Application of THz probe radiation in low-coherent tomographs based on spatially separated counterpropagating beams

A principle of designing a high-resolution low-coherent THz tomograph, which makes it possible to investigate media with a high spatial resolution (in the range λ₀ – 2λ₀, where λ₀ is the average probe wavelength) is considered. The operation principle of this tomograph implies probing a medium by radiation with a coherence length of 8λ₀ and recording a hologram of a focused image of a fixed layer of this medium using spatially separated counterpropagating object and reference beams. Tomograms of the medium studied are calculated using a temporal approach based on application of the time correlation function of probe radiation.