Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Telecommunications and Radio Engineering

Dispersional Restriction of the Transmission Link Length in Quantum Cryptographic Telecommunication Systems with Polarization Encoding

Р. И. Цехмистро, Murad Omarov

Published Jan 1, 2009• 0 citations
Publisher

Abstract

The existing means for increasing of transmission stability in quantum and fiber optic telecommunication systems with polarization encoding are analyzed. It is suggested the evaluation of signal propagation delay incurred by dispersion inherent to the present-day fiber optic applied in the systems of transmission up to 150...2000 km as compared to the coherence interval of GaAs semiconductor lasers. Recommendations on optimal application of optical fiber and laser in practically used quantum cryptographic transmission systems with polarization encoding are provided.

DOI
10.1615/telecomradeng.v68.i20.60

Related papers

To the question of quantum cryptography transmission system with polarized coding development

Р. И. Цехмистро, A.N. Kostuk

There is analysed the existing methods of stability increase for key transmission of quantum cryptographic optical communication system with polarized coding. Also there is estimated the mode dispersion delay for the modern optical fibers, used in communication system range 150-200 km, in comparison to coherency interval of semiconductor lasers, based on GaAs. The recommendations of optic using of optical fibers and lasers for real quantum cryptography systems are given.

International Workshop on Optoelectronic Physics and Technology•Jun 1, 2007•0 citations

Investigation on nonlinear polarization coupling in quantum key distribution

Dong Ying-d

Because of the effect of nonlinear polarization of transmission fiber,coupling ratio between local oscillator and quantum signal in a quantum key distribution system is decreased,signal jitters which leads to polarization multiplexing is increased,and security and stability of the system are decreased. To enhance technical performance of polarization encodement of quantum optics,after theoretical analysis and numerical simulation,operational experiment scheme was proposed to solve the polarization jitters caused by nonlinear polarization coupling of fiber. The results show that signal stability of polarization multiplexing enhances and transmission capacity of quantum key distribution increases to 61% by using feedback of spectral test results to control fiber nonlinear polarization coupling ratio between local oscillator and quantum signal. The research is helpful for practical application of polarization coding technology in quantum key distribution.

Laser Technology•Jan 1, 2015•0 citations

Enabling quantum communications through accurate photons polarization control

Álvaro J. Almeida, Nelson Jesus Muga, Nuno A. Silva +5 more

The rapid increase on the information sharing around the world, leads to an utmost requirement for capacity and bandwidth. However, the need for security in the transmission and storage of information is also of major importance. The use of quantum technologies provides a practical solution for secure communications systems. Quantum key distribution (QKD) was the first practical application of quantum mechanics, and nowadays it is the most developed one. In order to share secret keys between two parties can be used several methods of encoding. Due to its simplicity, the encoding into polarization is one of the most used. However, when we use optical fibers as transmission channels, the polarization suffers random rotations that may change the state of polarization (SOP) of the light initially sent to the fiber to a new one at the output. Thus, in order to enable real-time communication using this encoding method it is required the use of a dynamic control system. We describe a scheme of transmission of quantum information, which is based in the polarization encoding, and that allows to share secret keys through optical fibers without interruption. The dynamic polarization control system used in such scheme is described, both theoretically and experimentally. Their advantages and limitations for the use in quantum communications are presented and discussed.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 18, 2013•6 citations

Stable polarization coded quantum communication through single mode optical fibers

GUILHERME BARRETO XAVIER, G. Vilela de Faria, Guilherme P. Temporão +3 more

We perform a transmission of polarization encoded quantum bits through 16 km of single mode optical fiber in the 1550 nm window.The polarization drift caused by the changing birefringence of the fiber is kept stable through the use of a polarization control system we developed.This system employs 2 classical reference signals with 0.8 nm spacing from the quantum channel.We also send through the same fiber an extra reference classical signal used to trigger the single-photon detector.To the best of our knowledge this is the first time a quantum channel is multiplexed with 3 classical signals in the same optical fiber.

Anais de XXXV Simpósio Brasileiro de Telecomunicações e Processamento de Sinais•Jan 1, 2008•0 citations

A Review on Secure Communication in Fiber-Optic Networks

T.Naga Jyothi

Fiber optic systems are important telecommunication infrastructure for world-wide broadband networks. Wide bandwidth signal transmission with low delay is a key requirement in present day applications. Optical fibers provide enormous and unsurpassed transmission bandwidth with negligible latency, and are now the transmission medium of choice for long distance and high data rate transmission in telecommunication networks. This paper gives an overview of fiber optic communication systems including their key technologies, and also discusses their technological trend towards the next generation

International Journal of Advanced Research in Science and Technology•Jan 1, 2017•0 citations

