Eur. Phys. J. D 18, 141-146 (2002)
https://doi.org/10.1140/epjd/e20020017

Integrated quantum key distribution system using single sideband detection

¹ GTL-CNRS Telecom (UMR CNRS 6603) , Georgia Tech Lorraine, 2-3 rue Marconi, 57070 Metz, France
² Laboratoire d'Optique P.M. Duffieuxb, Université de Franche-Comté, 25030 Besançon Cedex, France

Corresponding author: ^a merolla@georgiatech-metz.fr

Received: 13 July 2001
Revised: 30 November 2001
Published online: 15 February 2002

Abstract

We report a new quantum cryptographic system involving single sideband detection and allowing an implementation of the BB84 protocol. The transmitted bits are reliably coded by the phase of a high frequency modulating signal. The principle of operation is described in terms of both classical and quantum optics. The method has been demonstrated experimentally at 1 550 nm using compact and conventional device technology. Single photon interference has been obtained with a fringe visibility greater than 98%, indicating that the system can be used in view of quantum key distribution potentially beyond 50-km-long standard single-mode fiber.