Strain sensor based on a pair of single-mode-multimode-single-mode fiber structures in a ratiometric power measurement scheme.
The strain and temperature dependencies of a step-index single-mode-multimode-single-mode (SMS) fiber structure are investigated numerically and experimentally. For intensity-based strain measurement using a single SMS fiber structure, at a selected wavelength, it is found that there is a high strain dependence, but also a temperature dependence that will induce strain measurement error. To minimize the temperature-induced strain measurement error, two SMS fiber structures are proposed and demonstrated in a ratiometric power measurement scheme; one SMS structure acts as the strain sensor, and the other SMS structure acts as the temperature monitor. The extracted temperature information is used to determine a strain value based on a suitable calibration of strain responses with temperature variations. It is demonstrated that for strain measurement from 0 to 1000 microepsilon within the temperature range from 10 degrees C to 40 degrees C, the proposed configuration can provide a strain and temperature resolution of 0.34 microepsilon and 0.14 degrees C, respectively, with a temperature-induced strain measurement error as low as 0.39 microepsilon.
Hatta
Agus Muhamad
AM
Photonics Research Center, School of Electronic and Communications Engineering, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland. ahatta@dit.ie
Semenova
Yuliya
Y
Wu
Qiang
Q
Farrell
Gerald
G