Fig. 1. (a) TEM image of the involved NbTiN superconducting thin film. (b) Superconducting to normal transitions for a 55-nm-wide detector. (c) Scanning electron microscope image of the fabricated SNSPDs, where the diameter of the sensitive area is 18μm. (d) Uniformity of the nanowire width.

Fig. 2. Temperature dependence of the system detection efficiency as a function of bias current.

Fig. 3. (a) Sketch of the electrical setup, integrating the bias circuit, the amplification circuit, and the pulse converter and counter. (b) Manufactured electrical setup.

Fig. 4. (a) Photo of drone-based superconducting nanowire single-photon detection system. (b) Bias current dependence of the SDE measured in a GM cryocooler (light green) and in the miniature liquid helium dewar (light blue). The measured IDE as a function of bias current of the drone-based SNSPD system, with a height of 30 m. (c) Dark count rate as a function of bias current under different operating environments.