Ultralow noise up-conversion single-photon detection for the 1550-nm telecommunications band is achieved using a PPLN waveguide, long wavelength pump, and narrowband filtering with a volume Bragg grating. The total-system detection efficiency reaches 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 Hz-1/2 was demonstrated, which was better than liquid nitrogen cooled InGaAs array. The new detector can find immediate applications in quantum cryptography, quantum communication, Optical Time Domain Reflectometer(OTDR), photon counting lidar and etc.
Guo-Liang Shentu, et al., Optics Express, 21, 13986, (2013).
Figure 1 Experimental Setup
Figure 2 DE and Noise vs Pump power