Mueller matrix imaging polarimetry: An overview

The design and operation of a Mueller matrix imaging polarimeter (MMIP) are presented. The instrument is configurable to operate in transmission, reflection, retroreflection, and variable-angle scattering to make a wide variety of polarimetric measurements. The sample may be a single element such as a lens, polarizer, retarder, spatial light modulator, or beamsplitter; the tested sample may also be an entire polarization-critical optical system containing many elements. The MMIP instrument combines a dual-rotating retarder polarimeter with high-resolution imaging capacity. Well-calibrated known polarized light states are incident upon the sample and the exiting state is precisely analyzed. By measuring a series of different generated and analyzed states, the Mueller matrix can be determined. "Decomposing" the measured Mueller matrix into retardance, diattenuation, and depolarization components can give a complete description of the sample's effect on an arbitrary light state. In one system configuration, the MMIP measures the polarization of a set of ray paths through a sample. Another configuration measures the sample's point spread matrix, a Mueller matrix relating the polarization state of a point object to the distribution of intensity and polarization across the image. The MMIP instrument and measurement capabilities are described along with an assortment of previous results.