基于正交频率变换的高功率蓝绿全固态激光器

对多横模全固态激光器使用正交频率变换进行了分析,计算了频率转换效率与激光发散角的关系。使用双KTP晶体正交倍频的方法,对Nd∶YAG激光器输出的含有高阶横模的激光进行倍频实验研究。在1064 nm Nd∶YAG激光基波功率密度为121 MW/cm2时,其谐波转换效率达到75.5%。研究表明,对于光束质量较差的基波激光,采用正交频率变换的方式,适当选择晶体参数,同样可以获得较高效率的二次谐波输出。

The effect of multi transversal mode on quadrature frequency conversion in a solid-state laser was analyzed, and the relation between the conversion efficiency and the divergent angle was conducted. A quadrature frequency conversion scheme using two KTP crystals was implemented in an all-solid-state Nd∶YAG laser with high-order transverse mode. An energy-conversion efficiency of 75.5% is obtained when the fundamental laser intensity is 121 MW/cm2. This experiment indicates that when the parameters of nonlinear crystals are properly optimized, high-efficiency frequency doubling can be achieved using quadrature frequency-conversion scheme even in a multimode solid-state laser.