Back أشعة تيراهيرتز Arabic Teraherts şüalanma Azerbaijani টেরাহার্জ বিকিরণ Bengali/Bangla Terahercno zračenje BS Raigs T Catalan Terahertzové záření Czech Terahertz stråling Danish Terahertzstrahlung German Radiación de terahercios Spanish امواج تراهرتز Persian
Frequency range | 0.1 THz to 10 THz |
|---|---|
Wavelength range | 3 mm to 30 μm |
| Radio bands | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ITU | ||||||||||||
|
||||||||||||
| EU / NATO / US ECM | ||||||||||||
| IEEE | ||||||||||||
| Other TV and radio | ||||||||||||
Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency[1] (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the International Telecommunication Union-designated band of frequencies from 0.1 to 10 terahertz (THz),[2] (from 0.3 to 3 terahertz (THz) in older texts,[3] which is now called "decimillimetric waves"[4]), although the upper boundary is somewhat arbitrary and has been considered by some sources to be 30 THz.[5]
One terahertz is 1012 Hz or 1,000 GHz. Wavelengths of radiation in the decimillimeter band correspondingly range 1 mm to 0.1 mm = 100 μm and those in the terahertz band 3 mm = 3000 μm to 30 μm. Because terahertz radiation begins at a wavelength of around 1 millimeter and proceeds into shorter wavelengths, it is sometimes known as the submillimeter band, and its radiation as submillimeter waves, especially in astronomy. This band of electromagnetic radiation lies within the transition region between microwave and far infrared, and can be regarded as either.
Compared to lower radio frequencies, terahertz radiation is strongly absorbed by the gases of the atmosphere, and in air most of the energy is attenuated within a few meters,[6][7][8] so it is not practical for long distance terrestrial radio communication. It can penetrate thin layers of materials but is blocked by thicker objects. THz beams transmitted through materials can be used for material characterization, layer inspection, relief measurement,[9] and as a lower-energy alternative to X-rays for producing high resolution images of the interior of solid objects.[10]
Terahertz radiation occupies a middle ground where the ranges of microwaves and infrared light waves overlap, known as the "terahertz gap"; it is called a "gap" because the technology for its generation and manipulation is still in its infancy. The generation and modulation of electromagnetic waves in this frequency range ceases to be possible by the conventional electronic devices used to generate radio waves and microwaves, requiring the development of new devices and techniques.
- ^ Jones, Graham A.; Layer, David H.; Osenkowsky, Thomas G. (2007). National Association of Broadcasters Engineering Handbook. Taylor and Francis. p. 7. ISBN 978-1-136-03410-7.
- ^ "Industry Specification Group (ISG) TeraHertz (THz)". ETSI. 2025.
- ^ "Article 2.1: Frequency and wavelength bands". Radio Regulations (zipped PDF) (2016 ed.). International Telecommunication Union. 2017. Retrieved 9 November 2019.
- ^ "Article 2.1: Frequency and wavelength bands". Radio Regulations (zipped PDF) (2024 ed.). International Telecommunication Union. 2024. Retrieved 2 February 2025.
- ^ Dhillon, S.S.; Vitiello, M.S.; Linfield, E.H.; Davies, A.G.; Hoffmann, Matthias C.; Booske, John; et al. (2017). "The 2017 terahertz science and technology roadmap". Journal of Physics D: Applied Physics. 50 (4): 2. Bibcode:2017JPhD...50d3001D. doi:10.1088/1361-6463/50/4/043001. hdl:10044/1/43481.
- ^ Coutaz, Jean-Louis; Garet, Frederic; Wallace, Vincent P. (2018). Principles of Terahertz Time-Domain Spectroscopy: An introductory textbook. CRC Press. p. 18. ISBN 978-1-351-35636-7 – via Google Books.
- ^ Siegel, Peter (2002). "Studying the Energy of the Universe". NASA. Education materials. U.S. National Aeronautics and Space Administration. Archived from the original on 20 June 2021. Retrieved 19 May 2021.
- ^ Gosling, William (2000). Radio Spectrum Conservation: Radio Engineering Fundamentals. Newnes. pp. 11–14. ISBN 9780750637404. Archived from the original on 7 April 2022. Retrieved 25 November 2019.
- ^ Petrov, Nikolay V.; Maxim S. Kulya; Anton N. Tsypkin; Victor G. Bespalov; Andrei Gorodetsky (5 April 2016). "Application of Terahertz Pulse Time-Domain Holography for Phase Imaging". IEEE Transactions on Terahertz Science and Technology. 6 (3): 464–472. Bibcode:2016ITTST...6..464P. doi:10.1109/TTHZ.2016.2530938. S2CID 20563289.
- ^ Ahi, Kiarash; Anwar, Mehdi F. (26 May 2016). "Advanced terahertz techniques for quality control and counterfeit detection". In Anwar, Mehdi F.; Crowe, Thomas W.; Manzur, Tariq (eds.). Proceedings SPIE Volume 9856, Terahertz Physics, Devices, and Systems X: Advanced Applications in Industry and Defense. SPIE Commercial + Scientific Sensing and Imaging. Baltimore, MD: SPIE: The International Society for Optics and Photonics. Bibcode:2016SPIE.9856E..0GA. doi:10.1117/12.2228684. S2CID 138587594. 98560G. Retrieved 26 May 2016 – via researchgate.net.