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JPRS ID: 8527 TRANSLATIONS ON USSR SCIENCE AND TECHNOLOGY PHYSICAL SCIENCES AND TECHNOLOGY QUANTUM ELECTRONICS

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APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 ~ ~ . ~ QUANTUM ELECTRONICS 20 JUNE i979 CFOUQ 33179~ i OF i APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047/02/09: CIA-RDP82-00850R000100060038-3 , - FOR OFFICIAL USE ONLY J'Pt2S L/~527 ' . 20 ~une 19 79 ~ ~ TRANSLAtIONS ON USSR SCIENCE AND TECHNOLOGY PHYSICAL SCIENCES AND TFCE~NOLOGY (FOUO 33/79) ~UANTUM ELECTRONICS U. S. JOINI' PI~BLICATIONS RESE~?RCH SER1/iCE FOR OFFICIAL USE ~ILY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 NOT~ ~ JPR5 publicaCione contain informaCion primarily from foreign - - ner~~spapers, periodicals end booke, but also from newg agency tr~nsmissinns and broadcasCs. MaeeY~ials from foreign-language sources are eranslaeed; Chose from ~nglish-language sources are tran~cribed or reprinted, with the original phrasing and - other characCerisCica retained. � Headlines, editorial reports, and material enclosed in brackets _ are supplied by JPRS. Procesaing indicators ~uch as [TextJ or [Excerptj in the �irst line of each irem, or following ehe last line of a brief, indicate how the original information was processed. Where no processing indicaCor is given~ the infor- : mation was aucnmarized or extracted. - Unfamiliar names rendered phonetically or transliCerated are enclosed in parentheaea. Words or naa~es preceded by a ques- - tion mark and encloaed in parentheses were not clear in the original but have been aupplied asappropriaCe in cnntext. Other unaCtribuCed parenthetical notes within the body of an item originat~ with the source. Times within items are as given by source. The contents of this publication in no way represent the poli- cies, views or attitudes o� the U.S. Government. - COPYRIGHT LAWS AND REGULATIONS GO'VERNING OWNERSHIP OF MATERIALS REPRODUCED HEREIN REQUIRE THAT DISSEMINATION OF THIS PUBLICATION BE RESTRI~TED FOR OFFICIAL USE ONLY. � - APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 FOR OFF'ICIAL US~ ONLY JPRS L/8527 - 20 June 1979 TRANSLATIONS ON USSR SCIENCE AND TECHNOLOGY ` PHYSICAL SCIENCES AND TECHNOLO~Y (EOUn 33/79) QUANTUM ELECTRONICS - Moscow KVANTOVAYA ELEKTRONIKA in Russi.an Vol 6 No. 3, i979 pp 466-472, 513-517, 548-552~ 592-593, 597-598, 629-63L, 635-691 646-648 CONTENTS PAGE QUANPUM ELEGTRONICS The InPluence oP Interference EPfects in Oxide Films on the Dynamics of Metal Heating Using Laser itadiation (M. I. Arzuov, et al 1 An bcperimental Investigetion of a Method of Controlling the Radiation Pulse Waveform oP a C02 Amplifier (V. V. Maksimov et a1.) 12 The Characteristics of a C42 ?aser Excited by an Alternating Current Capacitive Discharge (V. D. Gavrilyuk~ et al.~ 19 Letters to the Editor of 'QUAN'I'UM ELECTRONICS' ~ ~(B. Ya. Zel'dovich, et al~ 26 ' A Compact Periodic Pulsed C~ Laser (M. I. Arzuov, et al. 29 - Spatial Polarization Inversion oP a Wave Front Por th~ , Case of Four Photon Interaction (B. Ya. Zel'dovich, V. V. Shkunov) 33 - a- [ZII. - USSR - 23 S& T FOUOJ - FOR OFFICIAL USE 0'~1LY � APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047/02/09: CIA-RDP82-00850R000100060038-3 ~0[t OE~~ICIAL US~ nNLY CONT~NTS (Con~inued) ~16~ The Inf'luence of Pump Deple~ion on bhe 3uperrad~a~ton Procees Wi,th Raman L,i.ght Scattering (V. I. Yemel~yanov, V. N. Seminogov) 3f3 On ~he Poe~ibilitiy oP Fie].d Wt~v~ ~ron~ 7nversion by Means ~ o~ Non].inear Optics (I. M. He].~~h~in, et al.) 43 Optical Losgeg in I4~5-5 e,nd IQt5-6 crysta~s ~ ' (V. G. Artyuehenko, et al.) 4E3 � ~ - b - _ ~ FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047/02109: CIA-RDP82-00850R000100060038-3 FOR n~FIC1AL USL ONLY ` c2UANTIdM FL~CTRONICS - UDC 535.21 THE INFLUENCC OF INTERFERENCE EFFECTS IN OXInE FTLMS OPI THE UYNAMTCS 0~ MCTAL HEATING USING LASER RAU?ATION Moscow KVANTOVAYA ELEKTItONIKA in Russian Vol 6 No 3, 1979 pp 466-412 [Ar~icle by M.I. Arzuov, A.I. Barchukov, F.V. Bunkin, N.A. Kirichenko, _ V.I. Konov and B.S. Luk'yanchuk, Physics InsCitute imeni P.N. LPbedev of the USSR Academy of Sciences, Moscow, manuscript received 6 Apr 78] - [Text) A theoretical model is constructed for rhe oxidation of m~Cals by continuous laser radiation, Caking inCo account interf~rence phenomena in the oxide film. The problem irs solved by the simultane- - ous solution of a parabolic equation for the kinetics of ineCal oxidation, Che thermal conductivity equa- tion taking convective and radiative losses into - eccounC, as well as an equation which relatea the - absorpCivity of the oxide--metal sygtem to the thick- r.ess and the optical constants of the oxide film, as well as the.cold absorptivity of the metal. Heating kinetics are analyzed from room temperature up to the melting point of the thermally thin plate and Che ' semi-infinite t~rget. The results of the calculaCions are in good agree~nent with the experimental data for the oxidation of copper by the radiation of a CW CO? laser. - 1. Introductioci - As w1s noted in the literature [1-7J, the interaction of C02 laser radiation with metals in an oxidizing atmosphere possesses u number of special features. When metals are irradiated in a neutral gas medium or in a vacuum., their ab- _ sorptivity for radiation at the long wavelength of 10.6 um, as a rule, proves - Co be small. However, when irradiated in an oxidizing atmosphere, an oxide _ f~.lm is formed on the surface of the metal which has a considerable molecular absorptivity [8]. With an increase in the oxide film thickness, the absorp- ` tivity changes, and correspondingly, the rate of Cemperature inerease changes. _ To compute the process of inetal heaeing in an oxidizing atmosphere, it is 1 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 - FOlt 0~'~ICIAL U5~ UN1.~Y _ necessary to aimulCaneous~.y sol.ve rhe enuaCione of thermnl Canductiviey nnd me~al oxideCion kinerice Caking tn~o account the change in metal nbsorpCivi~y during oxidization. Papers [2 were devoCed Co an approxima~e solution - of Chis problem. _ The taw governing the g:�owth of ehe nxide film depends on its thickness. Ie was shown in paper [5] thaC the growCh Chin (x ~ r00 nm) oxide layer cnciCinucg - = for a rel.arively brief Cime, and this stage of Che process doe~ not play a substane:.al part in the problem of inetal henting with C02 laser r~di~tion. If the Chickness of tt~e film is x e 100 nm, Chen the oxidation kineCicg equatio:~ has the form - d C z e_ra~r ~ (1) - where t is tine; T is the di�fusion activation energy or nn ion of the metal (or oxygen) inAChe oxide; T is Che temperaCure, �K; the cons~c~nC d is related to the diffusion fac~ors for the meCa1 and oxygen ions in the - - oxide layer [9]. The thickness of Che oxide layer determines the absorptiviCy A of the metal. It was assumed in papers [2, 3] that: A=- A 2acx, ( 2) _ _ where AD is the absorptivity of Che metal in Che absence of the oxide film; a is the radiation absorptien factor in the oxide. ' - It is demonstrated in this paper Chat in the process of continuous heating ~ of a meCa1, Che thickness of the oxide film becomes comparable to the radia- tion wavelength, and formula (2) cannot be used. Moreover, durin~ t}1~~ growth of tlie oxide film, oscillations in the absorptiv~ty can arise in it by virtue of interference phenomena in the oxide--metal layer system, which must like- - wise be taken into account. 2. The Absorptivity of a Layered System The absorptivity A is expressed in terms of the values of the optical charac- teristics of Che oxide and metal. For Che case of normal incidence o~ the radi- ation, we have [10]: A=1- ~ R R= r~: exp 2it~) + i:a_ , exP ~ - ~ts~s~ r~e ~ ~ w x Ye = 1 + ia) x; i1z - I - Ve ; r:a = . ~3~ . c ~ where Z l-~- 1/e - I , 1-~ ris Ao~ w is the radiation frequency, c is the speed of light, r12 and r13 are the radiation amplitude reflection factors from the oxide and from the metal; e is the oxide dielectric permitCivity; n+ iK; a= 2Kw/c is the oxide absorption factor; 2nw/c. For good conductors [10], AD � 1, and r13 ~ - _ -1 O.SAp(i - 1). - 2 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 _ FOEt Ob"FICIAL US~ ONL,Y A grnl~h of ttie ~unction A(x) ploCted q ~rom formula (3) is ahown in Figure 1. 04 ~51 As cun be seen from rigure 1, the ~b- sorptivi~y oF n luyered sys~em is ~3~ I characCerized by the presence of 0,3 oacilla~ions due to inCerference phe- ~ nnmena in rhe oxide layer. 0,2 ~ ~ The position of the extrema of ehe funceion A(x) is determined from the ~ condition dA/dx = 0, which can be x,~um I written in Che form: _ . ~ 2 4 6 B s,nH~ th ~-1' t tg ~x -r ~p ~ lm 1/I l~e , Z ~ 2 Re ~/I - 1/e ' Figure 1. The funcCion A(x) for th az l t Sx -i- ~p Re 1/I = I%e ' the case of n= 1.098 and 2 g 2 � Im ~/I I%e ' x = 0.019, plotCed from - formulas (3) and (5): Almax~3) = 0.199; ~4) Almin~s~ � ~�222~ where Z=-ln~r23~; arg r23; the lmax ~ first equaCion detern?ines the maximum Almin~s~ ' 0.218. poinks and the second Che minimum points. _ As a rule, at the radiation frequency of a C02 laser, Che following conditions are m~t: 1~ Ir1212 � Ap, K� 1, and n> 1. Then within a precision of first _ - order terms wiCh respect to K and Ap, we have; Im Y1 e nAo nAo . ~ =n(n -1)~ 2 ~ ~P-~'-f' 2 � Fte Y1 - E - By virtue of the condition a 1 usec. a,M ~ c ~a~ MW/cm~ Figure 2. T~!~e small signal gain a(a) ~ and the amplified signal l,.,HBm/cn~ ---?