Abstract
Based on a rigorous mode theory and considering the wavelength dispersion of fiber Bragg grating (FBG), the conditions necessary for FBG-based Fabry–Perot interferometer (BFPI) to operate in single axial mode (SM) were investigated, as an extension of phase-shifted FBG, by analytical formulas and numerical simulation. Following the theoretical results, SM-BFPI of very narrow bandpass was designed and fabricated. Using that, the first of its kind to our knowledge, SM-BFPI-based WDM distributed (four-points) strain sensing was demonstrated which had a point-like ultrahigh spatial resolution of 2.1 mm and very high strain precision of <0.8 με. Using a specially designed acceleration pick-up and a path-imbalance Mach–Zehnder interferometer for wavelength interrogation, a fully automatic SM-BFPI accelerometer, capable of giving ultrahigh performance, was developed. The performance of the accelerometer, with a very high sensitivity of 0.5 mGal in 0.1–200 Hz for 0−±980 Gal, is superior to that of electric servo-type accelerometer. To enable the accelerometer to exactly work in the field, the interrogator was stabilized against ambient temperature changes and mechanical disturbances by means of a compensation technique, using the constant wavelength of a reference SM-BFPI. In the course of the experimental study, particular attention has been paid to performance comparison with FBG sensors, much improvement against them having been demonstrated.
© 2016 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription