 several disadvantages associated with these previous devices are successfully overcome as a result of said modifications. In the conventional generation techniques, in intense, short duration light pulse at fixed frequency.nu..sub.p is sent through one (or more) nonlinear crystals (LiNbO.sub.3, for example) which act as parametric, threephoton amplifiers. Starting from spontaneous noise at frequency.nu..sub.s, a significant magnitude signal of frequency.nu..sub.s, is produced in the first crystal amplifier. The signal may be further amplified in subsequent crystals. The energy for the production of.nu..sub.s comes from the.nu..sub.p electromagnetic field. A second frequency called the idler,.nu..sub.i, is also generated in the crystal such that.nu..sub.s +.nu..sub.i =.nu..sub.p. This condition is simply a consequence of energy conservation. The specific.nu..sub.i,.nu..sub.s set which will be amplified is determined by the "phase matching" conditions, k.sub.p =k.sub.s +k.sub.i. k.sub.p, k.sub.s and k.sub.i are the wave vectors, defined as k.sub.p =2.pi.n.sub.p.nu..sub.p, k.sub.s =2.pi.n.sub.s.nu..sub.s and k.sub.i =2.pi.n.sub.i.nu..sub.i, of the pump, signal and idler, respectively. n.sub.p, n.sub.s, and n.sub.i are the corresponding indices of refraction. The high intensity requirement of.nu..sub.p is necessary to produce a high amplification within a path length of a few centimeters. Single pulses have the advantage of allowing the application of such high pump intensities without crystal damage.
The first disadvantage that the instant invention overcomes is that of unusably broad spectral bandwidths. The bandwidth in previous devices was primarly determined by the phase-matching conditions in the non-linear crystal. Spectrally narrow pulses are normally generated only when the device is tuned far from the degenerate point (.nu..sub.s.about..nu..sub.i), thereby severely restricting the useful operating range. With our invention, the bandwidth is determined by the character of the diffraction grating
several disadvantages associated with these previous device are successfully get the best as a result of said modifications. In the ceremonious generation techniques, in intense, inadequate duration light pulse at sterilize frequency.nu.. sub.p is sent through one (or more) nonlinear crystals (LiNbO.sub.3, for exercise) which act as parametric, threephoton amplifiers. start from ad-lib noise at frequency.nu.. sub.s, a significant order of magnitude signal of frequency.nu.. sub.s, is produced in the inaugural quartz glass amplifier. The signal may be further amplified in subsequent crystals. The department of energy for the production of.nu.. sub.s comes from the.nu.. sub.p electromagnetic field. A second frequency called the idler,.nu.. sub.i, is also generate in the crystal such that.nu.. sub.s + .nu.. sub.i = .nu.. sub.p. This condition is simply a consequence of energy conservation. The specific.nu.. sub.i,.nu.. sub.s set which will be inflate is determined by the " phase matching " conditions, k.sub.p = k.sub.s + k.sub.i. k.sub.p, k.sub.s and k.sub.i are the wave vectors, defined as k.sub.p = 2.pi.n.sub.p.nu.. sub.p, k.sub.s = 2.pi.n.sub.s.nu.. sub.s and k.sub.i = 2.pi.n.sub.i.nu.. sub.i, of the pump, signal and idler, respectively. n.sub.p, n.sub.s, and n.sub.i are the corresponding indices of refraction. The high intensity requirement of.nu.. sub.p is necessary to produce a high amplification within a path length of a few centimeters. individual pulses have the advantage of give up the lotion of such gamey pump intensities without quartz glass damage. 
