Interference of Short Optical Pulses from Independent Gain-Switched Laser Diodes for Quantum Secure Communications
- 17 December 2014
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Applied
- Vol. 2 (6), 064006
- https://doi.org/10.1103/physrevapplied.2.064006
Abstract
Since the introduction of the decoy-state technique, phase-randomized weak coherent light pulses have been the key to increase the practicality of quantum-based communications. Their ultrafast generation was accomplished via compact gain-switched (GS) lasers, leading to high key rates in quantum key distribution (QKD). Recently, the question arose whether the same laser could be employed to achieve high-speed measurement-device-independent QKD, a scheme that promises long-haul quantum communications immune to all detector attacks. For that, a challenging high-visibility interference between independent picosecond optical pulses is required. Here, we answer the above question in the affirmative by demonstrating high-visibility interference from two independent GS lasers triggered at 1 GHz. The result is obtained through a careful characterization of the laser frequency chirp and time jitter. By relating these quantities to the interference visibility, we obtain a parameter-free verification of the experimental data and a numerical simulation of the achievable key rates. These findings are beneficial to other applications making use of GS lasers, including random number generation and standard QKD.Keywords
This publication has 31 references indexed in Scilit:
- Interference of dissimilar photon sourcesNature Physics, 2009
- Experimental Interference of Independent PhotonsPhysical Review Letters, 2006
- Quantum interference between two single photons emitted by independently trapped atomsNature, 2006
- Non-classical interference between independent sourcesJournal of Optics B: Quantum and Semiclassical Optics, 2005
- Decoy State Quantum Key DistributionPhysical Review Letters, 2005
- Quantum cryptographyReviews of Modern Physics, 2002
- A scheme for efficient quantum computation with linear opticsNature, 2001
- Quantum Repeaters: The Role of Imperfect Local Operations in Quantum CommunicationPhysical Review Letters, 1998
- Experimental quantum teleportationNature, 1997
- Measurement of subpicosecond time intervals between two photons by interferencePhysical Review Letters, 1987