THz Spectroscopy

Terahertz radiation sits in the electromagnetic spectrum between infrared and microwave — a range that's hard to reach with classical optical or microwave methods, but which offers unique insight into materials and processes.

How the measurement works

A sample is illuminated with THz radiation, and its absorption, transmission, and reflection are then analyzed. Together, these three quantities reveal information about molecular structure, layer thickness, refractive index, and surface condition.

Where it's applied

• Materials science: characterizing thin semiconductor layers and polymers.
• Biology & medicine: non-invasive examination of tissue, for example moisture distribution.
• Security screening: detecting hazardous substances via characteristic absorption spectra.
• Basic research: studying electron dynamics and lattice vibrations in solids.

Strengths & limits

The big advantage is non-destructive, highly sensitive measurement that works even through paper or plastic. The trade-off is demanding, expensive equipment that's also sensitive to humidity and temperature fluctuations.