Advances in Mid-Infrared Single-Photon Detection

TLDR

Mid‑infrared single‑photon detectors are critical for quantum communications, sensing, and metrology, demanding high efficiency, low dark counts, and short dead times, yet transitioning from near‑infrared technology presents significant challenges. This review surveys the current state of the art of mid‑infrared single‑photon detectors. Approaches span material engineering, novel materials, and tailored detection schemes. The most promising technologies are superconducting nanowires, avalanche photodiodes, and photovoltaic detectors.

Abstract

The current state of the art of single-photon detectors operating in the mid-infrared wavelength range is reported in this review. These devices are essential for a wide range of applications, such as mid-infrared quantum communications, sensing, and metrology, which require detectors with high detection efficiency, low dark count rates, and low dead times. The technological challenge of moving from the well-performing and commercially available near-infrared single-photon detectors to mid-infrared detection is discussed. Different approaches are explored, spanning from the stoichiometric or geometric engineering of a large variety of materials for infrared applications to the exploitation of alternative novel materials and the implementation of proper detection schemes. The three most promising solutions are described in detail: superconductive nanowires, avalanche photodiodes, and photovoltaic detectors.