【摘要】：光譜特性是光纖激光的基本物理特性之一。隨著光纖激光系統(tǒng)輸出功率的提高,非線性效應(yīng)對系統(tǒng)的影響越來越顯著:一方面,在光纖激光系統(tǒng)中,光譜特性是系統(tǒng)中非線性效應(yīng)及破壞效應(yīng)的直觀表征;另一方面,光纖激光的光譜特性也會(huì)對光纖器件及系統(tǒng)的穩(wěn)定性產(chǎn)生影響�；诖�,本文對高功率光纖激光系統(tǒng)的光譜特性展開了理論與實(shí)驗(yàn)研究。論文回顧了國內(nèi)外有關(guān)光纖激光系統(tǒng)光譜特性的研究進(jìn)展,分別介紹了摻鐿光纖激光器、拉曼光纖激光器及摻鐿光纖放大器的典型光譜特性模型,并總結(jié)了相關(guān)模型優(yōu)點(diǎn)及不足。通過對速率方程及非線性傳輸方程的分析,建立了多縱模振蕩器及超熒光光源的光譜特性模型,并分析了光纖光源參數(shù)對其輸出光譜特性的影響。研究結(jié)果表明,對多縱模振蕩器而言,其輸出光譜寬度隨高反射率光柵的反射譜寬、泵浦功率及腔長的增長是近似線性展寬的,而輸出光柵的反射譜寬對輸出光譜的影響可以忽略;對超熒光光源而言,隨著摻雜光纖長度的增加,其輸出光譜的中心波長逐漸向長波方向漂移。通過種子源特性及放大過程的描述,對光纖放大器的光譜演化過程進(jìn)行分析,建立了高功率光纖放大器的光譜特性數(shù)值仿真模型,并研究了種子源特性及放大器的參數(shù)對輸出光譜特性的影響;同時(shí)采用不同種子源進(jìn)行了相應(yīng)的實(shí)驗(yàn)驗(yàn)證,實(shí)驗(yàn)結(jié)果與理論仿真結(jié)果較好吻合。最后,推導(dǎo)了不同輸出功率下光纖放大器的光譜展寬因子的近似表達(dá)式。建立了包含受激拉曼散射效應(yīng)的光纖激光器動(dòng)力學(xué)方程,并研究了種子源特性及光譜濾波對其在放大過程中拉曼閾值特性的影響。數(shù)值仿真計(jì)算結(jié)果表明,種子源的時(shí)域特性會(huì)對光纖放大器的拉曼閾值特性產(chǎn)生顯著影響。
[Abstract]:Spectral characteristic is one of the basic physical properties of fiber laser. With the increase of the output power of the fiber laser system, the nonlinear effect becomes more and more obvious. On the one hand, in the optical fiber laser system, the spectral characteristic is the direct representation of the nonlinear effect and the destruction effect in the optical fiber laser system. On the other hand, the spectral characteristics of fiber laser also affect the stability of optical fiber devices and systems. Based on this, the spectral characteristics of high power fiber laser system are studied theoretically and experimentally. This paper reviews the research progress of optical fiber laser system at home and abroad, and introduces the typical spectral characteristic models of ytterbium-doped fiber laser, Raman fiber laser and ytterbium-doped fiber amplifier, respectively. The advantages and disadvantages of the models are summarized. Based on the analysis of the rate equation and the nonlinear transmission equation, the spectral characteristic models of the multi-longitudinal-mode oscillator and the superfluorescence source are established, and the influence of the optical fiber source parameters on the output spectral characteristics is analyzed. The results show that the output spectral width increases linearly with the reflection spectrum width, pump power and cavity length of the high reflectivity grating for the multi-longitudinal mode oscillator. The effect of the reflectance spectrum width of the output grating on the output spectrum can be neglected. For the superfluorescent light source, the central wavelength of the output spectrum drifts to the direction of long wave with the increase of the length of doped fiber. Based on the description of seed source characteristics and amplification process, the spectral evolution process of fiber amplifier is analyzed, and a numerical simulation model of spectral characteristics of high power fiber amplifier is established. The effects of the characteristics of the seed source and the parameters of the amplifier on the output spectral characteristics are also studied. At the same time, different seed sources were used to verify the results, and the experimental results were in good agreement with the theoretical simulation results. At last, the approximate expression of spectrum broadening factor of fiber amplifier with different output power is derived. The dynamic equation of fiber laser with stimulated Raman scattering effect is established. The effects of seed source characteristics and spectral filtering on Raman threshold characteristics during amplification are studied. The numerical simulation results show that the time domain characteristics of the seed source have a significant effect on the Raman threshold characteristics of the fiber amplifier.
【學(xué)位授予單位】：國防科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN24

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前2條

1 王文亮;大功率光纖激光器受激拉曼散射研究[D];國防科學(xué)技術(shù)大學(xué);2014年

2 肖虎;摻鐿光纖激光級聯(lián)泵浦技術(shù)研究[D];國防科學(xué)技術(shù)大學(xué);2012年

，

本文編號(hào)：2391494