Binary Arithmetic Using Optical Symbolic Substitution and Cascadable Surface-Emitting Laser Logic Devices

In this paper, we describe the design and operation of optical logic gates based on heterojunction phototransistor (HPT) and vertical-cavity surface-emitting laser (VCSEL) structures. We call the HPT/VCSEL structure a surface-emitting laser logic device. These structures will find use in optical communication systems as well as in parallel optical computing architectures. We illustrate complete sets of optical logic functions, upon which arithmetical logic units (ALU) are based, and provide specific examples of binary arithmetic operations based on optical symbolic substitution.