| Terahertz radiation is non-invasive and non-ionizing.
It can be used to simultaneously image objects (imaging) and identify
the type of object under investigation (spectroscopy). Objects can
be investigated in both reflection (analogous to radar) and transmission
(looking through the object). Since the advent of pulsed coherent
generation and detection, terahertz has been used to investigate flames,
the structure of water, biomolecules, drugs, explosives and toxic
substances to name but a few.
The ability of THz radiation to 'see through' many common materials
such as paper, clothing, plastic, and leather has opened up the technology
to several key markets. In the last ten years the dramatic increase
in research groups, conferences and papers in this area is testament
to the exciting future prospects of this emerging technology.
Although the role of terahertz technology remains to be determined,
four key markets are currently being investigated.