An electro-optic modulator plays the key role in fiber optic networks. Just as a transistor is a switch for electronic signals, an electro-optic modulator is a switch for optical signals. Optical communication uses light, so the modulator turns on and off the light that sends a stream of binary signals over optical fibers.

The new modulator is 10 times smaller and can potentially be 100 times more energy efficient than the best previous devices. It is roughly the size of a bacterium, measuring 0.6 by 8 microns.

"This is by far the most exciting research I have ever done because of the impact the device will bring and because of the challenge it was for design and fabrication," said Alan Wang, associate professor of electrical engineering in the OSU College of Engineering.

NanoLetters – Ultracompact Silicon-Conductive Oxide Nanocavity Modulator with 0.02 Lambda-Cubic Active Volume

For their invention, Wang and his doctoral student, Erwen Li, leveraged technology also developed at Oregon State: transparent conductive oxide materials. The structure they invented uses a transparent conductive oxide gate instead of a typical metal gate to combine a metal-oxide semiconductor capacitor with an ultra-compact photonic crystal nanocavity.