The Detecting Method Of Off-axis Aspheric Mirrors

With the wide application of aspheric lens, the testing of aspheric surface is also important. Testing methods of aspheric mirror which includes off-axis convex parabolic, off-axis concave parabolic, off-axis convex hyperboloid, off-axis concave hyperboloid, off-axis convex ellipsoid and off-axis concave ellipsoidal are mentioned in this paper, This paper researched on methods of different types of aspheric by aberration-free point test and compensation test, and the test project is suitable for the ZYGO interference test and 4D interference test.This paper introduced several test methods about the hyperbolic mirror, with which the diameter is 220mm and off-axis is 225mm. According to the actual situation, we chose the off-axis Hindle test which is based on the three-order aberration theory and aspheric surface characteristics. First, we calculate and derive the initial configuration of off-axis aspheric optical system, and optimize it by Zemax. Then, the designed result is given. The parameters were applied to the actual mirror processing, and build test configuration. Finally, we get the interferogram of the tested mirror with 4D dynamic interferometer. Besides, the measure error of test configuration is within the allowed error range by error anysis. Finally, The RMS of convex hyperbolic mirror is 0.0199λ, which has achieved the desired results.