University of Science and Technology of China

Zhenqiang Yin

Guangcan Guo

Zhengfu Han

Shuang Wang

Wei Feng Chen

Deyong He

Yang Yang

Zheng Zhou

Yonggang Wang

Dajun Huang

Yuhu Li

Wei Chen

Fengyu Lu

Yuanguanjie Fan

Jiaxuan Li

A quantum key distribution system is provided, including: a sending terminal, a measurement terminal, a receiving terminal, and at least one polarization controller. The sending terminal is configured to generate a quantum optical signal and receive a detection result. The measurement terminal includes a beam splitter and two single-photon detectors, the beam splitter is configured to generate two measurement optical signals based on the quantum optical signal, and the two single-photon detectors are configured to generate the detection result. The receiving terminal is configured to receive the detection result. The at least one polarization controller is provided in the sending terminal, the measurement terminal or the receiving terminal, and performs a polarization processing on the quantum optical signal or the detection result using a target transmittance matrix determined based on the detection result, so as to obtain a polarized quantum optical signal or a polarized detection result.

Quantum key distribution system

The present invention utilizes a high-speed serial data transceiver to generate two high-speed electric pulse signals. After passing through a gain network, the signals are used for driving an electro-optic phase modulator (PM) so as to realize phase modulation of photon signals. The present invention may directly use a high-speed digital signal to realize a four-phase modulation function needed by the BB84 quantum key distribution protocol without using a digital to analog converter or an analog switch. This can prevent modulation rate from being restricted by links including digital-to-analog conversion, switching of the analog and the like. A dual-electrode electro-optic phase modulator scheme can also effectively reduce requirements for amplitude of a modulation driving signal, thus facilitating realization of high-speed phase modulation, which meets requirements of quantum key distribution.

Photon phase modulating system

Growing community of inventors

Anhui, China

Zhenqiang Yin