Bend measurement with chirp of fiber Bragg grating

Abstract

The first measurements of curvature with chirp of fiber Bragg grating are described. The grating is bonded at a slant onto the lateral surface of a beam and chirped by the bend-induced strain gradient. The bandwidth of the grating is proportional to the curvature of the beam and independent of temperature, resulting in a curvature measurement with a resolution of 0.036 m-1 within the range of 4 m-1. Simultaneously, the thermal response of the central Bragg wavelength provides a temperature measurement within the range of 0-45 °C.