We experimentally demonstrate the nonlinear interaction between two chirped broadband single-photon-level coherent states. Each chirped coherent state is generated in independent fiber Bragg gratings. They are simulta...We experimentally demonstrate the nonlinear interaction between two chirped broadband single-photon-level coherent states. Each chirped coherent state is generated in independent fiber Bragg gratings. They are simultaneously coupled into a high-efficiency nonlinear waveguide, where they are converted into a narrowband singlephoton state with a new frequency by the process of sum-frequency generation(SFG). A higher SFG efficiency of1.06 × 10-7is realized, and this efficiency may achieve heralding entanglement at a distance. This also made it possible to realize long-distance quantum communication, such as device-independent quantum key distribution,by directly using broadband single photons without filtering.展开更多
基金National Natural Science Foundation of China(NSFC)(11564018,61125503,61235009)Foundation for Development of Science and Technology of Shanghai(13JC1408300)
文摘We experimentally demonstrate the nonlinear interaction between two chirped broadband single-photon-level coherent states. Each chirped coherent state is generated in independent fiber Bragg gratings. They are simultaneously coupled into a high-efficiency nonlinear waveguide, where they are converted into a narrowband singlephoton state with a new frequency by the process of sum-frequency generation(SFG). A higher SFG efficiency of1.06 × 10-7is realized, and this efficiency may achieve heralding entanglement at a distance. This also made it possible to realize long-distance quantum communication, such as device-independent quantum key distribution,by directly using broadband single photons without filtering.