Simultaneous Measurement for Displacement and Temperature Using Fiber Bragg Grating Cladding Mode Based on Core Diameter Mismatch

A novel fiber Bragg grating (FBG) sensing configuration for simultaneous measurements of temperature and displacement based on a core diameter mismatch is proposed and experimentally demonstrated. The configuration is formed by a short section of thin-core fiber (TCF) followed with a single-mode fiber (SMF) tip inscribed with an FBG. The TCF excites cladding modes into downstream SMF via the mismatch core splicing interface, and the low-order cladding modes can be reflected back to the fiber core via the FBG in which the recoupling efficiency is highly dependent on fiber bending. Experimental results show that the recoupled first-order odd mode (LP13) shows an extremely high sensitivity to fiber bending. The simultaneous measurements, including power-referenced for displacement and wavelength-referenced for temperature, have been achieved via selective cladding modes monitoring.

[1]  Jacques Albert,et al.  Temperature-independent tilted fiber grating vibration sensor based on cladding-core recoupling. , 2008, Optics letters.

[2]  F. Farahi,et al.  Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating , 1996, IEEE Photonics Technology Letters.

[3]  G. Johnson,et al.  Flexural beam-based fiber Bragg grating accelerometers , 1998, IEEE Photonics Technology Letters.

[4]  J. Albert,et al.  Compact fiber-optic vector inclinometer. , 2010, Optics letters.

[5]  Wojtek J. Bock,et al.  Highly sensitive bend sensor with hybrid long-period and tilted fiber Bragg grating , 2010 .

[6]  Hwa-Yaw Tam,et al.  Tilted fiber grating accelerometer incorporating an abrupt biconical taper for cladding to core recoupling. , 2009, Optics express.

[7]  Li Wei,et al.  Simultaneous measurement for strain and temperature using fiber Bragg gratings and multimode fibers. , 2008, Applied optics.

[8]  Ping Shum,et al.  Temperature insensitive accelerometer based on a strain-chirped FBG , 2009, International Conference on Optical Fibre Sensors.

[9]  Michael A. Davis,et al.  Fiber grating sensors , 1997 .

[10]  K. Hill,et al.  Fiber Bragg grating technology fundamentals and overview , 1997 .

[11]  Hwa-Yaw Tam,et al.  Cladding-mode-assisted recouplings in concatenated long-period and fiber Bragg gratings. , 2002, Optics letters.

[12]  Jacques Albert,et al.  Strain-optic coefficients of individual cladding modes of singlemode fibre: theory and experiment , 2006 .

[13]  J. Lit,et al.  Simultaneous Strain and Temperature Measurement With Fiber Bragg Grating and Multimode Fibers Using an Intensity-Based Interrogation Method , 2009, IEEE Photonics Technology Letters.

[14]  Lingyun Xiong,et al.  Directional Bend Sensor Based on Re-Grown Tilted Fiber Bragg Grating , 2010, Journal of Lightwave Technology.

[15]  James S. Sirkis,et al.  Optimal wavelength pair selection and accuracy analysis of dual fiber grating sensors for simultaneously measuring strain and temperature , 2002 .

[16]  Orlando Frazão,et al.  Sampled fibre Bragg grating sensors for simultaneous strain and temperature measurement , 2002 .

[17]  M. Jeong,et al.  Simultaneous Measurement of Refractive Index, Temperature, and Strain Using Etched-Core Fiber Bragg Grating Sensors , 2010, IEEE Photonics Technology Letters.