High efficiency WSi superconducting nanowire single photon detectors for quantum state engineering in the near infrared.
We report on high efficiency superconducting nanowire single photon detectors based on amorphous tungsten silicide and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity enhanced spontaneous parametric downconversion, this fiber coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral brightness of 0.6x104 photons/(s*mW*MHz) Beyond single photon generation at large rate, such high efficiency detectors open the path to efficient multiple photon heralding and complex quantum state engineering.
Optics letters