Long-Period Fiber Grating Within D-Shaped Fiber Using Magnetic Fluid for Magnetic-Field Detection

Author

Lei Gao ; Tao Zhu ; Ming Deng ; Kin Seng Chiang ; Xiaokang Sun ; Xiaopeng Dong ; Yusong Hou

Author_Institution

Key Lab. of Optoelectron. Technol. & Syst. (Minist. of Educ.), Chongqing Univ., Chongqing, China

Volume

4

Issue

6

fYear

2012

Firstpage

2095

Lastpage

2104

Abstract

A magnetic sensor utilizing long-period fiber grating (LPFG) written by high frequency CO₂ laser pulses in a D-shaped fiber and the magneto-optical effect of magnetic fluid is proposed. Because of the high evanescent field of the grating structure in D-shaped fiber, by immersing the LPFG with a period of 685 μm into a water-based magnetic fluid within a capillary tube, the redshift as high as 33.5 nm of the resonant wavelength of the grating is observed when the external magnetic-field intensity is 189.7 mT, resulting in a sensitivity of 176.4 pm/mT. The hysteresis effect is observed and explained by the characters of magnetic fluid. Such kind of sensors would find potential applications in magnetic sensing fields.

Keywords

diffraction gratings; fibre optic sensors; magnetic field measurement; magnetic fluids; magneto-optical sensors; red shift; D-shaped fiber; capillary tube; evanescent field; external magnetic field intensity; grating structure; high frequency carbon dioxide laser pulses; long period fiber grating; magnetic field detection; magnetic flux density 189.7 mT; magnetic sensor; red shift; water based magnetic fluid; Magnetic fields; Magnetic resonance; Magnetic sensors; Optical fiber sensors; Optical fibers; Sensitivity; Sensors; fiber gratings; light–material interactions;

fLanguage

English

Journal_Title

Photonics Journal, IEEE

Publisher

ieee

ISSN

1943-0655

Type

jour

DOI

10.1109/JPHOT.2012.2226439

Filename

6338993