角锥棱镜谐振腔激光模式模拟研究

为了探究角锥棱镜谐振腔激光模式,以角锥-平面镜腔为例,将角锥棱镜等效为衍射光栅,考虑角锥镜棱宽在谐振腔中的衍射效应以及二面角误差引起的附加相位分布对谐振腔激光模式的影响,在光学谐振腔理论的基础上,建立了求解本征模式的理论分析模型.采用快速傅里叶法数值模拟不同腔长、角锥镜棱宽和二面角误差情况下该无源谐振腔激光输出模式分布情况.结果表明,在腔长30 cm、角锥镜棱宽小于75μm、二面角误差在-10′~5′之间时,可实现光斑完整的圆形分布输出模式,且有较好的光束质量;棱宽不小于0.4 mm,二面角误差在-40′~10′之间时,光斑为TEM 03阶横模,光场呈六瓣分布;当角锥镜棱宽为0.4 mm、二面角误差为3′,腔长从30~90 cm范围内增加时,该谐振腔输出的激光模式从TEM 03转换成TEM 10.

Laser-mode Simulation of Corner Cube Resonator

In order to explore the mode of corner cube resonator,taking the cone plane mirror cavity as an example,the corner cube prism is equivalent to a diffraction grating.Considering the influence of the diffraction effect of the corner pyramid width in the resonator and the additional phase distribution caused by the dihedral angle error on the laser mode of the resonator,a theoretical analysis model for solving the intrinsic mode is established based on the theory of the optical resonant cavity.The fast Fourier transform method is adopted to simulate the distribution of the laser oscillation modes of the passive corner cube cavity in different cavity length,apex widths and dihedral angle error.When the cavity length is 30 cm,the width of the corner cube is less than 75μm,and the angle error of the two sides is between-10′and 5′,the complete circular distribution output mode of the light spot can be realized,and the beam quality is good.When the width of the edge is not less than 0.4 mm and the dihedral angle error is between-40′and 10′,the spot is a transverse mode of TEM 03 and the light field is a six-lobe distribution.When the width of the corner cone mirror is 0.4 mm,the error of the dihedral angle is 3′and the cavity length increases in the range of 30~90 cm,the laser mode of the resonator is converted from TEM 03 to TEM 10.