离轴正支共焦非稳腔横模“模式交叉”特性研究  

Research on the“Mode Crossing”Characteristic of the Transverse Mode in Off-axial Positive Branch Confocal Unstable Resonators

作　　者：李根 黄楚云 唐霞辉[2] 

机构地区：[1]北工业大学理学院,湖北武汉430070 [2]华中科技大学光学与电子信息学院,湖北武汉430074

出　　处：《应用激光》2015年第5期593-596,共4页Applied Laser

摘　　要：针对离轴正支共焦非稳腔中最低的三阶横模特征值随着腔参数的变化规律问题,基于适用于非稳腔结构的特征向量法,计算了有效菲涅耳数在63附近的不同腔参数下各阶横模的特征值。数值模拟结果表明,在几何放大率大于1.08的条件下,若有效菲涅尔数取在整数附近,1、2阶横模会周期性的发生模式交叉,所有基于Fox-Li迭代的算法很难得到自在现模。随着M的增加而增加,特征值的模值大小会随着几何放大率的增加而近似线性的减小,各阶模式的衍射损耗会线性增加,在非模式交叉的情况下,1、2阶横模特征值模值的差值会增加。On the question of the relationship between the eigenvalues of the three lowest-loss mode and the parameters of the off-axial positive branch confocal unstable resonator, based on the eigen vector theory, the eigen values are calculated when the effective Fresnel number is about 63. The numerical results show that when the magnification is larger than 1.08, ＂mode cross- ing＂ happens periodically where the effective Fresnel number is close to an integer, which means that the self-produced mode can be generated by Fox-Li iteration very hardly. When the magnification increases, the modulus of the eigen value declines linearly, the difference between the modulus of the eigen value of the 1st and 2nd order mode increases linearly when ＂mode crossing＂ doesn＇t happen, the diffraction losses of all order modes will increase linearly.

关 键 词：横模 离轴正支共焦非稳腔 特征向量法 板条激光器 

分 类 号：O433.4[机械工程—光学工程] TN249[理学—光学]