Inverting and latching optical logic gates based on the integration of vertical-cavity surface-emitting lasers and photothyristors

Inverting optical logic gates based on the monolithic integration of a vertical-cavity surface-emitting laser (VCSEL) with a heterojunction photothyristor (PNPN) are described. Logic functions INVERT, NAND, and NOR are experimentally demonstrated for the first time using latchable and cascadable PNPN/VCSEL switches, which can be triggered with very low optical energy, while producing high optical gain and optical contrast. These gates are integrable on a single epitaxial structure to provide multifunctional logic and memory arrays.>