中红外连续运转光学参量振荡器

发布时间：2018-01-12 12:39

本文关键词：中红外连续运转光学参量振荡器　出处：《北京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：3-5μm波段中红外连续相干光源在遥感、医疗、光谱分析、无线光通信及军事领域有着重要的应用价值和发展前景。全固态的光学参量振荡器具有结构紧凑、稳定性高、效率高、阈值低、调谐范围宽等优点，成为产生中红外激光输出最有效的手段之一。本文研究了以1064nm光纤放大器为泵浦源、以掺杂MgO的周期极化铌酸锂晶体(PPMgLN)为非线性介质的中红外连续运转(CW)光学参量振荡器(OPO)。通过对系统的优化设计，采用信号光单谐振（SRO）方式实现了低阈值、大功率的中红外激光输出。本文综述了国内外中红外OPO的研究现状及发展趋势，着重对中红外连续运转OPO的非线性晶体特性、谐振方式及获得单频输出的方法进行了分析和比较。针对信号光单谐振光学参量振荡器进行了理论研究，建立了准相位匹配(QPM)的波长调谐计算模型及基于三波耦合方程组的振荡阈值及转换效率理论模型，计算了单程光参量增益、振荡条件和振荡阈值、输出功率和转换效率；理论分析了相位失配产生的主要原因及其对OPO输出特性的影响。基于理论计算结果及光学谐振腔的稳定条件，完成了两镜直线腔OPO的设计；考虑了像散的影响，完成了bow-tie结构的四镜环形腔OPO设计。搭建了两镜直线腔OPO和bow-tie环形腔OPO实验系统，并对其输出特性进行了测试与分析。直线型OPO的阈值仅为1.35W，当泵源功率为18W时获得的闲频光输出功率为3.2W，波长为3.2μm，谱线宽度约为15nm。通过改变晶体的工作温度和极化周期，输出闲频光的波长调谐范围为2.9-3.8μm。环型腔OPO的工作阈值约为3W，当工作于3.4μm时可获得2.6W的闲频光输出。与直线腔相比，环形腔的输出光谱较窄，仅为1.6nm。通过对腔内振荡信号光进行选频，可获得单频中红外激光输出。
[Abstract]:3-5 渭 m infrared continuous coherent light source in remote sensing, medical, spectral analysis. The all-solid-state optical parametric oscillator has the advantages of compact structure, high stability, high efficiency, low threshold and wide tuning range. It has become one of the most effective means to produce mid-infrared laser output. In this paper, 1064nm fiber amplifier is used as pump source. The optical parametric oscillator with MgO doped periodically poled lithium niobate crystal (PPMgLN) as a nonlinear medium has been optimized. The low threshold and high power output of mid-infrared laser is realized by using signal-light single resonance resonator (SRO). In this paper, the research status and development trend of mid-infrared OPO at home and abroad are reviewed, with emphasis on the nonlinear crystal characteristics of OPO with medium-infrared continuous operation. The resonant mode and the method of obtaining single frequency output are analyzed and compared. The signal optical single resonance optical parametric oscillator is studied theoretically. The wavelength tuning calculation model of quasi phase matched QPMs and the theoretical model of oscillation threshold and conversion efficiency based on three wave coupling equations are established. The single pass optical parameter gain, oscillation condition and oscillation threshold are calculated. Output power and conversion efficiency; The main causes of phase mismatch and its influence on the output characteristics of OPO are analyzed theoretically. Based on the theoretical calculation results and the stability conditions of the optical resonator, the design of the two-mirror linear cavity OPO is completed, and the OPO design of the four-mirror ring cavity with bow-tie structure is completed considering the influence of astigmatism. The experimental system of two-mirror linear cavity OPO and bow-tie ring cavity OPO is built, and its output characteristics are tested and analyzed. The threshold of linear OPO is only 1.35W. When the pump power is 18 W, the output power of idler frequency light is 3.2 W, the wavelength is 3.2 渭 m, and the spectral line width is about 15 nm. The wavelength tuning range of the output idler light is 2.9-3.8 渭 m. The operating threshold of the ring cavity OPO is about 3W, and the output of the idling frequency light is 2.6 W when working at 3.4 渭 m, which is compared with the linear cavity. The output spectrum of the ring cavity is only 1.6 nm. By selecting the frequency of the intracavity oscillatory signal, the output of the single frequency mid-infrared laser can be obtained.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN753.91

【参考文献】