Simulation research on ring source of Fizeau interferometer

In order to solve the problem of coherent noise in the measurement of laser interferometer with point source, the method of suppressing coherent noise with ring source is described. The radiation intensity of the central noise point in the interference field under the illumination mode of the ring source is analyzed. In this paper, an optical system based on annular lens is used to generate ring source, and a Fizeau interferometer based on ring source illumination is built in ZEMAX Non-sequence mode. The simulation results show that the radiation intensity of the interference field noise point under the ring source illumination mode reaches 9.8357w/cm2, and the visibility of fringe is low. After adding the bulk scattering element with an average optical path of 0.2 and a scattering angle of 3°, the interference field radiation intensity becomes more uniform, and the fringe visibility was obviously improved.