Thomas J. Harris

Digital Light Deflectors

Several electrooptic digital light deflection techniques have been proposed. The maximum number of resolvable deflection positions for all methods is determined, essentially, by economic reasons, the tolerable amount of background light, and aberrations. In this paper, three different types of deflection methods (split angle, total internal reflection, Wollaston prism) are described. Design, construction details, and performance of three deflector models are reported. Combined deflection systems use the advantageous properties of each of these methods to economically obtain the maximum number of resolvable deflection positions. A suggested combination to achieve 1024x1024 positions arranged in a two-dimensional field would consist of one total internal reflection stage, seven stages of split angles, and two stages of Wollaston prisms for each dimension.

Laser wavelength selection.

The advent of multiwavelength lasers has stimulated considerable interest in wavelength selection, i.e., methods of selecting for various applications one or more of the available wavelengths from a given laser. This paper describes a technique for parallel wavelength separation or recombination of laser beams external to laser cavities. The device used is based on the optical activity of quartz crystals and on the polarization dependent reflection of birefringent calcite crystals.