Digital optical logic using optically switched directional couplers

Abstract

A novel optical logic gate with all-optical data signals is described. Control circuitry converts 100 MHz, −25dBm square-wave optical pulses at λ = 1.3/rai into electrical signals sufficient to switch the exchange state of LiNbO3 2 × 2 directional couplers in order to route similar optical pulses. Such optically-controlled directional couplers function as three-input, two-output logically complete gates for digital optical logic. Several digital optical circuits using these gates have been constructed and demonstrated.