非寻常光在单轴晶体薄膜中的反射－透射研究

摘要

By analysing the spreading of extraordinary ray in uniaxial crystal when the optical axis is parallel to the incident plane,the extraordinary ray reflection and transmission properties in uniaxial crystal film were studied.Based on the refractive index surface of uniaxial crystal and the relationship between extraordinary ray and wave normal and according to the phase matching condition of incident light,reflected light and refracted light,the boundary conditions at the surfaces of uniaxial crystal were obtained when optical axial is parallel with the incident plane. Then,the reflectance and transmittance of crystal thin film were calculated based on the phase relationship and the boundary conditions at the surfaces of two crystal thin films.The transmittance and the relationship between the change of refractive index with optical axis angle of quartz (positive crystal)thin film and lithium niobate(negative crystal)thin film were calculated by using the method proposed.The results show that the method is correct and suitable for both positive crystal and negative crystal.The formulation given in the paper is general and representative.%通过对非寻常光在光轴平行于入射面的单轴晶体中传播情况的分析，研究了光轴平行于入射面时，非寻常光在单轴晶体薄膜中的反射与透射特性。根据入射光、反射光和折射光之间的相位匹配条件，利用单轴晶体的折射率面和非寻常光光线与光波法线的关系，得到单轴晶体光轴平行于入射面时其表面的边界条件。然后根据晶体内部前后表面处电场量的相位关系，联系两表面处的边界条件，计算了单轴晶体薄膜的反射率与透射率。应用得出的计算方法，计算了石英（正晶体）薄膜和铌酸锂（负晶体）薄膜的透射率和折射率随光轴角度的变化关系。结果表明，计算方法正确，不仅适合正晶体对负晶体也适用，求解方法简单实用，所给的表达式具有一般性，可以直接使用。