Foreign object detection by sub-terahertz quasi-Bessel beam imaging.

Area of Science:

• Physics
• Food Science
• Imaging Technology

Background:

• Food quality and safety are paramount, necessitating advanced foreign object detection methods.
• Traditional methods like X-ray imaging pose safety concerns due to ionizing radiation.
• Terahertz (THz) imaging presents a non-ionizing, safe alternative for nondestructive food inspection.

Purpose of the Study:

• To investigate the application of quasi-Bessel beams (QBBs) for foreign object detection in food.
• To evaluate the performance of QBBs generated by a conical dielectric lens in terahertz imaging.
• To compare QBB performance against conventional Gaussian beams for food inspection.

Main Methods:

• Generation of a quasi-Bessel beam (QBB) using a conical dielectric lens.
• Numerical simulation using the finite-difference time-domain (FDTD) method to evaluate beam profiles.
• Experimental characterization including knife-edge and point-scanning methods.
• Detection of foreign objects (crickets) in food samples using QBB terahertz imaging at 210 GHz.

Main Results:

• The finite-difference time-domain (FDTD) method provided a precise estimation of QBB beam profiles.
• Quasi-Bessel beams demonstrated deep focus and high spatial resolution for foreign object detection.
• Experimental comparison showed QBBs outperformed Gaussian beams in terahertz imaging of food samples.

Conclusions:

• Quasi-Bessel beams are effective for safe, nondestructive foreign object detection in food using terahertz imaging.
• The developed QBB system offers improved performance over conventional methods for food quality monitoring.
• This technology holds significant potential for enhancing food safety and quality assurance.