Introducing Terahertz Waves
Referring to the above chart, the light wave and the radio wave which are the same electromagnetic wave, are applied at various sectors of society.
On the other hand, terahertz wave has not been applied for them. However, terahertz wave has the following attractive features and is expected that it is useful in various fields.
Properties of Terahertz Waves
Transmissivity similar to radio wave
Terahertz waves can be transmitted through various types of materials including paper, plastics, ceramics, wood, and textiles. Terahertz waves enable non-destructive analysis of hidden internal substances and are expected to lead to the development of novel methods of non-destructive analysis.
Directivity similar to light wave
Terahertz waves have directivity similar to laser light. Because the wavelengths of terahertz waves are measured in tens and hundreds of micrometers, terahertz waves can produce images with resolution similar to that of images viewed with the human eye under visible light, when the waves are detected in two or three dimensions after being transmitted through or reflected by the target object. In fact, terahertz waves can be transmitted through materials such as plastic and wood to enable analysis of their internal structure.
Identification of chemical substances
All materials consist of atoms and molecules joined by chemical bonds. When exposed to electromagnetic radiation of certain wavelengths, these chemical bonds each vibrate at a characteristic frequency. Information on these bonds enable the chemical composition of the substance, impurities, and other properties to be identified. By comparison with a known spectrum, differences between pharmaceutical products such as tablets can be analyzed non-destructively.
Safety of terahertz radiation
In contrast to X-ray radiation, terahertz radiation is non-ionizing and therefore safe for humans.
Potential Applications of Terahertz Waves
Non-destructive analysis of materials such as plastics and ceramics
Analysis in pharmaceutical research and inspection on pharmaceutical manufacturing lines
Security inspections of sealed packages and containers
Food and agricultural product quality monitoring
Biopsy of tissues such as skin
