a second harmonic of the applied voltage frequency in the current response arising from a voltage dependent conductivity.
It should also be noted that measurement of conductivity characteristics is an effect within the bulk of the material as well as being affected by the geometry of the conductive region and ambient conditions such as the presence of a plasma or liquid chemical etchant. Therefore, the technique disclosed by Heiber is unlikely to be usable in typical manufacturing process environments and is clearly inapplicable to monitoring the formation of insulator structures and problems such as the emitter opening technique described above, both of which involve monitoring of an area generally parallel to a surface rather than a current path through the bulk of a material. For instance, a current path could become discontinuous while substantial material remained unetched or could remain continuous while overetching was taking place in other portions of the area.
The most broadly applicable methods for real-time, in-situ analysis are based on optics. Optical methods can often be adapted to widely varying environmental conditions such as are found in chemical and reactive-ion etching, plasma-enhanced vapor deposition, etc. The purely optical approaches usually also have the advantage of being non-destructive and non-invasive. Moreover, the methods can generally yield lateral resolution (to approximately 1 .mu.m) by focusing the relevant light beams or by means of imaging techniques.
For the most part optical methods for direct examination of surface structures involve a direct measurement of the reflectivity of the sample. Since optical radiation typically penetrates hundreds or thousands of atomic spacings (distances greater than 100 nm), it is difficult to obtain sensitivity on the level of one or a few atomic layers, which is the resolution desired for very precise control of processing. The sensitivity of reflectivity measurements can be enhanced in various ways, such as a judicious choice of the wavelength of the light used in the measurement. The most common refinement involves use of ellipsometry.
In this well-established technique, the polarization of the reflected light is analyzed. Since polarization can be measured with great accuracy with suitable instrumentation, the method can be highly sensitive to changes in surface properties and the thickness of material layers. The method has, however, significant practical limitations. The very small changes in polarization associated variation in film thickness by a few atomic layers can easily be masked by other effects arising from the bulk materials. These effects include the influence of slight temperature changes, the presence of strain, etc. Also, measurement in a manufacturing environment is difficult given the stringent requirements on geometric arrangement and geometric stability. Further the optical properties of windows, notably stress-induced birefringence, may significantly distort the measurements.
A different improved optical technique for determining layer thickness and the detection of boundaries is disclosed by Tien, U.S. Pat. No. 4,713,140. The technique disclosed by Tien relies upon the luminescence of direct band-gap semiconductors. This approach has a number of significant limitations, as well. First the method is suitable only for direct band-gap semi-conductors, thereby excluding silicon, metals, and insulators, the materials of greatest importance currently in the electronics industry. Moreover, the emitted luminescence emerges as weak incoherent radiation. Therefore, while this technique can be applied to a small region, a lens is necessary for collection of the luminescent radiation which presents severe difficulties since the lens must be positioned closely to the irradiated region to collect the radiation of interest. Inaccuracies of lens positioning and sensitivity of the process to ambient radiation conditions could greatly distort the measurement results. The broad band luminescence radiation, typically at red regions of the spectrum at wavelengths greater than 800 nm, also presents particular difficulty in discriminating from background radiation (be it ambient light, plasma or thermal radiation) typically present or at least difficult to exclude from semiconductor manufacturing processes. The same problems are associated with the application of other techniques based on the emission of incoherent light, such as surface light scattering and Raman scattering.
Again, it should be noted that reflection observations, including ellipsometry, are bulk effects of the material and, although the effects are relatively strong, are inherently limited in accuracy due to the penetration of illuminating radiation into the bulk of the material and the thickness of that bulk which contributes to the response. This inherent limitation is also true of the technique of Tien, described above.
In more general terms, all of the optical techniques applied prior to the invention disclosed herein are difficult or impossible to adapt to yield sensitivity to surfaces or interfaces of materials with a sensitivity on the level of a single atomic layer or spacing, i.e., a fraction of a nanometer. This difficulty is inherent to the large penetration depth of the optical radiation, which implies that the effects of bulk materials will be far stronger than that of a thin layer comprising a surface or interface region. While sensitivity can sometimes be enhanced, as indicated above, this usually places severe restrictions on the choice of materials or on the instrumentation. Further, the measurements are generally subjected to potential errors from slight changes in the properties of the bulk materials, as may occur from strain, temperature or temperature gradients, and the like, as well as limitations on optical access and potential errors imposed due to the above-described imperfections of windows and other means of providing optical access to the material surface during processing.
