Optical Deisgn of polarimeter for Space Solar Telescope

摘要

A one-meter space solar Telescope (SST) is being developed in eijing Astronomical Observatory. This paper introduces its polarimeter that can get a polarimetric accuracy of 10~(-4). By the opticla design of this polarimeter we succeed in reducing the crosstalk between incident circular and linear polarization light when the polarimeter is installed in front of a birefringent filter. In this article, we select Mueller Matrix to describe the polarization characteristics of optical elements, and compare three kinds of design of polarimeter. From the error analysis we determine the orientation and retardation tolerance of the optical elements in order to control the instrumental polarization less than 10~(-4). As a result of this analysis, we demonstrate the polarimeter that utilizes a rotatable polarizer and a half waveplate, which has a rotary angle of half quantity of polarizer's, is the best design for minimizing the circular crosstalk and thus is the choice for the SST Polarimeter.