Low-Cost Transducer Based On Surface Scattering Using Side-Polished D-Shaped Optical Fibers

This work presents a new low-cost and environmentally friendly optical transducer based on surface scattering in a side-polished fiber mounted on a glass groove. The surface roughness caused by polishing is used to estimate the change in refractive index on top of the fiber. Changing the surrounding index affects the scattering properties and, consequently, the leakage of the guided mode. This effect is experimentally investigated through the change in the attenuation coefficient when the surrounding refractive index is changed by dropping different weight ratios of glucose solutions onto the polished side. The measured change of the attenuation coefficient is consistent with the finite-element calculations. The effect of different polished depths was theoretically investigated to optimize the working conditions.