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25 MHz clock continuous-variable quantum key distribution system over 50 km fiber channel.

Wang C, Huang D, Huang P, Lin D, Peng J, Zeng G - Sci Rep (2015)

Bottom Line: In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate.Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance.Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Key Laboratory on Navigation and Location-based Service, and Center of Quantum Information Sensing and Processing, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate. To reach high-rate, we have employed a homodyne detector with maximal bandwidth to 300 MHz and an optimal high-efficiency error reconciliation algorithm with processing speed up to 25 Mbps. To optimize the stability of the system, several key techniques are developed, which include a novel phase compensation algorithm, a polarization feedback algorithm, and related stability method on the modulators. Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance. Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions.

No MeSH data available.


Related in: MedlinePlus

The layout of 25 MHz CVQKD system.CW Laser, continuous wave laser; AM, amplitude modulator; BS, beam splitter; PM, phase modulator; PBS, polarizing beam splitter; FM, Faraday mirror; CWDM, Coarse Wavelength Division Multiplexer; ATT., attenuator; VOA, Variable Optical Attenuator; DPC, dynamic polarization controller. C.W. draws the whole Fig. 1.
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f1: The layout of 25 MHz CVQKD system.CW Laser, continuous wave laser; AM, amplitude modulator; BS, beam splitter; PM, phase modulator; PBS, polarizing beam splitter; FM, Faraday mirror; CWDM, Coarse Wavelength Division Multiplexer; ATT., attenuator; VOA, Variable Optical Attenuator; DPC, dynamic polarization controller. C.W. draws the whole Fig. 1.

Mentions: Our system consists of three key parts: optical module, controlling module and post-processing module. The optical module is employed to implement encoding and decoding of secret key by using quantum signal states and local oscillator (LO) signals. The optical module also includes synchronization and classical communication which are necessary in a CVQKD system. The controlling module is used to support the optical module so that the classical and quantum communication procedures can run well. The post-processing procedures module is employed to implement error correction and privacy amplification to output a final secure key. The layout of our proposed CVQKD system is plotted in Fig. 1.


25 MHz clock continuous-variable quantum key distribution system over 50 km fiber channel.

Wang C, Huang D, Huang P, Lin D, Peng J, Zeng G - Sci Rep (2015)

The layout of 25 MHz CVQKD system.CW Laser, continuous wave laser; AM, amplitude modulator; BS, beam splitter; PM, phase modulator; PBS, polarizing beam splitter; FM, Faraday mirror; CWDM, Coarse Wavelength Division Multiplexer; ATT., attenuator; VOA, Variable Optical Attenuator; DPC, dynamic polarization controller. C.W. draws the whole Fig. 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588593&req=5

f1: The layout of 25 MHz CVQKD system.CW Laser, continuous wave laser; AM, amplitude modulator; BS, beam splitter; PM, phase modulator; PBS, polarizing beam splitter; FM, Faraday mirror; CWDM, Coarse Wavelength Division Multiplexer; ATT., attenuator; VOA, Variable Optical Attenuator; DPC, dynamic polarization controller. C.W. draws the whole Fig. 1.
Mentions: Our system consists of three key parts: optical module, controlling module and post-processing module. The optical module is employed to implement encoding and decoding of secret key by using quantum signal states and local oscillator (LO) signals. The optical module also includes synchronization and classical communication which are necessary in a CVQKD system. The controlling module is used to support the optical module so that the classical and quantum communication procedures can run well. The post-processing procedures module is employed to implement error correction and privacy amplification to output a final secure key. The layout of our proposed CVQKD system is plotted in Fig. 1.

Bottom Line: In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate.Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance.Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Key Laboratory on Navigation and Location-based Service, and Center of Quantum Information Sensing and Processing, Shanghai Jiao Tong University, Shanghai 200240, China.

ABSTRACT
In this paper, a practical continuous-variable quantum key distribution system is developed and it runs in the real-world conditions with 25 MHz clock rate. To reach high-rate, we have employed a homodyne detector with maximal bandwidth to 300 MHz and an optimal high-efficiency error reconciliation algorithm with processing speed up to 25 Mbps. To optimize the stability of the system, several key techniques are developed, which include a novel phase compensation algorithm, a polarization feedback algorithm, and related stability method on the modulators. Practically, our system is tested for more than 12 hours with a final secret key rate of 52 kbps over 50 km transmission distance, which is the highest rate so far in such distance. Our system may pave the road for practical broadband secure quantum communication with continuous variables in the commercial conditions.

No MeSH data available.


Related in: MedlinePlus