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

Journal of Lightwave Technology

Measurement-Device-Independent Quantum Key Distribution With Hybrid Integrated Self-Injection Locking Lasers

Xiao-Lei Jiang, Y P Guo, Yan-Yang Zhou, Yu Zhou, X. L. Li, Yifei Lu, Yang Wang, Jia-Ji Li, Chun Zhou, Hong-Wei Li, Linjie Zhou, Wan-Su Bao

Published Jun 2, 2026• 1 citation
Publisher

Abstract

Breakthroughs in chip integration technology have accelerated the practical deployment and scalable implementation of quantum key distribution (QKD). On-chip quantum light sources are critical components of fully integrated QKD systems. Measurement-Device-Independent QKD (MDI-QKD) offers significant advantages in network communication by eliminating vulnerabilities to side-channel attacks at the detector side, while relying on high-visibility Hong-Ou-Mandel interference between photons emitted by two independent lasers. Here, we present an innovative design of the silicon-based hybrid integrated self-injection locking (SIL) laser chip that achieves high-frequency-stability operation with the frequency detuning between independent lasers suppressed to within 15 MHz, enabling high-visibility HOM interference in MDI-QKD. Leveraging this design, we experimentally demonstrate a loss-tolerant MDI-QKD system employing the setting-choice-independent correlation security framework explicitly accounting for state-preparation uncertainty. The system achieves a finite-key secret rate of 17 b/s under 34 dB channel loss (or 170-km standard fiber), surpassing previously reported MDI-QKD experiments that incorporated state preparation uncertainty under equivalent transmission loss conditions. Our result makes a promising contribution to practical applications of fully integrated quantum communication networks.

DOI
10.1109/jlt.2026.3698961

Related papers

High-Speed Measurement-Device-Independent Quantum Key Distribution with Integrated Silicon Photonics

Kejin Wei, Wei Li, Hao Tan +12 more

Measurement-device-independent quantum key distribution (MDI QKD) removes all detector side channels and enables secure QKD with an untrusted relay.It is suitable for building a star-type quantum access network, where the complicated and expensive measurement devices are placed in the central untrusted relay and each user requires only a low-cost transmitter, such as an integrated photonic chip.Here, we experimentally demonstrate a 1.25-GHz silicon photonic chip-based MDI QKD system using polarization encoding.The photonic chip transmitters integrate the necessary encoding components for a standard QKD source.We implement random modulations of polarization states and decoy intensities, and demonstrate a finite-key secret rate of 31 bit=s over 36-dB channel loss (or 180-km standard fiber).This key rate is higher than state-of-the-art MDI QKD experiments.The results show that silicon photonic chipbased MDI QKD, benefiting from miniaturization, low-cost manufacture, and compatibility with CMOS microelectronics, is a promising solution for future quantum secure networks.

arXiv:1911.00690•Physical Review X•Aug 10, 2020•233 citations

Gigahertz measurement-device-independent quantum key distribution using directly modulated lasers

Robert I. Woodward, Yuen San Lo, Mirko Pittaluga +5 more

Abstract Measurement-device-independent quantum key distribution (MDI-QKD) is a technique for quantum-secured communication that eliminates all detector side-channels, although is currently limited by implementation complexity and low secure key rates. Here, we introduce a simple and compact MDI-QKD system design at gigahertz clock rates with enhanced resilience to laser fluctuations—thus enabling free-running semiconductor laser sources to be employed without spectral or phase feedback. This is achieved using direct laser modulation, carefully exploiting gain-switching and injection-locking laser dynamics to encode phase-modulated time-bin bits. Our design enables secure key rates that improve upon the state of the art by an order of magnitude, up to 8 bps at 54 dB channel loss and 2 kbps in the finite-size regime for 30 dB channel loss. This greatly simplified MDI-QKD system design and proof-of-principle demonstration shows that MDI-QKD is a practical, high-performance solution for future quantum communication networks.

arXiv:2105.06748•npj Quantum Information•Apr 8, 2021•88 citations

Interference between independent photonic integrated devices for quantum key distribution

Henry Semenenko, Philip Sibson, Mark G. Thompson +1 more

Advances in quantum computing are a rapidly growing threat towards modern cryptography. Quantum key distribution (QKD) provides long-term security without assuming the computational power of an adversary. However, inconsistencies between theory and experiment have raised questions in terms of real-world security, while large and power-hungry commercial systems have slowed wide-scale adoption. Measurement-device-independent QKD (MDI-QKD) provides a method of sharing secret keys that removes all possible detector side-channel attacks which drastically improves security claims. In this Letter, we experimentally demonstrate a key step required to perform MDI-QKD with scalable integrated devices. We show Hong-Ou-Mandel interference between weak coherent states carved from two independent indium phosphide transmitters at 431 MHz with a visibility of 46.5±0.8%. This Letter demonstrates the feasibility of using integrated devices to lower a major barrier towards the adoption of QKD in metropolitan networks.

