According to thin film polarization effect and eigenmatrix,the Fresnel retarder s achromatic width is expanded by evaporating dielectric membrane in two total-reflection surfaces of the rhomb.

• 根据薄膜的偏振效应,从薄膜的特征矩阵出发,通过在菱体的两个全反射面蒸镀光学介质膜的方法拓宽了菲涅耳菱体型相位延迟的消色差宽度。