Pulsed light high-speed polarization locking method of continuous-variable quantum key distribution system
US11057202B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2019 |
| Grant date | Jul 6, 2021 |
| Priority date | — |
| Expiry date | Mar 10, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A pulsed light high-speed polarization locking method of a continuous variable quantum key distribution system is disclosed. An integral type optical detector is used for converting energy of a single pulsed light into a peak voltage of an output electric pulse in real time so as to achieve real-time measurement of light pulse energy without conducting high-speed data sampling and simplify the data acquisition and processing. By utilizing the FPGA hardware, a conditional simulated annealing algorithm is quickly operated to search the target polarization state and achieve high-speed polarization locking under the pulsed light. In addition, the power change of a local oscillator is monitored in real time to strengthen the resistance of the system against local oscillator dithering attack. The present invention can effectively solve a problem of rapid fluctuations of polarization state of pulsed light caused by complex external environments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.