Two-dimensional Displacement Optical Fiber Sensor Based on Macro-Bending Effect

This paper highlights a novel and simple approach for two-dimensional displacement sensor's design based on macro-bending loss and optical power coupling effect. Multimode plastic optical fiber offers flexibility in bending which can easily radiate bend loss and easily side coupled with second fiber (receiving fiber RF). In this approach of 2D system, dual-time repeated twisting has been carried out with transmitting fiber (TF). Two RFs were employed in experiment and twisted in such a way that for the measurement of x-axis displacement (First RF is twisted with TF) and for measurement of y-axis displacement (Second RF is twisted with TF. The experimental measurement results of two dimensions sensor have been achieved for forward and backhaul movement with good consistency up to 160 mm and system has linearity from 0 mm to 100 mm having sensitivity of 2.6 nW/mm. The 2D sensor has numerous industrial applications in robotics, precision alignment, bridges and many more. In this context, the aforementioned technique could be considered as more holistic and optimal in comparison to the existing techniques.