Momiyama H, Sasaki Y, Yoshimine I, Nagano S, Yuasa T, Otani C. Improvement of the depth resolution of swept-source THz-OCT for non-destructive inspection.
OPTICS EXPRESS 2020;
28:12279-12293. [PMID:
32403726 DOI:
10.1364/oe.386680]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
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.
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