Low-Noise Avalanche Photodiode Could Advance Data Communications

A new development in semiconductor technology, leading to an ultrafast, highly sensitive avalanche photodiode (APD) with extremely low excessive noise, could improve data transmission rates and/or enable longer transmission distances. Cardiff University researchers, led by professor Diana Huffaker, partnered with researchers at the University of Sheffield and the University of California, Los Angeles (UCLA) to develop the technology.

To limit noise and increase sensitivity, the researchers used molecular beam epitaxy (MBE) to grow the compound semiconductor crystal in an atom-by-atom regime. The researchers used a new MBE methodology to combine four different atoms to make the material. The resulting material was tested in a low-signal environment, at room temperature. The new AlAs_0.56Sb_0.44 avalanche photodiodes are compatible with the current InP optoelectronic platform used by most commercial communication vendors.

Professor Diana Huffaker, Institute for Compound Semiconductors, Cardiff University. Courtesy of Mike Hall Photography.

The faster, supersensitive APDs could be used in high-speed data communications and in lidar for high-resolution 3D mapping, with applications in geomorphology, seismology, and the control and navigation of autonomous vehicles.

“Our work to develop extremely low excess noise and high sensitivity avalanche photodiodes has the potential to yield a new class of high-performance receivers for applications in networking and sensing,” Huffaker said. The team is working with Airbus and the Compound Semiconductor Applications Catapult, located in England and Wales, to apply the new APD technology to future free-space optical communication systems.

The research was published in Nature Photonics (https://doi.org/10.1038/s41566-019-0477-4).