Freeform Liquid–Crystal Polarization Imaging Optics: A Practical Approach from Design to Fabrication

Abstract

AbstractFreeform liquid–crystal polarization imaging optics (LPIOs) have vast potential for application in next‐generation interactive displays like augmented reality and virtual reality. However, tailoring the phase profile of a freeform LPIO for flexible aberration correction and diffraction efficiency control is still a big challenge due to the difficulties arising from the non‐zero étendue of an imaging system and the finite bandwidth of LPIOs. Here, a practical approach to creating freeform LPIOs from design to fabrication is proposed. A freeform polarization exposure is developed to produce a flexible, precise, and ultra‐high‐resolution photoalignment pattern for a freeform LPIO. A cooperative optimization is performed between the freeform LPIO and the freeform polarization exposure system to find the optimal phase of the freeform LPIO and the optimal surface profiles of the freeform lenses employed in the exposure system to produce freeform wavefronts. The optimal phase of the freeform LPIO is then achieved by superposition interference of the engineered freeform wavefronts via freeform polarization exposure. The effectiveness of the approach and the advantages of freeform LPIOs is experimentally demonstrated. The proposed approach will significantly promote the widespread applications of freeform LPIOs in the field of optics and photonics.