大菲涅尔数非稳腔有源分析  

Analysis of Large Fresnel Number Unstable Resonator with Loaded Resonator Model

作　　者：王炜 万文 何琼[1] 肖彬[1] 杨晟[1] Wang Wei;Wan Wen;He Qiong;Xiao Bin;Yang Sheng(Wuhan Vocational College of Software and Engineering(Wuhan Open University),Wuhan 430205,Hubei,China)

机构地区：[1]武汉软件工程职业学院(武汉开放大学),湖北武汉430205

出　　处：《应用激光》2024年第10期179-187,共9页Applied Laser

基　　金：武汉市科学技术局2023年度知识创新专项曙光计划项目(项目编号:2023010201020486);武汉软件工程职业学院博士团队科技创新平台(自然科学与应用技术类,项目编号:BSPT2023002)。

摘　　要：在非稳腔的分析中,一般多采用无源腔模型,但当激光器增益介质体积较大,饱和效应以及增益的非均匀性会对激光器的模式分布、输出功率、传播特性产生不可忽略的影响,相比无源腔,有源腔还可以获得激光器的输出功率。为此,建立大菲涅尔数非稳腔有源分析的模型,对2 kW射频板条CO_(2)激光器进行了分析,并将分析结果同无源腔进行比较。两者输出平面上的光强分布、远场的光束半径及旁瓣中的能量存在差别,这些参数对于外光路整形系统具有重要意义。同时分析有源腔的失调特性,相比输出镜,尾镜失调对输出功率的影响更大,当尾镜失调角度为+8 mrad时,输出功率仅为未失调时的31%。因此对大菲涅尔数非稳腔进行有源分析对于激光器的设计和调试十分必要。The“bare resonator”model is conventionally employed in the analysis of unstable resonators.However,for lasers with large active volumes,the saturation effect and non-uniformity of the gain medium significantly impact laser mode structures,output power,and beam propagation characteristics.In contrast to the"bare resonator,"the"loaded resonator"model can provide output power predictions.In this paper,the“loaded resonator”model of unstable resonator with large Fresnel number was established,the characteristics of 2kW RF-excited slab CO_(2)laser have been studied and been compared with the“bare resonator”model.There is a clear difference in the intensity distribution on the output plane,far field beam half-width and the energy contained in the side lobes of the two resonators.These parameters are significant for output beam shaping system.Furthermore,the misalignment characteristics of“loaded resonator”have been analyzed,the rear mirror misalignment on output power are more serious than the output mirror.The output power is 31%of the aligned resonator when the rear mirror tilt angle is+8mrad.Consequently,the"loaded resonator"model is essential for analyzing large Fresnel number unstable resonators in laser design and commissioning.

关 键 词：非稳腔 有源腔 失调特性 光束质量 

分 类 号：TN243[电子电信—物理电子学]