Terahertz Nondestructive Stratigraphic Analysis of Complex Layered Structures: Reconstruction Techniques

Terahertz (THz) time-of-flight tomography (TOFT), a nondestructive-evaluation technique for the stratigraphic characterization of structures with layers on micron-to-millimeter scales, has proven to be challenging apply samples containing both micron-scale and millimeter-scale layers. In THz TOFT, echoes reflected from distant interfaces defects are often obscured as they may immersed in noisy background such features signal weak due attenuation dispersion, leading loss valuable information. Moreover, overlapping any optically thin layers, coatings thick specimens, likely mistaken single interface reconstructing stratigraphy. Thus, layered have problematic TOFT characterization. this paper, sparse-deconvolution (SD) technique, based an interior-point method, including propagation model accounting dispersion is demonstrated. The method shown successful extracting impulse response that combine challenges robustness effectiveness verified numerically experimentally. While proposed SD approach does not perform well cross-correlation (CC) techniques terms maximum thickness, it can provide clearer more accurate reconstruction moderately incorporating