Prism design for oil detecting systems based on terahertz attenuated total internal reflection

In order to obtain the attenuated internal reflection spectroscopy and realize on-line detection of oil in terahertz, the core components of total internal reflection system——the attenuated total internal reflection prism was designed by using the refraction law of light. At first, single reflection prism was designed and was used in terahertz attenuated total internal reflection system. According to the absorption of different material on terahertz wave, test experiments of water and product oil were carried out. Spectral data of samples were obtained. And then, multiple reflection prism was designed to increase the absorption of oil in terahertz, and optical simulation was carried out. The experimental results show that the absorption of oil after single total internal reflection is very limited, and the detection of oil cannot be achieved. The study is helpful for detection of oil quality.