TY - GEN
T1 - Measurement of subwavelength coating thickness in multi-layered carbon-fiber structures by sparse deconvolution of polarized terahertz time-domain pulses
AU - Karimi, Arash
AU - Heller, Erica
AU - Harris, Zachery B.
AU - Arbab, M. Hassan
N1 - Publisher Copyright:
© 2025 SPIE.
PY - 2025
Y1 - 2025
N2 - Terahertz time-domain spectroscopy (THz-TDS) is a valuable tool for non-destructive evaluation of coatings. However, complex anisotropic and non-uniform structures, such as interwoven carbon-fiber-reinforced polymers (CFRPs), present significant challenges for accurate thickness measurement. To address this complexity, polarimetric THz imaging was utilized to gain deeper insight into the structural variations of multi-layered coated CFRP. This insight contributed to refinements in coating thickness measurement. Additionally, due to subwavelength thickness of the coating layers, a sparse deconvolution algorithm was utilized to resolve the overlapped reflected echoes from the sample. The reproducibility of this method was validated across two commercial THz-TDS systems with distinct time-domain sampling methods.
AB - Terahertz time-domain spectroscopy (THz-TDS) is a valuable tool for non-destructive evaluation of coatings. However, complex anisotropic and non-uniform structures, such as interwoven carbon-fiber-reinforced polymers (CFRPs), present significant challenges for accurate thickness measurement. To address this complexity, polarimetric THz imaging was utilized to gain deeper insight into the structural variations of multi-layered coated CFRP. This insight contributed to refinements in coating thickness measurement. Additionally, due to subwavelength thickness of the coating layers, a sparse deconvolution algorithm was utilized to resolve the overlapped reflected echoes from the sample. The reproducibility of this method was validated across two commercial THz-TDS systems with distinct time-domain sampling methods.
KW - carbon-fiber reinforced polymer
KW - coating thickness measurement
KW - interwoven composites
KW - sparse deconvolution
KW - Terahertz time-domain spectroscopy
UR - https://www.scopus.com/pages/publications/105005939991
U2 - 10.1117/12.3045073
DO - 10.1117/12.3045073
M3 - Conference contribution
AN - SCOPUS:105005939991
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIII
A2 - Sadwick, Laurence P.
A2 - Yang, Tianxin
PB - SPIE
T2 - Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIII 2025
Y2 - 27 January 2025 through 30 January 2025
ER -