Dual-channel, single-photon upconversion detector at 1.3 μm

Abstract

We demonstrate efficient, single-photon upconversion detection of two wavelengths in the 1300-nm band. The upconversion detector is based on a phase-modulated, periodically poled LiNbO3 waveguide that simultaneously quasi-phasematches two sum-frequency-generation processes. The two channels exhibited 31% and 25% photon detection efficiency, as well as very low dark count rates (650 s-1 and 550 s-1, respectively). We investigate applications of the multi-channel upconversion detector as a beamsplitter and demultiplexer to increase the count rates before detector saturation, and to improve temporal resolution using multiplexing.