Abstract: The white-light equal-inclination interference is implemented by inserting a glass plate before a mirror of the Michelson interferometer, and features in appearing range, contrast and color of the interference fringes are observed. Based on dispersion, a concise digital computation expression and an approximate analytical expression are established to determine the contrast of the fringes, and the fringe features are completely explained.

Key words: Michelson interferoineter, white-light equal-inclination interference, dispersion