| Abstract: |
Single-photon sources and detectors enable a wide range of applications, from quantum information technologies to fundamental tests of quantum optics. Semiconductor quantum dots (QDs) have emerged as promising single-photon sources, and recent work has demonstrated their viability at wavelengths longer than 1 micron. Characterization of these sources, however, has been hindered by the poor quality of single-photon detectors in the infrared. Recently, supercon- ducting single-photon detectors (SSPDs) based on nanopatterned NbN have been shown to offer considerable advantages over conventional detectors. Unlike silicon-based devices, SSPDs are sensitive well into the infrared, and have been demonstrated with over 50 % detection efficiency at 1550 nm and operation at count rates as high as 1 GHz. Although SSPDs must be operated at temperatures near 4 K, we have minimized the associated difficulty and expense by packaging several fiber-coupled devices in a single cryogen-free refrigerator. |
