Title:  Terahertz Imaging for Nondestructive Evaluation and Material Characterization

Committee:

Dr. David Citrin, ECE, Chair , Advisor

Dr. Alexandre Locquet, GTL, Co-Advisor

Dr. Waymond Scott, ECE

Dr. Paul Voss, ECE

Dr. Justin Romberg, ECE

Dr. Nico Declercq, ME

Abstract:

The terahertz (THz) portion of the electromagnetic spectrum extends from ~100 GHz to 10 THz, lying between the microwaves and infrared light. Due to the penetrative capability of THz electromagnetic radiation in broad classes of nonmetallic material, THz imaging based on THz time-domain spectroscopy systems, which can provide a noninvasive, noncontact, and nonionizing modality to characterize advanced materials with multi-layered structures, has been considered as a new promising nondestructive evaluation (NDE) technique. This dissertation explores the potentials and enhances the capabilities of THz imaging for the NDE and material characterization in the fields of industry and cultural heritage conservation science. The outcomes of this dissertation can be divided into three parts: (1) 3D quantitative NDE of delaminations in glass fiber-reinforced composites and polarization-resolved THz imaging of impact damages in hybrid fiber-reinforced composites; (2) Development of advanced THz deconvolution techniques, such as sparsity-based time-domain deconvolution and deconvolution based on autoregressive spectral extrapolation, for stratigraphic characterization of multi-layered structures with optically thin layers in the THz regime; (3) THz reflectometry for 3D global mapping of stratigraphy in art paintings.