Quadratic Nonlipear Optical Properties Studied by Reflected Second-Harmonic Ellipsometry

已经确定了几种重要材料的二次非线性光学系数。研究的材料包括β-BaB_2O_4、CsLiB_6O_<10>、ZnSe和LiNbO_3。采用单模激光作为光源，采用非相位匹配二次谐波产生法进行测量。首次测定了用于紫外相干光源的重要材料β-BaB_2O_4和CsLiB_6O_<10>在可见光到紫外次谐波波段的非线性光学系数。ZnSe是一种很有前途的波长转换材料，其非线性光学系数分别为1.3和1.5 μ/m。化学计量LiNbO_3的非线性光学系数明显大于同等LiNbO_3的非线性光学系数。

The quadratic nonlinear optical coefficients of several important materials have been absolutely determined. The materials studied include β-BaB_2O_4, CsLiB_6O_<10>, ZnSe and LiNbO_3 . The measurement was made by the non-phase-matched second-harmonic-generation method using single-mode lasers as light sources. The nonlinear optical coefficients of β-BaB_2O_4 and CsLiB_6O_<10>, both important materials for ultraviolet coherent light sources, have been determined for visible to UV second-harmonic wavelengths for the first time. The nonlinear optical coefficients of ZnSe, which is a promising material for wavelength conversion over visible to IR wavelengths, have been determined at 1.3 and 1.5 μ/m . The nonlinear optical coefficients of stoichiometric LiNbO_3 have been found to be significantly larger than those of congruent LiNbO_3.