Optoelectronic exclusive-NOR gate operating at 200 mbit/s

An optoelectronic exclusive-NOR gate was demonstrated for the first time. The device consisted of a composite pair of GaAs metal-semiconductor-metal photodetectors. Special input pulse trains were constructed from a 0.83 μm laser diode to test its functionality. Output electrical signal shorter than 800 ps was achieved. On-off contrast ratio of 6.2 dB was obtained with an incident pulse energy below 100 fJ. The device is useful in bit pattern matching for optical signal processing and optical computing.