Fig. 1. Electro-thermal model of nanowire^[31]. (a) Schematic of thermal diffusion of nanowires; (b) equivalent circuit diagram when nanowires absorb photons

Fig. 2. Simulation results of 1D electro-thermal model^[32]. (a) Hot spot resistance versus time; (b) nanowire temperature versus time

Fig. 3. Simulation results of circuit element parameters^[32]. (a) Influence of dynamic inductance on output voltage pulse; (b) influence of additional resistance on output voltage pulse

Fig. 4. Influence of external parameters on time jitter^[45]. (a) Bias current; (b) substrate temperature

Fig. 5. Principle diagram of SNSPD^[46]

Fig. 6. Simulation results of cross-sectional effect based on 2D electro-thermal model^[46]

Fig. 7. Simulation results based on electro-thermal model and Monte Carlo method[48]. (a) Random fluctuation in critical temperature and linewidth of nanowires simulated by Monte Carlo method; (b) change of hot spots in nanowires with time obtained by 1D electro-thermal model; (c) output voltage waveforms of 1064 nm and 532 nm photons obtained by Monte Carlo random simulation; (d) statistical distributions of photon arrival time under four conditions in Fig.7(c)

Fig. 8. Experimental results of time jitter and spectral resolution ^[45]. (a) Time jitter test results of 532, 750, 980 and 1064 nm wavelength photons at different bias currents; (b) measured spectral resolution results of 750, 850, 900 and 980 nm wavelength photons based on ultrafast temporal resolution

Fig. 9. Experimental and simulation results of cross sectional effect ^[46]. (a) Experimental PDF curves of four different wavelength photons; (b) simulated delay time when four different wavelength photons incident at different cross sectional positions of nanowires

Fig. 10. Experimental setup of femtosecond X-ray SNSPD ^[78]

Fig. 11. Experiment of X-SNSPD^[78]. (a) Practical image of femtosecond X-ray SNSPD setup; (b) X-SNSPD time jitter measured by oscilloscope