A novel device for the detection and characterisation of static magnetic fields is presented. It consists of a femtosecond laser inscribed fibre Bragg grating (FBG) that is incorporated into an optical fibre with a femtosecond laser micromachined slot. The symmetry of the fibre is broken by the micro-slot, producing non-uniform strain across the fibre cross section. The sensing region is coated with Terfenol-D making the device sensitive to static magnetic fields, whereas the symmetry breaking results in a vectorial sensor for the detection of magnetic fields as low as 0.046 mT with a resolution of ±0.3mT in transmission and ±0.7mT in reflection. The sensor output is directly wavelength encoded from the FBG filtering, leading to simple demodulation through the monitoring of wavelength shifts that result as the fibre structure changes shape in response to the external magnetic field. The use of a femtosecond laser to both inscribe the FBG and micro-machine the slot in a single stage, prior to coating the device, significantly simplifies the sensor fabrication.
|Title of host publication||21st international conference on optical fiber sensors|
|Editors||Wojtek J. Bock, Jacques Albert, Xiaoyi Bao|
|Number of pages||4|
|Publication status||Published - Jan 2011|
|Event||21st International Conference on Optical Fiber Sensors - Ottawa, ON, Canada|
Duration: 15 May 2011 → 19 May 2011
|Conference||21st International Conference on Optical Fiber Sensors|
|Period||15/05/11 → 19/05/11|
Bibliographical noteG. N. Smith ; T. Allsop ; K. Kalli ; C. Koutsides ; R. Neal ; K. Sugden ; P. Culverhouse and I. Bennion "Femtosecond laser inscribed Bragg sensor in Terfenol-D coated optical fibre with ablated microslot for the detection of static magnetic fields", Wojtek J. Bock ; Jacques Albert ; Xiaoyi Bao (eds); Proc. SPIE 7753, 21st International Conference on Optical Fiber Sensors, 77536N (May 17, 2011).
Copyright 2011 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
- fiber Bragg gratings
- optical fiber sensors
- femtosecond laser
Smith, G. N., Allsop, T. D. P., Kalli, K., Koutsides, C., Neal, R., Sugden, K., ... Bennion, I. (2011). Femtosecond laser inscribed Bragg sensor in Terfenol-D coated optical fibre with ablated microslot for the detection of static magnetic fields. In W. J. Bock, J. Albert, & X. Bao (Eds.), 21st international conference on optical fiber sensors (SPIE proceedings; Vol. 7753). SPIE. https://doi.org/10.1117/12.885122