Differential optical switching at subnanowatt input power

An operating technique for a differential optical switching device based on a set of parallel-connected pnpn structures is discussed. The differential function at subnanowatt input powers was demonstrated with AlGaAs/GaAs pnpn devices. The highly sensitive devices are promising for applications both to optical neural networks and to optical digital computing because of the low power consumption of the light emitting devices and the large fan-in/fan-out ratio ( approximately 10/sup 5/).<
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