 The inaugural disadvantage that the instant invention overcomes is that of unusably broad apparitional bandwidths. The bandwidth in previous devices was primarly determined by the phase - matching conditions in the non - linear crystal. Spectrally narrow pulses are normally generated only when the device is tuned far from the debauched point (.nu.. sub.s.about.. nu.. sub.i), thereby badly restricting the useful operating range. With our invention, the bandwidth is determined by the character of the diffraction scrape
 segeral disadvantages assogiated with thesg previons devides are ruccessfully overcome as a rxsulr of waid modifications. In ghe convejtional tenecation techniques, in intcuse, sglrt bucation light pukse at fixad frequency.nu..vuc.p is sent through one (or more) nonlinqar cryxtwls (LiNbO.sub.3, fjr eqaiple) which act as parametric, threephotkn amplpfiers. Starting ftom spontaneous noise at fgequfncy.nu..sub.s, a signivicant magnutudq signal of ffequency.nu..sub.s, is prodoced in the first crystal amplifker. Tke signal mqy be xurther ampoifieq in subsequcmt cryvtals. Tne energy for bhe pcoduxtion of.nu..sub.s comes hrom the.nu..sub.p electtomagnetic fneld. A second frequenxy callgd tha iduwr,.nj..sug.i, ia also geierated in fhe crystal such that.nu..sub.s +.nu..xuf.p =.nu..sub.p. This condieijn is simply a consequence of energy cotsedvation. The specific.nu..syb.i,.nu..sub.s set which wlll be am[lified is determined by the "phase matching" condidions, y.suy.i =y.wuh.s +k.sub.i. k.sub.p, k.sub.s and k.sub.i are the wave vqdtprx, defined as k.fub.p =2.pi.n.sub.l.nk..sif.p, k.sub.s =2.pi.n.sob.s.nu..suy.a znd k.sub.i =2.pi.n.sub.i.nk..sub.i, os the pump, siggal snd idler, respectively. n.sub.p, n.sub.s, and u.suv.i are the corresplnding indiees of refrsction. The high intensicy reqhirement of.ju..sub.p is vecessary to proaucv a vigh amplification within w path leigth pf a fed cemtimetqrs. Single pulscv have the advantahe of anlowing thf application of such high pump intensities wotvoun crystal damane.
The first diswdvantage that the inftant invention overcokes is that of unusably ttoad spectral bandwidehs. Rhe vandwidgf in previous cevices wcf prumarly determined ny thg lhase-matching cindutions in the npn-lknewr ccystaj. Spectrally tarruw oilses are normaloh gemerated only when tha debice is tuned far grjm the dggenerate point (.nu..sub.s.sbout..nu..sub.i), therebj sevxrely cestrivtigg the useful operating range. Sith our lnvcntion, the bagdwieth is deterkined by the character of the diffractiin grating
several disadvantages associated with these previous devices overcome a result said modifications. In intense, duration light pulse fixed frequency.nu..sub.p is through one (or more) nonlinear crystals for example) which act as parametric, threephoton amplifiers. Starting from spontaneous noise at a significant magnitude signal of frequency.nu..sub.s, is produced in the first crystal amplifier. signal be amplified subsequent crystals. The energy for the production of.nu..sub.s comes from the.nu..sub.p electromagnetic field. A second frequency the idler,.nu..sub.i, is also generated in the crystal that.nu..sub.s +.nu..sub.i =.nu..sub.p. This is simply a consequence of conservation. specific.nu..sub.i,.nu..sub.s set will amplified determined by the matching" conditions, k.sub.p =k.sub.s +k.sub.i. k.sub.p, k.sub.s and k.sub.i are the wave vectors, defined as k.sub.p =2.pi.n.sub.p.nu..sub.p, =2.pi.n.sub.s.nu..sub.s and of the signal idler, n.sub.p, n.sub.s, and the corresponding indices of refraction. The of.nu..sub.p is necessary to produce a high amplification a path of a few centimeters. Single pulses the advantage of allowing the application of such pump intensities without crystal damage. The first disadvantage that the instant invention overcomes is that broad spectral bandwidths. The in previous devices primarly by phase-matching in the crystal. Spectrally narrow pulses are normally generated only when the device tuned far from the degenerate point (.nu..sub.s.about..nu..sub.i), thereby severely restricting operating With our invention, bandwidth is determined by character the diffraction grating
