本文计算了mm2型—水甲酸锂晶体的相位匹配角和有效非线性系数随基波波长变化的规律。发现对每个基波都存在着一个或两个最佳相位匹配角(θ,φ),并作出了θ,φ随基波波长变化的拟合公式。按计算所得的角度切割的—水甲酸锂倍频元件分别得到了0.53μ、0.35μ和0.266μ的倍频光.

In this paper, the variation of the phase matching angle and the effective nonlinear coefficient versus the fundamental wavelength in a second harmonic generation of the lithium formate roonohydrate (LiCOOH ‘HaO)of the mm 2 type crystal are calculated. It is found that there is one (or two) optimum phase matching angle {θ, φ) for each fundamental wave, at which the second harmonic conversion efficiency is highest. Fitted formula for the variation of the phase matching angle versus the fundamental wavelength is obtained.Second harmonic generation for 0.53μ, 0.35 μ and 0.266 μ are observed from the crystals cuied at the computative angle.