为了实现193 nm准分子激光器激光整形及均匀化,制作一种微透镜阵列光学元件。本文采用L_93~3多因子正交方法进行实验,获得3因子3水平下压缩模塑成型的微透镜阵列。通过Taylor Hobson轮廓仪测量微透镜阵列形状误差,并采用极差分析方法分析模具温度、保压压力、冷却时间3种工艺参数对形状误差的影响程度,确定微透镜阵列光学元件的最优工艺参数组合。结果表明:当模具温度为230℃,保压压力为120 MPa,冷却时间为30 s时,微透镜的形状误差最好,值为0.5276μm,满足193 nm准分子激光器激光整形及均匀化对微透镜阵列形状误差小、精度高等要求。
The micro-lens arrays,for laser beam shaping and beam homogenizing with 193 nm excimer laser beam,was fabricated by injection molding on substrate of polymethyl methacrylate(PMMA).The impact of the molding conditions,including the molding temperature,packing pressure and cooling time,on the form error of the micro-lens array was investigated with Taylor Hobson profilometer and by multi-factor orthogonal method(L933),three factors and three levels,to optimize the injection molding conditions.The smallest form-error,0.5276 μm,of the array was achieved under the optimized conditions:molded at 230℃,packed at 120 MPa,and cooled for 30 s.The measured results show that the micro-lens arrays fabricated under the optimized conditions satisfied the stringent requirements of the laser beam shaping and beam homogenizing with 193 nm excimer laser.