--~-~b~ power as a func~ion of Cime o , ~ ~'or del~ye Td a-0.05 uaec ~,.,hBm/rn' (b) , 0.5 usec (c) and 1.5 e usec (d), as well as th~ pe~k power aC Che output of 4 the amplifier in the absence p of Irp (1) and in Che presence l,.,nem/cn' of the optically acCive med- _ a~d~ ium Ir (2) where Td = 1.2 MW/cm~~ usec (e). . . The mixture of gases o ~--~8 C02:N2 = 1:2, Che toCal lrnem/cnt o ~ ~ 1 t,M"~ r ressure was 1 atm and lro,MBm/cn p ~ MW~~ra2 pp ~e~ ~ ~p the specif ic abaorbed . o.s energy density was Q/p = 0 ~oo � ?oo t,HC ~ = 0.16 J/ (cm3 � atm) . C, ns . The ratio of the energy Qrl radiated at the peak of a power of Ir a 0.5 Irax~ to the total radiation pulse energy at Che outpuC of Che amplifier, Qr, is ~chown in Figure ~a as a function of the absorbed energy denaity for various partial pressures of the C02 and N2 gases and Td =~.2 usec. The size of 4r1 was derermined by numerical integration of the oscillograms of Che radi- ation pulses. It can be seen from rhe results that w~th an increase in the - COZ partial pressure, the fraction of the energy in the initial high power peak reaches 80y. It is significant that when the overall pulse width of the master oscillator was about 3 usea, its gain when td > 1 usec was prac- tically terminated about 200 nsec after the signal was fed in, and despite - the fa~ct that the small signal gain reached abouC 3� 103, the ratio of _ I~/Ir~ was less than 30 for all cases. Thus, in the given mode, the energy and power of only the initial peak of the oscillator pulse were amplified. It is essential to note that we did.not study the possibility of obtaining . maximum efficiency of the amplifier system. The efficiency of the amplifier, ~5 _ F~R OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~n~ n~~icrnr. usL nrr~,Y eaeimaCed using eh~ ~cpression n=(Qoue - Qin~~4p ~Qoue nnd Q~,n are Che ouCpuC ~nd input ene~rgy o� Che amplifier; Qp n QpV1/Vp; Qp is rhe total _ energy absorbed in the diacharge having a volume Vp; VZ ia the volume Chrough attich Che rndi~tion p~seee), did noe depend on ~rd and amounted to aboue 10%. - IC is necessary Co note ehaC with changeg in ehe manner of tgpping Che energy, - - the amplifier efficiency practically did noC chnnge. The c~ode o~ energy liberation from the optiCally acive medium for the cuse o~ FasC pulse exciCa~ion is deeer?nined boeh by Che par~meters of Che rgdinrion , pulse being amplified and by Che collision proceasea which lead to Che populn- C~on of Che upper lasing level and the depl~Cion of the lower lasing 1eve1. Since the transfer rime �or the N2 oacillaCion energy to the C02 asymmetrical mode and �or Che deactivation a� the lower lasing level under ttie condiCione of our experiment were aubsCantially greater than ehe eimes for roC~Cionnl and intramodgl oecillaCory relaxaCion [6], apecifically Che first two processes were responsible �or Che quasiateady-sC~te energy mode for the case of small _ delays Td and oscillator radiation intensities of Irp � hv/(~T34) (where v is Che stimulated trasition cross-section; T34 ig the Cransfer time for energy �rom the N2 to the asymmeCrical C02 mode; hv is the energy of a radintion qu~ntum). - If the oscillator radiation pulse is in~ected inCo the amli~ier when Td > 1 usec, then the ma~or parC of the absorbed energy is stored in the asymmetricnl _ oscillations (especially in a gas mixture with a large partial content of COZ), something which permits shaping Che short radiaCion peak at the amplifier ouC- put, where the width of Che peak can be determined by both Che rotational nn~d intramodal oscillatory relaxation Cimes and the waveform of the oscillator r~.di- ation pulse. The study of the maximum energy output rate from the amplifier while maintain- _ ing its high efficiency was of particular interest. The deformation of the initial peak of the master oscillaLor pulse was studied when it passed through the two meter amplifier. The input signal energy flux with a width of about 70 nsec amounted to 0.1 0.2 J/cm2. Typical curves for the power density aC the maximum IraX and Che half-height % peak width At for the radiation pulse at the amplifier output are shown in Figures 3b and 3c as a function of the absorbed energy density Q/p. It can be seen from the data presented that the pulse power increases wirh an in- crease in the 3n~ected energy: Ir~ _(Q/p)3~2, however, the peak width At practically does not change, despite the substantiall,y the nonlinear gain. It is well known [7] that if the master oscillator pulse has an exponentially rising leading edge, then when propagating in the optically active medium, its maximum experiences an additional shift "ahead", while Che width can prac- tically remain con.stant. In order to check the influence of this process under our experime~ital condiCions, an additional invesCi~ation was made of = the radiation pulse waveform distortion in the amplification process. To - 16 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~Ott O~~~CIAI, USL ONLY - i7~/Q~ . ~ ge Q Q ~g~ � Figure 3. 'i'he ~r~Ceion oL the enerRy . a6 o-e , in ehe rndir?Cion pul~e penk Q4 ~ (n), eh~ hu1~-heighe pu1~c u--~"~' width (b) nnd th~ pnwer ap dengity ne th~ m~ximum Yadi- aCion peak (c) ag ~ func~ion at,NC n~ 6(b) of rhe specific in~ecCed - energy where Td ~ 1.2 ugec o g o~ 8 o for mixCures of C02:N2 = 1:2 ~ 6p n �,r,_ - (sqvares), 1:1 (circles) and _ sa e 2:1 (trianglea). tr nx~ MBm/c~ z o - 40 MW~ Cnq n � 30 ~ / v ~ I ZQ 0 0 D _ o ~C ~ ~ 1D ~ 4 S 6 ~ Q 9!0 ~0 _ (a/~� Io z ,4~+'l~M ~ amM) . Ji c~3 gtm~ preciaely measure the time of appearance of the pulse at the amplifier ouC- put relative Co the start of Che oscillator pulse, the aignals from botih recorders, decoupled in t3me, were fed to one beam of the S7-l0A oscillograph. Typical pulsea at the output of the working chamber without gain (curve 1) and witt? gain (curve 2) are shown in Figure 2e. The shift "ahead" of the maximum of ~hs intensity by 15---25 ngec was experimentally deCermined. On Che other hand, as was demonstrated in papers [8, 9], the total energy ro- tational and intramodal oscillatory relaxation times to the specified oscil-- latory-rota~ional level for the case af a mixture preasure of 1 atm fall within a range of 1-10 and 20-70 nsec respecCively, i.e., they are comparable with the width o~ the signal t~eing amplified. IC can be assumed that under our experimental conditions, the limiting of the energy liberation rate of the optically active medium, found to have a ~ chaxacteristic time of ~60 ns~c, was due to both the finite width of the ' l,eading edge of the master oscillator pulse and the time for the rotational and oscillatory relaxation of the energy.. Thus, a sisaple and reliable method of controlling the waveform and width of a radiation pulse in a C02 amplifier syatem for the case of a constant exci- tation time of the opCically active medium has been experimentally 17 FOR OFFICIAL USE ONI.Y APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 _ ~OR O~F'1CIAL U5~ dN1aY inveeCigg~ed for Che firg~ t~.ma in ehig p~p~r. The posgibil:ty of ~~nrying Che energy relegse ~im~ in a range of 0~06--2 usec aC nn ~ffi~~iency of ~ 10"d ha~ be~n demonsCrated. The auChora Are grateful eo L.x. I~oskutova ~or ~~gigtiine in th~ procesging oP ~he reaulCs and V.N. Tishchenko for hie useful dir,cugeions. BIBLIOGRAI'HY _ l. V.A. Arsen~yev, I.N. Matveyev, N.D. Ustynov, KVANTOVAYA ~L~KTRONTKA, 4, 2309, (1977), 2. A.G. Ponomarenko, V.N. Tiehchenko, "Prepr~ne IT~M SO AN SSSR" ["preprint of the TTPM of Che S~berian Departmene of Ch: USSR Academy of Sciences"], Novosibirsk- 1978, No 1. 3. Yu.V. Afonin, A.M. Orishich, A.G. Ponomarpnko, S.P. 5hglamov, "Preprint: ITPM SO AN SSSR'~, Novoaibirak, 1977, No 4. 4. A.M. Oriahich, A.G. Ponomarenko, V.G. Posukh, R.I. Soloukhin, S.P. _ Shalamov, PTS~MA V ZHTF [LETT'ERS TO THE JOURNAL OF ENGINEERING PHYSICS], 3, 39, (1977?. 5. L.M. Pakhomov, PT~ [TECHNICAL OPERATION 1tEGULATIONS], No 2, 252, (1976). . 6. S.A. Trushin, V.V. Churakov, KVANTOVAYA ELEK'TRONIKA, 4, 385, (1977). 7. P.G. Kryukov, V.S. Letokhov, UFN [PROGRESS IN THE PHYSICAL SCIENCES], - 99, 169, (1969). 8. J.F. Figueira, W.H. Reichelt, G.T. Schappert, T.F. Stratton, S.A. _ Fenstermacher, APPL. PHYS. LETTS., 22, 216 (173). 9. R.J. Harrach, IEEE. J. QE-11, 349, (1975). ~ COPYRIGHT: Izdatel~stvo "SoveCekoye Radio", "Kvantovaya elektronika", 1979 8225 CS0:8144/1216 18 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~ I~OR n~~rCIAL US~ ONIaY QUANmUM ~LCCmRONICS _ ~ UDC 621.378.324 THE CHARACT~RISTICS 0~ A C02 LA,5~R E}tCITED BY AN ALTEItNATING CUItR~NT CAPACITIVE DISCNAItG~ Mogcow KVANTOVAYA BLEKTItONIKA in Russi~n Vol 6 No 3, 1979 pp 548-552 (Artfcle by V.D. Gavrilyuk, A.F. Glova, V.S. Golubev, A.B. Ku2netsov, F.V. Lebedev and V.A. Feo�il~ktov, manuscript received 9 Jun 78j [Text] A model o� n steady-seaCe fast flow C0~ laser excited ~ by an AC capaciCive discharge aL� n frequency of 10 KHz was experimentally studied. The results of opCimizing the laser operat~ona7, modes are in agreemen~ with the calculated results. In accordance with them, at the level of the specific pumping par~uneters achieved in operation, an industrial laser can be designed with a power of ~ 20 KW with an overall efficiency of ~ 15~ and a specific radiaCion energy yield of ~40-45 J/g. 1. The utilizaCion of an alternating current capacitive discharge to pwnp gas - lasers is of inCerest in connection with the prospects for dispensing wiCh ballast resistors, as well as the simplif.ication of the power supplies and the structural design of the discharge chr~mber. The possibility of creating a homogeneous alCernating current discharge at a frequency of 10 KHz in a flow o~ N2 with C02 added was shown in paper [lJ, and the feasibility of attaining specific mass energy contributinns of Wg ~ 300-400 J/g at an overall oscilla- tory di'scharge ef~iciency of vcol " 60X was also demonsCrated. The results of experimental studies using a breadboarded fast flow C02 laser excited by a capacitive diseharge, for the purpose of determining the effici- ency of Che conversion of the AC generator energy into radiation, optimi2ing the operational modes of the device and investigating Che stabiliCy of the output radiation, are given in this paper. 2. The experimental setup of a fast flow C02 i.~ser (Figure 1), consisted of a rectangular channel with a cross-section of 200 x 60 mm, through which the ~rorking mixture of gases (N2, air, He, COZ) was pumped. The gas velocity at the�inlet to the discharge chamber was v~ 100 m/aec, and the static , pressure varied from 30 mm Hg. The transverse AC discharge aC a frequency 19 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 - rok d~,~T.