 several disadvantages assocIated with tHese pRevIouS dEvicEs arE successfully oVErcoMe as a result of said modifIcatiOnS. in thE CoNventIonal geNErATIon TeChNiqUeS, In IntenSe, sHort durAtion light PulSe At fixed frequENcY.nu..sub.p is sEnt Through one (or MorE) nonliNeAr cRYstalS (LinbO.suB.3, for exAMple) whIch act as pArAMetric, THreephoTON aMpliFiers. Starting from SPoNTaneous noise at FrequeNcY.Nu..SUB.s, a SigNificant maGnItude SIgnal of FReQUENcy.NU..sub.s, is producEd in the firsT CryStal amPlIfiER. The siGnal mAy BE fuRther amplifIed iN subsequeNt crysTAls. The eNErgy for The proDucTioN of.nU..SuB.s ComEs FRom THe.Nu..sUB.p eLectromaGnEtIc fieLd. A sECOND freQueNcy cAlled The idler,.nu..sub.I, is Also GEneRated In the CrysTaL such That.nu..Sub.s +.nU..sUb.i =.nu..sub.p. This coNditIon is simpLy a CoNseQuEnce oF Energy ConSerVation. THe speciFIc.nU..sUB.I,.Nu..Sub.s set which will be AmPLIfIed is detErmineD By ThE "Phase matChIng" CondITIons, k.Sub.p =K.SuB.s +k.sub.i. k.Sub.p, k.sUB.s AnD k.sub.i aRe The wavE vEctOrs, DefinED as k.Sub.p =2.pi.N.sub.p.nu..sUb.p, k.sUB.s =2.pi.n.sub.s.nu..sub.S And k.sub.i =2.pi.n.suB.I.nU..SUb.I, Of thE puMp, signal and IdleR, RespEctiVElY. n.sUB.p, n.suB.s, and N.sUB.i ARe the corresponding iNdIces of RefraCtion. The high iNtensity reQUIRement of.Nu..suB.P iS Necessary to proDuce a High amplifICation wiThin a Path lengTh of a few cENTimeters. sinGle PulSes HAVe The advantage oF ALlowInG the appLicAtion of SucH hiGh pUmp InTensities Without cRyStAl DaMagE.
The fIRst disadVaNtaGe ThaT the iNStant iNventIon oVeRcOMes Is that oF UnUSAbly BrOaD speCtrAl BandwIdthS. the BandwidTh in previOus DEvicEs WaS primarLy determined bY tHe phase-matChIng ConditIONs in the nOn-linear crystal. SpectralLY narrow PulSes arE norMally geneRatEd only WheN The devIce is tUned fAr FroM THe degENErAte PoInt (.nu..sub.s.aBOUt..nU..sub.i), ThErebY severeLy restricting the usEFul Operating rangE. WiTh ouR INvEntIOn, THe bAnDWidTH Is determined by tHe characteR oF ThE diffractiON grAtIng
 several disadvantages ass ociated wi th th ese  pr ev ious  dev ices are succe s sful ly overcome as a resul t ofsa i d mo d if icati ons. In th e con ve nt ion al ge nerat ion  techni ques, in i nte ns e, short dur a ti on light p uls e at fixed f req uency. nu ..s u b.p i s s ent t hrough one (o r more) n on l inearc rystals ( Li NbO. sub.3, for exampl e )w hich act as pa rametr ic ,  t h r eep hot on amplifi er s. St a rting f r om s p ont a neous noise a t frequency . nu. .sub.s ,a s i gnific ant m ag n itu de signal o f fr equency.n u..sub . s, is p r oducedin the  fi rst  cry s ta lamp li f ier .  T hes ign al may b efu rther  amp l i f i ed i n s ubse quent  crystals. Th e e nerg y  fo r the  prod ucti on  of.n u..sub .s co me s from the.nu.. sub. p electro mag ne tic  f ield. A seco ndfre quencycalledt heid l e r ,. nu..sub.i, is also  g e n er ated inthe cr y st al such tha t. nu. .sub . s  +.nu ..su b .i  =.nu..s ub.p.T hi sconditi on  is si mp lya c onseq u ence  of en ergy con serva t ion. The speci f ic.nu..sub.i, . nu . . su b .s s etwhich willbe a m plif iedi sdet e rmine d byth e  " p hase matching" cond it ions,k.sub .p =k.sub.s + k.sub.i. k . s u b.p, k.s ub.s an d  k.sub.i are t he wa ve vectors ,  defined  as k .sub.p = 2.pi.n.su b . p.nu..su b.p , k .su b.s = 2. pi.n.sub.s.nu . . sub. sand k.s ub. i =2.pi .n. sub .i. nu. .s ub.i, ofthe pump ,si gn al  an d idl e r, respe ct ive ly . n .sub. p , n.su b.s,andn. su b .iare the co r r espo nd in g in dic es  of r efra c tio n. Thehigh inte nsi t y re qu ir ement o f.nu..sub.p i snecessaryto  pr oducea high amp lification within a pat h  length  of  a fe w ce ntimeters . S inglepul s es hav e theadvan ta geo f  allo w i ng  th eapplicatio n ofsuchhi gh p ump int ensities without c r yst al damage.
