Abstract

Binary logic elements are the basic building blocks of digital optical computers. Various methods have been proposed for implementing binary operations optically. The polarization logic has several advantages: energy efficiency can be very high. Polarization logic is better suited for cascading, in particular if a logic-no output from one gate serves as the input for the next gate. Polarization logic also automatically provides dual-track outputs. We describe a new method of optically implementing binary logic gates based on polarization. The binary logic values 1 and 0 are represented by the vertical and horizontal polarizations. Although these two orthogonal states will not interact with each other, we can change them into a right-handed and a left-handed circular polarization, by a quarterwave plate, for processing. Based on the fact that the sum of these two circularly polarized beams will result in a linearly polarized beam, we can build logic gates consisting of only optical components such as lenses, polarizers, mirrors, halfwave plates, and quaterwave plates. Several configurations for achieving optical gates, such as nor, and, xor are considered. These processors have the advantages of parallel processing, high information density associated with optical data processors, and realtime capability.

© 1991 Optical Society of America