Spectrally Multiplexed Upconversion Detection With C-Band Pump and Signal Wavelengths

We demonstrate a multiplexing scheme for upconversion-based single-photon detection using a waveguide with multiple phase-matching peaks. Two different signal wavelengths are upconverted using two distinct pump wavelengths, where all the wavelengths are in the 1550-nm band. Background photon generation rates <; 10
^-4
per pulse with high internal conversion efficiencies are observed using 20-ps-long pump pulses.