In summary, a particular challenge has continued to exist in developing methods suitable for non-destructive, non-invasive measurements with a sensitivity approaching that of a single atomic layer.
Certain non-linear optical effects are known in fields heretofore unrelated to material processing, in general, or semiconductor device manufacture, in particular. For instance, the SHG effect consists of the production of light at twice the frequency of a pump beam. The process can be considered as the combining of two photons of energy E to produce a single photon of energy 2E, i.e., the production of light of twice the frequency (or half the wavelength) of the pump radiation. This effect can also be generalized to the combining of photons of different energies, corresponding to different frequencies, as well, as will be pointed out below (referred to as wave-mixing or sum- and difference-frequency generation). However, in the interest of clarity, the invention will be explained principally in terms of the second harmonic generation effect.
The existence of this effect was demonstrated shortly after the emergence of high-intensity laser radiation. The process is coherent and gives rise to collimated radiation when induced by a collimated pump beam. In suitable birefringent nonlinear crystals the SHG process can be quite efficient. As such, it is widely used to generate new frequencies of light in conjunction with high intensity lasers. The SHG process is, however, forbidden (to a very good approximation) within the bulk of many materials. These are all materials exhibiting a center of symmetry (inversion or centrosymmetric materials). Centrosymmetry materials include essentially all liquids and gases (because the random molecular positions therein appear similar, regardless of viewing direction) as well as essentially all elemental solids. Important examples of centrosymmetric materials for the electronics industry include silicon, germanium, most metals and silicides, and most insulators, such as (amorphous) silicon dioxide. For these materials, the SHG process is appreciable only at surfaces and interfaces where the inversion symmetry of the bulk materials is broken. SHG from these materials is then dominated by the contribution of roughly one atomic layer of the material at a surface or interface. This provides the SHG process with a sensitivity to surface and interface properties not found in other optical probes. Over the last few years the SHG process has been exploited in various scientific studies or the properties of surfaces and interfaces. Issues such as the question of the density and orientation of monolayers of adsorbed molecules have been examined. The technique has also been applied to elucidate the nature of ordering and electronic structure at surfaces under ultrahigh vacuum conditions.
A survey of scientific investigations in which this technique has been employed is provided by "Optical Second-Harmonic Generation from Semiconductor Surfaces" by T. F. Heinz et al., Published in Advances in Laser Science III, edited by A. C. Tam, J. L. Cole and W. C. Stwalley (American Institute of Physics, New York, 1988) p. 452, which is hereby incorporated by reference. Other publications which will be useful in understanding the SHG effect are: "Nonlinear Optics of Surfaces and Adsorbates" by T. F. Heinz, LBL-15255, Ph. D. Thesis, University of California, Berkeley, November, 1982; "Surface Studies by Second Harmonic Generation: The Adsorption of O.sub.2, CO, and Sodium on the Rh (111) Surface" by H. W. K. Tom et al., Physical Review Letters, Vol. 52, No. 5, January 1984, American Physical Society, pp. 348-351; "Study of Si(111) Surfaces by Second Harmonic Generation: Reconstruction and Surface Phase Transformation" by T. F. Heinz et al. Physical Review Letters, Vol. 54, No. 1, January 1985, American Physical Society, pp. 63-66; "Study of Symmetry and Disordering of Si(111)-7.times.7 Surfaces by Optical Second Harmonic Generation", by T. F. Heinz et al., J. Vac. Sci. Technol., B3(5), September/October 1985, American Vacuum Society, pp. 1467-1470; "Nonlinear Optical Study of Si Epitaxy", by T. F. Heinz et al., Mat. Res. Soc. Symp. Proc., Vol. 75, 1987, pp. 697-704, Materials Research Society; "Electronic Transitions at the CaF.sub.2 /Si(111) Interface Probed by Resonant Three-Wave-Mixing Spectroscopy" by T. F. Heinz et al., Vol. 63, No. 6, August, 1989, pp. 644-647, American Physical Society; and "Surface Studies with Optical Second Harmonic Generation", by T. F. Heinz et al., Trends in Analytic Chemistry 8, pp. 235-242, 1989, all of which are also hereby fully incorporated by reference as is the information contained in the articles noted in the extensive bibliographies of these articles concerning the SHG effect. Thus it can be seen that the scientific aspects of the SHG process have been investigated extensively and the effect is deemed to be well-understood.
To summarize the SHG effect and the accuracy it provides in characterizing surfaces and boundaries near the surface of centrosymmetric materials such as silicon, metals, and insulators, it is evident that the SHG effect cannot occur efficiently as a bulk effect in these materials because of their symmetry properties. Therefore, regardless of the depth to which a beam of illuminating radiation may penetrate into the material, the SHG radiation will arise predominantly from the asymmetry present at a surface of the material or at a boundary therein. This efficient SHG will occur only in a layer with a thickness comparable to a single atomic layer. This effect is demonstrated in the results shown in FIG. 1a concerning the oxidation of a Si(111) surface under ultrahigh vacuum conditions. In this case, the oxidation reaction proceeds only to the formation of roughly one atomic layer of oxide (approximately 0.2 nm). The dramatic change in the SHG efficiency can be clearly observed.