~zni, u5c nN~.,Y of ~.0 KHz was realized betiween tiwo ~1ae dielecCric plntes, spnced h~ 60 mm . aparC. The leng~h of ~he discharge zotte ~rnnaverae Co ehe flow amounCed Co 150 mm, and in Che direction of ~he flow (Z) v~ried from Y80 Co 390 mm. The disc:linrge was powered with a moCor-generator Chrough ~ secpup rrc~nsformer. A single-pass stable resonaCor, conaisting of Cwo copper reflectors with n diameCer of 60 mm and rndii of curvature of R~ n~ and R2 = 600 mm were plgced in Che downsCrenm portion of the discharge zone. There was ~ throu~h - pole wi~h a diame~er of d a 2 mm, covered by n plate of NaCl, in the cenCer of Che flat reflectox. The rad~ation absorption factor aC Che surtace of ehe reflecCors was determined by the method of multiple reflecC3ons and amounted - to r = 2 + 0.15~. ~ The conversion efficiency of ehe elec- - trical energy to lighC energy was charac- ~ _ p terized by Che electro-optical efficiency v_~ level, veO, defined as the raCio of the radiation power absorbed in the reflec- N tors of the reaonator and brought out � through the hole in the reflector, Co the to~a1 electrical power consumed Figure 1. The experfinental con- from the discharge power supply. figuration: The eapped off radiation power, accord- Key: 1. The excitaCion zone ing to calorimetric measurements, did (dischar~e.zone); noC exceed 5~6 0~ the power absorbed by 2. Zone for regisCering the reflectors, and was proporCional to the exciCation (the it. Tn determining neo in this fashion, - resonator region); we did not take into account the radi 3. Exhaust. ation losses due to diffusion scattering at the reflectors, something which could - - lead to understating the size of neO by 10 - 15%. The total power consumption of the laser was determined from oscil- loscope traces of the discharge and the voltage across the uutpuC Cerminals of the power supply. The specCra of the fluctuations in the discharge current and the radiation inCensiCy were studied using a S4-12 spectrum analyzer, to . the inpuC of which a signal was fed from a metering shunt or from an PSG~22-3A1 transducer. The calculation procedure we employed [2] allowed for the determination of the fraction of a11 of the oscillatory exeited molecules, the energy of which is comerted to atimulated radiation in the resonator (nr~, and the calculation of the system electro-optical efficiency rleO as rleo � nrnknq, where nk is the oscillatory efficiency of the excitation method, while n~ = 0.41 is Che quantum _ efficiency of the C02 laser. The calculations were per~ormed for the case of the electro-optical configuration of the laser shown in Figure 1, in accord- anc_E: with which the acCive medium is excited by a discharge which is uniform over the entire length of the zone L, while the excitation i3 regisCered in a resonator placed at the end of this zone, where the resonator is formed by two parallel reflectors with an absorption factor of r. 20 FOR OFFICIAL US~ ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 FOR U~'FICIAL USL UNI.Y Resu~,~s oP exp~r~menCs to esri- muCe rhe energy bal~nce in an '~~o~ p~,~�____ AC d~scharge were employed in ~ ~he calculdeiona i.e., it � 6 ~ ~ wgs Assumed Chat 60Y of the - 5 0~ ~ power ~upply energy goes Co ex- ~ cite ~he oscil~.a~ory levels o~ 4 % ~he nitrogen molecules, 25% ro 3!� direct hesC~.ng of the gas, while _ o a3 > >,s ~,o XMto, ~o'' tihe remaining 15% is expended in heaCing the electrodes and _ Figure 2. The theoretical (1) and sCructures, exciting the electron _ experimental (2) curves ~@ve1s, 3oniza~ion, plasma- _ for neo as a function of chemical. reactions and other processes. the water concentration at p m 30 mm Hg, v~ 100 m/sec, 4. The basic results were obtained ~E ~ 4.1 (1) and 4.5 (2), When using a helium free operating X~p2 = 6� 10'2, L= 180 mm mixture, consisting of commerc- (1) and 190 mm (2), XH2O ially pure nitrogen (02 content - was assured by Che air up to 2-3%), COZ and air aC a feed. total pressure of 30 mm Hg. The air rate of flow delivered water to the discharge chamber having a molar content of XH2p x(0.005-0.5)XCOZ� The quantity X~~2 was varied within a range of 0.01 - o.l. Tndividual measurements were also Caken with a mixture of N2 and He in a molar ratio of 1:1 wiCh C02 added. The discharge was visually homogeneous in practically all operational modes. = The maximal Fichieved values of the volumetric energy con~ribution ~E did not - exceed 4~.5 G~ratts/cm2 and were limited by the power supply and the size of the - ballasC capacitance of the electrode elements. The level of the specific mass energy contribution achieved 150 J/g at L x 190 mm and 280 J/g at L= 390 mm. The generation threshold, depending on X~p was reached at (~E)thr z 0.5-1.5 watts/cm3. The generation power depended ~E, and also on the X~p2 and Xg20 in the mixture. As can be seen from the curves in Figure 2, neo increases rapidly with an increase in XH2p up Co (0.01-0.02)X~p2 , and Chereafter is saturated, however, when Xg2p x 0.03-0.04)X~p2 visuaIly observable inhomo- geneities [3] appear in the plasma, and for 'this for reason, the optimal _ water content is X~Z~ x(0.02-0.03)XC02� The opCimum C02 content falls in a range of 4-7%. With optimum H20 contents, - the size of neo increases sharply with an increase in ~E within a range of (1-2) (~E)thr~ and thereafter remains at a constant level. Typical results of optimiz3ng X~p2 for helium mixtures (XN2:Xge = 1:1) for various discharge chamber lengths I; are shown in Figure 3. They are similar in nature to the function neo = f(X~p2) for the case of XHe = 0. i ~ 21 ' FOR OFFICIAL USE ONLY ~ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 FOR UFFLCIAL U5~ ONLY 5. The compueed curves �er n~o � E~XH 0~ XCO ~ L) shOwtl W3.tih '~he solid ,~~o~y~ 2 lines ~n 'Figuz~es 2 and 3~tre ~.n goc?d � ro 4-- � agreemenC w~.Ch the expPr3menCal resu~.ts, ~ i' somerhing which ~l~.ows ehe applicaCion e i ~ of Chig calculat~.on procedure [2~ Co the y,,.+,~ ~ estima~ion of the efficiency of employing 6~i 3`.~ an AC discharge for pumping C02 lasers, as we11 as for op~imixation o� Che oper- 4 ~ ational modes of such n laser acc~rdittg 2 4 6 x~o=, ~0': to the cdmposition of Che mixture, Che d~cnensic,ns of the gas d3.scharge chamber ~nd the resonaCor ~ransmiCCdnce. Figure 3. The Cheoretical (1,2) and exper3.mental (3,4) We cbrriecl out such ~n opticniz~tion - curves for rleo as a caLculation for Che toCal efficiency, function of K~p2 (for n~ for a Cypical variant [4, 5] of an a helium mixCure of 3ndustrial, fast flow C02 laser with a - XNZ;XHe = 1:1 where discharge chamber length in Che direc- p 100 m/sec; ~Eaa 4.1 tiion of the flow of L~ ~.+D cm, a height 3.2 (3) and 6 cm, and a widCh (along the optical ~1~2~~ axis) of about 1.5 m, which was equipped 3.0 (4) watts/cm3; with a fully inCegrated resonator, con- L= 360 mm (1), 180 mm Sisting of reflectors with r= 29'. In (2), 390 mm (3) and tihis case, the quanCiCy r1 was defined as - 190 mm (4). tihe fraction of the energy consumed from _ the power supply, transgormed into stimu- lated radiaCion and brought out of the laser resonaCor. According Co Che results obtained aC v= 100 m/sec, p= 50 imn Hg, ~E = 4 W/cm3, and when a mixture of He and N2 (in a molar ratio of 1:1) with C02 added (X~p2 = 0.06) was used as the working medium at the input to Che discharge chamber, the value of n atCained 14-15%, which carresponds to an output radiation power of = 20 KW. The magn3.tude o~ the specific energy yield in this case Funounts to about 40-45 J/g. By using an 3ndependent DC discharge to excite the medium, for the case of similar mass rates of gas flow and geometric parameters o~ the seCup [4,6], - only from 5 to 9% of the energy cons~ttned from the power supply can success- fully be changes to stimula~ed rad3ation. The bas3:c possibility of achieving a specific energy yield of 20-40 J/g in a laser with similar parameCers, when = ' the mediuna is excited with a Cransverse combination discharge with a gap of , 10 cm and L= 15 cm is indicated in paper [7]. The cited values of Che spe- cific and output characterist3cs permit the assumption that AC discharge is ' an extremely efficient method of pumping C02 lasers. ~ 6. In analyzing the model's radiation flucCuation spectrum, which is shown in " Figure 4a, it is necessary to segregate the fluctuations at a frequency of ~ 20 KHz, which correspond to the osc311ations of the exciting discharge current (f = 10 KHz), and the "lower frequency" oscillations, the spectrum of which 22 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 _ ~ ~OR t7~1~it.~I/~. U5~ dN1.Y Qt/1 rt jE Q ~g) c a e ~t ~e f Krw ~Cb~ ~,t~ ~'igure 4. The frequency apectra of the radigCion Ce) and Che discharge current (b). fill~ the range of frequencies from abouC 102 Hz up to aeveral kilohertz~ while the maximal amplitude is comparable to the amplitude corresponding to the prisnary frequency. The modulation level of the radiation amounted Co 3-SX at f= 20 KHz. A comparison of the spectra of the fluctuation of the radiation and current (Figure 4b) permits the hypothesis that the low frequency fluctuations are not related to the discharge, and are possibly caused by mechanical oscilla- tions of the refl.~tors of the resonator due to the vibration of the setup, since each of thew is secured to the houeing of the chamber independently aad no special measures were taken to counter relative motions of the reflec- tors. - The modulation of the radiation at f s 20 KHz was caused by fluctuations in Che power liberated in the discE~arge, and for the case of a fully incorpor- ~ ated resonator, its level under our condiCions should amount to: t 2fT ~1 + T rel ~ z 10 2- lOrl rel stim ~Trel is the time for the collision relaxation of the energy stored in the oscillatory degrees of freedom; TSt~ ~(10'1 - 1) � Trel i~ the ~haracteristic 23 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~U[t U~~IC~AL U5~ dN1,Y - ~timul~tpd r~dt~einn elme), which i~ in ngreem~nt with the expertmene. SuCh mc~dul~Cion ig n~e dangeroug when u~ing ~ i~~er fr~r indu~triai purpoge~ ~nd r~n in prin~ipl~ b~ r~duG~d Wh~n Chp ~cci~~Cion frpquency i~ inereggpd. Ie ia necese~~y C~ ~dee tihgt ~nder our ~onditiinn~, eh~ ~g~ill~tidn degcrib~d in - ~g~ in ~ rgng~ df 3- 20 KHx, ~e tteii ~s oscillationa gC rran~it frequenci~a df v~~~ng ~ v/It KHx, where tt ig th~ rgdiug of ehe osCiliaeion re~ic~n, - w~re noC obgerved. _ 7. The r~gu1C~ af the exp~rim~ner~.