Calibration features of a polarimetric backscattering setup based on a beamsplitter

We address the problem of calibrating a polarimetric backscattering setup that includes a beamsplitter, taking its optical properties into account. Using Fisher information, we justify a specific calibration configuration involving reference optical elements for the maximum likelihood method and demonstrate its effectiveness through Monte Carlo simulations. This approach leads to higher precision, as the described set of measurements allows the beamsplitter to be treated as an integral part of the setup without requiring separate processing or reconfiguration of the setup for the beamsplitter calibration. Furthermore, we emphasize the significance of considering the beamsplitter's optical properties by proposing a test to estimate the error that arises from neglecting these properties during the calibration procedure.