Design of interferometer system with common optical path structure

As a precision instrument of wavelength magnitude, interferometer plays an important role in the production of optical lenses, and it is an important instrument for optical profile detection. Based on the polarization Twyman-Green interferometer, the experimental device of surface detection is built. By analyzing the problems in the experimental process, the following improvements are made on the original basis: firstly, when using the dual optical path system to collect fringes, it is found that the interference of air has a great impact on the image quality, so we refer to the principle of Fizeau interference, In order to improve the anti-interference ability of the whole system, the double optical path structure of the Twyman-Green interferometer is combined into a common optical path structure. Secondly, because the detection aperture and surface type will be greatly limited by the standard mirror, so based on the previous research of the research group, this design designs a large F number and long focal length standard mirror for the detection of different lenses, especially the convex mirror. Finally, in order to improve the contrast of interference fringes, a plane mirror film with suitable transmittance and reflectance ratio is designed by using optical coating software to improve the contrast of interference fringes.