A second example is shown in FIG. 1b, showing the SHG radiation in arbitrary units at varying depths of deposition of amorphous silicon on crystalline silicon. Thus, it can be seen that the SHG effect is relatively pronounced based on crystal structure and boundary depth without the existence of a chemical difference between the two materials on either side of the boundary.
A third example concerning an interface is given in FIG. 2. The data show the SHG efficiency for various pump laser frequencies (photon energies) for two different samples: a silicon surface covered by an oxide layer (the materials shown in FIG. 1a), indicated by circles 230 and a silicon surface covered by a calcium fluoride overlayer, indicated by dots 210 and fitted curve 220. In this case, the depth of the overlayer remains constant while the frequency of the irradiating frequency is changed. The marked differences in response can be attributed to the different nature of the interfaces in the two cases. The marked variation of SHG response with frequency in curve 220 also shows that the effect is frequency selective for a given material and also between materials. Note especially that lower curve 230, while appearing relatively flat, is clearly shown to be similarly measurable by FIG. 1a.
As is pointed out in the above incorporated articles, and shown in FIGS. 1a, 1b and 2, also represented therein, measurement of the SHG effect can yield a substantial amount of information concerning the nature of a surface or an interface. It provides the possibility for the development of a body of empirical data characterizing boundaries and surfaces with extremely high sensitivity. It should be stated that the SHG process is capable of distinguishing not only boundaries between materials with different chemical composition, but also between materials with the same chemical composition but differing crystal structures, as, for example, between amorphous or polycrystalline and crystalline silicon, as demonstrated in FIG. 1b. The SHG effect from a boundary beneath the top of the surface will generally exhibit a strong dependence on the distance of separation. On an atomic scale, this sensitivity will arise from the perturbed structural and electronic properties of the interface as its separation from the top surface decreases to a few atomic layers. On a larger length scale other factors will become relevant. These are the efficiency of propagation of the pump radiation at the fundamental frequency to the surface and the efficiency of escape of the second harmonic radiation through the overlayer. Further, interference effects arising from the contributions of the top of the surface and from the bottom boundary of the overlayer may enhance the sensitivity of the observed SHG signal on the separation. As a consequence of these effects, the amount of second-harmonic radiation generated will generally vary strongly as a boundary and the surface of the material approach or diverge from one another.
The use of the SHG process in centrosymmetric media has to date been restricted to scientific investigations of surface and interface properties. In these scientific investigations it is possible to exercise a high degree of control over the environment. For example, the amount of ambient illumination could be reduced if required. More significantly, the studies shown in FIGS. 1a, 1b and 2 were performed under highly idealized conditions, typically under ultrahigh vacuum. No bright source of radiation as would be present in a plasma in reactive ion etching or plasma enhanced chemical vapor deposition was present. Further, the surface temperatures of the samples were generally sufficiently low that they did not emit a significant amount of visible thermal radiation. Under realistic processing conditions, this may not be the case, since temperatures approaching 1000.degree. C. are frequently encountered. It has also been found that the SHG effect in silicon grows markedly weaker with increased temperature, further compounding the problem. Given these difficulties the technique has not been considered to be even potentially suitable for measurements of etching, deposition, or other reactions under typical manufacturing conditions, notably in the presence of plasmas or high surface temperatures.
Consider then the above-noted operation of the emitter opening step in device processing. While the use of the SHG effect could potentially provide excellent results, the established approach would involve removing the wafer from the etching chamber to perform the measurements. Thus while the observation of the SHG effect could provide a resolution on the order of one atomic spacing, the realization of such accuracy in a practical device would require etching in steps of one atomic layer and checking after each step, thereby multiplying the complexity of the manufacturing process enormously.
In summary, the capability of the measurement technology and the present state of semiconductor manufacturing technology indicate a need for some arrangement whereby the full capabilities of both can be simultaneously realized. Specifically, while observation of the SHG effect can provide resolution of the position of a boundary to one atomic spacing and current techniques of material deposition and removal can ideally provide an equivalent accuracy, such capabilities cannot practically be implemented unless the SHG effect can be monitored during the course of such material deposition, removal or modification in order to observe and control it.

