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

Physical Review A

Subcarrier multiplexing optical quantum key distribution

Arturo Ortigosa-Blanch, J. Capmany

Published Feb 27, 2006• 46 citations
Publisher

Abstract

We present the physical principles of a quantum key distribution system that opens the possibility of parallel quantum key distribution and, therefore, of a substantial improvement in the bit rate of such systems. Quantum mechanics allows for multiple measurements at different frequencies and thus we exploit this concept by extending the concept of frequency coding to the case where more than one radio-frequency subcarrier is used for independently encoding the bits onto an optical carrier. Taking advantage of subcarrier multiplexing techniques we demonstrate that the bit rate can be greatly improved as parallel key distribution is enabled.

DOI
10.1103/physreva.73.024305

Related papers

Experimental demonstration of subcarrier multiplexed quantum key distribution system

Jose Mora, A. Ruiz-Alba, Waldimar Amaya +4 more

We provide, to our knowledge, the first experimental demonstration of the feasibility of sending several parallel keys by exploiting the technique of subcarrier multiplexing (SCM) widely employed in microwave photonics. This approach brings several advantages such as high spectral efficiency compatible with the actual secure key rates, the sharing of the optical fainted pulse by all the quantum multiplexed channels reducing the system complexity, and the possibility of upgrading with wavelength division multiplexing in a two-tier scheme, to increase the number of parallel keys. Two independent quantum SCM channels featuring a sifted key rate of 10 Kb/s/channel over a link with quantum bit error rate <2% is reported.

Optics Letters•May 29, 2012•36 citations

Subcarrier multiplexing quantum key distribution based on polarization coding

Guhao Zhao, Zhao Shang-Hong, Zhoushi Yao +4 more

A subcarrier multiplexing quantum key distribution is based on phase modulation polarization coding scheme. The key could be shared by several parallel sideband channels, and each sideband has a random and independent polarization which is synthesized by controlling the phase difference of subcarriers in two electro-optical phase modulators. The key rate could be increased multiply. The simulation result shows that the scheme works well.

Acta Physica Sinica•Jan 1, 2012•2 citations

Microwave Photonics Parallel Quantum Key Distribution

A. Ruiz-Alba, Jose Mora, Waldimar Amaya +4 more

The incorporation of multiplexing techniques used in microwave photonics to quantum key distribution (QKD) systems brings important advantages by enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information and QKD channels over a single optical fiber infrastructure. In this paper, we show, for the first time to our knowledge, the successful operation of a two-domain (subcarrier and wavelength division) multiplexed strong reference BB84 QKD system. A four-independent channel QKD system featuring a sifted key rate of 10 kb/s/channel over an 11-km link with quantum bit error rate (QBER)$<$2% is reported. These results open the way for multi-QKD over optical fiber networks.

IEEE photonics journal•May 24, 2012•14 citations

Microwave Photonics Parallel Quantum Key Distribution

Jose Mora, A. Ruiz-Alba, Waldimar Amaya +4 more

The incorporation of multiplexing techniques used in Microwave Photonics to Quantum Key Distribution (QKD) systems bring important advantages enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information and quantum key distribution channels over a single optical fibre infrastructure. Here we show, for the first time to our knowledge, the successful operation of a two domain (subcarrier and wavelength division) multiplexed strong reference BB84 quantum key distribution system. A four independent channel QKD system featuring 10 kb/s/channel over an 11 km link with Quantum Bit Error Rate (QBER) < 2 % is reported. These results open the way for multi-quantum key distribution over optical fiber networks.

arXiv:1112.3439•Dec 15, 2011•3 citations

Practical Quantum Key Distribution based on the BB84 protocol

A. Ruiz-Alba, David C. Calvo, Víctor García-Muñoz +5 more

[EN] This paper provides a review of the most important and widely used Quantum Key Distribution systems and then describes our recently proposed scheme based on Subcarrier Multiplexing that opens the possibility of parallel Quantum Key Distribution. We report the first-ever experimental implementation of parallel quantum key distribution using this technique showing a maximum multiplexing gain.

