POLYMER OPTICAL FIBER CURVATURE SENSOR: A REVIEW AND HYSTERESIS ANALYSIS
Arnaldo Gomes Leal Junior1; Anselmo Frizera Neto1; Maria José Pontes1
1 Universidade Federal do Espírito Santo
Resumo
Over the past few years, polymer optical fibers began to draw attention and research efforts for sensor applications due to its higher elastic strain limits, fracture toughness, flexibility in bend and relative low cost when compared with glass optical fibers. These advantages enable the polymer optical fiber application for measurement of strain, tempera-ture, level, pressure, angle, among other parameters. However, optical fiber sensors present some drawbacks, such as the refractive index variation and signal attenuation with different temperature and humidity. There is also a variation on the output signal due to light source power deviation. Although the first two drawbacks can be solved through a dummy sensor technique or dual-wavelength compensation, there is a lack of alternatives for the compensation of vis-coelastic effects of polymer optical fibers. This paper presents a review of polymeric optical fiber properties and sen-sor applications proposed throughout the years. Moreover, a quasi-static test is performed and shows a high hystere-sis for sensor application. For this reason, a dynamic bending analysis is proposed for evaluation of the viscoelastic effects in frequencies higher than the fiber relaxation time. The presented experimental setup provides a compensation method for the viscoelasticity of the polymeric fiber.
Palavras-chave: Fiber optic sensor; Polymer optical fiber; Curvature sensor; Quasi-static analysis; Viscoelasticity