1、共振原子體系光學(xué)瞬態(tài)過程理論研究博士生:王干全導(dǎo)師:周建英教授摘要本文研究、AG基質(zhì)材料中稀土離子Era.Nd3的光譜性質(zhì)和光在共振一維介質(zhì)、二維平面波導(dǎo)中的傳播特性。Er3由于能產(chǎn)生上轉(zhuǎn)換熒光而受到重視，本文用有一定延時(shí)的雙光束激光激發(fā)Er3:YAG固態(tài)樣品，同時(shí)測(cè)量樣品的線性熒光和上轉(zhuǎn)換熒光強(qiáng)度理論上用Bloch方程描述激發(fā)態(tài)吸收上轉(zhuǎn)換過程，通過數(shù)值方法解Bloch方程，得到與激發(fā)態(tài)吸收過程相關(guān)的各能級(jí)粒子數(shù)布居隨時(shí)間的變化關(guān)系，由

2、于粒子數(shù)布居對(duì)時(shí)間的積分結(jié)果和熒光強(qiáng)度成正比，因而可以計(jì)算出熒光強(qiáng)度。對(duì)于有一定延時(shí)的兩束光，用此方法可得到熒光強(qiáng)度隨延時(shí)的變化關(guān)系，即相干光譜。相干光譜的計(jì)算結(jié)果和實(shí)驗(yàn)結(jié)果一致。在Nd3:YAG晶體中，晶格的振動(dòng)對(duì)Nd3的光譜性質(zhì)會(huì)產(chǎn)生影響，這種影響可以用Brown振子模型描述。本文用Brown振子模型研究YAG基質(zhì)材料中Nd34f電子躍遷的電子一聲子相互作用過程，詳盡推導(dǎo)了電子一聲子輻合的表達(dá)式，模擬了Nd3:YAG的激發(fā)光譜，得出

3、了電聲44合常數(shù)和聲子頻率等參數(shù)用這些參數(shù)計(jì)算時(shí)間分辨的熒光相干光譜，結(jié)果與實(shí)驗(yàn)結(jié)果一致.結(jié)果表明，4f電子一聲子的藕合屬弱相互作用。第i頁TheoreticalstudyonthetransientopticalprocessesofresonantatomsystemsPhDcandidate:WangG.Q.Suppervisor:Prof.ZhouJ.Y.AbstractTheopticalpropertiesofraremet

4、alionsinYAGbasesandthelightpropagatingcharacteristicsin1dimensionalmediaand2dimensionalwaveguideswerestudiedinthisthesisStudyofEr3ionshasreceivedmuchattentionbecausetheycanproduceupconversion.Inthisstudyduallaserpulseswi

5、thvariabledelaywereusedtoexciteEr3:YAGsolidstatesamplewiththelinearfluorescentstrengthandupconversionstrengthbeingmeasuredsimultaneously.TheoreticallyexcitationstateabsorptionupconversionprocesswasdescribedbyBlochEquatio

6、nwhichwassolvedthroughnumericalmethodsandparticlepopulationdistributionsofvariousenergylevelsvaryingwithtimeandrelatedtoexcitationstateabsorptionwereobtained.Theintegrationoftheseparticledistributionsovertimeisproportion