Analysis of Threshold Logic for Applications to Optical Computing

Optical threshold logic implementions of register-level operations such as multiply-accumulate are considered. Specific 2- and 8-bit multiply-add designs using both conventional (Boolean) and threshold logic are described and compared. The threshold logic designs are shown to have advantages of factors of 2 or 3 in number of logic levels, number of logic elements, and number of interconnections. The possibility of all-optical implementations (optical logic elements and optical internal connections) of these designs is discussed in terms of integrated optical networks and nonlinear optical devices, particularly in GaAs structures.