Radius measurement of large aperture long-focal-length lens using computer-generated hologram

We present a method of using computer-generated hologram (CGH) to measure the radius of curvature of large aperture long-focal-length lens. In this method, a large aperture transmission CGH is used as a transmission sphere to generate the test and reference wavefronts by means of diffraction. To verify the feasiblity of this method, a 450 mm × 450 mm transmission CGH is designed and fabricated for measuring the radius of 440 mm × 440 mm spatial filter lens. Experimental results and error analysis show that the CGH test method features high accuracy and good repeatability.