高功率激光束中高頻位相畸變特性的研究.pdf

1、分類號(hào)鯉曼Lj二盟㈣UDC，密級(jí)公開(kāi)～編號(hào)中國(guó)工程物理研究院學(xué)位論文高功率激光柬中高頻位相畸變特性的研究劉紅婕指導(dǎo)教師姓名景蜂(劇研究員)(中國(guó)工程物理研究院四川綿陽(yáng))申請(qǐng)學(xué)位級(jí)別碩士專業(yè)名稱光學(xué)工程論文提交日期2005年5月論文答辯日期2005年5月學(xué)位授予單位和日期史國(guó)工程物理研究院答辯委員會(huì)主席楊經(jīng)鐲(教授)評(píng)閱人宋影松(研究員)2005年5月日羅斌(教授)高功率激光柬中高頻位相畸變特性的研究AbstractItiswellkno

2、wnthroughmanyfinishedphysicsexperimentsthatthecharacteristicoffocalspotisoneofthemostcrucialfactorswhichdeterminewhetherignitioncailrealizeornotPropertiesoffocalspotaremainlydeterminedbythequalityofthebeambeforefocusedIn

3、brief，themainoffocalspotliesonthelowfrequencycomponentsofwavefrontwhilethetailofitliesonthemiddle—highfrequencycomponentsofwavefrontManyresearchesaboutthelowfrequencycomponentsofwavefronthavecometoveryusefulconclusions，h

4、owever，forthemiddle—hi曲components，relativelylessworkhasbeendoneandnousefulresultshavebeenderivedaboutitsnonlinearpropagationoritsrelationwiththetailofthefocalspotbecauseofitscomplextransmissionThemiddlehighfrequencycompo

5、nentsofwavefrontinhi曲powerlasersystemmainlycomefromhundredsofopticsbecauseevenextremelysmallfiuctuationsonthesurfaceofoptiCSmaybecomenegligiblebyhundredsofadditionandnonlineartransmissionTheunwantedresultsfromitincludepi

6、nholeclosureandnonlinearsmall—scaleselffocusingwhichoriginatefromhigh—intensitytailofthefocalspotandnonlineartransmissionofthemiddle—hi曲frequencyunderhighintensitySoitisveryusefu／tostudythetransmissionofthemiddlehi曲frequ

7、encyanditsimpactonthetailofthefocalspotThecontentsaremainlydividedintofivesectionsasfollows：(1)DividingthespatialfrequencyofthephaseerrorsintoseveraldistrictsandmakingsurethedistricttostudyFirst，theB—Ttheoryitsassumption

8、sandanalysisofphaseerror’spropagationareintroducedThen，basingonthenonlinearpropagationofdifferentspatialfrequencyandtherequirementsofICFforthemainfocalspot，wedividethespatialfrequencycomponentsofphaseerrorsintoseveraldis

9、trictsfortheSG一17IsystemandmakesaretheemphasistOstudy(2)StudyingthetransmissionpropertiesofthemiddlehighfrequencycomponentsofphaseerroronthebasisofB—TtheoryWefirststudythetransmissionpropertiesofalocalphaseerroranddrawac

10、onclusionthatnoneofthephasecrrorsundergoapparentnonlinearincreaseexceptforthosewhosemainspatialfrequencycomponentsarcinthehi曲一gaindistrictThen，usingnumericalsimulation，westudytheimpactsofphaseerroronthenearfieldofthebeam

11、inpracticeandanalyzetherelationbetweenthe△BandthenearfieldcontrastFinallyweanalyzetheimpactsofpinholesanddifferentresourcesofphaseerroronthenearfieldmodulation(3)Impactsofmiddlevhi曲frequencycomponentsofphaseerroronthetai