本文介绍计算双轴晶体二阶有效非线性系数的严格理论，适用于双轴晶体非线性光学频率变换器件的设计。
We present an accurate route, which is suitable for the design of nonlinear optical frequency translator of biaxial crystals, to calculate the effective second-order nonlinear coefficients.
本文以偏硼酸钡晶体为例，分析了三个光波的二阶非线性相互作用，并推导单轴晶体的有效非线性系数的表达式。
The second order nonlinear optical effects on the three-wave is analyzed, and the nonlinear optical coefficient of the uniaxial crystal is deduced from an example of the BBO.
对BBO晶体的材料特性，有效非线性系数，以及BBO晶体的走离角与空间走离效应，群速度失配与时间走离效应进行了讨论。
The properties of nonlinear crystal BBO is presented. The walk-off Angle and the spatial walk-off effect, the group velocity mismatch and the temporal walk-off effect are discussed.
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