A Highly Sensitive Two-Dimensional Inclinometer Based on Two Etched Chirped-Fiber-Grating Arrays

Sensors

Wen-Fung Liu¹  Yu-Chung Chang²  Hung-Ying Chang³ 

[1] Department of Electrical Engineering, Feng-Chia University, 100 Wenhwa Rd., Seatwen, Taichung 40724, Taiwan;Department of Electrical Engineering, National Changhua University of Education, 2 Shida Rd., Changhua 50074, Taiwan;Program of Electrical and Communications Engineering, Feng-Chia University, 100 Wenhwa Rd., Seatwen, Taichung 40724, Taiwan;

关键词: etched fiber Bragg grating;    chirped fiber Bragg grating (CFBG);    level meter;    inclinometer;    tilt meter;    fiber sensor;   

DOI  :  10.3390/s17122922

来源: DOAJ

【 摘 要 】

We present a novel two-dimensional fiber-optic inclinometer with high sensitivity by crisscrossing two etched chirped fiber Bragg gratings (CFBG) arrays. Each array is composed of two symmetrically-arranged CFBGs. By etching away most of the claddings of the CFBGs to expose the evanescent wave, the reflection spectra are highly sensitive to the surrounding index change. When we immerse only part of the CFBG in liquid, the effective index difference induces a superposition peak in the refection spectrum. By interrogating the peak wavelengths of the CFBGs, we can deduce the tilt angle and direction simultaneously. The inclinometer has a resolution of 0.003° in tilt angle measurement and 0.00187 rad in tilt direction measurement. Due to the unique sensing mechanism, the sensor is temperature insensitive. This sensor can be useful in long term continuous monitoring of inclination or in real-time feedback control of tilt angles, especially in harsh environments with violent temperature variation.

【 授权许可】

Unknown