High Sensitivity Optical Fiber Curvature Sensor Based on Cascaded Fiber Interferometer

A highly sensitive optical fiber curvature sensor based on cascaded fiber interferometers (CFIs) is demonstrated theoretically and experimentally. Theoretical results show that the scheme of cascaded fiber interferometers can be regarded as an equivalent fiber interferometer with longer interference length and narrower FSR. It serves as a curvature sensor with sensitivity up to 4.362 nm/m−1 within the measurement range of 0–1.134 m−1. Compared to the single fiber modal interferometer, the curvature sensitivity of the CFI is almost doubled. In addition, simultaneous curvature and temperature measurement is achieved using the coefficient matrix method, eliminating the issue of temperature cross sensitivity.

[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]  Hwa-Yaw Tam,et al.  Temperature-insensitive strain sensor with polarization-maintaining photonic crystal fiber based Sagnac interferometer , 2007 .

[4]  Jianlin Zhao,et al.  A Mach–Zehnder interferometric humidity sensor based on waist-enlarged tapers , 2014 .

[5]  Bo Dong,et al.  Temperature insensitive curvature measurement with a core-offset polarization maintaining photonic crystal fiber based interferometer , 2011 .

[6]  K. Sooley,et al.  Tapered fiber Mach–Zehnder interferometer for simultaneous measurement of refractive index and temperature , 2009 .

[7]  Bo Dong,et al.  Temperature Insensitive All-Fiber Compact Polarization-Maintaining Photonic Crystal Fiber Based Interferometer and Its Applications in Fiber Sensors , 2010, Journal of Lightwave Technology.

[8]  Bo Dong,et al.  Simultaneous strain and temperature measurement using a compact photonic crystal fiber inter-modal interferometer and a fiber Bragg grating. , 2010, Applied optics.

[9]  Libo Yuan,et al.  Modal Interferometer Using Three-Core Fiber for Simultaneous Measurement Strain and Temperature , 2016, IEEE Photonics Journal.

[10]  Jing Zhao,et al.  Asymmetrical in-fiber Mach-Zehnder interferometer for curvature measurement. , 2015, Optics express.

[11]  Bo Dong,et al.  High sensitivity curvature sensor with a cascaded fiber interferometer , 2017, 2017 25th Optical Fiber Sensors Conference (OFS).

[12]  J M Baptista,et al.  All Fiber Mach–Zehnder Interferometer Based on Suspended Twin-Core Fiber , 2010, IEEE Photonics Technology Letters.

[13]  Thomas G. Giallorenzi,et al.  Polarization effects on single‐mode optical fiber sensors , 1979 .

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

[15]  Yi-Ping Wang,et al.  A novel long period fiber grating sensor measuring curvature and determining bend-direction simultaneously , 2005, IEEE Sensors Journal.

[16]  Yong Zhao,et al.  Investigation of the high sensitivity RI sensor based on SMS fiber structure , 2014 .

[17]  Tao Wei,et al.  Miniaturized fiber inline Fabry-Perot interferometer fabricated with a femtosecond laser. , 2008, Optics letters.

[18]  Elfed Lewis,et al.  A Curvature Sensor Based on Twisted Single-Mode–Multimode–Single-Mode Hybrid Optical Fiber Structure , 2017, Journal of Lightwave Technology.