An overview is given on the field of the terahertz-frequency electromagnetic waves, their properties and emerging applications. Some widespread sources with their advantages and drawbacks are presented; an emphasis is placed on the parametric generation sources that we build and use in our research. Several applications are then described: imaging techniques based on transmission, reflection and scattering, results in chemical imaging and electric field imaging, as well as linear scanning and the measurement of optical properties of highly-absorbing liquids.
Dobroiu, A., Otani, C., & Kawase, K. (2006). Terahertz-wave sources and imaging applications. Measurement Science and Technology, 17(11). https://doi.org/10.1088/0957-0233/17/11/R01