Despite losing traction for cancer and security screening, terahertz imaging continues to target several agricultural and industrial applications that may finally benefit terahertz equipment vendors.
|FIGURE 1. A schematic illustrates activity in terahertz technology and product development cycles. (Courtesy of Microtech)|
Terahertz to the rescue
Plasmonic detectors and upconversion imaging
|FIGURE 2. In visible light (a) and terahertz-range (100 GHz; b) images of hazelnuts, the terahertz images clearly show that the upper nut is infected with fungus, which is more absorptive in the terahertz spectral range. (Courtesy of TeraSense)|
|FIGURE 3. For the spectra of an upconverted signal (a), a notch filter is used to attenuate the pump at 1064 nm; next, a long-pass filter is used to remove the pump at 1064 nm (b). (Courtesy of Microtech)|