Technology of sub-aperture stitching testing optical flat mirror

As the fundamental factor of high precision optical producing, the testing accuracy of interferometry is the key of producing accuracy. In order to solve the problem of large optical flat mirror testing, a kind of stitching factor was provided for overlapped area values, based on the stitching algorithm. At the meantime, the stitching measurement was completed for a Φ120 mm flat mirror with a Φ100mm interferometer. Comparing the stitching result with the full aperture testing result with a Φ150mm interferometer, it turns out that the stitching result is smooth and the relative deviation of PV and RMS between the stitching result and the full aperture testing result is 7.25% and 7.14% respectively. The testing result is consistent, verifying the reliability and accuracy of the stitching testing.