Plastic optical fiber sensor based on in-fiber microholes for level measurement

A plastic optical fiber (POF) sensor with in-fiber microholes for level measurement is investigated. The sensor has eight 0.9-mm-diameter holes spaced 5 cm apart and fabricated by micro-drilling. When water is poured into a measuring cylinder equipped with a POF sensor for level measurement, the sensor transmittance increases with the number of holes immersed in water. The experimental data are in good agreement with the theoretical data. The research results show that a POF sensor with in-fiber micro-holes can be used to measure liquid level.