The Up-conversion Single-photon Detector And Its Application

Single-photon detection (SPD) is the most precise measurement technology of a single photon, which is the smallest unit of light. It has been widely used in quantum information, biological fluorescence detection, distributed fiber sensor, weak optical imaging and laser radar. In the field of quantum information, Quantum Key Distribution (QKD) can provide an unconditional security method of key distribution by using the nonorthogonal states of single photons. The security of QKD is guaranteed by physical laws. Single-photon detector is a core part of quantum communication. Its performance limits the transmission distance and key rate of quantum communication..In this thesis, we develop a new type up-conversion single-photon detector based on periodically poled lithium niobate(PPLN) waveguide in the1.5μm telecom band. The working principle, experiment setup and result are discussed. Based on the newly up-conversion single-photon detector, we achieved the first experiment of device-independent measurement QKD in the fiber up to50km, which closed all attacks from the source and detector. We firstly realized the experiment of QKD based on free-space in daytime up to52km with the1550nm; which solves the problem of wavelength mismatch in free-space QKD and fiber-based QKD. Further more, photon counting Optical Time Domain Reflectometer (OTDR) with217km, spectrometers in telecom band with high-sensitivity and the up-conversion single-photon detectors in2micron band are reported in this thesis.