Modulator-free coherent-one-way quantum key distribution

Abstract

Time-bin encoding is an attractive method for transmitting photonic qubits over long distances with minimal decoherence. It allows a simple receiver for quantum key distribution (QKD) that extracts a key by measuring time of arrival of photons and detects eavesdropping by measuring interference of pulses in different time bins. In the past, coherent pulses have been generated using a CW laser and an intensity modulator. A greatly simplified transmitter is proposed and demonstrated here that works by directly modulating the laser diode. Coherence between pulses is maintained by a weak seed laser. The modulator-free source creates time-bin encoded pulses with a high extinction ratio (29.4 dB) and an interference visibility above 97 %. The resulting QKD transmitter gives estimated secure key rates up to 4.57 Mbit/s, the highest yet reported for coherent-one-way QKD, and can be programmed for all protocols using weak coherent pulses.

4 pages, 3 figures

References in corpus (10)

• Quantum Cryptography
• The Security of Practical Quantum Key Distribution
• Practical challenges in quantum key distribution
• Provably Secure and Practical Quantum Key Distribution over 307 km of Optical Fibre
• Quantum cryptography without detector vulnerabilities using optically-seeded lasers
• Efficient decoy-state quantum key distribution with quantified security
• Quantum key distribution for 10 Gb/s dense wavelength division multiplexing networks
• Long-distance quantum key distribution secure against coherent attacks
• Continuous operation of high bit rate quantum key distribution
• Amplification of nanosecond laser pulse chain via dynamic injection locking of laser diode

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• Finite-Key Analysis for Coherent One-Way Quantum Key Distribution
• A direct GHz-clocked phase and intensity modulated transmitter applied to quantum key distribution
• Self-Tuning Transmitter for Quantum Key Distribution Using Machine Intelligence
• Manipulating photon coherence to enhance the security of practical quantum key distribution
• Low-error encoder for time-bin and decoy states for quantum key distribution
• Optical transmitter tunable over a 65-nm wavelength range around 1550 nm for quantum key distribution
• Experimental Coherent One-Way Quantum Key Distribution with Simplicity and Practical Security
• Simulations of distributed-phase-reference quantum key distribution protocols
• Photonic quantum information with time-bins: Principles and applications
• Increasing the secret key rates and point-to-multipoint extension for experimental coherent-one-way quantum key distribution protocol