Fig. 7: Illustration of the 100 km free-running RFI QKD experiment.
From: Free-running long-distance reference-frame-independent quantum key distribution
Two NI 6556 boards control the lasers and modulators. The computers are used for data acquisition, post-processing, and classical communication. An APD is used to measure the intensity of the signal and decoy states and the bits of Z basis, so that NI 6556 adjusts the control signal of IM1 and IM2. IM intensity modulator, BS beam splitter, PM phase modulator, PC polarization controller, AMZI asymmetric Mach–Zehnder interferometer, SNSPD superconducting nanowire single photon detector, TDC Time-to-Digital converter, APD avalanche photon detector, NI 6556 National Instruments 6556.
