Author Affiliations
Abstract
1 Key Laboratory for Laser Plasmas (MoE) and School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
2 Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
3 Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Separating lights into different paths according to the polarization states while keeping their respective path’s polarizations with high purification is keen for polarization multiplex in optical communications. Metallic nanowire gratings with multi-slits in a period are proposed to achieve polarized beam splitters (PBSs) in reflection and diffraction. The setting of multi-slits largely reduces the reflection of photons with a transverse magnetific field via the plasmonic waveguiding effect, which leads to highly polarized output lights with extinction ratio larger than 20 dB in each channel. The proposed reflection/diffraction PBSs enrich the approaches to control the polarization states with the advantages of wide incident angles and flexible beam splitting angles.
230.1360 Beam splitters 240.6680 Surface plasmons 230.1950 Diffraction gratings 060.4230 Multiplexing Chinese Optics Letters
2019, 17(5): 052303
Author Affiliations
Abstract
School of Science, Beijing University of Posts and Telecommunications, Beijing 1008762 Department of Mathematics and Physics, North China Electric Power University, Beijing 102206
Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system. A new idea is put up to design a quick single-photon detector. This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs). All of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal. The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector. The single-photon prompt detection can come true for high repetition-rate pulses. The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.
单光子探测器 雪崩二极管 量子通信 量子密钥分配 码率 时分模式 040.5160 Photodetectors 060.4510 Optical communications 230.5160 Photodetectors 270.5570 Quantum detectors Chinese Optics Letters
2008, 6(5): 320
