Terahertz imaging systems

A wide variety of imaging system architectures have been designed or proposed for millimeter-wave and terahertz imaging systems. These include passive FPAs, passive mechanically-scanned systems, active mechanically-scanned focused lens systems (both through transmission and reflection), active holographic scanned imaging, and SAR imaging. 

Terahertz imaging offers the possibility of understanding complex reactions in which the chemical state of the sample under study changes with time. An extension of this ability is the control of chemical reactions in a highly specific manner this will require the manipulation and channeling of the energy in a system such that the possible outcomes (degrees of freedom) are narrowed to those that one desires. 

Experimental terahertz imaging 5.1. Terahertz photo-mixing system... 

This increase in image resolution can be very significant in the millimeter-wave and terahertz frequency ranges because of the relatively long wavelengths involved compared with optical systems. 

The image of the generated terahertz radiation is then focused onto a sample through an optical system consisting of a Si hyper-spherical lens, a plane mirror, and an ellipsoid mirror. Although a sample is shown set at the position for a transmission measurement in Figure 19.2, other methods of spectral measurement are also possible, at least in principle. 

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