Patent ID: 7888199

Claim:
A method for producing light modulated with an input electrical signal, comprising the steps of: providing a bipolar transistor device that includes a p-type collector, an n-type base, and a p-type emitter; providing a first tunnel junction coupled with said collector, and a second tunnel junction coupled with said emitter; providing a collector contact coupled with said first tunnel junction, and providing an emitter contact coupled with said second tunnel junction, and providing a base contact coupled with said base; said step of providing a first tunnel junction comprises providing a layered n+/p+ region with the n+ layer of said n+/p+ region being coupled with said collector contact and the p+ layer of said n+/p+ region being coupled with said collector; applying electrical signals with respect to said collector, base, and emitter contacts to cause light emission by radiative recombination in the base region; and controlling the base current of said transistor device with said input electrical signal to modulate the light emission from said transistor device.