HIGHLY COMPACT INTEGRATED OPTICAL SET RESET MEMORY PIXELS FOR PARALLEL PROCESSING ARRAYS

We report an integrated optoelectronic device with a single-mesa struc ture, which functions as an optical set-reset memory or an optical inv erter. The device is composed of two heterojunction phototransistors a nd a light-emitting diode vertically integrated on an InGaAsP/InGaAs/I nP wafer grown by gas source molecular beam epitaxy. The set and reset beams are incident onto a single optical window on each device and ar e separated by wavelength. The prototype device has shown a large on/o ff contrast ratio (27) with relatively low input optical power levels (tens of microwatts). This device concept is extendable to large integ rated arrays which are capable of directly processing spatial light si gnals.