Title :
High-Resolution Strain/Temperature Sensing System Based on a High-Finesse Fiber Cavity and Time-Domain Wavelength Demodulation
Author :
Chen, Daru ; Liu, Weisheng ; Jiang, Meng ; He, Sailing
Author_Institution :
Center for Opt. & Electromagn. Res., Zhejiang Univ., Hangzhou, China
fDate :
7/1/2009 12:00:00 AM
Abstract :
A high-resolution strain/temperature sensing system based on a fiber Bragg grating-Fabry-Perot cavity (FBG-FPC) and a wavelength-swept single-longitudinal-mode laser diode (modulated by a sawtooth signal) is proposed. The high-finesse (~627) FBG-FPC formed by two uniform FBGs of high reflectivity (~99.5%) is used both as a strain/temperature sensor and a FPC with ultranarrow (~0.12 pm) transmission bands. Using a photodetector to detect the transmissive light of the laser diode through the FBG-FPC, wavelength demodulation is achieved by mapping wavelength measurement to time measurement. Both strain sensing and temperature sensing with a resolution of 0.11 muepsiv and 0.014degC, respectively, have been demonstrated.
Keywords :
Bragg gratings; Fabry-Perot resonators; demodulation; fibre optic sensors; measurement by laser beam; optical modulation; photodetectors; strain measurement; strain sensors; temperature measurement; temperature sensors; fiber Bragg grating-Fabry-Perot cavity; high-finesse fiber cavity; high-resolution strain sensing system; photodetector; sawtooth signal; temperature sensing system; time measurement; time-domain wavelength demodulation; ultranarrow transmission band; wavelength measurement; wavelength-swept single-longitudinal-mode laser diode; Fabry–Perot cavity; fiber Bragg grating; fiber sensor; strain/temperature sensor;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2008.2011498
