NIST Low-background infrared spectral calibration facility

Abstract

The goal of the Low-background Infrared (LBIR) calibration facility at the National Institute of Standards and Technology is to provide the infrared user community with a calibration base for broadband and spectral radiant power measurements. The LBIR facility began broadband radiant-flux calibrations of infrared sources in 1990 using a cryogenic vacuum chamber to provide the low background at 20 K. A second cryogenic-vacuum chamber is being brought into service for spectral calibrations in the LBIR facility. This new spectral calibration chamber will house the spectral instrument and be the centre for the spectral calibrations of sources and detectors and for the measurement of optical properties of materials. The LBIR spectral instrument is composed of a KRS-5 prism predisperser for order-sorting, followed by a grating monochromator. This calibration capability is currently being developed in three areas: spectral calibration of infrared detectors for use in low-background applications; spectral resolution of radiation from black-body sources such as cavities and other geometries such as spheres and plates; and characterization of optical components of interest to the community such as filters and window materials. This work will be carried out over the spectral range 2 µm to 30 µm.