Fig. 1. Long-distance optical fiber time transfer scheme based on single photon detection

Fig. 2. Time comparison sequence based on bidirectional time division multiplexing transmission over a single fiber with the same wavelength

Fig. 3. Experimental system for long-distance optical fiber time transfer based on single photon detector

Fig. 4. Relation of 4-channel 1 pulse/s time signals generated by field programmable gate array

Fig. 5. Gaussian fitted results of variations for two-way transmission delays. (a) First way (enable automatic time shift); (b) second way (turn off automatic time shift)

Fig. 6. Gaussian fitted results of variations for two-way transmission delays. (a) First way (local site to remote site); (b) second way (remote site to local site)

Fig. 7. Experimental results of long-distance optical fiber time transfer based on single photon detection. (a) Results of two-way comparison; (b) TDEV calculation results of two-way comparison