Author Affiliations
1Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China2Guangdong Polytechnic Institute, Guangzhou 510091, Chinashow less
Fig. 1. Polarization-independent phase-modulated polarization encoding module. LD, laser diode; ISO, isolator; PC, polarization controller; CIR, circulator; PBS, polarization beam splitter; DL, delay line; PM, phase modulator; FM, Faraday mirror.
Fig. 2. Point-to-point QKD based on encoding module. LD, laser diode; ISO, isolator; PC, polarization controller; CIR, circulator; PBS, polarization beam splitter; PM, phase modulator; FM, Faraday mirror; VOA, variable optical attenuator; DG, digital generator; EPG, electrical pulse generator; DL, delay line; RFA, radio-frequency amplifier; QC: quantum channel; BS, optical beam splitter; SPD, single-photon detector.
Fig. 3. Multi-user QKD networks based on point-to-point structure using DWDM. MWLD, multi-wavelength laser diode; ISO, isolator; PC, polarization controller; CIR, circulator; PBS, polarization beam splitter; DWDM, dense wavelength division multiplexer; PM: phase modulator; PD, photo diode; FM: Faraday mirror; VOA, variable optical attenuator; DL, delay line; QC: quantum channel; BS, beam splitter; SPD, single-photon detector.
Fig. 4. QBER of the four polarization states tested under polarization-independent phase modulation over 100 min.
Fig. 5. (a) QBER of CH34 over 100 min at 1 km; (b) QBER of CH35 over 100 min at 1 km; (c) QBER of CH34 over 100 min at 5 km; (d) QBER of CH35 over 100 min at 5 km.