A novel aspheric surface testing method using part-compensating lens

In contrast to null compensator method in aspheric surface testing, a novel method is presented that uses part-compensating lens and digital moire phase-shift interferometry. Researches are made on measurement principle, design method of part-compensating lens and calibrating lens, and calibrating method. Experiment is made by using spherical surface to simulate aspheric surface testing. The measurement precision is that the P-V value of the testing error can be lambda/10. Using the method presented in this paper, the structure of compensator is much simpler than that of C, null compensator. And one part-compensating lens can be used to test different aspheric surfaces in certain range.