Macrocurvature losses in optical fibers caused by soft and swellable materials for sensors

We present the results of measurements of fiber bend loss caused by soft an d swellable materials with periods of perturbation of 1 mm to 20 mm. We mea sured both single and multimode fibers over range of wavelength 1500 nm to 1600 nm. We used swellable materials that have different moduli of Young. W e show that the swell of soft materials cause macrobend attenuation that in crease when the period rise to 10 mm. The material that has higher modulus of Young cause higher attenuation. With this results we expect to choose su itable materials for assembling a fiber optics sensor based in bend loss.