Open AccessHybrid optical imaging with near-infrared, mid-infrared, and terahertz wavelengths for nondestructive inspection [Invited]
Author(s) -
Yu Tao,
Hikaru Ejiri,
Takeo Minamikawa,
Safumi Suzuki,
Masahiro Asada,
Takeshi Yasui
Publication year - 2021
Publication title -
applied optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.668
H-Index - 197
eISSN - 2155-3165
pISSN - 1559-128X
DOI - 10.1364/ao.415131
Subject(s) - terahertz radiation , optics , infrared , materials science , nondestructive testing , wavelength , detector , near infrared spectroscopy , optoelectronics , image resolution , multispectral image , terahertz gap , terahertz metamaterials , physics , far infrared laser , remote sensing , laser , quantum mechanics , geology
Optical imaging is a powerful tool for nondestructive inspection, with high spatial resolution and low invasiveness. As light-material interactions vary a great deal depending on the wavelength, it is difficult to select the best imaging wavelength without prior knowledge of the optical properties of the material. To overcome this difficulty, we constructed a hybrid optical imaging system using three different wavelengths: near-infrared (NIR), mid-infrared (MIR), and terahertz (THz) regions. The same imaging optics were integrated with different light sources and detectors. Depending on the light-material interaction and detection sensitivity, NIR and THz imaging indicated some potential for nondestructive inspection, but MIR imaging showed difficulty. A combination of NIR and THz imaging will be a powerful tool for optical nondestructive inspection.