An Optical Fiber Liquid Level Sensor Based on Side Coupling Induction Technology

Abstract EN

An optical fiber liquid level sensor based on two twisted polymer optical fibers twining around a racetrack column is demonstrated in this study.

The side-coupling power of the passive fiber is modulated by the refractive index (RI) of the environment medium and decreases while the liquid level increases.

The variation patterns of the side-coupling power in the bent section and the straight section form a step attenuation, which can improve the measurement range with a superior sensitivity and distinguish liquids with different RIs.

Furthermore, the cost-effective sensor also shows good reversibility and low temperature-dependent properties.