4. Heritage

In this field, the advantage of terahertz wave inspection is its non-invasive nature. If the object to be studied is fragile, such as ancient paintings or prehistoric artifacts, terahertz techniques (spectroscopy, imaging and tomography) will enable it to be characterized or analyzed without destroying or even, more simply, degrading it. The figure 19 shows the example of a fossilized ammonite, where the internal structure of the cephalopod is clearly revealed by terahertz transmission.