Terahertz imaging for water content measurement

We proposed a quantitative method to calculate water content of the thin materials by terahertz (THz) imaging. First, we constructed a THz imaging system by using a Tunnel injection Transit Time (TUNNETT) THz wave generator with automatic scanning control. Images of the plant leaves under different conditions were taken with the THz imaging system. We have introduced an algorithm with the attenuation law of Lambert-Beer to calculate the water contents from the THz imaging. To verify the accuracy of this method, we also took images of a piece of filter paper with different content of water. Comparing the calculated result with the measured value by the electronic balance showed that our method has a good possibility to measure the water content of the relative thin materials with non-contact and non-invasive method from the THz imaging.