Optical testing of large rough aspheric surface using far-infrared interferometer

摘要

An far-infrared interferometer which can test rough surface is presented. It is based on the optical configuration of classical Fizeau interferometer. In addition, the design and system performance of an infrared system is presented. Using the infrared system, the far-infrared interferometer is capable of testing rough aspheric surfaces. The measuringerror(RMS) is less than λ/200 ( λ=10.6μm ) , this accuracy is able to fulfill the need of grinding primary mirror.