新型光学晶体KABO的非线性频率变换特性

简述了新型非线性晶体KABO的光学特性.根据相位匹配角公式、非线性有效系数公式、走离角公式和允许角公式,详细计算了KABO晶体倍频时的相位匹配角、非线性有效系数、倍频时谐波走离角、允许角随波长变化的理论曲线.特别是对LD泵浦掺钕的全固态激光器532 nm输出时,得到了KABO晶体采用I类相位匹配进行四倍频的相位匹配角、非线性有效系数、倍频时谐波走离角、允许角分别为:58.1°、0.254×10^-12m/V、2.8°、1.8233 mrad·mm;并将该晶体与目前可应用于紫外倍频的晶体比较,在考虑走离效应的情况下,研究了四倍频转换效率随KABO晶体长度、基频光光斑半径的变化规律.

Properties of Nonlinear Frequency Conversion in a New Optical Crystal KABO

The properties of nonlinear frequency conversion in a new optical crystal KABO was discussed. The second-harmonic generation curves of phase-matching angle, effective nonlinear coefficient, walk-off angle and maximum acceptance angle were calculated in detail according to the formulations of those. Especially, for type Ⅰ phase matching of 532 nm→266 nm, the values of phase-matching angle, effective nonlinear coefficient, walk-off angle and maximum acceptance angle were 58.1°,0.254×10^-12m/V, 2.8°,1.8233mrad·mm, respectively. And KABO crystal was compared with KDP、BBO、CLBO crystals. The four parameters of fourth harmonic generation for KABO and the law for conversion ratio via a length of KABO and a laser radius of fundamental wave were also calculated in respect of walk-off effect.