High‐resolution surface sensing device using Bragg diffraction from multiplexed holograms in photorefractive crystal

Abstract

A novel high‐resolution surface sensing device is developed and demonstrated, which utilizes Bragg diffraction from the volume holograms in the photorefractive BaTiO3 crystal. In this device, the angular information of a surface is obtained as a diffraction pattern from the multiplexed holograms stored in the crystal. The resolution of this device is as high as submilliradian due to the Bragg selectivity. Additionally, a new method of surface structure comparison between two samples is also demonstrated using this device, which is applicable to the nondestructive surface inspection of optical components.