基于微尺度光阱中单原子操控的单光子源，与单分子、单量子点、单色心等单光子源以及基于光学参量振荡的预告式单光子源相比有更窄的带宽，在量子光学领域对在单光子-单原子层次深入理解光与物质相互作用、在量子信息领域的线性光学量子计算和量子保密通信方面具有重要意义；单光子的量子频率转换在探索量子网络构建方面是重要环节。拟在已掌握的单原子的冷却、俘获及操控的基础上，围绕852纳米窄带单光子源的制备、优化升级及其量子频率下转换至1.5微米光纤通信波段的目标，拟研究以下内容：1)、单原子在微尺度光阱中的高效制备和在有共振脉冲光激发时单原子俘获寿命的有效延长；2)、研究可用于激发原子的高重复率纳秒脉冲激光的产生方案，提高脉冲光的开关比和重复率，从而优化升级852纳米单光子源；3)、研究采用周期极化非线性波导对852纳米单光子向1.5微米量子频率下转换；4)、测量并表征量子频率转换前后的单光子源的物理特性。

The single-photon source based on manipulation of single atom trapped in a microscopic optical tweezer has much narrower bandwidth compared with the single-molecule-, single-quantum-dot-, single-N-V-center-based single-photon sources and the optical-parametric-oscillation-based heralded single-photon sources, therefore it will be very important for deeply understanding photon-matter interaction at single photon and single atom level in quantum optics and for linear optics quantum computation and quantum cryptography in quantum information precessing; Also quantum frequency conversions of the single photons will be very important parts for exploring implementation of quantum networks. Based on the techniques of laser cooling/trapping and coherent manipulation of single atoms we have already demonstrated and known well, we will focus on the preparation and optimization of 852-nm narrow-band single-photon source and its quantum frequency down-conversion to 1.5-micrometer telecom-band. The following aspects will be investigated in this proposed project: 1). High-probability preparation of the single cesium atoms in a microscopic tweezer, and effectively extending trapping lifetime of single atoms in the case of resonant pulsed optical excitation; 2). Exploring the optimized system of nanosecond laser pulses with a high repetition rate for atom excitation, and improving the ON/OFF ratio and the repetition rate, therefore optimizing and upgrading the 852-nm single-photon source; 3). Investigating quantum frequency down-conversion of 852-nm single photons to 1.5-micrometer telecom-band based on the periodically-poled nonlinear crystal waveguide; 4). Measuring and characterizing the properties of the single-photon sources before and after quantum frequency conversion.