论文标题
双向单光子级的频率转换在852nm和1560nm之间，用于连接Cesium D2线与电信C波段
Two-way single-photon-level frequency conversion between 852nm and 1560nm for connecting cesium D2 line with the telecom C-band
论文作者
论文摘要
已经实现了用于在852 nm和1560 nm之间进行双向单光级频率转换的紧凑设置，该设置已使用相同的定期固定的氧化镁氧化镁（PPMGO：LN）块晶体（用于连接Cesium d2 Line（852 nm）到电信c-Band cesemium cesium cylecom ceesium Crystals（PPMGO：LN）散装晶体。 By single-pass mixing a strong continuous-wave pump laser at 1878 nm and the single-photon-level periodical signal pulses in a 50-mm-long PPMgO:LN bulk crystal, the conversion efficiency of ~1.7% ( ~1.9%) for 852-nm to 1560-nm down-conversion (1560-nm to 852-nm up-conversion) have been achieved.我们分析了由强泵激光束诱导的噪声光子，包括自发拉曼散射（SRS）和自发参数下调（SPDC）光子，以及在级联的非线性过程中产生的光子。通过使用窄带过滤器并改变差异频率产生（DFG）过程中噪声光子的极化，可以显着改善信噪比（SNR）。通过采用PPMGO：LN波导而不是散装晶体，我们的研究可以进一步提高转化效率，我们的研究可以为量子网络中的环状光子转换提供基础。
A compact setup for two-way single-photon-level frequency conversion between 852 nm and 1560 nm has been implemented with the same periodically-poled magnesium-oxide-doped lithium niobate (PPMgO:LN) bulk crystals for connecting cesium D2 line (852 nm) to telecom C-band. By single-pass mixing a strong continuous-wave pump laser at 1878 nm and the single-photon-level periodical signal pulses in a 50-mm-long PPMgO:LN bulk crystal, the conversion efficiency of ~1.7% ( ~1.9%) for 852-nm to 1560-nm down-conversion (1560-nm to 852-nm up-conversion) have been achieved. We analyzed noise photons induced by the strong pump laser beam, including the spontaneous Raman scattering (SRS) and the spontaneous parametric down-conversion (SPDC) photons, and the photons generated in the cascaded nonlinear processes. The signal-to-noise ratio (SNR) has been improved remarkably by using the narrow-band filters and changing polarization of the noise photons in the difference frequency generation (DFG) process. With further improvement of the conversion efficiency by employing PPMgO:LN waveguide, instead of bulk crystal, our study may provide the basics for cyclic photon conversion in quantum network.
