Strain, Displacement, and Temperature Opportunities of a Periodically Etched Optical Fiber

In this work, we periodically modulate the diameter of a single-mode fiber (SMF) through simple procedures, namely, through the periodic deposition of photopolymerizable resin onto the surface of an SMF, followed by chemical corrosion in hydrofluoric acid. When subjecting the structure to an external load, a periodic refractive index modulation occurs along the fiber length, allowing the occurrence of attenuation dips in the transmission spectrum. The structure was characterized by displacement, longitudinal strain, and temperature, revealing promising capabilities, namely, a measurement range of 0–60 mm, for the displacement, which is 30 times larger than the one reported in the literature; showing the capability to measure strain with intensity detection schemes, showing low wavelength drift, which makes it promising for low-cost intensity detection schemes; and being also able to measure temperature through wavelength detection schemes.