Superconducting nanowire single-photon detectors: physics and applications

TLDR

Superconducting nanowire single‑photon detectors have rapidly emerged as a highly promising photon‑counting technology for infrared wavelengths. This review aims to capture a detailed snapshot of the emerging superconducting nanowire single‑photon detector technology at the threshold of maturity by examining its operating principles and device models. The authors review the SNSPD operating principle, device‑design evolution, performance improvements, noise mechanisms, refrigeration methods, and optical coupling schemes. The devices achieve high efficiency, low dark counts, excellent timing resolution, and enable applications from quantum cryptography to remote sensing.

Abstract

Single-photon detectors based on superconducting nanowires (SSPDs or SNSPDs) have rapidly emerged as a highly promising photon-counting technology for infrared wavelengths. These devices offer high efficiency, low dark counts and excellent timing resolution. In this review, we consider the basic SNSPD operating principle and models of device behaviour. We give an overview of the evolution of SNSPD device design and the improvements in performance which have been achieved. We also evaluate device limitations and noise mechanisms. We survey practical refrigeration technologies and optical coupling schemes for SNSPDs. Finally we summarize promising application areas, ranging from quantum cryptography to remote sensing. Our goal is to capture a detailed snapshot of an emerging superconducting detector technology on the threshold of maturity.