激光超声的原理及其在固体中的应用

(,100080)..,,..r:.,,AbstraetLasergeneratedultrasounddenotesthePulsedultrasoundexeitedinamediumbyapulsedlaser.This15arelativelynewmeansofgeneratingultrasound,themainadvantageofwhieh15thattheultrasoundmayberemotelyexeited(andreeePted),andthusmaybeappliedtomateriale-valuationinhostileenvironmentslikeelevatedtemperaturesanddangerousradiationaswellasonthepreduetionlinewithfastmovingproduets.UltrasoundexeitedbypieoseeondorfemtosecondlasershasreeentlybeenusedtostudytheeouPlingofeleetronsandphononsinsolids.ThispaPerreviewstheaeou,tiealpropertiesoflaserultrasoundinsolidsandtwoimportantmeehanismsofgeneration,thethermalandtheeleetronie.Keywordslaser-generatedultrasound,acoustiealproperties,twogenerationmeehanisms,.,.,,.,.,,.,,,,..,;B,,.60,.,,,,()..,,,,..19951214,1996227,25(1996)6:,,,,..,.,.,.,.,,.,.,.,:,.2,,,,,,,..,10ns,,.,,.,.,,.,.80,.,,,,,,;,,,.,,,.,,,.,:,.,.,.,,,.1[1,10ns.,,.,1(a),(b).,.1,().,,,,,,,,.,,.,1,.2,1.3[2].1MH:,.0--l--2--3Lƒ„0.00.30.6.....11111}}}ƒ„15022503(X)350X)0.9(ns)S1.22)300246s),LJ0.ƒ„0.60.93[z](,,,)Sl,20246810(s)1(a);(b),,=0o.,.80,,.,,.,.,,,,10nm,,,,.,,.,,,-,.3],(4),.,25(1996)6[4],5.5[5],,b.,3.0.110.070.030.0.030.070.110.15ƒ!Šl()4}(,.J).39rnm)5I};b(0.2mm)312,,.2.,.3,,,,.,,,.3,4,4..,.[],,.7].,,.,,,.,.,.-:,,,..1867,,.1941,.Hen,IK,,V.Peshkov1944.,.,,,:.1966,C.C.Aekermann4He.1970,T.F.Mc-NellyNaF.,,,,,,,.,.,,1020K,,.,,.,,,,.,.,.,,.,,,.,,,,.,.,q=kTq+kT.(1)c(r,,.,,cS,,S,~3~~zJJ.Sv:,c,~,~3L~~,JU,r:.,:Cv---,--,101045.(2),:,,(:+r):,t~/tt.,MeDonald[7,.,,,,.}..,,.,.p?-,:Tk_,_(1r)=T,(2)-ttq,T,k,p,C,:,,.(2)42TITk,,~=V1.JtTtr,,,.tlt,.,,,.,,,,25(1996)6,,,.,.,,,,.Eg,hoLEg,Eg,,,,.,.,.(),,.,,,,500600K,,.,,.,,.,,,,.,,.}610],.,235nm.:,,,,,,,.,,,,.6(),.,ab,,,b;,60x1015Wm3K.,.(p6(235nm),(,.200fs.,)560,,1980..,:,,,,[11[251[6]R.J.Dewhurstetal.,Ultrasones,25(1987),315.D.A.Hutehins,R.J.DewhurstandS.B.Palmer.J.Acoust.Am.,70(1981).1362.H.L.TelschowandR.J.Conant,J.A,oust.s.Am.,88(1990),1494.FangQiping,BaiYuhai,YingChongfu,Ch:noJ.Acou-z,:.14(1995),289.BaiYuhaieal.,UIraon:,32(1994),323.,.,,19949,.J.A.Menald.J.,nelruct:,Eluat,on,9(1990),223.,,,.19962,.ChengJianehun.Zhanghuy:,J.Appl.Ph74(1993).5718.().B.WrightandV.E.Gusev.IEEETrans.:,42(1995),331.1.....JJfr..L..L1.111,r.LL..L9l0,.,,,.,,.,,,,,,.100GH:,,.,,,.(,l()0080),,,...,{AbstraetTheinventionanddevelopmentofthepulsetuberefrigeration,andpartieularlythebreakthroughsaehievedinreeentyears,arebrieflyreviewed.TheprineiplesandtentialapplieationsofPulsetuberefrigeratorsarealsodeseribed.Keywortlspulsetube,refrigeration,eryogenies,ereooler,,,.60Gif-fordLongsworth],,?,,,,(19958).19951116.25(1996)6