Active optical NOR logic devices using surface-emitting lasers

Cascadable active laser logic devices are described, demonstrating NOR and INVERTER functions with a negative optical gain of five. The surface-emitting laser logic device consists of an AlGaAs superlattice surface-emitting laser discretely connected to an AlGaAs heterojunction phototransistor in parallel. The optical logic output of 0.5 mW is controlled off with 100 mu W incident power (44 mu W absorbed) on the heterojunction phototransistor part of the device.>