query: occupation isaac abella
supports: Arthur Leonard Schawlow (May 5, 1921  April 28, 1999) was an American physicist. He shared the 1981 Nobel Prize in Physics with Nicolaas Bloembergen and Kai Siegbahn for his work on lasers. In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-, and gamma radiation. Canadian Jews or, alternatively, Jewish Canadians are Canadian citizens of the Jewish faith or Jewish ethnicity. Jewish Canadians are a part of the greater Jewish diaspora and form the fourth largest Jewish community in the world, exceeded only by those in Israel, the United States, and France. As of 2011, Statistics Canada listed 329,500 adherents to the Jewish religion in Canada and 309,650 who claimed Jewish as an ethnicity. One does not necessarily include the other and studies which have attempted to combine the two streams have arrived at figures in excess of 375,000 Jews in Canada. This total would account for approximately 1.1% of the Canadian population. Isaac David Abella ( born June 20 , 1934 in Toronto , Ontario ) is Professor of Physics at The University of Chicago . He specializes in laser physics , quantum optics , and spectroscopy . Isaac is the cousin of Irving Abella . Abella received his Bachelor of Arts degree ( 1957 ) from the University of Toronto , Master of Arts ( 1959 ) degree , and Ph.D. ( 1963 ) in Physics from Columbia University in New York . He studied under Charles H. Townes and was involved in the early research work of laser development . Notably , Abella 's thesis under Townes was among the earliest work on two - photon absorption . He was married to the late Mary Ann Abella , Professor of Art , Chicago State University . He has a son Benjamin , and daughter , Sarah . Abella is known for his work with laser coherent transients , where photon echo techniques are used to probe metastable excited states in rare gas mixtures such as helium , neon , and argon . These states are produced in a weakly ionized RF plasma discharge , and nitrogen - pumped dye lasers are used to generate the coherent super-position states . The University of Chicago . He is also known for his work in spectroscopy of rare - earth laser materials . Samples of YLF and YAG crystals doped with erbium , thulium , and holmium are being studied with selective laser excitation in the region of 780 nm , the erbium bands . These materials can be efficiently optically pumped by the AlGaAs - GaAs laser diode arrays , but dye laser excitation is used instead . He is interested in the energy transfer process : Er to Tm , to Ho , which concentrates energy emission at 2.085 µm at room temperature and at liquid nitrogen . The process is a radiationless , almost resonant transfer of energy between sites and depends on the relative concentrations of the rare earth ions . In particular his experimental interests are measuring decay rates , excited state absorption , and branching ratios and detailed theories of such processes . A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light "coherently". Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond. In the classical physics observed in everyday life, if something has mass and takes up space, it is said to be composed of matter; this includes atoms (and thus molecules) and anything made up of these, but not other energy phenomena or waves such as light or sound. More generally, however, in (modern) physics, matter is not a fundamental concept because a universal definition of it is elusive: elementary constituents of atoms may not take up space individually, and massless particles may be composed to form objects that have mass (even when at rest). Stimulated emission is the process by which an incoming photon of a specific frequency can interact with an excited atomic electron (or other excited molecular state), causing it to drop to a lower energy level. The liberated energy transfers to the electromagnetic field, creating a new photon with a phase, frequency, polarization, and direction of travel that are all identical to the photons of the incident wave. This is in contrast to spontaneous emission, which occurs at random intervals without regard to the ambient electromagnetic field. In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: In physics, the wavelength of a sinusoidal wave is the spatial period of the wavethe distance over which the wave's shape repeats, 
  and thus the inverse of the spatial frequency. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. 
  Wavelength is commonly designated by the Greek letter "lambda" (). The concept can also be applied to periodic waves of non-sinusoidal shape. 
  The term "wavelength" is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Laser cutting is a technology that uses a laser to cut materials, and is typically used for industrial manufacturing applications, but is also starting to be used by schools, small businesses, and hobbyists. Laser cutting works by directing the output of a high-power laser most commonly through optics. The laser optics and CNC (computer numerical control) are used to direct the material or the laser beam generated. A typical commercial laser for cutting materials would involve a motion control system to follow a CNC or G-code of the pattern to be cut onto the material. The focused laser beam is directed at the material, which then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high-quality surface finish. Industrial laser cutters are used to cut flat-sheet material as well as structural and piping materials. Spectroscopy is the study of the interaction between matter and electromagnetic radiation. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, by a prism. Later the concept was expanded greatly to include any interaction with radiative energy as a function of its wavelength or frequency. Spectroscopic data is often represented by an emission spectrum, a plot of the response of interest as a function of wavelength or frequency. Irving Martin Abella, (born July 2, 1940) is a Canadian writer, historian and academic. He specializes in the history of the Jews in Canada and the Canadian labour movement Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its periodthe time interval between beatsis half a second (that is, 60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio (sound) signals, radio waves, and light.
candidates: academic canada computer engineering historian physicist physics radio research science travel writer
answer: physicist