•Jan 1, 2011•19 citations

QUANTUM KEY DISTRIBUTION IN OPTICAL COMMUNICATION NETWORKS

Akabarsaheb Babulal Nadaf, RajeshKumar Rameshbhai Savaliya, Vinay Kumar Nassa +1 more

Background: Quantum Key Distribution (QKD( is a promising technology for secure communication, leveraging the principles of quantum mechanics to provide theoretically unbreakable encryption. With the exponential growth in data traffic and the increasing need for secure communication in backbone fiber networks, integrating high-bit-rate multiplexing techniques into QKD systems can enhance their efficiency and scalability. Problem: Traditional QKD systems face limitations in terms of data rate and network scalability, particularly in high-capacity optical communication networks. As data demands increase, there is a critical need for methods that can support high-bit-rate multiplexing while maintaining the security and performance of QKD. Method: This study proposes a novel QKD approach using high-bit-rate multiplexing in backbone fiber networks. The method involves encoding quantum keys using multiple optical channels simultaneously to increase the data throughput of the QKD system. We employ a combination of time-division multiplexing (TDM( and wavelength-division multiplexing (WDM( to optimize the use of fiber resources and enhance key distribution rates. Results: Simulation results demonstrate that the proposed method achieves a key distribution rate of 10 Mbps over a 200 km fiber link with a quantum bit error rate (QBER( of 1.5%. This represents a 50% improvement in key rate compared to conventional QKD systems without multiplexing. Additionally, the method shows enhanced scalability and network utilization, supporting up to 16 multiplexed channels with minimal impact on security.

ICTACT Journal on Communication Technology•Sep 1, 2024•0 citations
We present the physical principles of a quantum key distribution system that opens the possibility of parallel quantum key distribution and, therefore, of a substantial improvement in the bit rate of such systems. Quantum mechanics allows for multiple measurements at different frequencies and thus we exploit this concept by extending the concept of frequency coding to the case where more than one radio-frequency subcarrier is used for independently encoding the bits onto an optical carrier. Taking advantage of subcarrier multiplexing techniques we demonstrate that the bit rate can be greatly improved as parallel key distribution is enabled.
We provide, to our knowledge, the first experimental demonstration of the feasibility of sending several parallel keys by exploiting the technique of subcarrier multiplexing (SCM) widely employed in microwave photonics. This approach brings several advantages such as high spectral efficiency compatible with the actual secure key rates, the sharing of the optical fainted pulse by all the quantum multiplexed channels reducing the system complexity, and the possibility of upgrading with wavelength division multiplexing in a two-tier scheme, to increase the number of parallel keys. Two independent quantum SCM channels featuring a sifted key rate of 10 Kb/s/channel over a link with quantum bit error rate <2% is reported.
The incorporation of multiplexing techniques used in microwave photonics to quantum key distribution (QKD) systems brings important advantages by enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information and QKD channels over a single optical fiber infrastructure. In this paper, we show, for the first time to our knowledge, the successful operation of a two-domain (subcarrier and wavelength division) multiplexed strong reference BB84 QKD system. A four-independent channel QKD system featuring a sifted key rate of 10 kb/s/channel over an 11-km link with quantum bit error rate (QBER)$<$2% is reported. These results open the way for multi-QKD over optical fiber networks.
The incorporation of multiplexing techniques used in Microwave Photonics to Quantum Key Distribution (QKD) systems bring important advantages enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information and quantum key distribution channels over a single optical fibre infrastructure. Here we show, for the first time to our knowledge, the successful operation of a two domain (subcarrier and wavelength division) multiplexed strong reference BB84 quantum key distribution system. A four independent channel QKD system featuring 10 kb/s/channel over an 11 km link with Quantum Bit Error Rate (QBER) < 2 % is reported. These results open the way for multi-quantum key distribution over optical fiber networks.
Background: Quantum Key Distribution (QKD( is a promising technology for secure communication, leveraging the principles of quantum mechanics to provide theoretically unbreakable encryption. With the exponential growth in data traffic and the increasing need for secure communication in backbone fiber networks, integrating high-bit-rate multiplexing techniques into QKD systems can enhance their efficiency and scalability. Problem: Traditional QKD systems face limitations in terms of data rate and network scalability, particularly in high-capacity optical communication networks. As data demands increase, there is a critical need for methods that can support high-bit-rate multiplexing while maintaining the security and performance of QKD. Method: This study proposes a novel QKD approach using high-bit-rate multiplexing in backbone fiber networks. The method involves encoding quantum keys using multiple optical channels simultaneously to increase the data throughput of the QKD system. We employ a combination of time-division multiplexing (TDM( and wavelength-division multiplexing (WDM( to optimize the use of fiber resources and enhance key distribution rates. Results: Simulation results demonstrate that the proposed method achieves a key distribution rate of 10 Mbps over a 200 km fiber link with a quantum bit error rate (QBER( of 1.5%. This represents a 50% improvement in key rate compared to conventional QKD systems without multiplexing. Additionally, the method shows enhanced scalability and network utilization, supporting up to 16 multiplexed channels with minimal impact on security.