Optical information processing characteristics of the microchannel spatial light modulator

The microchannel spatial light modulator (MSLM) is a versatile, highly sensitive, and optically addressed modulator that is well suited for low-light level real-time optical information processing. The image processing operations that can be achieved with the MSLM include contrast reversal, contrast enhancement, edge enhancement, image addition and subtraction, analog and digital intensity level thresholding, and binary level logic operations such as AND, OR, EXCLUSIVE OR, and NOR. Several of these operations are demonstrated herein. Recent prototype MSLMs have exhibited a halfwave exposure of 2.2 nJ/cm(2), an optical information storage time of more than two months, and a framing rate of 40 Hz with full modulation depth (200 Hz with 20% modulation depth). The role of secondary electron emission in the operation of the MSLM is discussed, and design modifications that would yield a spatial resolution of ~10 cycles/mm at the 50% point on an MTF curve are proposed.