Modeling and characterizing transmission windows for in-situ interferometric measurements of cryogenically cooled mirrors

Abstract

In this paper we report on the modeling and characterization of transmission windows for in-situ interferometric measurements of cryogenically cooled mirrors. Specifically, we present a model of the temperature distribution and strain in the transmission window, and the corresponding spatial dependence of the window’s index of refraction. We also present experimental results which characterize the effect of the windows on interferometric measurement.