Differential Strain Sensitivity of Higher Order Cladding Modes in Weakly Tilted Fiber Bragg Gratings

摘要

In this paper, we present the differential strain sensitivity characteristics of core and cladding modes in weakly TFBG. Both experiment and analysis results are presented, and they are well matched. The results show that there are three different strain sensitivity regions for cladding mode resonances: the short wavelength region, the ghost mode region and the nearly linear sensitivity change region between them. By monitoring the cladding modes with different strain sensitivities, and noting that the different cladding modes have similar temperature sensitivities, weakly TFBG are attractive candidates for more accurate temperature-independent strain sensors.