Producing an Optical Diode That Can Help Speed Data on Fiber Optic Networks

Achievement date: 
2013
Outcome/accomplishment: 

Data could move faster and more accurately across the fiber optic backbones of computer networks with the discovery of a way to keep light moving in one direction using a silicon chip. The discovery was made by a team from the Center for Integrated Access Networks (CIAN), an NSF-funded Engineering Research Center (ERC) headquartered at the University of Arizona.

Impact/benefits: 

While data moves at the speed of light photons across fiber optic cables, it runs into “speed bumps” in the form of underlying technology that is based on electronic chips, which are also more prone to data errors than are photonic chips. The problem has been developing photonic chips that can keep data moving in one direction, much as the diodes in electronics do.

Explanation/Background: 

A collaborative team of researchers from two CIAN partner universities, California Institute of Technology and the University of California at San Diego, discovered a way to establish non-symmetric mode propagation on a silicon chip. The team developed a metallic-silicon optical waveguide system to channel light so it travels in different modes depending on its propagation direction. The mode is symmetric when traveling forward and asymmetric when reflected backwards along the same path. Similar to a diode in electronics, the backscattered light is dissipated and is not able to reach the source.

This discovery will help to realize a long-term goal of combining electronics with photonics to enable chip-scale integrated circuits and systems that in turn will enable scalable, energy efficient and cost-effective technology that will impact such information systems as supercomputers, the internet, and data centers.