Detection of interfaces with atomic resolution during material processing by optical second harmonic generation

International Business Machines Corporation


The resilient fastener for fixing two parts onto each other, having a general V-shape including an intermediate portion (2) in the shape of a pincer with two limbs (3, 4), and adapted to be engaged on a first part and from at least one of the limbs of which extends at least one lateral wing (6, 7) equipped with means, passing an over-center position, for fastening onto a corresponding edge of the second part in order to attach the fastener, and therefore the first part, to the second part, is characterized in that it has at the junction zone of the or each lateral wing (6, 7) and the corresponding limb (3, 4) of the intermediate portion, at least one cut-away portion in the shape of a barb (10, 11) extending in prolongation of the corresponding wing (6, 7) and in the direction of the intermediate portion, in order to lock the intermediate portion of the fastener on the first part

1. Field of the Invention
The present invention concerns a resilient fastener for fixing two parts onto each other.
More particularly, the invention relates to such a fastener which has a general V-shape including an intermediate portion in the shape of a pincer with two limbs, and adapted to be engaged on a first part and from at least one of the limbs of which extends at least one lateral wing equipped with means, passing an over-center position, for fastening onto a corresponding edge, for example, of an opening of a second part, in order to attach the fastener, and therefore the first part, to the second part.
Such resilient fasteners find numerous applications in particular in the automobile industry for fixing two pieces of equipment of a vehicle onto each other.
2. Description of the Prior Art
In the prior art there are resilient fasteners of this type in which the lateral wings of the fastener are equipped with means forming an outer leg having means in the form of resilient hooks, passing an over-center position, for attaching the fastener to the edges of an opening, for example, of one part, and with means forming an inner leg equipped with means for attaching the other part in order to fix the parts onto each other.
In the prior art, the means forming an inner leg of the fastener extend from the intermediate portion thereof, over a part of the height of the means forming an outer leg, and define a passage for receiving the other part.
However, fasteners of this type have a certain number of drawbacks, especially with regard to the difficulty of introducing the other part into the passage defined by the means forming an inner leg of the fastener and with regard to the reliability of the fixing and in particular to its resistance to tearing off.
Moreover, such fasteners may also be sources of vibration and therefore of noise.
The Applicant has already proposed different solutions for solving these problems.
The aim of the invention is to propose variants of resilient fasteners of this type.

Resilient fastener for fixing two parts onto each other


Providing information to a module is disclosed. A first query and one or more subject type concepts associated with the first query is received. A second query to be provided to the module based at least in part on the received first query and subject type concepts is determined. The second query is sent to the module.

Determining whether text-based content should be provided as a result to a query is typically a straightforward activity. For example, the text of the query can be matched against text appearing in the content and a text match score can be determined. If the score is high enough, the result is returned. Unfortunately, while techniques such as tagging and metadata can be used to describe non-text content, it is still typically more difficult for users to locate non-text content in which they are interested than text-based content.
Additionally, content providers, such as image hosting sites which allow users to upload and share photographs, are increasingly offering users ways of embedding dynamic content in their pages, such as by providing a JavaScript-based photo gallery widget. Some widgets, such as a quote of the day display, provide dynamic content (e.g., a different quote each day) but do not allow user interaction. Other widgets, however, such as the above mentioned gallery widget, might accept input from a user, such as a search query. Unfortunately, it can be difficult to determine what dynamic content should be returned to such a user.


