Optical and near-infrared photon detection with superconducting transition-edge sensors

There is increasing interest in using high-performance cryogenic optical photon detectors in a variety of applications in quantum information science and technology. These applications require detectors that have extremely low dark count rates, high photon count rates, high quantum efficiency, and moderate energy resolution or photon number resolution for near-infrared and optical photons. In this paper, we describe the operation, fabrication, and performance of superconducting transition-edge sensors designed for quantum optics and information applications.