关于分振幅等倾双光束干涉条纹反衬度的讨论

为讨论单色平面光经过透明平行平板后出现的两束主要反射光之间干涉条纹的反衬度,在给出了它们的光矢量方位角的定义之后,利用方位角之差表示出两束光波光矢量之间的夹角;再利用菲涅耳公式表示出两束光波的光强比,从平面波干涉的角度来求两束光之间干涉条纹的反衬度,最终得出了复杂而普遍的表达式。并针对海定格干涉的反衬度进行了讨论,认为小角度入射形成的海定格干涉条纹,其反衬度只决定于平行平板的折射率;利用光学材料制作的平行平板,其海定格干涉条纹具有很高的反衬度。

Study on the contrast in the amplitude splitting double beam equal inclination interference

To discuss the contrast of interference between the two main reflected beams from a light which is incident into an optical plane-parallel transparent slab (OPPTS), the azimuth angle of their light vectors are defined, and the included angle between the two light vectors is denoted using the difference between the two azimuth angles; and also the ratio of intensity of the two lights is expressed utilizing the Fresnel formula. In this way, the complicated and universal expression of the contrast is obtained from the point of plane wave interference. And the contrast of Haidinger's interference is discussed. The conclusion is that the contrast is determined only by the refractive index of an OPPTS, and that the Haidinger's interference has high contrast if the slab is made of optical materials.