本文選題：光纖激光器 + 隨機(jī)激光�。� 參考：《電子科技大學(xué)》2015年碩士論文

【摘要】：2010年,S.K.Turitsyn等學(xué)者提出了隨機(jī)分布反饋光纖激光器(RDF-FL)的概念,即基于單模光纖(SMF)中隨機(jī)分布的瑞利散射(RS)和拉曼放大增益的光纖激光器。得益于其穩(wěn)定連續(xù)的輸出、很高的光子簡(jiǎn)并度和較低的空間相干性,RDF-FL在激光光源,光通信和光傳感等應(yīng)用領(lǐng)域具有獨(dú)特優(yōu)勢(shì),其中涉及的激光物理,無(wú)序系統(tǒng)理論及非線性光學(xué)等問(wèn)題也具有重要的學(xué)術(shù)價(jià)值。目前,基于SMF的RDF-FL增益由拉曼(Raman)放大提供,其激射閾值較高、需要光纖長(zhǎng)度較長(zhǎng),且輸出光譜依賴于SMF的增益譜,如隨著泵浦功率的增加,激光光譜會(huì)出現(xiàn)雙峰結(jié)構(gòu),峰值也會(huì)移動(dòng)。基于有源光纖的RDF-FL閾值很低,但在短距離的有源光纖中瑞利散射效應(yīng)較弱,通常無(wú)法得到隨機(jī)激光激射現(xiàn)象。鑒于上述原因,本文通過(guò)兩種不同增益類型光纖的組合及一定反饋增強(qiáng)手段,實(shí)現(xiàn)了高效、低閾值的隨機(jī)激光輸出。主要工作和發(fā)現(xiàn)如下:首先,基于非線性薛定諤方程并融入拉曼增益、光纖損耗及瑞利散射的頻譜相關(guān)性,獲得拉曼放大系統(tǒng)的穩(wěn)態(tài)傳輸方程;通過(guò)Giles速率方程獲得增益與泵浦的關(guān)系,由此建立EDF增益系統(tǒng)的仿真模型;利用邊界條件,結(jié)合兩類增益系統(tǒng)的穩(wěn)態(tài)傳輸模型,實(shí)現(xiàn)了混合光纖結(jié)構(gòu)的理論仿真。結(jié)果能夠反映RDF-FL的功率分布、閾值及頻譜演變特性,且與實(shí)驗(yàn)結(jié)果吻合。其次,我們實(shí)驗(yàn)分析了EDF的隨機(jī)激光激射情況。在中心波長(zhǎng)1480 nm泵浦單獨(dú)激勵(lì)下,100 m EDF的自發(fā)放大輻射譜(ASE)上出現(xiàn)了少量隨機(jī)模式激射。當(dāng)加入SMF后,不管是非對(duì)稱還是對(duì)稱結(jié)構(gòu),單獨(dú)泵浦下的EDF產(chǎn)生的光譜都在1569 nm波長(zhǎng)附近出現(xiàn)了大量無(wú)序混亂的隨機(jī)激射模式,且ASE背景噪聲明顯被壓窄。然后,我們分析了非對(duì)稱結(jié)構(gòu)下的RDF-FL輸出特性。EDF在腔內(nèi)時(shí),可為SMF中產(chǎn)生的背向散射光提供增益,前向傳輸?shù)墓β瘦斎?輸出曲線沒(méi)有明顯的閾值現(xiàn)象,且?guī)缀醪浑SEDF的泵浦功率變化;后向傳輸?shù)募す獯嬖诿黠@的閾值,且隨著EDF泵浦功率的增加,曲線整體向高功率平移。當(dāng)EDF不在腔內(nèi)及從外部提供種子光時(shí),前后兩端同樣得到了寬帶的輸出光譜,而且EDF泵浦的功率可以調(diào)控前后向傳輸?shù)募す獾某龉庑�。最�?我們分析了對(duì)稱結(jié)構(gòu)下的RDF-FL輸出特性�；旌显鲆鏃l件下,隨機(jī)激射的閾值極大的降低,光譜輸出經(jīng)歷了從混亂-穩(wěn)定-混亂-穩(wěn)定的交替變化過(guò)程,穩(wěn)定輸出時(shí),光譜為單波長(zhǎng)、無(wú)模式的隨機(jī)激光輸出,其線寬約1 nm、信噪比大于25 dB,且中心波長(zhǎng)穩(wěn)定,幾乎不隨泵浦功率變化。
[Abstract]:In 2010, S. K. Turitsyn and others put forward the concept of random distributed feedback fiber laser (RDF-FL), which is based on random distributed Rayleigh scattering RSs and Raman gain fiber lasers. Thanks to its stable and continuous output, high photon degeneracy and low spatial coherence RDF-FL have unique advantages in applications such as laser light sources, optical communications and optical sensing, which involve laser physics. The theory of disorder system and nonlinear optics are also of great academic value. At present, the RDF-FL gain based on SMF is provided by Raman Raman amplification, which requires a long optical fiber length, and the output spectrum depends on the gain spectrum of SMF. For example, with the increase of pump power, the laser spectrum will have a double peak structure. The peak also moves. The threshold of RDF-FL based on active fiber is very low, but the Rayleigh scattering effect is weak in the short distance active fiber. In view of the above reasons, the high efficient, low threshold random laser output is realized by the combination of two kinds of optical fiber with different gain types and a certain feedback enhancement method. The main works and findings are as follows: firstly, based on the nonlinear Schrodinger equation and the spectral correlation of Raman gain, fiber loss and Rayleigh scattering, the steady state propagation equation of Raman amplification system is obtained. The relationship between gain and pump is obtained by Giles rate equation, and the simulation model of EDF gain system is established, and the theoretical simulation of hybrid optical fiber structure is realized by using boundary conditions and the steady-state transmission model of two kinds of gain systems. The results can reflect the power distribution, threshold and spectrum evolution characteristics of RDF-FL, and are in good agreement with the experimental results. Secondly, we analyze the random laser emission of EDF experimentally. A small number of random mode excitations have been observed on the spontaneous amplified emission spectra of 100m EDF pumped at a central wavelength of 1480 nm. With the addition of SMF, no matter asymmetric or symmetric structure, the spectra produced by EDF pumped by single pump have a large number of disordered random emission modes near the wavelength of 1569 nm, and the background noise of ASE is obviously compressed. Then, we analyze the output characteristics of RDF-FL in asymmetric structure. When the RDF-FL is in the cavity, it can provide the gain for the backscattered light generated in SMF. The power input-output curve of forward transmission has no obvious threshold phenomenon. The back propagation laser has obvious threshold, and the curve shifts to high power with the increase of EDF pump power. When the EDF does not provide seed light in the cavity and from the outside, the broadband output spectrum is obtained at both the front and the back, and the output efficiency of the backward and backward laser can be regulated by the power pumped by the EDF. Finally, we analyze the output characteristics of RDF-FL in symmetric structure. Under the condition of mixed gain, the threshold of random laser emission is greatly reduced, and the spectral output goes from chaos to stability and from chaos to stability. When the output is stabilized, the spectrum is a single wavelength, modeless random laser output. The line width is about 1 nm, the SNR is more than 25 dB, and the center wavelength is stable, almost no change with pump power.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN248

