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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Active polarization stabilization in optical fibers suitable for quantum key distribution.
1State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, People's Republic of China.
Optics Express
|June 25, 2009
Summary
Stable quantum key distribution is now possible over long fiber optic cables. Polarization control of single photons over 10 hours ensures secure, long-term quantum communication.
Area of Science:
- Quantum Information Science
- Optical Communications
- Quantum Cryptography
Background:
- Quantum key distribution (QKD) offers enhanced security over classical cryptography.
- Maintaining polarization stability in single-photon signals over long distances is a significant challenge in fiber-based QKD.
Purpose of the Study:
- To demonstrate long-term polarization feedback control for single-photon pulses in optical fibers.
- To enable stable, one-way polarization-encoded quantum key distribution over extended periods.
Main Methods:
- Implementing a polarization feedback control system for single-photon pulses.
- Conducting experiments using 75 km of optical fiber.
- Monitoring quantum bit error rate (QBER) over extended operational times.
Main Results:
- Achieved polarization feedback control of single-photon pulses for over 10 hours.
- Demonstrated a typical quantum bit error rate (QBER) of (3.9+/-1.5)% in 75 km fiber transmission.
- Confirmed long-term stability for polarization-encoded quantum key distribution.
Conclusions:
- Polarization feedback control is effective for stabilizing single-photon signals in long-distance fiber optic channels.
- This technique facilitates robust and secure one-way quantum key distribution with practical long-term operational capabilities.