~nd C~lcul~rinns pregenVted in ehig pgper - m~k~ it pd~~ible eo come tn th~ following eonclugionss 1) An AC di~chgrge gt ~ frequenCy of 10 KHx i~ gn effective method of exciC- ing the m~dium of lager, which permitg g gubstgneinl ~implif!.carion of ehe ~truceur~l d~~ign probleme and po~aer ~uppiy problem~~ gs well as allovg for the c~~gtion of n eimple indugtri~l CdZ la~er with g power of = 20 KW With ~n over~ll Cnnvergion efficienny of N 15~: ~nd g ep~cifi~ ~nergy yipld o� 40-4S J/g; 2) The fluctuation~ in the rgdiatian rel~ted to the method of excitation do not exceed a�~w p~rcent, an~ can in principle be decreased; 3) The methnd uged far mndeling a laser by mean~ c~f a"degd end~~ resonator in conjunction with the calculations allows for the investigation of the specific characteristics of the radiatidn, the es~imation of the efficiency of an ecrual lgser, and can be useful in studying the efficiency of pumping fg~r f1oW gas diacharge lasers uaing prototypes with a emall opCical acceas length. $IBLIOGRAPHY 1. V.D. Gavrtlyuk, A.P. Glova, V.S. Colubev, F.V. Lebedev, KVANTOVAYA E1.EKTRONIKA, 4, 2034, (1977). 2. B.F. GordiyeCs, A.I. Osipov, Ye.V. Stupenchenko, L.A. Shelepin, UFN [PROGRESS IN THE PHYSICAL SCIENC~5j, 108, 655, (1972). 3. A.F. Glova~ V.S. Golubev, A.Ye. Katomin, F.V. Lebedev, FIZIKA PLAZMY [PLASMA PHYSICS], 3, 1396, (1971). 4. F.K. Kosyrev, N.P. Kosyreva, Ye.I. Lunev~ AVTOMATICHESKAYA SVARKA [AUTOMATIC WELDING~, No 9, 72, (1976). 5. S.O. Brown, J,N. Davis, APPL. PHYS. LETTS., 21, 480, (1972). 6. A.V. Artamonova, et al., KVANTOVAYA ELEKTRONIKA, 5, 920, (1978). 24 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~ox o~~icta~. us~ oNi.Y - 7. A.p. haparts,vich, V.G. Naumo~v,~ V.M~ ~hg~hkdv, ~IS~MA V zH~T~ [L~mT~ttS 'CO T!~ JOUItNAL n~' ~~R~I~NTAL ANb ~Nf3TN~~RYN~ PHY5rC5j ~ 3~ 349, (1g77). 8. A.V. Are~mmanov, V.G. N~utnnv, KVAN'rOVAYA ~L~KTttONIKA~ 4, 17R, (1977). COPYItIGNTt TzdaCpl~etvo "Sov~tskoy~ ttadio", "Kvnntov~y~ e1~kCrnnikg", 1979 8225 C50:8144 /l.~l~i - 25 _ FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~Olt n~I~ICIAL U5~ ONLY QVA2~TUM ELLCTRONICS , UDC 535.375.5 LETTERS TO TH~ EDITOR OF QUAN'I'UM EL~CTRONTC5 Moscow KVANTOVAYA LLEKTRONIKA in Russian Yol 6 No 3, 1979 pp 592-593 . [Letter by B.Ya. ~el~dovich, I.G. Zubarev, G.A. F'asmanik gnd V.C. Sidorovich, . recei~~ed 21 Jun 78; reply by V. Geragimov, rec~ived 19 Jul 78) [TexC] Concerning the Papera of V.B. Gerasimuv and CoguChors ArCiclea by V.B. Geraeimov and hi.~ ~�~authors, devoted Co certain aspecta of VKR and VI'.MB [expansions unknown), were re~ently published in the ~ournal KVANTO'VAYA ELEKTRONTKA. UnsubstanCiated assertions, as well as explicie errors are found in a number of these papers. Correct theoretical c~ncepts - of the operation of stimulated scatCering lasera a~nd concerning the inversion _ of the wave front for the case of VRMB are nonetheless especially needed ae the present time in connection with the facC that several practical appli- cations have been noted for Chese cransducers, the d.psign of which is en- gaging an increasing number of experimenters. We shall consider the three latest publications. The incorrect assertion . that when wideband, spat:.ally incoherent pumping is used, the selective proper- ties of a VRMB reflector increase significantly, was advanced in paper [1]. ?,n actual fact though, the strictional f~,...~ ~.:::~i:.b*t;~e amplification of the Rypersonic waves, is given by the expression f~ EgEB, and for thie reason, with the inversion of the wave front, when E8 ~ Eg, we obtain f~ EH. It follows from this that Che hypereound intensity, oCher conditions being equal, ~ attenuates with a pumping spectrum widCh Avg, which considerably exceeds the lfne Width of spontaneous Mandel~shtam-Brillouin scattering, evsp (by AvHAv~p times). The sCokes wave incremeat also falls off ~ust ae many t~mes (in- - cluding that reproducing the pumping). Consequently, the selective proper- ties of a VRMB reflector do not increase wiCh an increase in Avg. It is likewise asserted in this paper that the selective properties increase when the path length of the accoustic wave Zaw is greater than the diffrac- tion intermixing len.gth of the radiation Zd = a/8~. This assertion is not based on anything and:ts in error. 26 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~OR O~FICIAL US~ ON1.Y p~per [2] gppaka n~ nn "gedugCic" r~f~.ectnr wiCh g plan~ wav~ frone uf ~cou~Ci~ phonone. Nowever, such g r~fl~ctor reflecCa lighr ~u~e gg a con- venCional ~1~C refl~cedr gnd ie do~s noC m~kp ~pnee ea compgr~ iC wieh ~ _ VRMB r~fl~c~or, which inver~s ehe wavp frune (in ehe laeCer cn~e, wirh a suffici~nely high ateenu~eion of the hyper~ound, iee wgve front reproducea th~ pumping wave fronC). In paper [3], based on the previous work~ of V.B.Gerasimov, including Chog~ considered above, ehe ~~me ~rrora are repe~r~d ~nd ungub~taneiated and fnlse concluaione are drawn concerning the op~ration of a VRMB lgser. P.S.: We were acquainted wiCh the reply of V.B. Ger~simov to our letter, which is published below, and in our opininn, no proven posiCive asserCione are contain~d in this reply. _ BTBLTOGRAPHY 1. V.B. Gerasimov, 5.A. Geraeimova, V.K. Orlov, "0 znachiCel~nom uvelichenii selektiruyuahchikh svoystv VRMB zerkala~' ["On a Significant Increase in ehe SeleCtive ProperCies of a VRMB Reflector'~], KVANTOVAY,A ELEKTRONIKA, 4, No 4, 932 (1977). 2. V.B. Gerasimov, V.K. Orlov, "Vosproizvedeniye volnovykh frontov pri rasseyanii aveta na akusticheskikh volnakh i dinamicheskaya golografiya~~ ["The Reproduction of Wave Fronts with Light ScaCtering aC Acoustic Waves, and Dynamic Holography"], KVANTOVAYA ELEKTRONIKA, 5, No 2, 436 (1978). 3. V.B. Gerasimov, V.K. Orlov, "0 vliyanii effekta obrashcheniya volnovykh frontov na rabotu VFtMB-lazera" ["On the Influence of the WavE Front Inversion Effect on the Operation of a VRMB Laser'~], KVANTOVAYA ELEKTRONIKA, _ 5, No 4, 906 (:~978) . Reply to the Letter to the Editor of B.Ya. Zel~dovich, I.G. Zubarev, G.A. Pasmanik and V.G. Sidorovich _ In the papers considered in the ~etter, dealing with the analysis of stimu- lated back scattering (VRN) of wideband laser radiation, we proceeded from the equations [1]: LEr ~ iYrX*E1 ; LE1 = iYlX~r, ~1) - erroneously assuming that when the condition L< 1/AvH is met (where L is the effective scatCering length; Avg is the pumping s~�ecCral width), the form of the operator L is the same both for the pumping field and for the - 27 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~dx d~~zcr~. us~ nNLY bnck ~~~re~red radi~eian. B.Y~. z~l~dnvich pdine~d ehig error nut en ehe guChors followi.n$ eh~ publication of p~pers ~~.-3~. An analysis of equaCions (1) led to the errnneoug conclugion for VRN, Ch~t in the procese of scatCering widebgnd r~di~Cion intio ~ cnmponenC with nn inv~rCed wav~ front, a predominantly plane, monochromatic h}?personic wav~ is exciC~d in Che medium (someChing which~ however, is ~useified fnr foreward gcaCCer, fo~ example, �or a wave of opCiCal phonons in the cage of VICIt [1J). - This resulC generaeed oCher erron~~ug regults, which were noe~d in rhe _ leCCer: ehe conclusion thnC Che sel~ctive prop~rCies n� a VRMB r~flector = increased when using wideband pumping and pumping, the radigtion intermixing ~ _ diffraceion length of which is less Chan the gCOUBC~C wnve paeh length ~2J, ag we11 as the conclusion of the possibility of inverting a wave front aC a plane acousCical wave [1]. (The conclusion concerning the possbility of _ reproducing a wave front at a pLane wave of optical phonons in the c~se of - VKR remains valid.) , - An erroneous reault concertting rhe ggin increment of the component with Che inverted wave fron~ [2] was used in paper (3] in analyzing the VRMB generator. However, we will noCe thaC if Chis erroneous result is replaced by Che correct . - one, in accordance with which the gain increment of Che mirror refl~cCed com- ponent is Avg/~vgk times gr.eater than the gain incremenC of the laser mode, - Chen the resulta of paper [3] remain valid. It should be noted that the VRN - pumping mode, whict? cannot be represented in the form �p(r,z)~(r~)(see[4~) under the conditiona L� 1/AvHAvgk � ~vg and L� a/AH, was noC considered prior to our papera [1-3] for afCer them (see [4]). The conclusion concerning the predominant excitation of a monochromatic hyper- sonic wave in the case of scatCering of wideband radiation under the conditions we indicated [1-3) remains valid, if scattering intu the mirror reflecCed com- ponent is considered. On behalf of the authors o� papers [1-3j, V. Gerasim~v. BIBLIOGRAPHY 1. V.B. Gerasimov, V.K. Orlov, KVANTOVAYA ELEKTRONIKA, 5, No 2, 436 (1978). 2. V.B. Gerasimov, S.A. Gerasimova, V.K. Orlov, KVANTOVAYA ELEKTRONIKA, 4, No 4, 932 (1977). - 3. V.B. Gerasimov~ V.K. Orlov, KVANTOVAYA ELEKTRONIKA, 5, No 4, 906 (1978). 4. G.A. Pasmanik, PIS~MA V ZHTF [LETTERS TO THE JOURNAL OF ENGINEERING PHYSICS], 4, No 9, 504 (1978). COPYRIGHT: Izdatel~stvo "Sovetskoye Radio", "Kvantovaya elektronika", 1979 8225 CS0:8144~1216 28 FQR OFFICIAL USE UNLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~OIt O~~ICIAL US~ ONLY . (~UANTUM CLGCTRONICS ~ UDC 621.373.826.038.823 A COMPACT P~RIODIC PUL5~U C02 LA5~R Moscow KVANTOVAYA ELEKTRONIKA in Rusaian Vol 6 No 3, 1979 pp 597-598 [Article by M.I. Arzuov, S.K. Vartapetov, M.Ye. Kargsev, V.I. Konov and V.V. Kostin~ Phyaics Inatitute imeni P.N. Lebedev of the USSR Academ;y of - Sciencea, Moscow, manuscript received 28 Jul 78] - [Text] The construction of a laboraCory C02 laser is described having a pulse repetiti~n raCe of f~ 350 Hz and an average power P of up to 80 watts for a h~lf- - heighC pulse width of ~ 3 usec. The average power is studied as a function of f, as we~.l as Che timewise stability of P. For Che case of continuous operation a~ a frequency of 100 Hz, without renewing the gas mix- - Cure for a period of 30 minutea, the average radiation power falls off by no more than 15X. It is shown that discharge contraction occurs not because of overheatiiig ~ of Che mixture, but as a resulC of its chemical decompo- sition. Atmoapheric pressure C02 lasers with a high pulae repetition rate have lately been attracting increasing attention. On one hand, such lasers make it pos- sible to obtain high average radiation power lpvels, comparable to CW C02 ~].asers, and on the other hand, high peak radiation powers chaxacteristic of pulsed TEA lasers. These properties make periodic pulsed C02 lasers ex- - tremely promising for physics research and for industrial applicaCion. To obtain a uniform discharge in each pulse, it is necessary Co prevenC excess heating of the gas by the acattered pumping energy. When the exceas heat is _ diverted to the walls solely by virtue of the heat conductivity of Che mechan- _ ism, the maximum pulse repetition rate does not exceed 30-50 Hz, something which limits the average radiation power [lJ. However, ~his limitation can be removed if fast pumping of the gas mixture through the discharge region is - employed [2]. The most convenient configuration is that where the direction of gas flow, and the axes of the resonator and discharge are mutually perpen- l dicular. In lasers of this structural design it proves possible to realiza ~ a pulse repetition rate up to several kilohertz. 