High Efficient Single-photon Detection By Frequency Up-conversion

Advanced detection technology plays an important role in the process of human being's exploration into the natural world. The detection of infrared single photons-the ultimate limit in detector sensitivity- is the core technology and of great application value for future long-distance quantum information network construction as well as many infrared physics technology, such as lidar, guidance and sensor etc. While the performance of current widely-used infrared single-photon detectors are much worse than the ones for visible light, and this significant difference has inspired us with an assumption: should we up-convert the infrared single-photons to the visible region? During the past decade, the feasibility of this assumption has been proved theoretically and experimentally.Our purpose is to establish a practical infrared single-photon detection system, so efficiency, stability and sensitivity are most emphasized in our research. This dissertation documents our main results on single-photon frequency up-conversion detection at 1.55μm and 1.06μm respectively, which are both important and typical wavelength in infrared region.1. We discussed experimental feasibility for quantum-state preserving frequency translation with single-photon frequency up-conversion and its experimental conditions for near-unity up-conversion, including pumping intensity, phase matching and space coincidence conditions.2. Based on diode-pumped solid-state laser, we realized efficient and stable single-photon detection at 1.55μm by intra-cavity frequency up-conversion in a unidirectional ring laser, with the efficiency and standard deviation of stability being 96% and 1.9% respectively. And with this experimental setup we also made exploration on tunable frequency up-conversion.3. Aiming at more portable and sensitive infrared single-photon detection, we obtained single-photon detection at 1.06μm with ultra-low dark counts, which was pulse pumped by an amplified passively mode-locked fiber laser at 1.55μm. With the energy of the pump photon lower than that of the signal photon, the sensitivity of this long-wavelength-pumping setup was greatly enhanced, with its signal-to-noise ratio larger than 12000.