## Abstract

We demonstrate a directional curvature sensor based on tilted few-mode fiber Bragg gratings (FM-FBGs) inscribed by a UV laser. The eigenmodes of ${\mathrm{LP}}_{01}$ and ${\mathrm{LP}}_{11}$ mode groups are simulated along with the fiber bending. The directional curvature sensor is based on the ${\mathrm{LP}}_{11}$ mode resonance in the tilted FM-FBG. For curvature from 4.883 to $7.625\text{\hspace{0.17em}}{\mathrm{m}}^{-1}$, the curvature sensitivities at direction of 0° and 90° are measured to be $-2.67$ and $0.128\text{\hspace{0.17em}}\mathrm{dB}/{\mathrm{m}}^{-1}$, respectively. The temperature variation barely affects the resonance depth of ${\mathrm{LP}}_{11}$ mode. The proposed curvature sensor clearly demonstrates the potential to simultaneous directional curvature and temperature measurement with the resolutions of $9.15\times {10}^{-4}\text{\hspace{0.17em}}{\mathrm{m}}^{-1}$ and 0.952°C, respectively.

© 2018 Optical Society of America

Full Article | PDF Article**More Like This**

Tiegen Liu, Anqi Chen, Mei Sang, Jingchuan Zhang, Shuang Wang, Junfeng Jiang, and Jie Dong

Appl. Opt. **60**(30) 9280-9286 (2021)

Ya Gao, Junqiang Sun, Guodong Chen, and Chaotan Sima

Opt. Express **23**(8) 9959-9967 (2015)

Piotr Kisała, Damian Harasim, and Janusz Mroczka

Opt. Express **24**(26) 29922-29929 (2016)