2008/05/19 by Z. L. Yuan, A. R. Dixon, J. F. Dynes +2 · 3 citations
Computer Science · Physics and Astronomy · #Advanced Frequency and Time Standards #Advanced Optical Sensing Technologies #Quantum Information and Cryptography #quant-ph
paper · pdf · doi:10.1063/1.2931070
published as Appl. Phys. Lett. 92, 201104(2008) · 4 pages, 4 figures
openalex publication_date 2008/05/19 · arxiv created 2008/05/22 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report a demonstration of quantum key distribution (QKD) at gigahertz clock rates with InGaAs avalanche photodiodes (APDs) operating in a self-differencing mode. Such a mode of operation allows detection of extremely weak avalanches so that the detector afterpulse noise is sufficiently suppressed. The system is characterized by a secure bit rate of 2.37Mbit∕s at 5.6km and 27.9kbit∕s at 65.5km when the fiber dispersion is not compensated. After compensating the fiber dispersion, the QKD distance is extended to 101km, resulting in a secure key rate of 2.88kbit∕s. Our results suggest that InGaAs APDs are very well suited to gigahertz QKD applications.