Bent of plastic optical fiber with structural imperfections for displacement sensor

An arrangement of bending and structural imperfection in a plastic optical fiber (POF) for a displacement measurement system has been investigated. An evaluation on the output power of the POF caused by the displacement which induced the bending alongside the POF’s structural imperfection was determined. The experimental measurement clearly revealed that the sensor exhibited an increasing sensitivity and better resolution for the shorter sensor and more structural imperfection. Additionally, the sensor can be applied for measuring the displacement in the range of 15 mm by means of infrared LED. The maximum sensitivity of 0.2401 μW/mm and the finest resolution of 4.2 μm were obtained by the sensor length of 6 cm with 3 structural imperfections. The proposed displacement sensor offers a very simple design, high sensitivity and resolution, low fabrication cost and good suitability for large displacement measurements