Miniature optical fiber strain sensor based on Fabry-Perot interferometer

Abstract

We studied a miniature optical fiber sensor based on in-line Fabry-Perot interferometer for strain measurement. The sensor was fabricated by splicing a section of hollow core tube (HCT) between two single mode fibers. The reflective spectrum of the interferometer exhibits a number of resonance wavelength dips owing to destructive interference of two reflective lights. The experiment results demonstrate that, as the strain increased, the resonance wavelength exhibits a redshift behavior. The maximal strain sensitivity obtained by linear fitting is 4.55pm/με. The device proposed has high potential in construction engineering, industry production, and high speed rail due to its merits of electromagnetic immunity, miniature structure and ease of fabrication.