Research On Dark Field Scattering Microscopic Detection System For Surface Defects Of Laser Gyro Reflector Substrate

RLG mirror is an super-smooth optical device, of which the surface defects on the substrate contribute directly to the lock-in threshold, which has a great influence on the linearity and stability of the output of RLG. Accordingly, the test of surface defects of the RLG mirror substrate is considered as one of the key parts of the high-precision RLG manufacture.In this paper, the tolerance of surface defects is calculated by simulating the relationship between surface roughness and the scattering of RLG mirror substrate, and the improved dark field light scattering microscopic imaging method is proposed, based on which the test of surface defects of the RLG mirror substrate is built. The stray lights of different light sources are simulated, and the light structure of dark field scattering microscopic is improved, using a semiconductor lase to reduce the influence of stray light. A flat field infinity imaging system is designed to get a resolution better than 3?m. By using the methods of sub-aperture image stitching and fusion, and selecting the optimal image scanning path and image processing scheme, we obtain the automatic testing system, with which the surface defects of lateral dimensions greater than 3 ?m in the ?4mm testing area can be identified, and the work area that meets the surface defect requirement is given as the testing report result.