29 FOR OF'F~CIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ' FOR O~~ICIAL U5L ONLY This pgper reportg dn tihe degi~n o� ~ compncC period~.c pul~e COZ l~gpr wieh gag circulgeion in n closed cynl~, opergCing nt frequ~nC~.~~ up Co 350 Nz aiCh a dcgree of Cime gCabiliry of Ch~ radintidn. A numb~r of uttiCe gimilhr in terme nf ouCpuC pnrnm~Cer~ hnv~ been d~~crib~d in the lie~:ruCur~. ilnw~vcr, data on ehe tiimewise gtgbil3ty of the radiation is eitiher lncking in ?~hie lie~r~ture [2, 3], or th~ ~v~ru~e ouCpue power f~llg off rapidly wieh eime [5~. A echemaCic n~ Che lager seCup is shown in ~igure 1. Its working vnlume nf 1.5 x 1.5 x 30 cm is formed by Cwo flae stginleas gteel eleatrod~s, Che edg~e of which gre rounded off to obtain a uniform digcharge. Preliminxry volu- meCric ionizaCion of the gns mixtiure was accomplished by means of gpark dis- charges, poaiCioned at a die~ance of 10 cm from ehe resonaCor axis on the downstream side. Approximate~.y lOX o� the en~rgy stored in ehe etorage cai:a- citor of 0.03 uF wae aplit o�f Co th~ diachargea, where this ~sapacitor was charged up Co a voltage of x 20 KV. Electrical power wag sup~lied gor Che , discharge by means of a TGT1-1000/25 ehyraernn. The laser resonator wgs formed by a fully enclosed meCal reflector with a radiua of curvaCure ~~f 4 m and a germanium ouCput refLecror. ~ y ~ 4 A gas mixture of C02:N2:He = 1:1:8 aC a press!~re slightly above aCmospheric pressur~ was used in Che laser. The _ gas was pumped through Che working 5 volume in a closed cycle uaing an nero- ~ dynamic tube of stainless steel wiCh a ~ ~l nozzle and a diffuser (the overall di- ~ / mensions of 150 x 80 x 20 cm, a u3eful volume of ~ 80 liters). The maximum _ flow velocity in Che interelectrode Rap Figure 1. The configuration of was Q 10 m/sec and was varied by changing the C02 laser. the rotational speed of the bl.~wer� Key: Electrodes; ~e energy in a single radiatf^n puls~~ - 2. Pre-ionizer; was 0.35 J. The pulse waveform was c1~4e ~ 3. Diffuser; to triangular with a steep leading edge 4. Blower; 200 nsec) and a half-height of 3 usec. 5. Nozzle; The average radiation power is ahown ns 6. Working chamber; a function of the pulse repetition rate 7. Turning blades (the in Figure 2. It can be seen that when direction of flow is f a 150 Hz, the function P(f) is linear. shown with the arrow). The de~iati~n from a linear function at = high frequencies is related to the insufficient pump-through velocity of the gas mixture; when f> 350 Hz, Che discharge became unstable and the output power fell off sharply. We will note that at f= 350 Hz, the level of P reaches ~ 70 watts. 30 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~l~it d~~ICIAL USC dNLY ~or Ch~ cg~~ nf CW np~rnCion ~t ldd ~iz �nr 30 minuCeg wiet~nue renew~.ag ~he ggg mixeur~, ehe ~v~rgge power fe11 off by nd mdr~ tih~n 15%. Wieh fureher _ opexae~.on, r~res appegred i.n ~he di~ch~rge gnp in individuul pulge~, which, hnwever, hgd a w~ttk in�luenc~ on ehe gize of p. Nn gpecial hp~C exchunger wn~ provid~d in rh~ laspr gnd ngtur~l caoling aE rh~ gag mixturg wa~ ug~d by virtue of C:+e cnnC~ne wieh the durfnC~ of the pump-~hrough tube and eh~ Curning blad~~. The gag eemper~t~r~ ~C Ch~ inpuC eo Che discharge gap wae monitinred by menns nf n chrom~l-glumel eh~rmocoupl~, Chn signal from which wgg fed to an ~ueor~norder. IC turned out th~C ~v~n ` with natiural cooling, ~he gas mixCur~ Cemp~r~eur~ during 30 minuC~g o~ lgg~r operaCion gC a frequency of 100 Hz did noC ri~e above 50� C. Suah ~n insig- nificant eempergtui~e inereas~ ehould have no effecC on ehe disch~rge gCabiliCy. Contraceion of the disch~rge and reduc- ~ion of Che output rad~tation power during N~ wgCtig long Cerm operaCion of Ceh laser were, in 60 our opinion, re1~C~d to chemic~l reac- - Cion~ in ehe discharge plasmg. Indi.cative of Chis, in pgrticular, is Che facC Chat ~ � wiCh repeated, ahort Cerm acCu~Cions of ~ the l~ser, when the gas mixture temper- aCure changed insignificanCly (i:z a range . of a few degrees), ehe discharge stabi- lity was determined by the totgl number ~ ' of discharges, which was close to the correaponding number of discharges in ' f, Hz Che quasi-conCinuous mode. No chemical analysis Nas made in Chis work of the ~ chAnge in Che composition of the gas - mixCure in Che procesa of running the laser. Figure 2. The output power as a function of the pulse We will note in conclusion that in our rep^tition rate. experiments, the stability of the output radiation parameters increased even with a slighC renewal (a few liCers per minute) of Che gas mixturea BIBLIOGRAPHY 1. O.R. Wood, PROC. IEEE, 62, 355, (1974); TRUDY IIER, 62, No 3, 83 (1974). 2. A.E. Hill, APPL. PHYS. LETTS, 12, 324, (1968). 3. G.S. Dzakowic, S.A. Wutzke, J. APPL. PHYS., 44, 5061, (1973). ' 4. D.C. Hamilton, D.F. James, S.A. Ramsden, J. PHYS. E.: SCI. INSTR., 8, 849, (1975). 31. ' FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 , . _ , ' _ ~Ott (~~~IC~At, US~ ONt,Y 5. M. '~urg~oct, IL~~L~ J. , Q~-7, 495, (1971) . COpYRIGK'~t Izd~~el~eCvo "Soveeekoy~ Itgdio'~, "Kvantov~ya el~keronika", 1979 g225 CS0:8144/~^l6 32 FOR OFFICIAL USE ONLY ~ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~O1Z 0~~'ICIAL USL' ONI.Y QUANTUM CL~CTItONTC5 _ UUC 5~5.375 SpATIAL ~dLARIZATION INV~1tSTON 0~ A WAV~ ~ItONT ~OIt TH~ CAS~ 0~ FOUIt pHOTON INT~ItACTION - Moecow KVAN'rOVAYA EL~KT1tONIKA in ttusaign Vol 6 No 3, 1979 pp 629-631 _ [Artiicl~ by B.Ya. Zel~dovich and V.V. Shkundv, Phyeice IngtieuCe imeni P.N. Lebedev of ~he USSR Academy of Sciences, Moscow, manuscripC received 2 Aug 7~] [Text] The problem of the wave front inversion of depolarized light i~ theoretically analyzed for the case of four-phoeon interac~ion. MeChods which allow for total gp~eial polgriz~Cion inversion are indicated. The wave front inversion (OVF) of 1ighC in the case of etimulated bnck-scaC- Cering was atudied in detail both experimentally [1] and theoreC~cally [lJ. Recently, following thenrecical proposals of [3], OVF was experimentally re- _ alized on the basis of four-photon interaction (ChFV) (4J. All of theee woxks applied Co OVF of completely polarized beams. At the same time, in a number of OVF applicariona, it is necessary to invert a beam wiCh a spaCially inhomogeneous polarization state. The physical processes occuring with OVF of depolarized light uaing the stimulated scattering method have already been atud~ed both theoretically and experimentally [5]. The problem of the OVF uf depolariaed radiation using the ChFV method is treated theoretically in this communication. - An abbreviated equation for an inverted wave Eq(r) of frequency w in a cubic medium ia written in Che form ~ ~e aa= ~ t~k fIP"" ; (1) ~Xf A6n'~'Xl/An~) EiAE~tE3,,,~ ~ 2 ~ where A is the angle between the direction 11 = k4/k of the Eq wave and the normal to the input surface of the nonlinear medium (Che incfdent angle, read taking into account the refraction within the medium; see Figure 1); - k= e1~2c~/c. The operator IIik = dik ' nink of the pro~ection onto a plane 33 _ FOR OFFICIAL USE ONLY ~ ~ ~ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~Olt O~t~'ICIAL US~ Ortt,Y ~ p~rpendicul~r ro rh~ direceinn nf ~4 b~~m propc~g~Cinn w~~ lik~w~.~~ i.nrroducnd in (1); ~h~ ~pp~~rnnc~ nf such ~n opergeor reln~ed Co rhr. trnnsv~rge nn~ur~ of the e1~c~romagneC~.c wgves. W~ nsgum~ eh~r Ch~ wnve ~3, which 3.g eo be in- verCed, and thi~ nlsn me~n~ Ch~ inver~ed wgv~ ~4, oCCUpy ~ compuraCiv~ly smnll golid angle abouC ~he c~nCra]. direc~ion 11. Then the polarization vectora oE Ch~~~ waves can be congidered ae falling Che indicaked plgne. The quan~ity xiklm ie the nubic nonlinear~.Cy eengor of Che medium. Of gll of Che terms in ~h~ cub3,c pn~griz~tion vecCorPPHn we lefC only thoee which describ~ Che exci- Ca~ion of the complex cott~uggCe w~v~ ~4 in tihe presence of gtrong nounCer W~~~g ~L~~k~,r gnd ~2~-ik~r of the same frequency w. ~'or prnctical applic~tions, iC is necessary ro ~chieve Cotal polarizgtiion invereion of Che form ~4(r) ~~(r). AC the same time, even wiChin the non- _ - linear medium, ~a can be aeen from (1) and (2)~ the polarization atate of the ~4 wave dif �ers in the general cgse from Che requiaiCe (E~): (~Jtyr~~Ea~~ (3) rt~~nt~ex~~rk-+-x,~r~~~e~~r~ - wher~ el and e2 are complex unit veceors of the polariz~tion of strong waves and E2. In ehis case, we conaider the unit vecCors el and e2 Co be con- atant over the entire volume of Che nonlinear medium and we nelglect (in a _ Born approximaCion) the change in the E~ veceor space. Moreover, Che polnri- zation sCate of boCh fields E~ and E4 can differ markedly in the cas~ of oblique refraction at the boundary of a nonlinear medium. X ~ If the fields of Che incident and in- - verted waves in sir are designated as El E~ B3 and B4, then in a Born approximation: - - E ~B~)1�DIA~g9~k~ DIA~~~mrml~ll~� ~4~ ~ - . The two-dimensional matrix Dik acts in a - E~ plane perpendicular to the direction n~ � of E3 wave propagation in afr. The matrix Y C describes the change in the elecCric 2 field amplitude of the wave when enterinR the nonlinear medium, taking Fresnel re- - Figure 1. flection into account; the matrix t* yields the same when exiting Che medium. We shall now pose the problem of achieving total spatial polarization OVF. For rhis, it is necessary to require that the two-dimensional matrix Dik - from (4) be a multiple of a unit matrix. For a medium with a specified tensor Xiklm� we have available a number of free parameters, a variation of which can in principle achieve this result; thLa, for example, one can vary the o~~ien- Cation and sttate of E1 and E2 strong wave polarizatiol, employ transmitting . 