Real-Time 0.89 THz Terahertz Imaging with High-Electron-Mobility Transistor Detector and Hydrogen Cyanide Laser for Non-Destructive Nut Detection.

Abstract

We present a method for real-time terahertz imaging that employs a hydrogen cyanide (HCN) laser as a terahertz source at 0.89 THz and an AlGaN/GaN high-electron-mobility transistor (HEMT) terahertz detector as a camera. We developed an HCN laser and constructed a transmission imaging system based on it. This combination utilizes a high-power HCN laser with a highly sensitive terahertz detector, enabling practical applications of real-time terahertz imaging. A resolution test plane was produced to determine that the system could achieve a lateral resolution of 2 mm, and real-time terahertz imaging was carried out on Siemens star, pistachios, and sunflower seeds. The results demonstrate that the hidden structures inside nuts can be observed by terahertz imaging. Through our analysis of terahertz images of both sunflower seeds and pine nuts, we successfully assessed their fullness and demonstrated the capability to distinguish between full and unfilled nuts. These findings validate the potential of this technique for future applications in nut detection. We discuss the limitations of the current setup, potential improvements, and possible applications, and we outline the introduction of aspherical lenses and terahertz transmission tomography.

Plant phenotyping relevance

テラヘルツ画像システムの構築・性能評価が中心で、種子内部構造と充実度を非破壊測定する植物フェノタイピング手法に該当する。

Code and data availability

The supplied blocks describe terahertz imaging of nuts (sunflower seeds, pistachios, pine nuts) with image processing in MATLAB, but contain no data availability statement, no public dataset or image deposit, and no author code repository or URL. The MATLAB processing is described only as performed with commercial 'MAT

No evidence-backed public reproduction asset is currently recorded.