Quantum key distribution with coherent states at telecom wavelength

A complete set-up implementing quantum key distribution (QKD) with coherent states at 1550 nm, entirely made of fibre optics and standard telecom components such as integrated-optics modulators, couplers and fast InGaAs photodiodes is built. The whole set-up is fully interfaced and includes a synchronous automatic data processing software. It is designed to operate with continuous variable error correction and privacy amplification algorithms. The present acquisition electronics limits the repetition rate to 1 MHz, but optical components can go as fast as 10 GHz. Therefore, one can envision an extension of this device yielding up to 100 MHz rates.