3~ FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~o~ o~~YCr.aL us~ ort~.,Y cnaCings, nx ch~nge ~he oxientigCiot~ nf rhe medium wieh xe~pect tio the direc:~ Cion of wave pxopagation, ' We aha11 Crea~ in more de~ail tihe c~se of att ~.soeropic medium, �or which - Xtklm� Xts! aalm~l' Xa8A~8tm~ ( 5) The cnnsCanCs x~ and x2 can be de~erm~.ned from auCofncusing Cests and from Che auCorotation of the polariza~~.on ellipse (see for example, [6]). ~'or a puzely~electronic nonlinearity mechanism, where w� w p(wp gre the main absorp~ion bands), the relaCionship XZ = 2X2; this is appnren~ly the sieuu- tion fox polycrystialline germanium at rhe waveleng~h of a C02 laser. ror the Kerr nonlinesrity (for example, Che orienration of CSZ molecules), = X2 = 3x1~ and for a stricCional nonlinear3ty, X2 = 0. _ One of the possibilities of ~chieving Cot~l OVF (Figure 1) consistis in the chooaing of Che incidenC angle 63 (in air). In this case, we are working fxom a configuraCion in which the plane-parallel lnyer o� ehe nonlinear medium is placed inside Che laser resonatior. The polariz~tion of boCh strong waves is chosen linear in the direction of the Y axis, perpendicular to the plane of drawing. The boundary of Che nonlinear medium corresponda Co the XY plane, while the beam being inverted E3 Falls in Che XZ plane. Then Che condition for precise inversion, Dik = const � d~~~, assumes the form Xa~(Xi-4-x:)=cos'(0,-As). (6) - Fresnel formulas for oblique incidence on to the nontransmittir.g surface ~ were employed ~n deriving (6). We sha11 clarify the physical cause of pre- cise reproduction, when condition (6) is met. The nonlinear polarization within Che medium in our case is equal to (7) J pnnwl9PNA= 2E~Es { x~ey( Ea~y)-I- X~ E3 r In the general case, xl > 0 and X2 > 0, the E3 wave component with Y polar- _ ~.zation is inverCed with a greater coeFficient, greater by (X2 + X1)/XZ times - Chan Ch~ component orthogonal to it wiCh polarization in the XZ plane. How- ever, this 1aCter componenC possesses a greater Fresnel transmission factor. Preciae co~rrpensation of these two factors is achieved exacCl}� when expression (6) is observed. For example, for germanium (an index of refraction of n= 4, X1 = 2X2), the angle A3' = 68.04� and A3 = 13.41�. In this case, the single transit factor of the boundary (with respect to energy) for XZ polari- zation amounts to = 0.96 (83 is close Co the Brewster angle); the same co- efficient for Y polarization is equal to 0.32 (for the case of normal in- cidence, this quantity is identical for both polarizations and is equal to 0.64). 35 ~ FOR OFFICIAL USE ONLY e APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 - F'OR 0~'FICSAL US~ ONLY ~ X AndCher conf~.~uraeion which realixeg toCal OVI~ is shown in I~igure 2. The and ~2 sCrong plane w~veg ptiop~gaCe along Che Z ax is and have n lin~ar polarizaeion ex. The w~ve being 3nverted is introduced through the otiher boundnry E~ of Che nonlinear medium (eh~ Yz plane), where this wave propagates in the direc- Ez tion of Che X axis. In this c~set ; flP"a=po'~~, 2X~~~~t gg (g ) y~ Z and refraction at ehe boundary likewiae ' E~ does not change the polarization stiate. We wi11 note that transmission augmenCa- Figure 2. ~ion of all aurfaces of the nonlinear medium can be employed in thia config- uration. Finally, the latter configuration, which permits obtaining Cotal OVF, cor- reaponds ro the case where all four waves propagate in a direction close to the normal to the boundary of the plane-para11e1 layer of Che nonlinear medium. ~n this case, the pro~~c~ton operaCor can be replaced by a unit operator, and: - I]P"a=EiEs t2Xa~~i~:)Ej-I-Xil~ei~3~~i-I-~hEg)~i~)~ ~9) It is not difficult Co verify that PHn E3~ only in the sin$le case where the the strong waves are c3rcularly and mutually orChogonally polarized: , or vice versa. The authors are grateful t~ V.I. ICovalev and I.I. Sobel'man for their stimu- - lating discussions. _ BIBLIOGRAPHY 1. B.Ya. Zel~dovich, V.I. Popovichev, V.V. Ragul~skiy, F.S. Fayzullov, PIS~MA V ZHETF [LETTERS TO THE JOURNAL OF EXPERIMENTAL AND THEORETICAL PHXSICS], 15, 160 (1972); V.V. Ragu1'skiy, TRUDY FTAN [PROCEEDINGS OF THE PHYSICS INSTITUTE IMENI P.N. LEBEDEV OF THE USSR ACADEMY OF SCIENCES], 85, 8(1976); V. Wang, C.R. Giu~iano, OPTICS LETTS, 2, 4(1978); B.Ya. Zel'dovich, N.F. P~lipet~akiy, V.V. Ragul'skiy, V.V. Shkunov, Ky~N'~OVAY?~ ~:t~'.TRONIKA, 5, 18~~0 (1978) . 36 FOR OFFICIAL USE ONLY _ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~dit ~~~ICIAI. U5~ ~NLY 2. V.G. 5idorovich, zHT~ [JUUKNAL 0~ ~NG~NN.~1tiNG pNYStC5]~ 46, x16g (ig76); I.M. Bel~dyugin~ M.G. Gdlughkin, Yh.M. z~m~kov, V.i. M~ndrn~~v~ KVAN'TOVAYA 1~,i.H:K'TRONIKA, 2467~ (1g76); If.Y~t. %r]'~tuvlr.h, V.V. :~likunav~ KVAN'I'nVAYA I:I,I,K'l'iZUN1KA, ~i~ 1O~)(l, 'l'l~i'~ (1977); 5, 36 (197d)? N.B. Bar~n~v~, V.Y~. Z~1~ddvieh, V.V. 5hkun~v, KVANTOVAYA ~L~K~RONIKA~ S~ 9~3 (1978). I~.W. KellwarCh~ J. OpT. 50C, AM~I~., 67, 1(1977)s A. Ygriv~ U.M. Pepper, OpTIC5 L~'I"r5, 1~ 16 (1977); J. Mgrburger, APpL. PNY5. L~1'TS, 32, 372 (1.9~8). 4. U. Bloom, G.C. B~orkluud~ APPL. ~KYS. L~TTS~ 31~ 592 (1977); P.F. Liao, N.P. Economoy, R.it. ~reem~n~ Pt~YS. REV. LE'i"r5~ 39~ 1473 (1977). 5.M. J~ngpn~ R.N. H~ilw~rrh~ Ap~L. pNY5� L~TT5, 32, 166 (197g); _ U.M. Bloom, P.~. Li~n~ N.P. Eaonomny, OpTICS L~TT$, 2. 5g, (197g). Bergm~n, I.J. Bigin, B.J. Feldmgn, R.A. ~isher, "I'reprinC LA-UR ~ 78-1305 (1918); OPTICS LETT5 (In prese). 5. B.Ya. Ze1'dovich, V.V. 5hkunov, zl'.~T~, 75, 428 (1978); PR~PRINT ~IAN~ Moscow, 1978, No 1. V.N. $lashchuk, E.Ya, zel~dovich, V.N. Kraehennikov, N.A. Mel'nikov, N~F. Pilipetekiy~ Y.V. Ragul~skiy, V.V. 5hkunov~ UAN S5SR (1t~PORT5 0~ Tli~ U55R ACAD~(Y OF 5CIE~iCES 241 ~ 1322 (1978) ; OPTICS COMMS, 27, 137 (1978). N.C. Basov, V.F. Yefimkov. I.G. Zubarev~ A.V. Kotov, S.I. Mikhaylov, ` M.G. Smirnov, PIS'MA V~HETF, 28, 215 (1978). 6. R.W. HellaarCk~, PROGR. QUANT. ELECT1tON.~ Vol S, No 1(1977). COPYRIGHT: Izdatel'stvo "Sovetskoye Radio'', "Kvantovaya elektronika", 1979 8225 CSO:t~144/1216 37 FOR OFFICIAL U5E ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~ox o~~rctAr. us~ orrLY ~ . Qtravrurt ~t~cTxoNZCs UDC 535.375.5 TH~ INFLULNC~ 0~ PUMY DEPL~TION ON Tli~ SUP~RRAI)IATION PROCESS WITH RAMAN _ LYGHT SCATTSEiTNG Mogcow KVANTOVAYA ~L~KTRONIKA in Ruesi~n Vol 6 No 3, 1979 pp 635-638 [ArCicle by V.I. Yemel~yanov and V.N. 5eminogov, M~~scow 5tate UniversiCy imeni M.V. Lamonosov, manuecript received 7 Aug 78] [TexC~ The proceea of superradiation for the case of Raman light ~catteri.ng (SIIQt) is analyzed in a single mode approximati~n taking pump depletion inCo accounC. The dynamice of population difference Cime waveform of the SIKR pulse are etudied. It is ehown thaC accounting for ~ump depletion clears up an additional condition of SIIQt obseryation: an upper limit on the medium density at the ~ 1019 ~-3~ It is noted that because of thie, the observation of SIKR is more probable in gaseous � med ia. 1. The superradiation effect for the case of Raman ecattering (KR) of light (SIKIt) in mole*,ular and atomic systems is analyzed in an approximation of a specified pumping field in paper [1]. The scattered stokes radiation for the case of SIKR is produced in the form of a pulae, the width of which is Tp = ~ 1/N, where N is the number of scattering atoms. The scattered power in the case of SIKR is maximum at the point in t:.me t= tm and is proportional to N2. In the approximaCion of thespecified pumping field, the theoretical descripeion of SIKR [1J proves to be similar to the description of the super- radiation resonance process in a system of originally iaverted two-level aComs [2, 3~. The conditions for observing SIIQt are also similar: tm = = 1/n < T2 (T2 is the transverse relaxation time, and n is the numerical ~ density of the scattering particles). This means that for a specified pumping intensity, IL, there exists a lower limit on the density of the medivm, i.e., n > nmin (IL)� The SIKR process is treated in this paper taking pump depletion into accounC. An equatian which describes population dynamice and the radiation power in the case of SIKR is derived snd analyzed in a single mode approximation. It turns cut that accounting for pump depletion reveals an additional condition 38 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~ox n~~YCiAr, us~ oNLY for nb~~rving 5IKIt: b~gideg Clie low~r limit nn n, tihere nlgo exi~tig ~n upp~r l~nitt nr!:.: ~r:,i i~~ nmgx " lOLg cm^~. Thig is relgCed td eh~ fvice ChgC Ch~ ~up~rr~diaCive ~e~e~ ari~~e ~r thgt point in eime when ehe papul~- Cic~ne o� Che wurking level~ df N p~rCicl~g ~r~ ~qu~liz~d by virCue nf pump ~b~~rption. In g~uffici~nCly denge medium~ pump energy i~ depleCed b~fnre Cht~ ~qualizaCion occure, attd ehere ig no superr~di~tion. We will nne~ ChgC Che vglup of t~~ do~~ not d~pend on rhe pumping inCeneiey ~nd i~ deeermined by Che pgrameC~r~ of Che m~dium. A numeric~l egeimaCion nf n~~ showg Chnt obeexving 5IItIt ig mo~C probabl~ in gageoug media. Accnuneing for ehe moeidn of th~ popnlation ig ehe principle fe~ture which distingui~h~g SIKR from th~ nonateady`-sCaCe Kit mode, in the descripeion of which one can neglect the chgnge in the populaCion [4]. Single mode eff~cts of the SIKR procpg~ are nnC taken into account in Chis _ paper. MulCimode SIKR rheory h~~ been developed in pgper [5~ in approximat- ing a specified pump f ield. 2. We shall coneid~r ~~ygC~n nf N multilevel aComs (or molecules), en- closed in a volume V with a cylindrical shape (L and 5 are the length and - cr~ss-sectional are of the cylinder, the axis of the cylinder is directed ~ along the X axis). The following elecCromagnetic field acts on Che system: ` EL lx, n a ~c (E~ Itl e rtrLr-~~x~.