Open AccessA high sensitivity fiber-optic torsion sensor based on a novel ultra long-period fiber grating
Author(s) -
Zhu Tao,
Yunjiang Rao,
Mo Qiu-Ju
Publication year - 2006
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.55.249
Subject(s) - torsion (gastropod) , materials science , optics , long period fiber grating , fiber bragg grating , birefringence , fiber optic sensor , grating , optical fiber , demodulation , optoelectronics , polarization maintaining optical fiber , physics , telecommunications , computer science , medicine , channel (broadcasting) , surgery
A high sensitivity fiber-optic torsion sensor is described,which measures twist rate and determines twist direction simultaneously by using a novel ultra long-period fiber grating (ULPFG) with periods of up to several millimeters fabricated by high frequency CO2 laser pulses. The torsion characteristics of a ULPFG are analyzed based on the coupling theory and birefringence phenomena. The experimental results show that a higher torsion sensitivity of 0.2244nm/(rad/m) for high order resonant modes was obtained, which is four times higher than that of the long-period fiber grating written by high frequency CO2 laser pulses. Finally, an intensity-type demodulation approach for the realization of real-time torsion measurement is proposed and demonstrated based on the edge filtering effect of the ULPFG.