With the development of suitable sources and detectors the Terahertz (THz) gap in the elec-tromagnetic spectrum (0.1 THz – 3 THz) has become accessible for a variety of applications related to imaging, spectroscopy and communication. The "big" breakthrough of THz technology has however not happened yet. THz technology has nonetheless a promising future due to some unique properties of electromagnetic radiation in this frequency range.
So far activities related to THz were mostly focused on R&D, application and feasibility with no or only limited focus on metrological aspects. Some THz metrology is pursued at larger NMIs, but there are nonetheless various "metrology gaps". The project proposal has been formulated with this background in mind.
METAS has so far no activity in the THz domain and this project aims at establishing a metrology base for THz measurements at METAS. THz frequencies can be "approached" from the electronics side and from the optics side and the project takes an integrated approach by pursuing both routes and focusing on uncharted territory in the THz metrology landscape. Using electronic technology the project aims at establishing traceability for power measurements in waveguide and traceability for material measurements in a novel type of measurement cell with corrugated low-loss wall structure. Using optical heterodyne down-conversion techniques (photo-mixing) it further aims at establishing a free-space THz source, which is frequency-locked to an optical frequency comb. With the help of femtosecond laser technology it envisages to realize a free-space THz spectrum analyzer, which is able to perform traceable measurements of THz frequencies.
Based on the metrological basis established in this project, further developments in future projects are conceivable. Possible options would be to extend frequency ranges, intensify the activity related to material characterization, development of a broadband free-space THz vector network analyzer, use of electro-optical THz source in waveguide, etc.
