Applications

Terahertz methods become useful when measurement physics, sample properties, and application constraints are considered together. These pages organize the portfolio by problem domain rather than by instrument alone.

The central question is not whether terahertz radiation can produce a signal, but whether that signal carries information that is sufficiently specific, reproducible, and useful for the application. Interfaces, thickness, porosity, hydration, refractive index, absorption, and subsurface morphology can all generate contrast. The experimental design must identify which mechanism is expected and which independent measurement will be used to validate the interpretation.

Application domains

From feasibility to validation

A credible study starts with dielectric contrast, penetration depth, geometry, acquisition time, and comparison with complementary methods. Industrial or biomedical readiness is never assumed from a laboratory result alone.

Representative samples are essential. A feasibility study may establish that a defect, layer, fracture, pigment response, or tissue contrast is measurable under controlled conditions. Broader transfer then requires larger and more varied datasets, blind or independent testing, repeatability measurements, uncertainty estimates, and an acquisition workflow compatible with the real environment.

Terahertz methods are often most valuable as part of a multimodal strategy. Depending on the question, they may complement ultrasound, X-ray imaging, thermography, optical microscopy, spectroscopy, histology, or expert inspection. The purpose of comparison is not to claim universal superiority, but to determine what additional information the terahertz measurement contributes.

Related publications

Linear to radial polarization conversion in the THz domain using a passive system — DOI
Near-field wire-based passive probe antenna for the selective detection of the longitudinal electric field at terahertz frequencies — DOI
Continuous‐wave scanning terahertz near‐field microscope — DOI
Coupling and Propagation of Sommerfeld Waves at 100 and 300 GHz — DOI
Propagation beam consideration for 3D THz computed tomography — DOI
Room temperature thermopile THz sensor — DOI
Aeronautics composite material inspection with a terahertz time-domain spectroscopy system — DOI
Review of Terahertz Tomography Techniques — DOI

Questions shared across application domains

Although the samples differ, the same questions recur across industrial, heritage, geological, and biomedical research. Is the feature accessible in reflection or transmission? Does the useful contrast remain distinguishable from water, roughness, curvature, or thickness variation? Can the measurement be repeated, and can an independent method confirm the interpretation? What acquisition time and positioning accuracy are realistic?

These questions guide the transition from an illustrative image to an evidence-based study. The application pages describe both positive results and the boundaries observed in the corresponding publications, because knowing when a modality fails is essential to designing a credible next experiment.

The portfolio also shows that an application label can hide very different measurement problems. Detecting an interface in a dry composite, mapping varnish-related contrast in a painting, estimating a fracture opening in rock, and studying an ex vivo tissue section require different frequencies, sample preparations, references, and standards of evidence.

Readers can use the application pages to move in both directions: from a domain problem toward the relevant expertise and technology, or from a publication toward the conditions under which its result was obtained. This cross-linking supports informed collaboration rather than presenting a fixed catalogue of solutions.