Optimization and calibration of a polarization-camera-based Mueller imaging polarimeter for biological samples examination

We present the optimization and calibration of a Mueller matrix imaging polarimeter. The polarimeter is intended to be used as a compact tool for biomedical diagnosis, in particular for skin examination. The device uses a pixelated-polarization camera along with a fixed variable retarder for the polarization state analyzer, minimizing the number of elements used in the device for Full-Mueller matrix measurements. For the polarization state generator the device uses an LED as light source, and a polarizer followed by a pair of LCVRs to generate any polarization state over the Poincare sphere. With this system the polarization properties of a sample can be obtained with a total of 8 measurements to extract the 16 elements of the Mueller matrix. We study the optimization strategies by minimizing the condition number of the instrument matrix, to maximize the signal to noise ratio, and reducing the effect of experimental errors on the optimization. As a compact and transportable tool, the polarimeter will be used in different environments, so an auto-calibration method is also required. In this work we explore the necessary conditions to successfully use the Eigenvalue calibration method in a polarized-camera and liquid crystals based polarimeter. The study presented will help to measure the Mueller matrix of a sample with high accuracy and precision levels, needed for the study of biological samples.