Two-dimensional full-Stokes characterization of parallel-aligned liquid crystal on silicon spatial light modulators

Parallel-aligned liquid crystal on silicon (PA-LCoS) spatial light modulators (SLMs) are critical components in advanced optical systems due to their high resolution and dynamic phase control. It is well known that these devices present different limitations such as inter-pixel crosstalk, phase flicker, and spatial inhomogeneities that prevent optimal device performance. This article presents a comprehensive Stokes polarimetry-based two-dimensional (2D) characterization of a PA-LCoS SLM, detailing its operational principles, experimental setup, and a systematic analysis of key performance metrics as retardance, phase flicker, and LC-director orientation variations across the display as a function of voltage (gray level). The availability of voltage-dependent 2D maps of these three parameters is one of the main results of this paper. These findings offer valuable insights into calibration and alignment protocols, highlighting potential impacts on applications that require high polarization fidelity and accurate 2D performance.