arXiv:1901.05706•Optics Letters•Jan 4, 2019•30 citations

Free-Space and Fiber-Integrated Measurement-Device-Independent Quantum Key Distribution under High Background Noise

Yu-Huai Li, Shuang-Lin Li, Xiao-Long Hu +16 more

Measurement-device-independent quantum key distribution (MDI QKD) provides immunity against all attacks targeting measurement devices. It is essential to implement MDI QKD in the future global-scale quantum communication network. Toward this goal, we demonstrate a robust MDI QKD fully covering daytime, overcoming the high background noise that prevents BB84 protocol even when using a perfect single-photon source. Based on this, we establish a hybrid quantum communication network that integrates free-space and fiber channels through Hong-Ou-Mandle (HOM) interference. Additionally, we investigate the feasibility of implementing HOM interference with moving satellites. Our results serve as a significant cornerstone for future integrated space-ground quantum communication networks that incorporate measurement-device-independent security.

Physical Review Letters•Sep 6, 2023•40 citations

Practical Source Security of On-chip Continuous Variable Measurement Device Independent Quantum Key Distribution

Lang Li, Tao Wang, Peng Huang +4 more

In the evolving field of Continuous Variable Quantum Key Distribution (CV-QKD), notable for its synergistic potential with existing optical communication infrastructures, a high channel capacity, and an anticipated surge in secret rates, the Measurement Device Independent (MDI) framework stands as a bulwark against side-channel vulnerabilities at the measurement juncture [1] –[4]. Recent years have witnessed quantum photonics technology leapfrogging into a realm that promises the realization of fully integrated CV-MDI-QKD transmitter terminals, a cornerstone for large-scale CV-MDI-QKD networks. However, integrating high-efficiency on-chip light sources while effectively navigating the treacherous waters of practical security challenges remains a formidable task [5], [6]. This study is pioneering in its focus on the practical security intricacies stemming from imperfections in on-chip light sources within CV-MDI-QKD systems. We propose defense mechanisms tailored to shield against the risks associated with source defects, thereby laying a robust foundation for secure, reliable on-chip CV-MDI-QKD transmission terminals. This advancement is a critical enabler for the widespread adoption of CV-MDI-QKD, signaling a paradigm shift in secure communications.

Photonics & Electromagnetics Research Symposium (PIERS)•Apr 21, 2024•4 citations

Real-field Hong–Ou–Mandel interference of indistinguishable coherent photons via long optical injection-locking over 50 km fiber

Seoyeon Yang, Danbi Kim, Hansol Jeong +1 more

Measurement-device-independent quantum key distribution (MDI-QKD) has garnered significant attention for enabling security-loophole-free quantum communication. Successful MDI-QKD protocols rely on performing a two-photon Bell-state measurement at an intermediate node, where achieving a high-visibility Hong-Ou-Mandel (HOM) interference pattern between two independent coherent photons is crucial. In this study, we present an approach for developing indistinguishable coherent photon sources over 50 km of optical fiber under real-world conditions. We introduce the long optical injection-locking (long-OIL) technique, which enables frequency locking between two long-distance coherent photons separated by distances exceeding the coherence length of the master laser. Utilizing the long-OIL technique, we achieved time-resolved HOM interference with a visibility of 48(2)%, which is close to the theoretical limits of 50% for two independent continuous-wave coherent photons. Our results indicate that the long-OIL platform is a promising solution for MDI-QKD with repeaterless secret-key capacity.

