Researchers from Oregon State University have designed and fabricated the smallest electro-optic modulator in the world. This could mean huge reductions in energy used by data centers and supercomputers.
From left, OSU electrical engineering researchers Erwen Li, Alan Wang and Qian Gao (photo by Gale Sumida). Source: Oregon State University
An electro-optic modulator plays the key role in fiber optic networks. Similar to a transistor as a switch for electronic signals, an electro-optic modulator is a switch for optical signals. Optical communication uses light, so the modulator turns the light on and off 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.
For this invention, Wang, with the help of his doctoral student Erwen Li, leveraged technology that was developed at Oregon State – transparent conductive oxide materials. The structure 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. The design, which combines innovations in material and devices, enhanced the interaction between electronics and photonics, which enabled the researchers to create a smaller electro-optic modulator.
Wang consulted his colleagues in the industry about whether he was on the right track for developing something they could use.
"They told me reducing the size and reducing the energy consumption is going to be the trend in the next five to 10 years in the industry. So this is exactly the kind of device they're looking for," Wang said.
The paper on this research was published in Nano Letters.
