Fig. 4: Signal-to-noise ratio (SNR) in single-photon DC-GIS.
SNR as a function of the measurement time \(T\) under different photon count rates of 5 × 105 photons/s, 1 × 106 photons/s, 3 × 106 photons/s, 5 × 106 photons/s and 7 × 106 photons/s (pink dots, red dots, blue dots, green dots and orange dots). The black line is the linear fitting curve with a slope of 1/2. The insets are the fitting curves with the experimental SNR curves of the photon counts of 1 × 106 and 5 × 105 photons/s, respectively.
