Terahertz imaging achieved with low-cost CMOS detectors

摘要

Subwavelength antennas in the metal interconnection layer of an inexpensive CMOS chip couple terahertz radiation to the chip's electronics, enabling the creation of inexpensive, compact imagers. The electromagnetic spectrum has historically been exploited using one of two kinds of technologies: optics for shorter wavelengths, and radiofrequency and electronics for longer ones. The terahertz region, which is situated between the optical and the electronic domains, has until recently remained mostly inaccessible due to the lack of practical sources and detectors (see Fig. 1). Today's strong interest in the terahertz region is motivated by the specific characteristics of terahertz radiation. The energy of a terahertz photon ranges around 4 meV, a value corresponding to vibrations of some heavy complex molecules, including explosives. Such low photon energies make terahertz radiation nonionizing; it is therefore considered to be safe in terms of health concerns.