QBER Estimation in QKD Systems With Polarization Encoding

Nelson Jesus Muga, Mário F. S. Ferreira, Armando N. Pinto

A model for quantum BER estimation in polarization encoded quantum key distribution systems is presented. Both TDM and WDM based polarization control schemes are analyzed. It is shown that TDM presents some important advantages when compared with the WDM control scheme. In WDM, the polarization decorrelation between the reference and data signals is an intrinsic and very limitative impairment. This effect has a contribution to quantum BER that increases with the propagation distance, and is highly dependent on the fiber polarization mode dispersion. In the TDM control scheme, the polarization decorrelation is less critical and other issues, like the single photon detector and feedback polarization control system performance tend to dominate. We show that for long distances the fiber losses represent the main contribution to the total quantum BER. Nevertheless, for distances shorter than 70 km and frequencies higher than 5 MHz the after pulse detections provide an important contribution to the total quantum BER.

Journal of Lightwave Technology•Dec 22, 2010•43 citations
The existing means for increasing of transmission stability in quantum and fiber optic telecommunication systems with polarization encoding are analyzed. It is suggested the evaluation of signal propagation delay incurred by dispersion inherent to the present-day fiber optic applied in the systems of transmission up to 150...2000 km as compared to the coherence interval of GaAs semiconductor lasers. Recommendations on optimal application of optical fiber and laser in practically used quantum cryptographic transmission systems with polarization encoding are provided.
Because of the effect of nonlinear polarization of transmission fiber,coupling ratio between local oscillator and quantum signal in a quantum key distribution system is decreased,signal jitters which leads to polarization multiplexing is increased,and security and stability of the system are decreased. To enhance technical performance of polarization encodement of quantum optics,after theoretical analysis and numerical simulation,operational experiment scheme was proposed to solve the polarization jitters caused by nonlinear polarization coupling of fiber. The results show that signal stability of polarization multiplexing enhances and transmission capacity of quantum key distribution increases to 61% by using feedback of spectral test results to control fiber nonlinear polarization coupling ratio between local oscillator and quantum signal. The research is helpful for practical application of polarization coding technology in quantum key distribution.
The rapid increase on the information sharing around the world, leads to an utmost requirement for capacity and bandwidth. However, the need for security in the transmission and storage of information is also of major importance. The use of quantum technologies provides a practical solution for secure communications systems. Quantum key distribution (QKD) was the first practical application of quantum mechanics, and nowadays it is the most developed one. In order to share secret keys between two parties can be used several methods of encoding. Due to its simplicity, the encoding into polarization is one of the most used. However, when we use optical fibers as transmission channels, the polarization suffers random rotations that may change the state of polarization (SOP) of the light initially sent to the fiber to a new one at the output. Thus, in order to enable real-time communication using this encoding method it is required the use of a dynamic control system. We describe a scheme of transmission of quantum information, which is based in the polarization encoding, and that allows to share secret keys through optical fibers without interruption. The dynamic polarization control system used in such scheme is described, both theoretically and experimentally. Their advantages and limitations for the use in quantum communications are presented and discussed.
We perform a transmission of polarization encoded quantum bits through 16 km of single mode optical fiber in the 1550 nm window.The polarization drift caused by the changing birefringence of the fiber is kept stable through the use of a polarization control system we developed.This system employs 2 classical reference signals with 0.8 nm spacing from the quantum channel.We also send through the same fiber an extra reference classical signal used to trigger the single-photon detector.To the best of our knowledge this is the first time a quantum channel is multiplexed with 3 classical signals in the same optical fiber.
Fiber optic systems are important telecommunication infrastructure for world-wide broadband networks. Wide bandwidth signal transmission with low delay is a key requirement in present day applications. Optical fibers provide enormous and unsurpassed transmission bandwidth with negligible latency, and are now the transmission medium of choice for long distance and high data rate transmission in telecommunication networks. This paper gives an overview of fiber optic communication systems including their key technologies, and also discusses their technological trend towards the next generation
A model for quantum BER estimation in polarization encoded quantum key distribution systems is presented. Both TDM and WDM based polarization control schemes are analyzed. It is shown that TDM presents some important advantages when compared with the WDM control scheme. In WDM, the polarization decorrelation between the reference and data signals is an intrinsic and very limitative impairment. This effect has a contribution to quantum BER that increases with the propagation distance, and is highly dependent on the fiber polarization mode dispersion. In the TDM control scheme, the polarization decorrelation is less critical and other issues, like the single photon detector and feedback polarization control system performance tend to dominate. We show that for long distances the fiber losses represent the main contribution to the total quantum BER. Nevertheless, for distances shorter than 70 km and frequencies higher than 5 MHz the after pulse detections provide an important contribution to the total quantum BER.