23 March 2015 Phase-shifted helical long-period grating-based temperature-insensitive optical fiber twist sensors
Author Affiliations +
Abstract
In smart structure monitoring, twist angle is one of the most critical mechanical parameters for infrastructure deterioration. A compact temperature-insensitive optical fiber twist sensor based on multi-phase-shifted helical long period fiber grating has been proposed and experimentally demonstrated in this paper. A multi-phase-shifted helical long period fiber grating is fabricated with a multi-period rotation technology. A π / 2 and a 3π / 2 phase shift is introduced in the helical long period fiber grating by changing the period. The helical pitch can be effectively changed with a different twist rate, which is measured by calculating the wavelength difference between two phase shift peaks. Although the wavelength of the phase shift peak also shifts with a change of the temperature, the wavelength difference between two phase shift peaks is constant due to two fixed phase shifts in the helical long period fiber grating, which is extremely insensitive to temperature change for the multi-phase-shifted helical long period fiber grating. The experimental results show that a sensitivity of up to 1.959 nm/(rad/m) is achieved.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ran Gao, Yinian Zhu, Sridhar Krishnaswamy, Jiang Yi, "Phase-shifted helical long-period grating-based temperature-insensitive optical fiber twist sensors", Proc. SPIE 9438, Health Monitoring of Structural and Biological Systems 2015, 94381D (23 March 2015); doi: 10.1117/12.2084306; https://doi.org/10.1117/12.2084306
PROCEEDINGS
10 PAGES


SHARE
RELATED CONTENT

Er-doped, LPFGs -based, all fibre temperature sensing device
Proceedings of SPIE (September 19 2016)
Chiral fiber sensors
Proceedings of SPIE (April 23 2010)
Principle and the application of an etched fiber-optic sensor
Proceedings of SPIE (December 04 1998)
Intelligent fiber sensing system for the oil field area
Proceedings of SPIE (August 26 2010)
Response analysis of thermal field disturbance sensor
Proceedings of SPIE (September 30 2011)

Back to Top