Challenges and impact of the grating vector direction in high-frequency LC-SLM binary phase gratings

Spatial Light Modulators (SLMs) typically use PA-LCoS microdisplays, known for high resolution and small pixel size, for phase-only modulation. However, different phenomena related to the cross-talk, fringing fields between pixels, and out-of-plane reorientation of the liquid crystal director degrade the performance of pixelated SLM devices. The technology faces the challenge of overcoming these phenomena as novel applications require higher pixel size resolutions and smaller pixel sizes. This work applies a numerical workflow that permits the analysis of the different parameters that set up a PA-LCoS microdisplay, e.g., fill factor, pixel size, external voltage and the influence of the LC director and the interaction of light through the structure. Specifically, we focus our analysis on the impact of high-frequency binary phase gratings on the radiometric and polarimetric response with orthogonal grating vectors. The heterogenous LC distribution as a function of the grey level along the 3D structure and the inhomogeneous distribution of the Stokes parameters are analysed, setting up a framework to analyse the nonlinear behaviour of the system and its impact on diffraction and polarimetric performance in future microdisplays with higher resolutions and smaller pixel sizes.