Optoelectronic exclusive-OR (XOR) gate

An optoelectronic circuit that implements the exclusive-OR (XOR) logic function is described. The circuit uses two unmatched heterojunction phototransistors and a light amplifying optical switch (LAOS) monolithically integrated on an InGaAs/InP wafer grown by gas-source molecular beam epitaxy. The circuit was operated from DC up to the limit of the probe stand (90 kHz). The ease of operation and high ON/OFF contrast ratio (>50) make this XOR gate ideal for applications that require optical binary comparison or addition.<
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