Imaging Polarimeter Software Model

The Polarization Laboratory in the UA College of Optical Sciences recently received an RGB950 AxoStep polarimeter. The instrument consists of extremely bright light-emitting diodes, a polarizer, two rotating retarders, a second polarizer, and a camera. It operates at four wavelengths and has a particularly large field of view, so there is some angular variation in the performance, which this project seeks to understand. The RGB950 polarimeter was used to obtain Mueller matrices based on air measurements at various angles in order to characterize the instrument’s angular dependence. Additionally, software models for different optical elements tested by the polarimeter were developed and the Mueller matrix results were compared to Mueller matrix data. This includes models for a nonpolarizing cube beam splitter and a solid corner cube. Each model was built using Polaris-M, a library of polarization ray tracing functions developed by Airy Optics for use in Mathematica. The resulting software characterizing the polarimeter gives the lab a tool for predicting polarimetric measurements and verifying instrument performance.