Gaussian-modulated coherent state quantum key distribution experiment over 20km telecommunication fiber

Bing Qi; Lei-Lei Huang; Yue-Meng Chi; Li Qian; Hoi-Kwong Lo

doi:10.1117/12.793854

5 September 2008 Gaussian-modulated coherent state quantum key distribution experiment over 20km telecommunication fiber

Bing Qi, Lei-Lei Huang, Yue-Meng Chi, Li Qian, Hoi-Kwong Lo

Author Affiliations +

Proceedings Volume 7092, Quantum Communications and Quantum Imaging VI; 70920J (2008) https://doi.org/10.1117/12.793854
Event: Optical Engineering + Applications, 2008, San Diego, California, United States

Abstract

In most implementations of quantum-key-distribution (QKD) protocols the secure keys originate from single-photon signals. However, due to the unavoidable channel losses and the low efficiencies of single photon detectors, the key generation rate of a single-photon QKD system is low. Recently, there has been a growing interest in the Gaussianmodulated coherent state (GMCS) QKD protocol because it can be implemented with conventional laser sources and high efficiency homodyne-detectors. Here, we present our experimental results with a fully fiber-based one-way GMCS QKD system. Our system employed a double Mach-Zehnder interferometer (MZI) configuration in which the weak quantum signal and the strong local-oscillator (LO) go through the same fiber between Alice and Bob. We employed two novel techniques to suppress system excess noise. First, to suppress the LO's leakage, an important contribution to the excess noise, we implemented a scheme combining polarization and frequency multiplexing, achieving an extinction ratio of 70dB. Second, to further minimize the system excess noise due to phase drift of the double MZI, the sender simply remaps her data by performing a rotation operation. Under a "realistic model", the secure key rates determined with a 5km and a 20km fiber link are 0.3bit/pulse and 0.05bit/pulse, respectively. These key rates are significantly higher than that of a practical BB84 QKD system.

Citation Download Citation

Bing Qi, Lei-Lei Huang, Yue-Meng Chi, Li Qian, and Hoi-Kwong Lo "Gaussian-modulated coherent state quantum key distribution experiment over 20km telecommunication fiber", Proc. SPIE 7092, Quantum Communications and Quantum Imaging VI, 70920J (5 September 2008); https://doi.org/10.1117/12.793854

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
9 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Quantum key distribution

Polarization

Homodyne detection

Sensors

Modulators

Laser energy

Multiplexing

Show All Keywords

Keywords/Phrases

Search In:

Publication Years