圆形高斯镜平凹腔腔镜倾斜时光场模式分析

运用边界元素法把圆形高斯镜平凹腔的自再现模的衍射积分方程转化为有限阶矩阵方程。计算了谐振腔在理想情况和高斯反射率平面输出镜倾斜情况下基模的场强分布、相位分布和本征值。研究表明,腔镜倾斜使激光场模式分布沿发生倾斜的方向向镜边缘偏移,而且在腔镜倾斜较严重时模式分布发生畸变,不再是对称的拉盖尔-高斯基模分布。基模本征值随倾斜角增大而变小,光束远场分布变差。减小高斯分布反射率的膜斑半径,则能减弱因倾斜引起的模式畸变。

Analysis of the laser field distribution of circular plano-concave resonator with a tilted Gaussian reflectivity mirror

By means of boundary finite-element method,the field distributions and eigenvalues of the fundamental mode of the plano-concave resonator with a tilted Gaussian-reflectivity plane mirror are calculated and discussed.The results show that the laser mode moves along the direction of the mirror tilting.When the tilt angle of the mirror is big enough,the mode is distorted,no longer with a Laguerre-Gaussian distribution.Furthermore,following the increasing of the tilt angle,the far field distributions become bad,and the eigenvalue decrease.By decreasing the characteristic radius of the Gaussian-reflectivity,the distortion of the mode that is induced by the mirror tilting is decreased.