Transistor laser optical switching and memory techniques and devices

A ring cavity light-emitting transistor device, including: a planar semiconductor structure of a semiconductor base layer of a first conductivity type between semiconductor collector and emitter layers of a second conductivity type; base, collector, and emitter metalizations respectively coupled with the base layer, said collector layer, and said emitter layer, the base metalization including at least one annular ring coupled with a surface of the base layer; and an annular ring-shaped optical resonator in a region of the semiconductor structure generally including the interface of the base and emitter regions; whereby application of electrical signals with respect to the base, collector, and emitter metalizations causes light emission in the base layer that propagates in the ring-shaped optical resonator cavity.