Calibration of far-IR and sub-mm detectors traceable to the International System of Units

摘要

Precision power measurement of electromagnetic radiation is required to establish metrological applications, e.g. remote sensing. The Physikalisch-Technische Bundesanstalt (PTB), as the national metrology institute of Germany, has started to determine the spectral responsivity of detectors for THz radiation. In this work, the THz spectral range denotes the wavelength range from 60 jim to 300 urn, corresponding to 5 THz to 1 THz, which is traditionally the overlap between far-IR and the sub-mm range.Traceability of power measurement to the international system of units (SI) has been missing in the THz region in the past. The PTB establishes this traceability by using two complementary optical approaches, source- and detector-based radiometry. Both methods have been successfully prototyped. These primary investigations led to the design of a new measurement facility for the determination of THz radiant power and the responsivity calibration of THz detectors traceable to the SI.