Optical design of wollaston-prism digital light deflectors

The optical design of Wollaston-prism digital light-deflection systems is analyzed. It is found that the performance of the system is limited by (1) the diffraction spreading of the incident light beam, (2) the walk-off of the beam at the exit aperture, (3) the generation of spurious light, and (4) distortions in the angular deviation of each prism. The magnitude and functional dependence of these limitations are calculated, and criteria are supplied for the design of practical Wollaston-prism light-deflection systems. The design procedure is outlined, and numerical examples are given. The examples show that high-speed Wollaston-prism systems having a capacity of more than 10(6) bits are practical at the present time.