Now researchers have developed a way of manufacturing lenses operating at this frequency that are simple and inexpensive, but are claimed to produce near-flawless images which could vastly improve biomedical imaging as well as biological and explosive security scanning.

Terahertz frequencies are located between the microwave and infrared frequencies in the in the electromagnetic spectrum, at a wavelength range between 1 mm to 0.1 mm, and have some particularly remarkable properties. Many ordinary materials and living tissue, for example, are semi-transparent to this radiation and produce their own unique "fingerprints," that allows them to be individually identified as well as imaged and analyzed. 

"Terahertz is somewhat of a gap between microwaves and infrared," says Northwestern University's Associate Professor of Mechanical Engineering, Cheng Sun. "People are trying to fill in this gap because this spectrum carries a lot of information."