The letter T- from TeraHertz (THz).
T-wave (plural T-waves)
- (engineering) Electromagnetic waves with frequencies intermediate between, and sharing properties of both, short radio waves and long IR optical waves. This region is defined variously as 0.1–10 THz, 0.3–3 THz or 0.3–30 THZ.
- Proceedings of the IEEE, Volume 95, Number 8, August 2007, Special issue: T-Ray Imaging, Sensing, & Retection