本文在考虑了振幅的横向分布和基波的衰减时,给出了一些关于倍频的有价值的结果。借助于求解三维耦合波方程,导出了二次谐波功率的最一般的表达式,讨论了基波功率和晶体长度的影响。作为一个特例,也给出了低转换效率下二次谐波功率的表达式。讨论了类高斯光束倍频的平面波近似处理方法,这里借助于类高斯光束的光线方程。作为小结,我们列出了八种不同情况下二次谐波功率的表达式,其中后五种来自本文的推导。 最后,阐明了一种处理内腔倍频激光器的新方法。在我们的模型中,对于在腔内循环的基波功率而言,由于倍频的功率损耗,可视为一种可变的损耗。借助于速率方程的数值解,我们求得了激光腔参数和倍频晶体的最佳值。

This paper presents some valuable results of frequency doubling, considering the transversal variation of the amplitude and the depletion of the fundamental wave power. By solving three dimension-coupling wave equation, the most common expressions of second harmonic wave power are driven. The influences of the fundamental wave power and the crystal length are discussed. As a special example the expressions of second harmonic wave power at low conversion efficiency are given. As a summary, eight expressions of the second harmonic wave power at different cases are listed, in which five cases come from this paper. Finally, a new way of dealing with the intracavity frequency doubled laser is given. In our model the power loss due to SHG is considered as a viriable loss for the fundamental waye power which is circulating in the cavity. By solving the rate equations numerically, the optimum parameters of the cavity and of the frequency doubling crystal are found.