Multichannel acousto-optic Bragg cell for real-time electroholography

Abstract

A multichannel acousto-optic Bragg cell was made by the joining of acousto-optic cells that have the shape of symmetrical trapezoidal prisms. This acousto-optic Bragg cell has an aperture length equal to the sum of its component acousto-optic cells but has an aperture time equal to that of each acousto-optic cell. We tested the performance of the multichannel acousto-optic Bragg cell by joining six TeO(2) acousto-optic cells together with 300-microm gaps between one another. The holographic fringe data prepared by computer were divided into six equal segments. Each data segment was again divided into six equal parts and then fed into the corresponding acousto-optic cell. The holographic images were reconstructed by the periodical illumination of a green (lambda = 0.5145 microm) pulse laser beam onto the multichannel acousto-optic Bragg cell. The reconstructed images are sharp and clear. This indicates that the multichannel acousto-optic Bragg cell is working properly.

Properties of DMDs for holographic displays

“…Time multiplexing means combining reconstructed images from different frames as a multiplexed image in a time-wise manner. The multiplexed image is, in most cases, larger than the reconstructed image from a frame [9,10], though it can be laden with a distortion induced by the scanning process. DMD's high speed can also cause the image from each DMD frame to have low brightness because the illumination time period of each frame can be very short.…”