Research on co-propagation of QKD and classical communication by reducing the classical optical power

He Ru-Shi^{1, 2}, Jiang Mu-Sheng^{1, 2, †}, Wang Yang^{1, 2}, Gan Ya-Hui^{1, 2}, Zhou Chun^{1, 2}, Bao Wan-Su^{1, 2, ‡}

The schematic diagram of the sinusoidally gated APD. DC: direct current, RF: radio frequency, APD: avalanche photodiode, BSF: band-stop filter, and AMP: amplifier.