HIGH-RESOLUTION SURFACE SENSING DEVICE USING BRAGG-DIFFRACTION FROM MULTIPLEXED HOLOGRAMS IN PHOTOREFRACTIVE CRYSTAL

A novel high-resolution surface sensing device is developed and demons trated, which utilizes Bragg diffraction from the volume holograms in the photorefractive BaTiO3 crystal. In this device, the angular inform ation of a surface is obtained as a diffraction pattern from the multi plexed holograms stored in the crystal. The resolution of this device is as high as submilliradian due to the Bragg selectivity. Additionall y, a new method of surface structure comparison between two samples is also demonstrated using this device, which is applicable to the nonde structive surface inspection of optical components. (C) 1996 American Institute of Physics.