Pilot-assisted intradyne reception for high-speed continuous-variable quantum key distribution with true local oscillator
Fabian Laudenbach, Bernhard Schrenk, Christoph Pacher, Michael Hentschel, Chi-Hang Fred Fung, Fotini Karinou, Andreas Poppe, Momtchil Peev, Hannes Hübel · Quantum · 2019
We present a pilot-assisted coherent intradyne reception methodology for CV-QKD with true local oscillator. An optically phase-locked reference tone, prepared using carrier-suppressed optical single-sideband modulation, is multiplexed in polarisation and frequency to the 250 Mbaud quantum signal in order to provide optical frequency- and phase matching between quantum signal and local oscillator. Our concept allows for high symbol rates and can be operated at an extremely low excess-noise level, as validated by experimental measurements.