2kW射频板条CO_2激光器输出光束整形特性研究  

Shaping Characteristics of Output Beam of 2kW Radio Frequency Slab CO_2 Laser

作　　者：肖龙胜[1] 唐霞辉(指导)[1] 秦应雄[1] 周泳全[2] 杨卫红[1] 韩蒙蒙[1] 

机构地区：[1]华中科技大学光学与电子信息学院,激光加工国家工程研究中心,湖北武汉430074 [2]深圳信息职业技术学院,广东深圳518000

出　　处：《中国激光》2014年第4期38-44,共7页Chinese Journal of Lasers

基　　金：高等学校博士学科点专项科学研基金(20110142110046);中央高校科研业务(HUST2013TS048);武汉市晨光计划(2013070104010006)

摘　　要：针对2kW射频板条CO2激光器离轴负支非稳波导混合腔的近场分布存在较多高空间频率分量,导致聚焦后会产生不可忽略的旁瓣,无法直接应用于激光加工的问题,对谐振腔的近场分布使用特征向量法和矩形波导的解析表达式进行了数值模拟和实验研究。并结合Collins公式研究了输出光束整形过程中光场分布的变化和整形系统中空间滤波器的优化设计。理论和实验结果表明:激光器输出光束在整形前为有较多高空间频率振荡的长条形的简单象散光束。通过带空间滤波器的整形系统消除旁瓣,并将初始的长条形的简单象散光束整形成近圆形、近基模高斯分布的光束。整形后的光束非稳方向的光束质量因子M2为1.1,波导方向M2为1.08。For side lobes caused by the high spatial frequency oscillations in the output beam of offaxis negative branch unstablewaveguide hybrid resonator of 2 kW radio frequency slab COz laser, the nearfield distributions of the hybrid resonator are investigated by numerical simulation and experimental method. The eigenvector method and the analytical expression of the rectangular waveguide resonator are used for the numerical simulation. The variations of intensity profiles of the output beam in the beam shaping system and the spatial filter design of beam shaping system are also studied with Collins integral expression. The results show that the laser emits a simple astigmatic beam with a rectangular intensity distribution. The unshaped beam has severe high spatial frequency oscillations in the unstable direction. The side lobes of the unshaped beam are eliminated and the unshaped beam is changed into an approximately circular, nearly Gaussianshaped beam beam by a beam shaping system with a spatial filter. The shaped beam tion factor is 1.10 in the unstable direction and M2 is 1.08 in the waveuide direction.

关 键 词：激光光学 射频板条CO2激光器 离轴负支非稳腔 简单象散光束 光束整形 空间滤波器 

分 类 号：O436[机械工程—光学工程]