Photon transport transistor

Abstract

A novel optoelectronic device is presented which consists of a light-emitting diode (LED) on top of a photodiode, with very tight optical coupling. The device is similar to a bipolar transistor except that photons rather than minority carriers are transported through the base. Devices fabricated with the GaAs-AlGaAs material system yield a current gain of up to four and the modest transit frequency of 70 MHz. The potential of the device lies in its use as an optoelectronic device for monolithic optoelectronic building blocks since the same structure can be used as a laser/LED, photodiode, phototransistor, and photon transport transistor. The same structure also allows lower laser thresholds to be achieved owing to photon recycling.