Distribution profiling of a transverse load using the DGD spectrum of chirped FBGs

Abstract

In this paper, we propose a new method to determine the longitudinal distribution of a non-uniform transverse force applied to an optical fiber. For that purpose, we use a chirped fiber Bragg grating (CFBG) for which we monitor the polarization parameters in reflection. In particular, we demonstrate that the differential group delay (DGD) spectrum of the CFBG is an imprint of the load profile so that it can be used for the shape determination of an applied load. Thereafter, we discuss the influence of the CFBG parameters on the achievable accuracy and resolution of our technique. An experimental validation is finally reported with two 48 mm long CFBGs subject to step transverse load profiles.

Continuous-Wave Fiber Cavity Ringdown Pressure Sensing Based on Frequency-Shifted Interferometry

“…The principle of FBG-based pressure sensors is the fact that the Bragg wavelength changes with the variation of pressure. But due to cross sensitivity to other parameters (such as temperature, strain, and vibration) and low sensitivity pressure, FBG-based pressure sensors also require specific mechanical devices and sensitization measures [ 10 , 11 , 12 , 13 ]. Therefore, it is crucial to explore new methods for developing fiber pressure sensors that are simple, inexpensive, and highly sensitive.…”