Polarization Efficiency Control of Freeform Liquid-Crystal Polarization Imaging Optics

Abstract

Liquid-crystal polarization imaging optics (LPIOs) have attracted significant interest in near-eye displays. However, the diffraction efficiency of LPIOs is very sensitive to the change of polarization state due to their strong polarization sensitivity, which may result in low diffraction efficiency and poor uniformity of diffraction efficiency over the field of view of an LPIO display system if the change of polarization state is not considered. Here, we developed an approach for polarization efficiency control of freeform LPIOs. The bandwidths of freeform LPIOs were considered, and the change in polarization state was calculated by use of a self-built rigorous coupled-wave analysis (RCWA) module. An optimal balance between aberration correction and efficiency control can be achieved by optimizing the flexible phase profiles of freeform LPIOs. The effectiveness of the proposed method was verified by an example. This work could promote the application of freeform LPIOs in optics and photonics.