arXiv:2502.04772•Optics Express•Jun 16, 2025•0 citations
Breakthroughs in chip integration technology have accelerated the practical deployment and scalable implementation of quantum key distribution (QKD). On-chip quantum light sources are critical components of fully integrated QKD systems. Measurement-Device-Independent QKD (MDI-QKD) offers significant advantages in network communication by eliminating vulnerabilities to side-channel attacks at the detector side, while relying on high-visibility Hong-Ou-Mandel interference between photons emitted by two independent lasers. Here, we present an innovative design of the silicon-based hybrid integrated self-injection locking (SIL) laser chip that achieves high-frequency-stability operation with the frequency detuning between independent lasers suppressed to within 15 MHz, enabling high-visibility HOM interference in MDI-QKD. Leveraging this design, we experimentally demonstrate a loss-tolerant MDI-QKD system employing the setting-choice-independent correlation security framework explicitly accounting for state-preparation uncertainty. The system achieves a finite-key secret rate of 17 b/s under 34 dB channel loss (or 170-km standard fiber), surpassing previously reported MDI-QKD experiments that incorporated state preparation uncertainty under equivalent transmission loss conditions. Our result makes a promising contribution to practical applications of fully integrated quantum communication networks.
Measurement-device-independent quantum key distribution (MDI QKD) removes all detector side channels and enables secure QKD with an untrusted relay.It is suitable for building a star-type quantum access network, where the complicated and expensive measurement devices are placed in the central untrusted relay and each user requires only a low-cost transmitter, such as an integrated photonic chip.Here, we experimentally demonstrate a 1.25-GHz silicon photonic chip-based MDI QKD system using polarization encoding.The photonic chip transmitters integrate the necessary encoding components for a standard QKD source.We implement random modulations of polarization states and decoy intensities, and demonstrate a finite-key secret rate of 31 bit=s over 36-dB channel loss (or 180-km standard fiber).This key rate is higher than state-of-the-art MDI QKD experiments.The results show that silicon photonic chipbased MDI QKD, benefiting from miniaturization, low-cost manufacture, and compatibility with CMOS microelectronics, is a promising solution for future quantum secure networks.
Abstract Measurement-device-independent quantum key distribution (MDI-QKD) is a technique for quantum-secured communication that eliminates all detector side-channels, although is currently limited by implementation complexity and low secure key rates. Here, we introduce a simple and compact MDI-QKD system design at gigahertz clock rates with enhanced resilience to laser fluctuations—thus enabling free-running semiconductor laser sources to be employed without spectral or phase feedback. This is achieved using direct laser modulation, carefully exploiting gain-switching and injection-locking laser dynamics to encode phase-modulated time-bin bits. Our design enables secure key rates that improve upon the state of the art by an order of magnitude, up to 8 bps at 54 dB channel loss and 2 kbps in the finite-size regime for 30 dB channel loss. This greatly simplified MDI-QKD system design and proof-of-principle demonstration shows that MDI-QKD is a practical, high-performance solution for future quantum communication networks.
Advances in quantum computing are a rapidly growing threat towards modern cryptography. Quantum key distribution (QKD) provides long-term security without assuming the computational power of an adversary. However, inconsistencies between theory and experiment have raised questions in terms of real-world security, while large and power-hungry commercial systems have slowed wide-scale adoption. Measurement-device-independent QKD (MDI-QKD) provides a method of sharing secret keys that removes all possible detector side-channel attacks which drastically improves security claims. In this Letter, we experimentally demonstrate a key step required to perform MDI-QKD with scalable integrated devices. We show Hong-Ou-Mandel interference between weak coherent states carved from two independent indium phosphide transmitters at 431 MHz with a visibility of 46.5±0.8%. This Letter demonstrates the feasibility of using integrated devices to lower a major barrier towards the adoption of QKD in metropolitan networks.
Measurement-device-independent quantum key distribution (MDI QKD) provides immunity against all attacks targeting measurement devices. It is essential to implement MDI QKD in the future global-scale quantum communication network. Toward this goal, we demonstrate a robust MDI QKD fully covering daytime, overcoming the high background noise that prevents BB84 protocol even when using a perfect single-photon source. Based on this, we establish a hybrid quantum communication network that integrates free-space and fiber channels through Hong-Ou-Mandle (HOM) interference. Additionally, we investigate the feasibility of implementing HOM interference with moving satellites. Our results serve as a significant cornerstone for future integrated space-ground quantum communication networks that incorporate measurement-device-independent security.
In the evolving field of Continuous Variable Quantum Key Distribution (CV-QKD), notable for its synergistic potential with existing optical communication infrastructures, a high channel capacity, and an anticipated surge in secret rates, the Measurement Device Independent (MDI) framework stands as a bulwark against side-channel vulnerabilities at the measurement juncture [1] –[4]. Recent years have witnessed quantum photonics technology leapfrogging into a realm that promises the realization of fully integrated CV-MDI-QKD transmitter terminals, a cornerstone for large-scale CV-MDI-QKD networks. However, integrating high-efficiency on-chip light sources while effectively navigating the treacherous waters of practical security challenges remains a formidable task [5], [6]. This study is pioneering in its focus on the practical security intricacies stemming from imperfections in on-chip light sources within CV-MDI-QKD systems. We propose defense mechanisms tailored to shield against the risks associated with source defects, thereby laying a robust foundation for secure, reliable on-chip CV-MDI-QKD transmission terminals. This advancement is a critical enabler for the widespread adoption of CV-MDI-QKD, signaling a paradigm shift in secure communications.
Measurement-device-independent quantum key distribution (MDI-QKD) has garnered significant attention for enabling security-loophole-free quantum communication. Successful MDI-QKD protocols rely on performing a two-photon Bell-state measurement at an intermediate node, where achieving a high-visibility Hong-Ou-Mandel (HOM) interference pattern between two independent coherent photons is crucial. In this study, we present an approach for developing indistinguishable coherent photon sources over 50 km of optical fiber under real-world conditions. We introduce the long optical injection-locking (long-OIL) technique, which enables frequency locking between two long-distance coherent photons separated by distances exceeding the coherence length of the master laser. Utilizing the long-OIL technique, we achieved time-resolved HOM interference with a visibility of 48(2)%, which is close to the theoretical limits of 50% for two independent continuous-wave coherent photons. Our results indicate that the long-OIL platform is a promising solution for MDI-QKD with repeaterless secret-key capacity.