Timing Jitter of Fractal Superconducting Nanowire Avalanche Photodetectors in the 2-Micrometer Wavelength Range

We developed a femtosecond, mode-locked thulium-doped fiber l aser t o characterize fractal superconducting nanowire single-photon detectors at 1993 nm. The lowest timing jitter was 64.8 ps, which should be compared with 29.2 ps at 1560 nm.