Simultaneous strain and directional bending sensor based on eccentric-core fiber Bragg grating

Abstract

A fiber sensor based on cascaded eccentric-core fiber Bragg grating (ECFBG) and single mode fiber Bragg grating (SMFBG) is proposed and experimentally demonstrated to realize bending and axial strain measurement simultaneously. The ECFBG is sensitive to both bending and axial strain, and the SMFBG is insensitive to bend but sensitive to axial strain. The maximum bending sensitivities of the ECFBG are 36 pm/m⁻¹ and −37 pm/m⁻¹ at the bending direction of 0° and 180°, respectively. The strain sensitivities of the ECFBG and SMFBG are 0.76 pm/με and 0.72 pm/με, respectively.