本文从单色平面波无吸收损耗三频耦合波方程,小信号近似出发,计算了KDP、ADP、BBO、LiIO_3和LiNbO_3等晶体(1.064μm激光倍频、三倍频、四倍频)的光谱和角度接收半宽Δλ_A、Δθ_(FW),从而为选择宽频带激光频率转换所用的晶体及匹配类型提供了依据。给出了宽频带锁模激光倍频方程,并得出窄频带下二次谐波加强因子(2N~3+N)/3,表明边带和频作用对锁模激光脉冲具有更大的贡献。

According to the equations of three interacting plane waves (without absorptions and losses) and small-signal approximation, the calculations of spectral and angular acceptance half-widths are done with KDP, ADP, BBO, LiIO3, LiNbO3 for frequency doubling, tripling and quadrupling (λ1=1.064μm), so that we can select crystals used for frequency-conversion in a wide-band Nd: glass laser. The doubling equations for wide-band mode-locked lasers are given. The calculated enhancement factor 2N3+N/3 of SH shows that processes of side-band sum-frequency for mode-locked laser pulse are of important roles.