Measurement of the absolute spectral responsivity in the mid-infrared based on the cryogenic electrical substitution radiometer and an optimized thermopile detector

摘要

The Physikalisch-Technische Bundesanstalt (PTB) expanded its capabilities ofthe absolute measurement of radiant power to the spectral range of themid-infrared (MIR) by implementing additional MIR laser radiation sources atone of the PTB's cryogenic electrical substitution radiometer facilities.This extension enables absolute calibrations of the spectral responsivity ofdetectors in the MIR traceable to the International System of Units (SI). The thermopile detector TS-76 was characterized and calibrated in view of itsspectral responsivity s(λ) in the wavelength range between 1.5 and10.6 µm at the expanded cryogenic electrical substitutionradiometer facility. The relative standard measurement uncertainty wassignificantly reduced to 1.4 % by developing an optimized and thermallystabilized detector housingdesign. The TS-76 was established as a mid-infrared transfer detector for theSI traceable measurement of radiant power and the dissemination of thespectral responsivity s(λ) in the MIR.