Quality metrics in holographic lenses recorded in a low toxicity photopolymer

Abstract

Holographic Lenses (HLs) are holograms obtained from the interference of an object point (object beam) and a plane beam (reference beam). Unlike conventional refractive lenses (RLs), their physical principle is diffraction, and in addition to spectral dependence, they also exhibit angular dependence. One of the main applications of such HLs is their use in AR optical systems such as head mounted displays (HMD). HLs also exhibit aberrations. To measure the impact of these aberrations, diffraction efficiency is not a suitable optical parameter. For this purpose, different quality metrics can be used. In this work, the quality of positive symmetrical and negative asymmetrical HLs has been evaluated by studying different metrics: optical quality metrics (Zernike and Seidel coefficients, RMS for Zernike and Seidel aberrations, and critical pupil fraction (PF); and image quality metrics based on the impulse response of the system (Strehl Ratio (SR), Entropy and cut-off frequency).