Terahertz waves have previously been used mainly by astronomers to observe distant parts of the Universe. But terahertz radiation can also be used to scan materials, such as plastic, paper, and fabrics, and to communicate information faster than the current 4G. Future 5G and 6G wireless communication will use terahertz waves as information media.

THz waves were first used for biological object imaging 25 years ago. The scanned object was a leaf, and the image showed its veins for transporting water, and the process of water loss/absorption during drying/watering. Today we know that THz waves can be used, e.g., to see how fat tissue levels change, and to distinguish between the normal and abnormal ones.

Electrically Insulating Flexible Films with Quasi‐1D van der Waals Fillers as Efficient Electromagnetic Shields in the GHz and Sub‐THz Frequency Bands
Zahra Barani
F. Kargar, Y. Ghafouri, S. Ghosh, K. Godziszewski, S. Baraghani, Y. Yashchyshyn, G. Cywiński, S. Rumyantsev, T.T. Salguero, and A.A. Balandin
Advanced Materials, 2021, 33(11)
DOI: https://doi.org/10.1002/adma.202007286

Room-Temperature Amplification of Terahertz Radiation by Grating-Gate Graphene Structures
S. Boubanga-Tombet, W. Knap, D. Yadav, A. Satou, D.B. But, V.V. Popov, I.V. Gorbenko, V. Kachorovskii, and T. Otsuji
Phys. Rev. X, 2020, 10: 031004
DOI: https://doi.org/10.1103/PhysRevX.10.031004

Suppressed Auger scattering and tunable light emission of Landau-quantized massless Kane electrons
D. B. But, M. Mittendorff, C. Consejo, F. Teppe, N. N. Mikhailov, S. A. Dvoretskii, C. Faugeras, S. Winnerl, M. Helm, W. Knap, M. Potemski, and M. Orlita
Nature Photonics, 2019, 13:783–787
DOI: https://doi.org/10.1038/s41566-019-0496-1