Draper Inventors Honored for Single-Photon Detector

CAMBRIDGE, MA—Draper earned an award for its patent of a single-photon detector (SPD) that shows promise for improving the way LiDAR systems detect vehicles and objects on the road and enhancing applications in imaging, bioscience, surveillance and quantum communications.

The achievement was recognized by the Boston Patent Law Association at its 10th Annual Invented Here! event on November 17, 2020.

Draper’s SPD is the first of its kind in that it is intended to be configured in an array of multiple SPDs capable of detecting a single photon with high timing resolution, speed and efficiency over an unparalleled wavelength range, from visible to infrared.

An SPD works by detecting single photons and converting them into electrical signals. Conventional SPDs are made of silicon or compound semiconductor materials, such as gallium arsenide. The silicon versions are limited in wavelength range of operation, while the compound semiconductor devices require cooling to far below zero temperatures, limiting overall performance.

Draper’s SPD uses a silicon-germanium photodiode, which enables detection of the longer wavelengths of light and performance similar to a conventional silicon SPD. It can also function at room temperature. The longer wavelengths are of particular interest to the LiDAR industry as they are safer for the human eye. The performance of the new detector is intended to enable ultralow dark-counting rate and timing resolution of better than one nanosecond.

Steven Spector, principal member of Draper’s technical staff, developed the technology with a team at Draper. He said, “Draper’s SPD is so fast and efficient that it can absorb and detect a single particle of light and reset itself for the next one within a nanosecond.”

As single-photon detectors progress in their development, new capabilities are emerging. There are growing expectations in the field that SPDs will enable cameras to see through opaque media, inside the body and behind walls. A range of bioscience applications for SPD have also been explored, including super-resolution microscopy and positron emission tomography (PET). SPD can also be used in embedded security techniques, where the quantum nature of light is used in the generation of true random numbers for encryption and other information hiding purposes.

The inventors responsible for the patent, titled “Single Electron Transistor Triggered by Photovoltaic Diode,” are Steven Spector, Robin Dawson, Michael Moebius and Ben Lane. The patent application was prepared and submitted by Sunstein LLP. Draper earned similar honors in 2019, 2018 and 2017.

The Boston Patent Law Association, established in 1924, is one of this country’s oldest associations of intellectual property lawyers and professionals. The BPLA’s Invented Here! award highlights inventions made by New England inventors or New England companies.