晶体物理主轴坐标系对三阶有效非线性系数的影响

由于晶体的折射率主轴与其晶体物理主轴有着不同的配对方式，其三阶有效非线性系数计算公式将发生变化．考虑到配对方式的影响，首次得到变换后的三阶非线性系数的矩阵形式，然后推导出了任意配对方式下，晶体主平面上三阶有效非线性系数的最一般解析表达式．

Effect of Crystallographic-Physical-Axes Coordinate System on Expression of the Third-Order Effective Nonlinear Coefficient

Different relationships between principal-axes and crystallographic-physical-axes result in different expressions of the effective nonlinear optical coefficient. Taking this effect into consideration, we have presented here the corresponding matrix forms of the third-order nonlinear susceptibility for the first time, and derived the expressions of the third-order effective nonlinear coefficient on the principal planes for the most general case: triclinic crystal classes.