Ultralow noise up-conversion detector and spectrometer at telecom band

We demonstrate upconversion single-photon detection for the 1550-nm band using a PPLN waveguide, long-wavelength pump, and narrowband filtering using a volume Bragg grating. We achieve total-system detection efficiency of around 30% with noise at the dark-count level of a silicon APD. Based on the new detector, a single-pixel up-conversion infrared spectrometer with a noise equivalent power of -142 dBm was demonstrated, which was better than liquid nitrogen cooled InGaAs arrary.