SURFACE-EMITTING LASER LOGIC FOR DIGITAL OPTICAL COMPUTING

DIGITAL OPTICAL COMPUTING HAS EVOLVED TO THE POINT WHERE VIABLE ARCHITECTURES HAVE BEEN DESCRIBED IN DETAIL. HUNDREDS OF PAPERS ARE PUBLISHED AND SEVERAL TOPICAL CONFERENCES ARE HELD ANNUALLY ON THE SUBJECT. HOWEVER, FEW DEMONSTRATIONS HAVE BEEN REPORTED OF ACTUAL OPERATING SYSTEMS DUE TO THE UNAVAILABILITY OF AN "IDEAL" OPTICAL LOGIC GATE HAVING: OPTICAL GAIN, CASCADABILITY, HIGH ON/OFF CONTRAST, THE APPROPRIATE TWO-DIMENSIONAL GEOMETRY AND NXN PIXEL DENSITIES, ADEQUATE SWITCHING SPEEDS, AND TOLERABLE SWITCHING POWER REQUIREMENTS. CLEARLY, ARCHITECTURE DESIGN HAS OUTPACED DEVICE DEVELOPMENT. IN THIS PROPOSAL WE DESCRIBED A REVOLUTIONARY NEW DEVICE WHICH WILL MEET ALL OF THE ABOVE DEVICE REQUIREMENTS. WE CALL IT A SURFACE-EMITTING LASER LOGIC (CELL) DEVICE. THE DEVICE CONSISTS OF A VERTICAL-CAVITY SURFACE-EMITTING LASER MONOLITHICALLY INTEGRATED WITH A PHOTOTRANSISTOR. THE CELLS ARE CASCADABLE; HAVE HIGH OPTICAL GAIN (LARGE FAN OUT CAPABILITY);FUNCTION NATURALLY TO PERFORM ABOOLEAN DIGITAL OPTICAL LOGIC; CAN BE FABRICATED USING SIMPLE TWO-DIMENSIONAL PLANAR VLSI TECHNOLOGY AND EMIT LIGHT PERPENDICULAR TO THE SURFACE. THE PHASE I PROJECT WILL: DEMONSTRATE A CASCADABLE, HIGH-GAIN CELL; DESIGN AN OPTIMIZED SECOND GENERATION CELL; DESIGN A DIGITAL OPTICAL SWITCHING ARRAY; AND OUTLINE PHASE II. PHASE II WILL ENTAIL THE DEMONSTRATION OF A WORKING DIGITAL OPTICAL LOGIC ARRAY AND SUBSEQUENTLY A DIGITAL OPTICAL COMPUTING PROCESSOR.