Recently, Japan’s Toyohashi University of Technology and the Nagoya Institute of Technology and NTT Electronics jointly developed a foreign object detection device that uses “terahertz waves”. The terahertz wave is a special electromagnetic wave between the electric wave and the light, and its characteristics can detect X-rays and foreign matter such as insects that cannot be detected by the metal detector. The research team plans to conduct field verification of the test device next year and expects to sell the goods after 2020.

The research group first realized the miniaturization of the terahertz wave generating device by using the technology of the optical communication field, thereby manufacturing a small detecting device (about 180 cm in height, width and height of about 100 cm) using terahertz waves.

When detecting foreign matter such as flies mixed in chocolate, the detection depth of the near-infrared detector is only about 5 cm, and the depth of detection of the terahertz wave is about 15 cm. The foreign bodies of insects such as flies are more similar to foods, and it is difficult to use X-ray detection for detecting metal sheets.