A method for providing a roof structure of the type having a plurality of purlins spaced apart from one another in a parallel arrangement is disclosed. A first section of the roof structure, which includes purlins, a support sheet, insulation material, and hard roofing material, is completed. A carriage is then moved in a first direction along the length of the purlins and away from the first section of the roof structure to define a gap between the completed first section and the carriage. The movement of the carriage pays out a support sheet from the carriage so that the support sheet depends from adjacent purlins in the gap. A wind barrier, which is in a generally horizontal position to prevent wind from blowing vertically through the gap, is provided, thereby hindering wind disturbance of the support sheet.

Metal roof structures typically comprise a series of parallel rafter beams extending across the building in one direction and purlin beams parallel to each other mounted on top of the rafters extending in a direction normal to the rafters. The purlins are often joined together by support bracing or straps for extra support. Insulation material in long sheets is placed in the area between purlins. The sheets of insulation material can be laid along the length of the purlins or across the purlins in a direction normal to the purlins. Hard roofing material such as metal decking is then attached on top of the purlins over the insulation material. Because the hard roofing material comes in long sheets and the roofs generally have two sloped sections, it is customary to construct along the width of the sloped section and then proceed along the length of the structure from one end to the other. The workers stand on the previously laid section of roof to construct the next section.
The insulation material must be supported between the purlins, and various methods of support have been used. Mounting straps or wire mesh that are attached to the purlins by forming a lattice have been used. This is referred to as banding. A sheet, typically made of vinyl and acting as a vapor barrier, is then rolled onto the lattice, and insulation material is placed between adjacent purlins and over the sheet. If the installation of the lattice is done from underneath the roof structure, scaffolding or lifting equipment is required.
Some systems dispense with the lattice and use the sheet itself to support the insulation material. The support sheet is draped from the adjacent purlins and the insulation material is placed on top of the support sheet. A carriage is used to aid in the dispensing of the support sheet. The carriage is positioned on top of the purlins and travels the length of the purlins during the roof construction. A roll of the support sheet material is mounted on the carriage and the support sheet is dispensed from the roll and placed on top of the purlins. As the carriage travels the length of the purlins the support sheet is draped across the purlins.
Wind can hinder or even prevent the workers from building the roof structure because of the handling of the large strips of insulation and roof decking. Because the roof is elevated from the ground level, the velocity of wind is generally greater and can cause problems for the workers constructing the roof. Even light winds which blow across or through the purlin support structure can disturb the insulation by causing the insulation material to lift up or shift positions after the workers have laid the insulation down in its proper installation position. For strong winds, it can be nearly impossible to handle the insulation and keep it in position before the hard roofing material is attached to the purlins.
Strong winds are also a safety concern for the workers on the top of the roof structure. A known safety feature for workers constructing a purlin type roof structure is to provide a platform which is movable along the tops of the purlins and which provides fall protection for the workers to prevent them from falling off the leading edge of the previously completed section of roof.
It would be desirable to have a method of building a roof structure which provides for wind protection and which is convenient and efficient.

Wind protection for apparatus for paying out an insulation support sheet

Owens Corning Fiberglas Technology, Inc.


A system and method for iteratively deploying a workload pattern are provided. The system and method determines a current set of requirements for at least one piece of the workload pattern that is initiated in a designer and generates a stability metric for at least one of the current set of requirements. The system and method further compares the stability metric to an acceptance threshold and calculates an estimated time to deploy the at least one piece of the workload pattern based on the comparing of the stability metric to the acceptance threshold.

The present disclosure relates generally to a concurrent workload deployment to synchronize activity in design palette, and more specifically, to a management system configured to partially deploy into an operation environment pieces of an application workload concurrent to a designing of the application workload topology in an editor.
In general, there is a need in cloud environments to provision virtual machines and application workloads as fast as possible. Yet, while the provisioning of virtual machines and application workloads may be optimized via containers, thin-provisioning, and multi-tenant technologies, the provisioning of thick-provision virtual machines presently take longer to deploy.

