Researchers say a new discovery on a U.S. Army project for optoelectronic devices could help make optical fiber communications more energy efficient. A new design of optical devices radiate light in a single direction. This single-sided radiation channel for light can be used in a wide array of optoelectronic applications to reduce energy loss in optical fiber networks and data centers. The journal Nature published the findings. Light tends to flow in optical fibers along one direction, like water flows through a pipe. On-chip couplers are used to connect fibers to chips, where light signals are generated, amplified, or detected. While most light going through the coupler continues through to the fiber, some of the light travels in the opposite direction, leaking out. A large part of energy consumption in data traffic is due to this radiation loss.