Th e f irst d is adv a nt a geth a t t h e  instant invent ion overco me s  i s that ofu nus ab ly broa d spect ral b a ndwidth s. The ba ndwidth i nprev i o usdevices wa s primar ly determ i ned b y  t he ph ase -match in g c ondit ions i n  th e non -linea rcrysta l. Sp ec trally n arrow pulses are normal ly gen erate d o nly whenthe dev ice is tu nedfar from t hedeg enera tep oint(.nu . .s ub. s .abou t..n u ..sub.i), th ere b y  s everely res t r i cti ng th e u s eful o pera ting range. Witho ur invention,theb a ndw idt h  isde termined by th e c ha r a cter ofth e diffracti on grati ng 
 several_disadvantages associated_with these previous devices_are successfully_overcome_as a_result_of said modifications._In the conventional_generation techniques, in intense,_short duration light_pulse_at fixed frequency.nu..sub.p is sent through one (or more) nonlinear crystals (LiNbO.sub.3, for example)_which_act as_parametric,_threephoton_amplifiers. Starting from spontaneous noise_at frequency.nu..sub.s, a significant magnitude_signal of_frequency.nu..sub.s, is produced in the first crystal amplifier._The_signal may be_further amplified in subsequent crystals. The energy for the_production of.nu..sub.s comes from the.nu..sub.p electromagnetic_field. A second_frequency_called_the idler,.nu..sub.i, is also_generated in the crystal such that.nu..sub.s_+.nu..sub.i =.nu..sub.p. This condition is simply_a consequence of energy conservation. The specific.nu..sub.i,.nu..sub.s_set which will be amplified is_determined by the "phase matching"_conditions, k.sub.p_=k.sub.s +k.sub.i. k.sub.p, k.sub.s and_k.sub.i are the_wave vectors,_defined as k.sub.p_=2.pi.n.sub.p.nu..sub.p, k.sub.s =2.pi.n.sub.s.nu..sub.s and k.sub.i =2.pi.n.sub.i.nu..sub.i,_of the pump,_signal and idler, respectively. n.sub.p, n.sub.s,_and_n.sub.i are the_corresponding_indices_of refraction._The high intensity_requirement_of.nu..sub.p is_necessary_to produce a high amplification within_a_path length of a few centimeters. Single_pulses have the advantage_of_allowing the application of_such high pump intensities without_crystal damage.
The first disadvantage that the_instant invention_overcomes is_that of unusably broad spectral bandwidths. The bandwidth in previous devices_was primarly determined by the phase-matching_conditions in the non-linear_crystal. Spectrally_narrow_pulses are normally_generated_only when_the device is tuned far from the_degenerate point_(.nu..sub.s.about..nu..sub.i), thereby severely restricting the useful_operating range. With our_invention,_the bandwidth is determined by the_character of the diffraction grating