Depth-resolving THz imaging with tomosynthesis

Abstract

We demonstrated a depth-resolved 3D imaging technique based on absorption contrast using tomosynthesis. Tomosynthesis is similar to computed tomography except that the number of projections is much smaller. We constructed a tomosynthesis imaging system, which detects a transmitted continuous THz wave. We applied a backprojection method that was suitable for the constructed detection configuration, to reconstruct an image. Using this system, we imaged a test sample made from paper and reproduced characters written by pencil.

Terahertz and Cultural Heritage Science: Examination of Art and Archaeology

“…Since THz-TD imaging was already evaluated for the inspection of postal envelopes [67], it was also tested with encouraging results for stacked papyrus layers written with carbon black ink [68]. Recently, even more successful results were obtained with a new and more sophisticated THz method called tomosynthesis [69] which was applied to image pencil writing on a stack of 50 paper sheets. THz tomography has been applied to resolve text on both sides of a single papyrus sheet [70,71].…”

Review of Terahertz Tomography Techniques

“…Tomosynthesis (TS) is a straightforward but useful method for reconstructing few slices of a 3D object from a limited number of projections [141]. It does not require measurements in all directions, and can reconstruct tomographic images using only projections within small angles.…”

Refractive-index based tomosynthesis using dark-field imaging optics

“…If one regards the geometrical relationship of the imaging system as important, one should select SAA. Here, we note that SAA can be implemented by backprojection in the case of parallel incident beam geometry like the proposed imaging method [8]. Therefore, one can obtain a pseudo-3-dimensional image by applying SAA, or the backprojection method, to the angular deviation projections.…”