Ultralow-filling-factor superconducting nanowire single-photon detector utilizing a 2D photonic crystal

Superconducting nanowires enable the operation of outstanding single-photon detectors, which are required particularly for quantum information and weak-light measurement applications. However, the trade-off between detection speed and efficiency, which is related to the filling factors of superconducting nanowires, is still a challenge. Here, we propose a fast, efficient single-photon detector fabricated by integrating ultralow-filling-factor meandered superconducting nanowires atop a photonic crystal (PhC) resonator. This unique structure enables a fast photon response due to the low kinetic inductance of the short nanowires and ensures efficient photon ab-sorption due to the resonant effect of the PhC structure. The proposed detector has a filling factor of only -12% while maintaining a high maximum absorption in our simulation of 90%. The fabricated device exhibits a maxi-mum system detection efficiency of 60%, a maximum count rate of -80 MHz, and a recovery time of only -12 ns, which is three times faster than that of the conventional meandered structure at the same sensing diameter (18 mu m). This work helps advance the movement toward high-efficiency, high-speed single-photon detectors and promotes their future application in quantum communication and imaging. (c) 2023 Chinese Laser Press