Deflection measurement using long-period grating sensor fabricated on side-hole single-mode fiber by CO 2 -laser

Abstract

In this paper, an optical Long-period fiber grating (LPG) fabricated by CO 2 laser in side-hole single-mode fiber (SHLPG) for cantilever deflection measurement was demonstrated according with LPG flexural character. resonance wavelength of SHLPG (1547.3nm) has a total blue shift of approximately -0.83nm for deflection ranging from 0 to 40mm, and a red shift of 0.74nm with deflection ranging from 0 to -40mm. The results indicated that the SHLPG owns higher deflection sensitivity than that of normal LPG and fiber Bragg grating. The deflection sensitivity coefficient of SHLPG is -0.202nm/mm. The resonance wavelength shift has a good linear with the deflection increasing. The correlative coefficient is 0.9966. Factual deflection measuring can be got with high sensitivity through SHLPG easily.