{.E` cn ~tOL~-~Ls~, tl) We ehall assume that at the iniCial point in time p~ 0, all of the atoms are in the ground state, while the average polarization is equnl to 0. As a result~ KR in the medium generatea a stokes field at a frequency of ws �~L -~ab+ Where ~ab > 0 is the transition frequency for the segregated pair of levels a ar~d b(a is the upper level): E, (z~ n= e, (E; e t(a~,r-kix) E~ ~t~ ~t~~,t-+,Y)~ ~2) ~le neglect the dependence of the slow amplitudes of EJ~~S(t) on x, assuming thaC Che condition Tpc > L is met. We introduce the collective variables: Pa6 =~j Pa6~-~ ~kL-ka s�% v Da lPa~-Peb~' (3) a a a where pgb is the slowly changing part of the nondiagonal element of Che density matrix of an atom located at the point xa; paa and ~b are the pop- ulations of the a and b levels. By employing the avera~ino method of [6~, we obtain equations for pab and D: ' , '~4_ Ti P�b � t E~ E' D' (4) 39 FOR OFFICIAL USE ONLY ~ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~o~ o~uYCSnL usE orn.Y ~ ` ~~i Ei Pea - E~ 6i Pes~~ ~ (5) - ltere ~ ~db�~t) (dgae~) ~dbr~~l ~dra~tl - ~nb ~ ~ { 61bp tOL Nbp m~ Th~ amplieude of ehe ~(t) �ield within the medium can b~ repr~sent~d in the form o� Che eum of two parte: ' ~ � A SB~ ~6~ wh~re A and ~ L are the ~olutions of homogeneous and inhomogeneous Maxwell equationa, and A correeponde to a pump field specified from wiChouC (A � d consC). The truncated Maxwell's equation for ~L has ehe form at~ ~ ~r~ ~ -I~ Yt~ ~ - 2nrt~~ "jP' reuEi poe � Here Y= c/(2L) is a phenomenologically introduced field attenuation constant. Since an external field aC a frequency of ws ia lacking (ES '~8), we write the equaCion for E8: ' a~ yE; _ - 21ct~u~ ~ ~.e Ei Pea � ~B) We shall assume that Y ia the greatest of the inverse times of Che problem, and Che following conditions are met: p~1/tp, l/lm~l/T=. (9) � - When Che right inequality of (9) is met, equations (4) and (5) have the intKgral of motions [1, 2J: , ~PaePbo~'D'~ R'~,y~.}.4N. (10) Neglecting the terms diB~/ae, a iB,-Idt, , we obtain the follqwing from (7), (8) and (6): A (11) E~ � 1-~' 4xPo6Pbn ~ Ef ~ ~ robPDa 1'k' 4xPnbPOa ~ Where xas~�~,~nL I~oe I'~Y'~� By substituting (li) in (4) and (5), and using (10), we derive the closed equation for D: ~ ~..Q(Rs-~ ~.~x~ p~~i; D(~)�-N~ C12~ where fl~?1cto~(Iae ~A ~~lfi ~ V. 40 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~Ott O~FICIAL USE ONLY I� Che Cerm~ wieh K(when KNZ � 1.) are negleCC~d itt (lx), eh~n equaCion (12) becomes equival~nt to ~quaCion (8) from p~p~r [1], whi.ch de~cribeg 5IKlt in an approximaCion nf g ep~cifed pump field. Th~ ~olutinn o� (12) has Ch~ form: ln ~N ~(R-I~D)!(R-D) ~?'~'Z.~Qt-4kN (d-}-N)-2x~N~ (D-I-NI�I�l~~k'N (D~-~N~). (13) In implicit form, eh~ BoluCinn for D cgn glso be r~pr~gent~d in ehe form usu~lly employed when de~cribing the euperradigtive dyngmicg of the differenc~ _ in populaCion [1 ~ 3]: p Nth (t~-lm)Itp~: ~14 ) ~ ,cp~U~nnr); (is) ~~,��1/~tp (InN-~-4xN (D-I-N1-}-2xlN~ (D-}-N)-'l~x+N (Dr-~-N')1, (16) we set lt = N with a precision of 1/N in (14) -(16). By employing (ii) and (12),,Che expression for SIKR power, IS(C) ~ 2YV~Eg~2(2n), can be written in the form: ~w~ x~rD! ~2 ~ ~ ) - A (R'=o;)1~� ' 17 It follows from (14) and (17) that radiation is generated at the stokea fre- ~ quency in the form of a pulse with a width tp, the maximum of which ts achieved at the point in time in which case, at the point t~ pm, D(CID) ~ 0 and the ~ radiation power is I8(tm) ~ ~2. If Che terms with K are neglected in formula (16), it transforms to the ex- pression for the time delay derived in paper [1~. Thus, the condition for neglecting the pump depletion effect is the inequality: ~cN2 < 1 ~18~ i.e., an upper l~~it is placed on the numerical density of the particles. - When inequality ~18) is violated, with an increase in the density n, tID begins to grow proportionally to n3. This quickly leads to a violation of the condition for observing SIKR: tm < T2. Thus, accounting for pump de- pletion specifies an additional condition for observing SIKR. From (18) and (11), we have: ~ :am~z� n~?~L d~my~rl (19) The result obtained can be explained with the following argument. The pump- ing field can be considered specified if the energy delivered over the radi- ati.on time Tp is greater than the energy derived from the pumping field in the SIKR process: [ IA ('~(2.z)j ccDS>n1E~LSL. . . . � 41 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~'OR OFPICIAL U5~ ONLY , SubatiCuCing tp grom (1S) in thie expr~~gion, wh~re S2 i~ gpecifi~d in (12), - we nrrive aC esCimnte (19). When I. ~ 0.5 cm, wy ~ w~, ~ 10~5 s-1, ~ r 10"4 cgs ~5U, we f ind nm~x �t ~ lOl9 em"3. Thus, obaerving 5IKR is more prob~ble ~n ga~eous media. The guthore gre grateful to 5.A. Aktunanov ~nd K.N. Drabovich for Cheir u~eful d3scusaiona. BIBLIOGRA;PHY 1. S.G. Rauei~n, B.M. C4lernobrod, ZHETF [JOURNAL OF EXPERIl~tENTAL AND ENGINE~RING ' PHYSYCS], 72, 1342, (1977). 2. R. Bonifacio, L.A. Lugi~to, PHYS. REV. A, 11~ 1507 (1975); 12, 587 (1975). 3. V.I. Yemel~yanov, Yu.L. KlimonCovich, OPTTKA I SPEKTROSKOPIYA, 41, 913 (1976). 4. 5.A. Aktnaanov, K.N� Drabovich, A.G. Sukhorukov, A.S. Chirl:.i~1, 2HET~', ' 59, 485, (1970). ~ 5. V.I. Yemel~yanov, V.N. Seminogov, "Texisy II Vsesuyuz. kon~, po apektro- sitopii kombinatsionnogo rasseyaniya" ("Topice of the Secon;l All-Union Conference on Raman Scattering Spectroscopy"), Moacow, June, 1978. 6. V.S. Butylkin, Yu.G. Khronopulo, Ye.I. Yakubovich, 2HETF, 71, 1712 (1976). COPYRIGHT: Tzdatel~stvo "Sovetskoye Radio'~, "Kvantovaya elektronika", 1979 _ 8225 C30;8144/1216 42 FOR OByICI~1I. USE OHI.Y APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~'Olt ONF'ZCYAI. t18E ONLY - QUANTUM ~L~C~RUNICS UllC 535.375 ON THE POSSIBILITY OF FIELD WAVE ~RONT INV~itSION BY MEANS 0~ NONLINEAR OP~ICS Moscow KVANTOVAYA ~L~KTttONIKA in Rusaian Vol 6 No 3, 1979 pp 638-641 [ArCicle by I.M. Bel~dyagin, V.N. Seminogov and Ye.M. Zemskov, manuecript received 10 Aug 78~ - [TextJ IC is shown that the effect of field wave fronC reversal can be manif~at when fields inCeract aC nonline- arities of any order. A clasaification is given for non- linear processes which permit ~he observation of the indi- - caCed effecC. Nonlinear optical phenomena are well known at the preeent time, in which in- version of the wave fronts (OVF) of the interacCing fields takes place: VRMB , and VKR processea [1 - 3], the process of firat and second harmonic mixing [4J, as uell ~s the four-wave parameCric process of the form 2c,r~ m w2 + wg [Sj. It is shown in this paper that the field OVF effect is possible not only with the processes emmmerated here, but also with the interaction of fields at nonlinearities of any order. Let a field act on a system of two-level atoms (or molecules), wyere the field has severa~. quasimonochromatic componenCe at frequencies of c?r~: E - ~ ~~lr ~r Q eXP (f~t~Ii !ul aa (p�fi ~ ~~f~ 1~ I~ j~ ~ ~~~fD./~ r~ ~1~ ! The frequencies of the existing fields satisfy several resonance conditions: ~ nis~~,~ ~ mu v.~ r ~2~ where w21 is the transitian frequency for t~e segregat~d pair ~f levels; vg is the mistuning from the s-th resonance; n 8~ > 0; ~n B~ = q8 is the order of the s-th resonance. With the action of field (1), nonlinear polarization appears in Che medium, which we write in Che form: 43 Boa o~ici~t. ua$ oxt,Y APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 1~OR OP'FYCYAL V8L ONLY P (r, ~ ~'i ~ (~r, r~ ~I ~p (t~t~I ~ ~ 3 ) , t We ehall asaume Chat Ch~ f~.e1d ~C a frequency w~ propaga~es along Che Z axis. Then Che equaeion for Che slowly changing ~mpli.tude of Chie field can be wriC~en in the form: _ ~ ~ + s'~ � y~~ ~ .~L ~ ~o~i. t) exP (lkl:), ( 4 ) . where a, a~ ~ (mJ~ r~ ~ ry (i~ ~I !xP ~ - lkl:); k~ - k.~; ~l -I- ~ . Thp amplitude of the ttonl3near polarizaCion arising itt the medium ie, in Che genera]. case, proportional to Che product of the ~nplitudea of the inCeracting fielda. If the proceas is described by nonlinear polariza~ion of the type: n ~ ~m/~ 1? ~ I ~~O~S 1 1 ~~r~ ~~J~ l f/, l~ (the fields at a frequency of w Z with Z~~, Zp are plane ones, the ampli- tudes can be considered specified; the field a~ a frequency bf wZ propa- 3 ga~es counter to Che ~-th wave), and the condi~ion 1.m �~ZO~~~~O ~8 met - (Zm is the length of Che medium, aZ~ is the wavelength, AZ~ is the diffrac- tion divergence angle), then the propagation conditions for the ~-th wave prove to be identical to the conditiona Created in [1 - 3], and OVF of Che j-th wave should occur. However, if Zm � a3/e3, while the process is described by polarization of the type ~~01/r fr !r �I^~g~\0~~~ r~ Zr n~~ ~~Ir r~ t~ t~~n~ ~6~ ~1~/ (the fields at a frequency of w~ with Z f~ are plat?e ones, and their amplitudes are specified), then the propagation conditions for the ~-th ~wave are similar to the conditions Created in [4, 5], and OVF of the ~-th wave should occur wiChout a frequency shift. Thus, the question of finding the processes in which OVF is possible redu~:es to finding the processes in which nonlinear polarization is described by expressions (5) or (6). General formulas for quasis~atic polarization for ~ any multiple photon process were derived in [6]. l.� Nonresonant Parametrie Proeesses. Let there be one reaonance condition of the form: ~i"~m~~~~ '"rn!�Q~ ~7) t t The polarization amplitude at the frequency w~ can be written as: 4~+ ~o~ or~sa:~w u1= 01tLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 gOR OFFICIAL U8E ONLY ~ (t~~, r, ~ ~ - ~ i (v - n)+~'~ ( xiv~~~~ ~ Y ~w~o)~! n I ~ (wt)I~~� l. (1 z ) The poasible incnherenC proc~ages during wh~.ch nVF cgn et~k~ place ~re shnwn in ~igure 2. 3. N~sonusz~ Parame~ri~s ProQe~gee, gre poggible, wh~re eevergl r~songnce con- dttiong (2) (s > 1) ~re meC. ~or eimpliciey, we shgll coneider Che cgs~ where there are rwo resonance conditions (s ~ 1, 2), where w eneers into one resonttnce condirion wiCh x negtttive eign (s ~ 1), and ~oes noC enter into Che second one ut nll (s = 2). An nnalysis of the general express~.on for Che polariznCion [6j leads to the concl s~on: in orde o obrxin polarizntion of - the type (6), ie is necessary thaC n~~ ~ 2, gnd n~2~ are arbitrgry The expression for ehe polarizaeion ie writeen in expliciC form: - . y~c--~~,r,:,~~- T' ~'j~"~v`n~T~ n ~ 1 + (v - A)~Ts ~~x ~ , x S 2 ~ x10J~~ ~~~wJ~~~~ tu/~ n ~ g' ~~l)~~Dll . ~ f~~ `f'2x(o~)x(~~1~'~--~/) n (~l)1" n I~'(~dl" � (13) _ ~ ~f~ c ~ ~i ~ ~i ? ~i ~i ~i ~ tc. u ar.a / x z~~~ X~~~ z~y x~ x~~ . Figure 3. Here, wi q2. In contrast to the processes described in section 1, the processes considered here are resonance ones; they are shown in Fi~ure 3. Th~ question of the phase matching of the interacting waves should be dealt with individually in each specific experimental situation. BIBLIOGRAPHY _ 1. B.Ya. zel~dovich, V.I. Popovichey, y.V. Ragul~skiy, F.S. Fayzulov, PIS~MA y ZHETF jLETTERS TO THE JOURNAL OF EXPERIMENTAL AND ENGINEERING PHYSICS], 15, 160, (1972). 