The testing and analysis of accuracy of a large space optical window

For the purpose of testing optical path difference of a large optical window, a method of testing a large optical window with a concave spherical mirror is introduced. First, the principle of testing the optical window with a concave spherical mirror was provided; second, the geometrical and wavefront expressions were derived in detail to evaluate the accuracy of testing the large optical window with a concave spherical mirror;third, The accuracy of the method was simulated and analyzed with the derived expressions, the factors of influencing accuracy were gave at the same time. It was shown that the method has a high accuracy when the used concave spherical mirror had a proper relative aperture.