Simple 2.5 GHz time-bin quantum key distribution

Alberto Boaron, Boris Korzh, Raphael Houlmann, Gianluca Boso, Davide Rusca, Stuart Gray, Ming-Jun Li, Daniel Nolan, Anthony Martin, and Hugo Zbinden

Applied Physics Letters 112, 171108 (2018)

We present a 2.5 GHz quantum key distribution setup with the emphasis on a simple experimental realization. It features a three-state time-bin protocol based on a pulsed diode laser and a single intensity modulator. Implementing an efficient one-decoy scheme and finite-key analysis, we achieve record breaking secret key rates of 1.5 kbps over 200 km of standard optical fibers. You can find the full article here.

Schematics of the experimental setup. Filter: 270 pm bandpass filter; Piezo: piezoelectric fiber stretcher; FM: Faraday mirror; IM: intensity modulator; AMP: RF amplifier; DCF: dispersion compensating fiber; VA: variable attenuator; SMF: single-mode fiber; BS: beamsplitter; and SPD: single-photon detector. Dashed lines represent temperature stabilized boxes.