Abstract A subwavelength transmission imaging system based on Bessel–Gauss beam focusing in the 140 GHz frequency band (λ = 2.14 mm) was constructed for food quality inspection purposes. The system employed a low-cost beam source for imaging via mechanical raster scanning, and the high resolution (0.75 λ) focusing module had an extended depth of focus (12.6 λ) and supported a large scan area (800 × 400 mm2, 30 min scan time). The performance of the proof-of-concept system was nondestructively investigated by using a variety of food products, such as chocolate bars, dried laver, red ginseng, and walnuts.

中文翻译：

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用于无损食品质量检测的大扫描面积亚太赫兹成像系统

摘要 基于贝塞尔-高斯光束聚焦在 140 GHz 频段 (λ = 2.14 mm) 的亚波长透射成像系统被构建用于食品质量检测。该系统采用低成本光束源通过机械光栅扫描成像，高分辨率（0.75 λ）聚焦模块具有扩展的焦深（12.6 λ）并支持大扫描区域（800 × 400 mm2，30 min扫描时间）。通过使用各种食品，如巧克力棒、干紫菜、红参和核桃，对概念验证系统的性能进行了无损研究。