Jitter is one of the key parameters for a superconducting nanowire single photon detector (SNSPD). Using an optimized time-correlated single photon counting system for jitter measurement, we extensively studied the dependence of system jitter on the bias current and working temperature. The signal-to-noise ratio of the single-photon-response pulse was proven to be an important factor in system jitter. The final system jitter was reduced to 18 ps by using a high-critical-current SNSPD, which showed an intrinsic SNSPD jitter of 15 ps. A laser ranging experiment using a 15-ps SNSPD achieved a record depth resolution of 3 mm at a wavelength of 1550 nm

We developed a time-correlated single-photon counting (TCSPC) system based on the low-jitter superconducting nanowire singlephoton detection (SNSPD) technology. The causes of jitters in the TCSPC system were analyzed. Owing to the low jitter of the SNSPD technology, a system jitter of 26.8 ps full-width at half-maximum was achieved after optimizing the system. We demonstrated timeof-flight laser ranging at 1550 nm wavelength at a stand-off distance of 115 m, based on this TCSPC system. A depth resolution of 4 mm was achieved directly by locating the centroids of each of the two return signals. Laser imaging was also performed using the TCSPC system. This low-jitter TCSPC system using the SNSPD technology presents great potential in long-range measurements and imaging applications for low-energy-level and eye-safe laser systems.