Micro-displacement or bending measurement using a long-period fibre grating in a self-referenced fibre optic intensity sensor

• Published in: Optics communications 2006-04, Vol.260 (1), p.8-11
• Main Authors: Baptista, J.M., Santos, S.F., Rego, G., Frazão, O., Santos, J.L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); General equipment and techniques; Gratings; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated optics. Optical fibers and wave guides; Long-period fibre gratings; Measurements common to several branches of physics and astronomy; Metrology, measurements and laboratory procedures; Optical and optoelectronic circuits; Optical elements, devices, and systems; Optical fibre intensity sensors; Optical fibre sensors; Optics; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Spatial dimensions (e.g.: position, lengths, volume, angles, displacements, including nanometer-scale displacements)
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2005.10.004

The measurement of micro-displacement or bending using a long-period fibre grating (LPG) in a self-referenced fibre optic intensity sensor is presented. The sensing head is based on a LPG whose attenuation peak changes as a function of its micro-displacement or bending and the fibre optic intensity sensor is referenced in frequency. Two other LPGs were used as rejection filters, located at the output of the optical source to shorten its spectral width. The implemented experimental set-up is described and, the results are presented being considered the measurement range and the intrinsic resolution.