Study Of Free-Space Quantum Communication Experiment

Quantum Information (QI), a young discipline as cross-field of quantum physics and information science, has been recently attracting world-wide emphasis and greatly developing for its advantages and foreground compared to classical information technology.Quantum communication is the most rapidly developing field towards pratical quantum information. Generally, quantum information channels utilize free-space channel or optical fiber channel. Due to the limitations of current technology, fiber-optic quantum communication distance has reached the limit. While free-space quantum communication can make use of the space platform to establish high-stability low-loss channel and do ultra-long-distance quantum experiment. This makes a global quantum communication network desirable in the future. Free-space quantum communication therefore becomes the most popular research direction.The present dissertation is mainly about some experimental work that I involved and led. We have experimentally simulated a single-photon transmission from satellite to earth and developed polarization maintaining technical for satellite-based quantum conmmunication. We have also demonstrated experimental realization of two-way"Quantum Pseudo-Telepathy"game with four-dimension entanglement, synchronized generation of independent entangled photon pairs, and fault-tolerant quantum key distribution in a decoherence-free subspace.The techniques developed in this dissertation would dramatically facilitate progresses in many important fields of scientific research, including long distance free-space quantum communication based on space bench, practical quantum cryptography and linear optics quantum computation.