Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators

Details Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators

2006-04-25

arxiv.org/abs/quant-ph/0604187v1

Optics Express Vol. 14 p4264-4269 (2006)

Physics

Quantum Physics

4 pages

Scientific paper

10.1364/OE.14.004264

We present a design for a quantum key distribution(QKD) system in a Sagnac loop configuration, employing a novel phase modulation scheme based on frequency shift, and demonstrate stable BB84 QKD operation with high interference visibility and low quantum bit error rate (QBER). The phase modulation is achieved by sending two light pulses with a fixed time delay (or a fixed optical path delay) through a frequency shift element and by modulating the amount of frequency shift. The relative phase between two light pulses upon leaving the frequency-shift element is determined by both the time delay (or the optical path delay) and the frequency shift, and can therefore be controlled by varying the amount of frequency shift. To demonstrate its operation, we used an acousto-optic modulator (AOM) as the frequency-shift element, and vary the driving frequency of the AOM to encode phase information.The interference visibility for a 40km and a 10km fiber loop is 96% and 99%, respectively, at single photon level. We ran BB84 protocol in a 40-km Sagnac loop setup continuously for one hour and the measured QBER remained within the 2%~5% range. A further advantage of our scheme is that both phase and amplitude modulation can be achieved simultaneously by frequency and amplitude modulation of the AOM's driving signal, allowing our QKD system the capability of implementing other protocols, such as the decoy-state QKD and the continuous- variable QKD. We also briefly discuss a new type of Eavesdropping strategy ("phaseremapping" attack) in bidirectional QKD system.

Affiliated with

Also associated with

No associations

Rating

Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum key distribution based on a Sagnac loop interferometer and polarization-insensitive phase modulators will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-433954