Open AccessTapered fiber Mach-Zehnder interferometers for vibration and elasticity sensing applications
Author(s) -
NanKuang Chen,
Yu-Hsin Hsieh,
Yi-Kun Lee
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.011209
Subject(s) - optics , materials science , beat (acoustics) , interferometry , cladding (metalworking) , optical fiber , mach–zehnder interferometer , cladding mode , astronomical interferometer , laser , vibration , wavelength , elasticity (physics) , fiber optic sensor , polarization maintaining optical fiber , optoelectronics , acoustics , physics , composite material , metallurgy
We demonstrate the optical measurements of heart-beat pulse rate and also elasticity of a polymeric tube, using a tapered fiber Mach-Zehnder interferometer. This device has two abrupt tapers in the Er/Yb codoped fiber and thus fractional amount of core mode is converted into cladding modes at the first abrupt taper. The core and cladding modes propagate through different optical paths and meet again at the second abrupt taper to produce interferences. The mechanical vibration signals generated by the blood vessels and by an inflated polymeric tube can perturb the optical paths of resonant modes to move around the resonant wavelengths. Thus, the cw laser signal is modulated to become pulses to reflect the heart-beat pulse rate and the elasticity of a polymeric tube, respectively.