Fiber curvature sensor based on spherical-shape structures and long-period grating

Abstract A novel curvature sensor based on optical fiber Mach–Zehnder interferometer (MZI) is demonstrated. It consists of two spherical-shape structures and a long-period grating (LPG) in between. The experimental results show that the shift of the dip wavelength is almost linearly proportional to the change of curvature, and the curvature sensitivity are −22.144 nm/m −1 in the measurement range of 5.33–6.93 m −1 , −28.225 nm/m −1 in the range of 6.93–8.43 m − and −15.68 nm/m −1 in the range of 8.43–9.43 m −1 , respectively. And the maximum curvature error caused by temperature is only −0.003 m −1 /°C. The sensor exhibits the advantages of all-fiber structure, high mechanical strength, high curvature sensitivity and large measurement scales.

[1]  Xinyong Dong,et al.  An Optical Fiber Curvature Sensor Based on Two Peanut-Shape Structures Modal Interferometer , 2014, IEEE Photonics Technology Letters.

[2]  Xinyong Dong,et al.  An optical fiber curvature sensor based on photonic crystal fiber modal interferometer , 2013 .

[3]  Xinyong Dong,et al.  Polarization-dependent curvature sensor based on an in-fiber Mach-Zehnder interferometer with a difference arithmetic demodulation method. , 2012, Optics express.

[4]  P. Caldas,et al.  All-fiber Mach-Zehnder curvature sensor based on multimode interference combined with a long-period grating. , 2007, Optics letters.

[5]  Yi Li,et al.  Curvature sensor based on two cascading abrupt-tapers modal interferometer in single mode fiber , 2014 .

[6]  Ming Ding,et al.  Intensity measurement bend sensors based on periodically tapered soft glass fibers. , 2011, Optics letters.

[7]  Ye Cao,et al.  High temperature fiber sensor based on spherical-shape structures with high sensitivity , 2014 .

[8]  Tao Zhu,et al.  Highly sensitive bend sensor based on Mach–Zehnder interferometer using photonic crystal fiber , 2011 .

[9]  Changyun Miao,et al.  High-sensitivity all single-mode fiber curvature sensor based on bulge-taper structures modal interferometer , 2015 .

[10]  Shecheng Gao,et al.  Fiber-optic bending vector sensor based on Mach-Zehnder interferometer exploiting lateral-offset and up-taper. , 2012, Optics letters.

[11]  J. G. Burnett,et al.  Bend measurement using Bragg gratings in multicore fibre , 2000 .

[12]  Qida Zhao,et al.  A smart bending sensor with a novel temperature- and strain-insensitive long-period grating , 2004 .

[13]  Yuehua Wu,et al.  All-Fiber Curvature Sensor Based on Multimode Interference , 2011, IEEE Photonics Technology Letters.

[14]  Byeong Ha Lee,et al.  Fibre-optic sensing applications of a pair of long-period fibre gratings , 2001 .

[15]  John E. Sipe,et al.  Long-period fiber gratings as band-rejection filters , 1995 .