Open AccessImprovement of the depth resolution of swept-source THz-OCT for non-destructive inspection
Author(s) -
Homare Momiyama,
Yu Sasaki,
Isao Yoshimine,
Shigenori Nagano,
Tetsuya Yuasa,
Chiko Otani
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.386680
Subject(s) - optics , optical coherence tomography , terahertz radiation , materials science , nondestructive testing , repeatability , metrology , image resolution , resolution (logic) , zone plate , fourier transform , image processing , physics , diffraction , computer science , image (mathematics) , chemistry , chromatography , quantum mechanics , artificial intelligence
We construct a terahertz swept source optical coherence tomography system using a continuous-wave diode multiplier source in the 600-GHz band for defect inspection in multilayer objects and evaluate its performance. Using this system, we image a multilayer plastic sample to demonstrate the effectiveness of nondestructive three-dimensional imaging. To enhance the depth resolution, we apply an annihilating filter to the analysis and confirm that two surfaces of a 1-mm-thick plastic plate can be resolved. In addition, the repeatability of measured thicknesses is 0.22 mm. These values are approximately one-half and one-tenth of the resolution achievable by conventional Fourier analysis, respectively.