Increasing the Memory Capacity of the Digital Light Deflector by 'Color Coding'

This paper describes a scheme for increasing the memory capacity of an optical beam deflecting device, such as a digital light deflector, by utilizing the full wavelength bandwidth of the system. For convenience the scheme is referred to as "color coding". The digital light deflector 1 is designed to deflect a monochromatic light beam to any one of an array of positions on a memory plane. The absence or presence of an obstruction at the memory plane produces a yes or no signal in a detector placed behind the memory plane. The capacity of the system is determined by the ratio of the maximum angular deflection of the beam to the smallest angular deflection that can be resolved by the system. Increasing the capacity by increasing the maximum beam deflection requires lenses that can operate over a larger angular field of view. On the other hand, increasing the capacity by reducing the minimum resolvable angle requires larger diameter components. Assuming the diameter of the components and the angular field of view of the lenses are at their maximum values, then other means of increasing the capacity must be investigated. The capacity may be increased by paralleling information through the system so that each resolvable angular location in space becomes a word. This may be accomplished by splitting the deflected mono597