FOOD INSPECTION SYSTEM USING TERAHERTZ IMAGING

A terahertz (THz) transmission imaging system using a 0.2 and 0.4 THz gyrotron as a high power source was evaluated. In the gyrotron, 0.2 THz is the first main mode and 0.4 THz is the second harmonic mode. The output power of gyrotron is about 100 W at 0.2 THz and 1 W at 0.4 THz. For fast imaging, the source output was shaped into a line beam and an array detector was used. Two reflecting mirrors were utilized for a reflective imaging system. A 0.8 mm resolution was obtained using a 0.4 THz transmission image. The feasibility of fast THz imaging for the inspection of foreign substances in food is demonstrated. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1211-1214, 2014