【共引文獻(xiàn)】

相關(guān)期刊論文 前6條

1 楊永佳;周自剛;邱榮;蔣勇;閆匯;;白光頻譜干涉原理及其應(yīng)用[J];大學(xué)物理實(shí)驗(yàn);2014年03期

2 姚雪;樊玉勤;王偉;廖帥;吳致平;李天宇;;“聲光衍射與液體中聲速的測(cè)定”實(shí)驗(yàn)改進(jìn)探析[J];大學(xué)物理實(shí)驗(yàn);2014年04期

3 何其銳;李立萍;周鷹;高椿明;;聲光頻譜儀頻率分辨率判斷方法研究[J];光電子.激光;2014年10期

4 閆淼;王軍;楊明;吳志明;蔣亞?wèn)|;;基于Tracepro的太赫茲探測(cè)陣列光學(xué)鏡頭設(shè)計(jì)[J];激光與紅外;2014年04期

5 王世燕;曹長(zhǎng)霄;袁順東;李書(shū)光;劉偉華;王小萌;;淺議分光計(jì)實(shí)驗(yàn)中的問(wèn)題[J];實(shí)驗(yàn)科學(xué)與技術(shù);2015年04期

6 梁一機(jī);;牛頓環(huán)干涉測(cè)透鏡的曲率半徑研究[J];智富時(shí)代;2015年07期

相關(guān)會(huì)議論文 前1條

1 孫敏;;照明燈具中藍(lán)光危害新認(rèn)知[A];產(chǎn)業(yè)競(jìng)爭(zhēng)力與創(chuàng)新驅(qū)動(dòng)——2014年山東省科協(xié)學(xué)術(shù)年會(huì)論文集[C];2014年

相關(guān)碩士學(xué)位論文 前4條

1 胡建敢;基于光譜吸收技術(shù)的農(nóng)藥殘留檢測(cè)系統(tǒng)[D];重慶理工大學(xué);2012年

2 嵇得宸;光電極納米結(jié)構(gòu)中光傳播和光電轉(zhuǎn)換機(jī)理研究[D];華東理工大學(xué);2014年

3 王超群;基于法拉第旋光效應(yīng)的兩級(jí)調(diào)制旋光儀研究及設(shè)計(jì)[D];河南師范大學(xué);2014年

4 彭家忠;光纖熔接機(jī)激光注入和光功率探測(cè)對(duì)準(zhǔn)系統(tǒng)的研究[D];福建師范大學(xué);2014年

，

本文編號(hào)：1906001