本文選題：非線性光學(xué) + 相位匹配　； 參考：《天津理工大學(xué)》2017年碩士論文

【摘要】：非線性波長(zhǎng)轉(zhuǎn)換在光信號(hào)處理、光信息存儲(chǔ)、生物醫(yī)學(xué)檢測(cè)、遙感探測(cè)、工業(yè)加工及環(huán)境監(jiān)測(cè)分析等方面起者重要的作用。隨著超短脈沖激光技術(shù)的不斷發(fā)展,寬帶激光的波長(zhǎng)轉(zhuǎn)換受到廣泛關(guān)注。光子晶體光纖激光器以其高光束質(zhì)量、高電光效率、可靠性高、占空小及高重頻等優(yōu)異的特性,成為目前國(guó)內(nèi)外研究熱點(diǎn)。本論文基于光通信波段、高功率飛秒光纖激光系統(tǒng),利用周期極化非線性晶體實(shí)現(xiàn)高效頻率轉(zhuǎn)換,提出了相位匹配和群速度匹配的溫度調(diào)諧方案,分析討論了諧波時(shí)域和頻域特性及轉(zhuǎn)換效率的影響因素,為實(shí)現(xiàn)結(jié)構(gòu)緊湊、性能穩(wěn)定的多波長(zhǎng)輸出系統(tǒng)提供了參考;結(jié)合渦旋光束在光通信領(lǐng)域的新應(yīng)用,研究了波長(zhǎng)轉(zhuǎn)換過(guò)程的模式分布特性。具體內(nèi)容如下:1、歸納總結(jié)了準(zhǔn)相位匹配技術(shù)及其特點(diǎn),在小信號(hào)近似下對(duì)二階非線性參量過(guò)程的耦合波方程進(jìn)行了理論推導(dǎo),分析了走離效應(yīng)和群速度失配對(duì)寬帶波長(zhǎng)轉(zhuǎn)換過(guò)程的影響。2、針對(duì)光子晶體光纖激光頻率轉(zhuǎn)換過(guò)程進(jìn)行了理論模擬和實(shí)驗(yàn)研究。分析了全光波長(zhǎng)轉(zhuǎn)換過(guò)程的溫度依賴性,以及轉(zhuǎn)換效率和輸出波長(zhǎng)的調(diào)諧特性。實(shí)驗(yàn)分別在100℃和75℃獲得了最大轉(zhuǎn)化效率為27.5%的二次諧波和4.3%的三次諧波,討論了輸出光譜的二、三和四次諧波轉(zhuǎn)換過(guò)程。3、提出了一種同時(shí)滿足相位匹配和群速度匹配的高效飛秒激光倍頻方案。在特殊的偏振配置e+e-?o下,基頻光波和倍頻光波的群速度可以在特定溫度匹配。將耦合波方程應(yīng)用于1550nm波段摻鎂周期性極化晶體波長(zhǎng)轉(zhuǎn)換過(guò)程,數(shù)值分析了基頻和倍頻光波的時(shí)域和頻域特性,獲得了最佳轉(zhuǎn)換效率的條件。4、研究了軌道角動(dòng)量光束在準(zhǔn)相位匹配晶體中波長(zhǎng)轉(zhuǎn)換過(guò)程,得到了頻率變換后光束的模式分布特性。
[Abstract]:Nonlinear wavelength conversion plays an important role in optical signal processing, optical information storage, biomedical detection, remote sensing detection, industrial processing and environmental monitoring and analysis. With the development of ultrashort pulse laser technology, the wavelength conversion of broadband laser has been paid more and more attention. Photonic crystal fiber laser (PCF) has become a research hotspot at home and abroad for its excellent characteristics such as high beam quality, high electro-optic efficiency, high reliability, small duty cycle and high repetition frequency. Based on optical communication band and high power femtosecond fiber laser system, a temperature tuning scheme based on phase matching and group velocity matching is proposed. The influence factors of harmonic time domain and frequency domain characteristics and conversion efficiency are analyzed and discussed, which provides a reference for the realization of compact and stable multi-wavelength output system, and combines the new application of vortex beam in optical communication field. The mode distribution of wavelength conversion process is studied. The specific contents are as follows: 1. The quasi-phase matching technique and its characteristics are summarized. The coupled wave equation of the second order nonlinear parametric process is derived theoretically under the small signal approximation. The influence of walk-off effect and group velocity mismatch on the broadband wavelength conversion process is analyzed. The theoretical simulation and experimental study on the laser frequency conversion process of photonic crystal fiber are carried out. The temperature dependence of all optical wavelength conversion process and the tuning characteristics of conversion efficiency and output wavelength are analyzed. The second harmonic and the third harmonic with the maximum conversion efficiency of 27.5% and 4.3% were obtained at 100 鈩，

本文編號(hào)：2014256