关键词: 单轴晶体 , 边界条件 , 透射率 , 反射率

Abstract: In order to analyze the energy loss of a beam at crystal surfaces, a method was proposed to calculate the corresponding reflectivity and transmissivity. According to the electromagnetic boundary conditions and the phase matching conditions, reflection and refraction of a beam incident from a crystal upon an isotropic medium were studied, and the Fresnel formulas at the interface between the crystal and the isotropic medium were deduced. As the orientation of optical axis is arbitrary, the polarization states and the amplitudes of the o ray and e ray and the refracted ray were given, and the theoretical expressions of the reflectivity and the transmissivity representing energy relations between the rays were obtained, which provide a theoretical basis for developing and applying crystal devices. Numerical simulations show that the results are accordant with conservation of energy; electrical field or magnetic field of the ray refracted to the isotropic medium does not parallel to the electric field or the magnetic field of original incident ray; the direction of optical axis and the magnitude of incident angle have a great effect on the energy and the polarization direction of the refracted ray.

Key words: Uniaxial crysta ,  Boundary condition ,  Transmissivity ,  Reflectivity