Improved Single Photon Detectors for Telecom Wavelengths

Abstract : In this final report for the DARPA QuIST program entitled "Single Photon Detectors For Telecom Wavelengths," we describe progress made in Year Three of the program. We describe continued progress by UT Austin and UCSD in developing novel semiconductor detectors that perform well as single photon counters and in understanding the sources of dark counts that limit the single-photon-counting performance of these devices. We also report on IBM's production and distribution to QuIST partners of research prototype single photon detectors based on commercially-available InGaAs APDs coupled with specialized electronic circuitry developed at IBM. Finally, we report progress toward using nonlinear sum-frequency generation as an alternative to InGaAs detectors.