DocumentCode :
1306471
Title :
An autocompensating fiber-optic quantum cryptography system based on polarization splitting of light
Author :
Bethune, Donald S. ; Risk, William P.
Author_Institution :
IBM Almaden Res. Center, San Jose, CA, USA
Volume :
36
Issue :
3
fYear :
2000
fDate :
3/1/2000 12:00:00 AM
Firstpage :
340
Lastpage :
347
Abstract :
We have developed a system for quantum key distribution (QKD), based on standard telecommunication lasers, detectors, and optical fiber, that passively compensates for time-dependent variations of the fiber-optic path due to stress, temperature changes, or birefringence. This approach allows information encoded in phase shifts imposed on single-photon-level pulses to be accurately read out after transmission over many kilometers of uncontrolled fiber. Cooled InGaAs avalanche photodiodes, pulse-biased using a special noise canceling circuit, are used to detect single 1.31-/spl mu/m infrared photons with a high efficiency, low dark-count rate, and subnanosecond time resolution. A single optical fiber carries both the quantum information and precise 1.55 /spl mu/m timing pulses between the two end stations. Overall synchronization of end-station activities, public discussion of basis choices, error correction, and privacy amplification have all been implemented over a local area network (LAN). The system at present generates raw, error-corrected, and privacy-amplified key data at rates of /spl sim/1000, 600, and 200 bits/s, respectively, over a 10-km single-mode fiber link.
Keywords :
III-V semiconductors; avalanche photodiodes; birefringence; error correction; gallium arsenide; indium compounds; infrared detectors; optical fibre LAN; optical fibre communication; optical fibre polarisation; photodetectors; quantum cryptography; timing; 1.31 mum; 1.55 mum; 10 km; 1000 bit/s; 200 bit/s; 600 bit/s; InGaAs; InGaAs avalanche photodiodes; autocompensating fiber-optic quantum cryptography system; basis choices; birefringence; detectors; encoded information; end-station activities; error correction; error-corrected key data; fiber-optic path; infrared photons; light; local area network; noise canceling circuit; optical fiber; phase shifts; polarization splitting; privacy amplification; privacy-amplified key data; quantum information; quantum key distribution; single optical fiber; single-mode fiber link; single-photon-level pulses; standard telecommunication lasers; stress; subnanosecond time resolution; synchronization; temperature changes; time-dependent variations; timing pulses; transmission; Cryptography; Fiber lasers; Infrared detectors; Laser transitions; Optical detectors; Optical fiber LAN; Optical fibers; Optical pulses; Standards development; Telecommunication standards;
fLanguage :
English
Journal_Title :
Quantum Electronics, IEEE Journal of
Publisher :
ieee
ISSN :
0018-9197
Type :
jour
DOI :
10.1109/3.825881
Filename :
825881
Link To Document :
بازگشت