A Fiber Bending Vector Sensor Based on M–Z Interferometer Exploiting Two Hump-Shaped Tapers

A novel, compact, and simple in-line Mach-Zehnder interferometer (MZI) formed by cascading two hump-shaped tapers in a segment of single-mode fiber is proposed and fabricated. This optical fiber device has recognizable features for different bend directions while high sensitivities for ambient temperature and axial force. In the range of 0-1.2 m-1, the sensitivities of the sensor with the length of 13.4 mm are 10.224 and -4.973 nm/m-1 for opposite bending directions 0° and 180°, respectively. The responses for temperature and force of the MZI are also investigated in experiment. The results show that the shift of the dip wavelength is linearly proportional to the change of temperature or force. The sensitivities of temperature and force are 0.049 nm/°C in the range of 20°C-80°C and -3.643 nm/N in the range of 0-0.98 N.

[1]  Bo Liu,et al.  Fiber modal interferometer with embedded fiber Bragg grating for simultaneous measurements of refractive index and temperature , 2013 .

[2]  Yongqin Yu,et al.  High-Sensitivity Mach–Zehnder Interferometric Temperature Fiber Sensor Based on a Waist-Enlarged Fusion Bitaper , 2011, IEEE Sensors Journal.

[3]  Weigang Zhang,et al.  Reconfigurable and ultra-sensitive in-line Mach-Zehnder interferometer based on the fusion of microfiber and microfluid , 2015 .

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

[5]  Xueguang Qiao,et al.  An In-Fiber Mach–Zehnder Interferometer Based on Arc-Induced Tapers for High Sensitivity Humidity Sensing , 2013, IEEE Sensors Journal.

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

[7]  Jian Ju,et al.  Compact In-Fiber Interferometer Formed by Long-Period Gratings in Photonic Crystal Fiber , 2008, IEEE Photonics Technology Letters.

[8]  Peiguang Yan,et al.  Ambient refractive index-independent bending vector sensor based on seven-core photonic crystal fiber using lateral offset splicing. , 2013, Optics express.

[9]  Xiaopeng Dong,et al.  Ultrasensitive refractive index sensor based on a Mach-Zehnder interferometer created in twin-core fiber. , 2014, Optics letters.

[10]  C. Liao,et al.  Microfiber in-line Mach-Zehnder interferometer for strain sensing. , 2013, Optics letters.

[11]  Y. Rao,et al.  Novel fiber-optic sensors based on long-period fiber gratings written by high-frequency CO/sub 2/ laser pulses , 2003 .

[12]  Chi Chiu Chan,et al.  Miniature refractometer based on Mach–Zehnder interferometer with waist-enlarged fusion bitaper , 2013 .

[13]  Shecheng Gao,et al.  Long-Period Fiber Grating Cascaded to an S Fiber Taper for Simultaneous Measurement of Temperature and Refractive Index , 2013, IEEE Photonics Technology Letters.

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