本文關(guān)鍵詞：中強場下稀土離子上轉(zhuǎn)換發(fā)光超快控制的研究　出處：《華東師范大學》2017年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 稀土離子 上轉(zhuǎn)換發(fā)光 脈沖整形 相干控制 偏振 微擾理論

【摘要】：稀土離子上轉(zhuǎn)換發(fā)光被廣泛地應(yīng)用于激光光源、光纖通信、發(fā)光二極管、色彩顯示和生物系統(tǒng)等領(lǐng)域,因此實時、動態(tài)、可逆地控制稀土離子上轉(zhuǎn)換發(fā)光對于它們的應(yīng)用是非常重要的。對于通過光物質(zhì)相互作用控制多光子吸收過程來說,飛秒激光的相位和偏振調(diào)制已經(jīng)被證明是一種非常簡單而且行之有效的方法。在早期的研究中,上轉(zhuǎn)換發(fā)光控制主要集中在較弱的飛秒激光場。在這里,我們進一步拓展了這一控制手段,從弱的飛秒激光場進一步拓展到中強的飛秒激光場。在較弱的飛秒激光場中,二階微擾理論可以很好地解釋非共振雙光子吸收過程。但是,在中強飛秒場下可以產(chǎn)生更高階非線性效應(yīng)(例如,四光子吸收),為此我們建立了一個新的理論模型(也就是四階微擾理論)來解釋這一物理控制機制,這里上轉(zhuǎn)換發(fā)光過程涉及了雙光子吸收過程和四光子吸收過程。具體研究內(nèi)容如下:(1)我們通過實驗研究和理論分析驗證了摻雜Dy3+離子的玻璃上轉(zhuǎn)換發(fā)光可以用π相位掃描調(diào)制來人為地控制,同時上轉(zhuǎn)換發(fā)光控制行為依賴飛秒激光強度。研究結(jié)果表明,上轉(zhuǎn)換發(fā)光強度在弱的飛秒激光場中可以被有效地抑制,而在強的飛秒激光場中則被增強。理論分析結(jié)果顯示,在整個激發(fā)過程中四光子吸收的相對權(quán)重隨著飛秒激光強度的增強而增加,而共振雙光子吸收和四光子吸收的干涉導(dǎo)致了不同的激光強度下上轉(zhuǎn)換發(fā)光調(diào)制的改變。(2)飛秒激光場的偏振調(diào)制已被證明是控制稀土離子上轉(zhuǎn)換發(fā)光的一個很好的方法。我們通過四階微擾理論模型來研究在中強飛秒激光場的激發(fā)下Sm3+摻雜玻璃中的上轉(zhuǎn)換發(fā)光的偏振控制行為。實驗結(jié)果表明,Sm3+摻雜玻璃中的上轉(zhuǎn)換發(fā)光的偏振控制效率將受飛秒激光強度的影響,且隨激光強度的增加而減小。我們理論上提出四階微擾理論來解釋包括非共振雙光子吸收和四光子吸收的實驗觀察結(jié)果,由于其不同的偏振控制程度,雙光子和四光子吸收之間的相消干涉將導(dǎo)致偏振控制效率被抑制。
[Abstract]:Rare-earth ion up-conversion luminescence is widely used in laser light sources, optical fiber communications, light-emitting diodes, color display and biological systems, so real-time, dynamic. Reversible control of the upconversion luminescence of rare earth ions is very important for their applications. The phase and polarization modulation of femtosecond laser has been proved to be a very simple and effective method. In the early research upconversion luminescence control mainly focused on the weak femtosecond laser field. We further extend this control method from weak femtosecond laser field to medium strong femtosecond laser field in the weaker femtosecond laser field. The second-order perturbation theory can explain the non-resonant two-photon absorption process well, but the higher-order nonlinear effect (for example, four-photon absorption) can be produced in the medium-strong femtosecond field. Therefore, a new theoretical model (i.e. the fourth order perturbation theory) is established to explain the physical control mechanism. The up-conversion luminescence process involves two-photon absorption process and four-photon absorption process. We have verified that the up-conversion luminescence of glass doped with Dy3 ion can be artificially controlled by 蟺 -phase scanning modulation through experimental research and theoretical analysis. The up-conversion luminescence control behavior depends on the femtosecond laser intensity. The results show that the up-conversion luminescence intensity can be effectively suppressed in the weak femtosecond laser field. The theoretical analysis shows that the relative weight of four-photon absorption increases with the increase of femtosecond laser intensity during the whole excitation process. The interference of resonant two-photon absorption and four-photon absorption leads to the change of up-conversion luminescence modulation with different laser intensity. The polarization modulation of femtosecond laser field has been proved to be a good method to control the upconversion luminescence of rare earth ions. We study Sm3 under the excitation of medium-intensity femtosecond laser field by using the four-order perturbation theory model. Polarization-controlled behavior of up-conversion luminescence in doped glass. The polarization control efficiency of up-conversion luminescence in Sm3 doped glass will be affected by the femtosecond laser intensity. We propose a four-order perturbation theory to explain the experimental results including non-resonant two-photon absorption and four-photon absorption due to their different degree of polarization control. The interference between two-photon and four-photon absorption will result in the suppression of polarization control efficiency.
【學位授予單位】：華東師范大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：O482.31

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相關(guān)期刊論文 前1條

1 程文靜;張詩按;賈天卿;馬婧;馮東海;孫真榮;;Coherent control of two-photon absorption of Pr~(3+) ion by shaped ultrashort laser pulses[J];Chinese Optics Letters;2013年04期

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本文編號：1363046