Title :
A novel long period fiber grating sensor measuring curvature and determining bend-direction simultaneously
Author :
Wang, Yi-Ping ; Rao, Yun-Jiang
Author_Institution :
State Key Lab. on Local Fiber-Opt. Commun. Networks & Adv. Opt. Commun. Syst., Shanghai Jiao Tong Univ., China
Abstract :
A novel long period fiber-grating (LPFG) sensor that can not only measure curvature directly, but also determine every bend-direction within the circular range of 0°-360°, is proposed and demonstrated in this paper. Such a bend-sensor consists of one LPFG induced by a UV laser and two LPFGs induced by high-frequency CO2 laser pulses. The curvature is measured by the UV laser-induced LPFG whose bend-sensitivity is independent of the bend-directions, and the bend-direction is determined by the CO2 laser-induced LPFGs whose bend-sensitivities depend strongly on the curved directions. In addition, the unique bend-characteristics of LPFGs induced by high-frequency CO2 laser pulses are demonstrated.
Keywords :
bending; curvature measurement; diffraction gratings; fibre optic sensors; measurement by laser beam; CO2 laser-induced LPFG; UV laser-induced LPFG; bend direction determination; bend sensitivity; bend sensor; curvature measurement; curved directions; fibre optic sensors; gas lasers; high-frequency CO2 laser pulses; laser beam effects; long period fiber grating sensor; optical fiber sensor; Bragg gratings; Fiber gratings; Fiber lasers; Optical fiber devices; Optical fiber polarization; Optical fiber sensors; Optical fiber testing; Optical pulses; Optical sensors; Resonance; Bend-direction; bend-sensor; curvature; fiber-Bragg grating (FBG); long period fiber grating (LPFG); optical-fiber sensor;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2005.844335
