Liquid-crystal variable retarders for aerospace polarimetry applications.

We present the optical effects of different tests that simulate the aerospace environment on the liquid-crystal variable retarders (LCVRs) used in the Imaging Magnetograph eXperiment postfocal instrument of the SUNRISE payload within the NASA Long Duration Balloon program. Analysis of the influence of vacuum, temperature, vibration, and gamma and ultraviolet radiation is performed by measuring the effects of these tests on the optical retardance, the response time, the wavefront distortion, and the transmittance, including some in situ measurements. Outgassing measurements of the different parts of the LCVRs are also shown. From the results obtained it can be concluded that these optical devices are suitable and seem to be excellent candidates for aerospace platforms.