Concurrent workload deployment to synchronize activity in a design palette

INTERNATIONAL BUSINESS MACHINES CORPORATION


Systems and methods for optically pumping alkali-metal atoms using Coherence Population Trapping (CPT) resonances are disclosed. An illustrative push-pull optical pumping system for inducing CPT resonances in a resonance cell containing an admixture of alkali-metal atoms and one or more buffer gasses may include a laser assembly adapted to produce alternating orthogonally polarized light, and at least one DC current source adapted to output a constant-intensity carrier current signal for inducing laser emission from the laser assembly at a carrier wavelength of the alkali-metal atoms. An RF modulated signal outputted from an RF modulation source can be rectified, split, and phase-shifted for inducing a time-dependent polarization of the laser light that can be used to enhance CPT resonances. The alternating orthogonally polarized light from the laser assembly can then be used to optically pump the alkali-metal atoms within the vapor cavity, producing a dark state that can be detected with a photodetector or the like.

Atomic frequency standards are used in a number of applications demanding a high level of accuracy and precision in time keeping. In communications and navigational systems, for example, such atomic frequency standards are often used in atomic clocks as a means to maintain the long-term frequency stability necessary to accurately guide satellites, missiles, aircraft, or other objects through space. In positioning systems such as a Global Positioning System (GPS), such atomic frequency standards are often used in atomic clocks to coordinate the positioning of multiple GPS satellites in orbit. A slight variation in time measured by each GPS satellite can cause significant positioning errors in the guidance system used by many communications and navigational systems, affecting the ability of the system to accurately guide objects through space.
An atomic clock uses the principle of atomic energy transition to output a reference frequency that is relatively insensitive to vibration, shock, or other such noise. In a typical intensity-based atomic frequency standard using an alkali-metal such as cesium 133 or rubidium 85 or 87 as the source of resonance atoms, the energy states of the source atoms are often prepared by optically pumping a resonance cell containing an admixture of the alkali-metal atoms and one or more buffer gases. The intensity of a laser source such as a diode laser is then used to achieve the desired optical pumping.
More recent developments in the art have focused on the use of Coherent Population Trapping (CPT) resonances to prepare the energy states of the alkali-metal atoms. CPT is a nonlinear phenomenon in atoms in which coherences (i.e. electromagnetic multipole moments) between atomic energy levels are excited by pairs of radiation fields. Instead of controlling the intensity of the laser source to achieve the desired optical pumping, CPT systems typically rely on modulated light in order to induce resonances in the alkali-metal atoms, causing coherent optical pumping to occur from two hyperfine ground states to an excited state, commonly referred to as the lambda (Λ)transition. CPT systems thus rely on the coherence property of the laser source, and not its intensity, to accomplish the optical pumping.
For conventional optical pumping techniques using CPT, the radiation fields are usually generated by two lasers phase-locked to each other, or from the sideband of a single laser modulated at a sub-harmonic frequency of the alkali-atom hyperfine frequency. The effect of the laser radiation is to produce a strong coherence in the ground state at the hyperfine frequency, thus inhibiting all transitions to the excited "P" state. At the exact resonance, no transitions take place from the ground state to the excited P state, and no energy is absorbed from the laser radiation by means of transitions.
To increase the signal-to-noise (SNR) ratio of the system, the CPT resonances induced within the resonance cell may be enhanced by directing alternating left and right-handed circularly polarized light (σ+, σ−) into the cell. Such "push-pull" optical pumping allows a greater amount of the alkali-metal atoms within the resonance cell to be pumped into the important 0-0 superposition state, thus producing nearly pure, coherent superposition states. This ability to enhance CPT resonances has widespread implications in the performance of atomic clocks, laser systems, maser systems, or other such systems that utilize highly accurate atomic frequency standards to measure time.
While push-pull optical pumping is capable of producing CPT resonances several magnitudes greater than more conventional optical pumping schemes, such technique often requires additional components that are not readily miniaturized for compact systems such as microelectromechanical systems (MEMS). MEMS-based systems are typically created using semiconductor fabrication techniques by etching various components onto the surface of a silicon or glass wafer, forming structures that are often several times smaller than their non-MEMS counterparts. As a result, components such as a Mach-Zehnder intensity modulator and/or an interferometer, which are not readily miniaturized for a given wavelength, are therefore difficult to implement in smaller-scale systems such as MEMS.

Technique for optically pumping alkali-metal atoms using CPT resonances