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<sup>-1</sup> and -37 pm/m<sup>-1</sup> 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.
A simultaneous temperature and bend sensor based on an eccentric core fiber Bragg grating (ECFBG) cascaded with a Fabry-Perot cavity is presented and demonstrated. The hybrid structure is composed of a piece of hollow core fiber, which is sandwiched in between a piece of multimode fiber and an ECFBG. The curvature sensitivities of the ECFBG at the two opposite most sensitive directions are 52.2 pm/m<sup>-1</sup> and -51.7 pm/m<sup>-1</sup> respectively, and those of the FPI are 58.6pm/m<sup>-1</sup> and -61.4 pm/m<sup>-1</sup>, respectively. The temperature sensitivities of the two parts are very different. The temperature sensitivity of the ECFBG is 10.3 pm/°c, and that of the FPI is as low as 0.7 pm/°c.