Micromechanical optoelectronic switch and amplifier (MIMOSA)

We report for the first time the monolithic integration of a micromechanica l modulator and a p-n photodiode on a silicon substrate yielding a versatil e optoelectronic device, Because both devices are monolithically integrated on a silicon substrate, the combination is compact with minimal parasitic elements. We demonstrate that such a device combination yields a transistor -like element with positive and negative small-signal voltage amplification , The maximum small-signal voltage gain achieved is 500 while the modulated current of the device exhibits a maximum ON-OFF ratio of 3:1, In addition, while the theoretical current gain of the device is infinite, a 10-pA nois e level limited the measured de current gain to 10(6).