Controlling a sine wave gating single-photon detector by exploiting its filtering loophole

Feng Lin-Xi^{1, 2, †}, Jiang Mu-Sheng^{1, 2, †}, Bao Wan-Su^{1, 2, ‡}, Li Hong-Wei^{1, 2}, Zhou Chun^{1, 2}, Wang Yang^{1, 2}

(color online) The count rate as a function of the average photon number μ_b. Here we use a single clock source with frequency of 1GHz to trigger both of the pulse laser and sine-wave gating generator in the SG-SPD. In Fig. 3, the dotted line represents the dark count rate of the SG-SPD. Limited by our laser source, the biggest μ_b we can obtain is 10⁶ photons/pulse, and in this case, the count rate is already very close to the dark count rate.