Results and Conclusion\ The number of beams is increasing in geometric series when the light propagates in the two layer system, and it is necessary for study of the interference pattern of the system and for further .

Young’s two slits interference of discrete double light source is numerically simulated,and the curve of visibility, curve of light distribution and interference pattern are solved with different type of line and line width.

Young experiment of discrete double-lined spectrum is simulated by the way of Matlab in order to study how the type or width affects interference pattern.

Discussion on the influence of additional optical path difference to interference fringe figure when using Michelson interferometer;

According to the condition of coherent light,after assaying the inconsistency of the dark stripe equation in Tomas Young s tow-slit experiment,and the inconsistency with the actual interference diagram,I expounded some opinion for amelioration.