Aspheric surface test by digital moire method

Abstract

Research is conducted on digital moire method based on partial compensation lens and its application on aspheric surface test Compared with the null compensator method, the partial compensator method for aspheric surface test proposed by the authors has the characteristics of large compensation range, general usage field, and easier to manufacture of the partial compensator lens, it has also lower efficiency and is non intuitionistic used in ordinary interferometer directly. By the use of digital moire method, the interference fringe between virtual standard reference aspheric surface constructed by digital technology can be obtained and real surface can be tested, and then the interference fringe can be analyzed by moire method. In consideration of real-time intuitional display of the aspheric surface error interference fringe is convenient for setting and adjusting the optical system, we also made a real-time moire fringe processing equipment, which composes and filters moire fringe between real interference fringe captured by a 2k×2k CMOS camera and the virtual standard reference fringe by hardware circuit. The moire fringe is showed on a SXGA display, whose frame frequency is up to 10f/s.