Investigation on Influence of Reflectivity of the Film on Interference Fringes and its Optimization with Theoretical Analysis

In view of the problem that the low visibility of interference fringes of interferometer affects the accuracy of measurement, the intensity distribution of the interference of thin film is investigated with theoretical calculation. The influences of the reflectivity of the film on the intensity distribution and the visibility of the fringes are discussed and the relation between the reflectivity and the visibility is deduced. The results show that the optimal numerical range of the reflectivity with high clarity of the fringe is in the vicinity of 0.5.