45 - t0~ 0!!=0lAL UI' 0l~LY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 - FOR 08FYCIAI~ USB ONLY , J JD ~mf~ ~~'r/~~~01 r~ ~~~n/"~~ ~ ~~~(W~~ I~ 2~ n1 plU ~,~i ~g~ wher~ k~q~ i~ eh~ po1~r~.zgbiliCy of ehe q-Ch order; p~ ig ehe, opu].nCidn of th~ ~ower level; w~ and w Z gre choeen wi~h ehe s~m~ sign witi~ whi.ch Ch~y appegr in resonance condition (7). Tt can be aeen from (8) that to obCgin polgrizatioe of ~he type (6), iC i~ necessary that n~ r 2, n~ ie arbitrary cz 4m~ -1- ~ n~d~ ~ 0, r. e. . t f/ ' ~co1~~ m r:~ n(t�(mr' r' t�~ 9 d~ (m/, r~ ~ r ( 1~ ~ ~ )1 P~;~ ( ) ! f~ - The posaible proceasea of th3s claes are ahown schematiically in ~igure 1. 2. Tnaoherent ProQesses. Let there be only one resonance condition of ~ ~ ~ ~ ~ the form: ~t ~f ~ ~1 kCc. ~ ntwt ~ m~i ~I- v; nt 9. (10) _ ! fJi , ~ x x~ x J x~ (Yarivl~Pue~ (X~?~0~ (Heliwartlf) , The polarization ampliCude at the �frequency wi ia written as: ' yu (m~~ r~ ~@-_.~. 1'}' (v A) T~ sl z ~ 1-}- (v - Qp Tz ~c:nl ~ xfo)~ x Figure 1. xl 8(w~)I~ (~l) n( g(wt)I~~~� (11) where T2 is the transverse relaxation time; S2 is the StArk level shift fre- quency; D~~ is the steady-state difference in the populaCions of the levels; w~ and w are incorporated in expression (11) with the same sign as in condi- t3on (10~j. rr; rr~ ~ ~ ~ , ? ~ ~ ~ ~ d~ ~ � x~ x~'~ x~ ' Figure 2. It can be seen from (11) that to obtain polarization of the type (5), it is necessary that n~ ~ 1, nZ~ m 1, nZ is arbitrary (Z Zp), where ~~.}.~u~ + �S'~ n~ot ~ m~1-{- v . We Chen have: ' lt/. 46 !0~ 0l~tOZAL il1~ O~tLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~OR O~~ICIAI. US~ dNLY - 2. T.M. B~1'dyugin, M.G. Ga~ushkin, Ye~M. zem~kov, V.T. Mnndrngov, KVANTOVAYA EL~KTRONTKA, 3, ~467~ (1976). 3. V.G. Sido~rovich, ZHT~ (JOUI2NAL OF ~NGTNE~RTNG ~HYSICS], 46, ~16~, (~.976). 4. A. Yariv, OPTICS COMMS., 21, 49, (1977). 5. R.W. Nellwarrh, J. OPT. SOC. AMER., 6~, 1, (1977). 6. V.S. BuCylkin, Yu.G. Khronopulo, Ye.T. Yakabovich, ZH~TF, 71, 1712, (1976). CO~XRTGHTt IxdaCel~atvo "Sovetskoye Radio", "Kvantovaya elektronika~~, 1979. 8225 CS0:8144/1.216 47 _ ; FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~Olt O~~ICIAL US~ ONLY QUANTUM ~L~CTItON~CS ~ - UDC 535.341 ~ OPTZCAL LOSSES IN KRS-5 AND KRS-6 CitYSTAL5 Moscow KVANTOVAYA LL~KTItONIKA in ltuasian Vo1 6 No 1979 pp 646-648 [Article by V.G. Artyushenko, Ye.M. Bianov, L.V. Zhukova, F.N. Kozlov, _ V.I. Masychev, Ye.G. Morozov, and V.G. Plotnichenko, Phyaica TnsCituCe imeni P.N. Lebedev of the USSR Academy of Scinecea, Moecow, manuscripC received 1 Sep 78] [Text] The bulk and aurface abeorption factors, as well as the rotal ecattering factora in KRS-5 and KRS-6 crystals were measured laser calorimetry at wavelengths - of 0.647, 1.06, 5.5 and 1.06 um [sic]. The minimal volumetric absorption coefficients amount to (3 - 5) � 10-~ - cm-1 (100 - 200 dB/km). - Materials which are transparent in the central IR band are attracting con- ~ siderable attention for two basic reasons. In the first place, the radia- , tion wavelengths of a number of high power lasers (C02, C0, DF and HF lasers) fall in this band. Secondly, the calculated fundamental absorption levels of many compounds in the central IR band are enormously lower than the limit , of optical losses achieved in fused quartz in the 1.3 um region and equal to 10~6 cm-1 0.5 dB/km) [1]. In terms of the set of phyeical properties, one of the most promising mater- ia~.s, especially from the viewpoint of fiber opCics, is the crystalls of solid solutions of thallium halides: KRS-5 (T1Br-T1J) and I~tS-6 (T1Br-T1C1). Thus, according to paper [2J,, the optical lossea in them in the radiation range of a CO laser 5.5 um) can achieve a level of 10-2 - 10'S dB/km. AC the present Cime, only the absorption factors of Chese crystals have been measured at a few wavelengths: in papers [3, 4], at 10.6 um, and in paper - [5], at 2.7 and 3.8 um in KRS-5 crystals. The absorption factors in KRS-5 _ and KRS-6 crystals were not measured in the radiation range of a CO laser. Radiation scattering in the central IR band likewise has not been studied in these crystals, as far as we know. The results of ineasurements of the bulk and surface absorption coefficients are given in this paper, as well as of the total scattering in KRS-5 and IQtS-6 crystals at wavelengths of 0.647, 1.06, 5.5 and 10.6 um. 48 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 P'OA 0~''r'ICIA~ U8E ONLY , The crysCal~ which wEre inveaeigae~d were grown by ehe Stiockb~rger meChod on aeeda, or~,en~ed in ~he [100] cryAtallographic direc~ion, and in th3s case, Ch~J.7.~.um halides were used as ehe initic~l mn~cri~1 Pollowing rcpe~Ced cry~enl- lizaC~.on purificntion, cnrried ou~ unCil th~ ~ompleCe ~liminaCion of nontrnn~- pnrent maCeria]., even the upper parC of Ch~ rods. 13aged on ehe d~ta of B~~C- - tral chemical analysig, caCion~.c impur~.ty conCenC did no~ exceed the following values: for Ag, Mn � ~.0-6 % by weighC, Cu 3� 10-6 Y, by weighr, Cd, Pb, In 1� 10-5 X by wieght, Sn, Ni, Mg, I~'e 3� 10'5 % by we3ght, and A1 5� 10-5 _ X by weigh~. Based on the data of a chemical ~ngiy8~s, the sulfur content in Che samples was on the order of 10-5 ~6 by weight. The oxygen contenC in the KRS~S crysCala, determined by acCivation analyais, did noe exceed 10~5 Y by weighC, For the sCudies, the samples were cue in the form of cylindri- _ ca7. roda (50 mm x 5 mm diameter), oriented ~long tihe [100] cryetal axis. For one parC of ~he samples, ~he surfaces were polished, and for Che other, Chey were sub~ected to chemical etching. ' The bulk and Che surface 2ss absorpCion facCors were measured by meana of laser calorimetry [6, 7J based on the iniCial slope of the heating curve. The _ influence of heaC dissipation from Che surface of the sample was taken into account using the procedure of [7]. The total acattecing factor ~y was measured in an Ulbricht sphere with a thermocouple rad3ation detector. The bulk and the surface (2SS) absorption facCor, and the total - scattering factor (Y) in indusCrial samples of KRS-5 and KRS-6 at - wttvelengths of 0.647, 1.06, 5.5 and 10.6 um (measurement precision: (1Sv/Sv a 20%, ~Rs/Rs ~ 3~r ~Y/Y ~ 30%). YKN micrometers 0,847 I,OB ~ b,b 10,8 06paae4 S~q ],e a l0~ Y ao 10~ Y 10~ ~p 10~ 4~~ 10~ Y ~0 10~ Y - ~ ~CM ~CM 1~ ~CN 1~ I~CN 1~ ~CN-1~ ~CY 1~ I~CM 1~ ~CN 1~ I~CM 1~ KPC�5~~ ~4 210 3,6 50 3,3 3 21 5,1 2,4 - KPC-5~~ 7,3 200 6,3 45 3,6 15 3,1 2,6 KPC-5'~ 4l 170 18 51 il - 19 13 4,6 KPC�6~~ 19 56 20 I6 5,5 6 I 13 4,2 2,6 KPC-6~~ 28 5d 10 13 3,5 10 14 6,0 2,9 ti:nC-6~~ 20 32 8,8 6 12 - 8 8,6 3,4 KFC-6~~ 9,7 14 3,4 9 10 - 12 7,0 1,2 , ? 1) Polished sample; 2) Etched sample. The side surface of the samples was polished. To avoid the influence of surface scattering by the end faces, bulk scattering was measured in only ~9 !0~ 0!!'t0lAL V/~ O~PLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 _ BOA OFFICIAL U8E ONLY Che cenCral part of the sample (wiCh a length of 1 cm), while the remuining side surEace was ~ncloaed with an absorbing ~ncket. The fol~.owing were used as Che radiation sources: a"Specera-Physica-164" krypCon laser wiCh a wavelength o� a= 0.647 um, YAG:Nd3~' laser ~t a= 1.06 um, an induetrial aealed-off CO laser wiCh water cooling a radiation spectrum in Che vicinity of a= 5.5 um, and a"LG-22" C02 laser at 1U.6 um. IC should be noted Chat since the CO laser employed had a raCher wide radia~ion spectrum, the experimental reaulCs obtained yield average values in th3s specCral range. The measurement resulCs are preaented in the Cable. The values of the absorp- tian fac~or ae the aurface of both end faces are given only fox a wavelengCh of 5.5 um, since s~ � 2Sg was obtained for Che remaining wavelengChs. The . scaCter in the s3.zes of 2Ss for various samples indicates their dependence on the qualiey of surface treaCment. A comparison of the surface absorpGion fac- = tors of the polished and etched surfaces allows for the hypothesis thaC the surface layer which is damaged and contaminated dur3ng polishing, and which is removed by etching, is a source of additional absorption of Che thr.ough radiation. However, it must be noted that with chemical treatment of the surfaces, the etching of which 3s accomplished manually, there flatness is destroyed and they 3ntensely scatter the through rad3ation. It can be seen from the table that the levels obCained for the optical losses in the samples investigated cone3derably ~xceed the supposed fundamental loss - 1eve1; in this case, the minimum bulk absorpC�ion facCora~ amount to (3-5) � 10"'4 cm 1, which corresponds to 120-200 dB/lan. The exceptionally high total scattering factors in these crystals should also be noted, which ' significantly exceed the bulk absorpt3on factors for a11 wavelengths, with ~Ae excep~ion of a= 10.6 um. Preliminary estimates show that mosC likely, _ - Che basic cause o~ such a high scattering 1eve1 is sc.aCtering aC tne end faces of ~he sampS,es. ' In conclusion, the authors express their gratitu~le to T.I. Darvoid, V.B. Neustruyev and Ye.P. Nikitin for Cheir assistance in performing the work and Cheir useful discussions. BIBLIOGRAPH'~ . 1. M~ Horiguchi, T. Osanai, ELECTR. LETTS., 12, 310 (1976). ~ 2. D.A. Pinnow, A,.L. Gentlee, A.G. Standlee, A.T. T:[mper, L.M. Hobrock, APPL. PHYS. ZETTS., 33, 1, 28 (1978). 3. T.I. Darvoid, Ye.K. Karlova, N.V. Karlov, G.P. K~uz~min, I.S. Lisitskiy, _ Ye.V. Sisakyan, KVANTOVAYA ELEKTRONIKA, 2, 765 (1975). : _ 50 = ~'0~ ~~~O~ll~ ~1~ @~Y ~ , ~ APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3 APPROVED FOR RELEASE: 2047102109: CIA-RDP82-00850R000100060038-3 ~'nR O~FICIAI. U5~ dN[,Y 4. V.G. Doro~~y~v~ V.A. Kareva, V.S. M~kin~ V.N. Smirnov~ OrT1K0-M~KFWVTCHESKAYA p1tCH~tY5!{L~NNOST' [Tlt~ OPTOM~CHANrCAL TNllU5TltY~ ~ 6~ 35~ 1g78. 5. I.A. NarrtngCon, prn~. gCh AS'IM Symp. on L~ser Ind. U~m~~~ in Opt. Mnecr.~ x, 45, (1976). b. y~G. Ati~yu~th~ttkd~ Xe~M� llianov~ Ye.P~ Ntkit3n, KVANTOVAYA ELEKTRONIKA~ s~ io6s, (i9~~). 7. N.g. Itogengtock~ M. Hg~~~ D.A. Cxegory, I.A. Harrtngton, APPL. UPTICS, 16, 2837, (1977j. � CO~YRICIiT: Izd~tel'stvo "SoveCskoye Radio'~~ '~Kvantovaya elektxonika", 1919 8225 C5os8144/1216 IIdD 51 FOR OFFICIAL USE ONLY APPROVED FOR RELEASE: 2007/02/09: CIA-RDP82-00850R000100060038-3
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