  We developed superconducting nanowire single-photon detectors (SNSPDs) based
on tungsten silicide (WSi) that show saturated internal detection efficiency up
to a wavelength of 10 um. These detectors are promising for applications in the
mid-infrared requiring ultra-high gain stability, low dark counts, and high
efficiency such as chemical sensing, LIDAR, dark matter searches and exoplanet
spectroscopy.
