Polarization Grid Hologram with Red and Green Light Bands for Enhanced Light Transmission

The design work utilizes red and green light bands and includes a polarization grid hologram reflecting on four layers. The first layer diffracts right-handed circularly polarized red light, the second layer diffracts left-handed circularly polarized red light, the third layer diffracts right-handed circularly polarized green light, and the fourth layer diffracts left-handed circularly polarized green light. We take measures to avoid introducing dispersion, using a symmetric mirror image design for the corresponding output coupling group and input coupling group. Specifically, the circularly diffracted right-handed red and green light enters the waveguide of the second layer and propagates to the right by total reflection until it is diffracted by the circular right-handed output coupling grid of the second layer into parallel light. The circularly diffracted left-handed red and green light enters the waveguide of the second layer and propagates to the left by total reflection until it is diffracted by the circular left-handed output coupling grid of the second layer into parallel light.