Single Photon Detector
The simplest and least expensive way of detecting single photons relies on the Geiger mode of operation of avalanche photodiodes (APDs). In this mode, the bias voltage is brought above breakdown so that a single photon is able to create a macroscopically measureable current. In order to keep dark counts low, especially at telecommunication wavelengths where Si-based APDs are not sensitive, the APD bias is raised above breakdown only for a short time period when the optical pulse is expected to arrive. The time-varying voltage bias, or gate, arms the detector to count a single photon during this time interval. Single-photon detection is important in various aspects of science and engineering, and is a critical technology for measuring quantum-correlated light beams such as streams of entangled photons. In order to measure and characterize quantum correlations, not only the single-photon counts but also the correlations between multiple detectors need to be calculated.
NuCrypt offers an easy-to-use integrated system of single-photon detectors and processing electronics so that the output from multiple detectors can be both counted individually and correlated. Please visit our product page to find out more about our correlated photon detection system. Please visit our contact us page to contact NuCrypt with your questions about this product.