Temperature- and strain-independent torsion sensor using a fiber loop mirror based on suspended twin-core fiber.
In this Letter, we present a fiber loop mirror configuration based on a suspended twin-core fiber for sensing applications. Using the suspended twin-core fiber, the fringe pattern is due to the differential optical patch of the light in the two cores associated with a refractive index difference of approximately 10(-3), which indicates an advantage of this approach compared with those based on high-birefringent fibers, namely, the possibility of using a small length of fiber. The sensing configuration was characterized for torsion, temperature, and strain. Using the fast Fourier transform technique, it is possible to obtain measurand-induced amplitude variations of the fringe pattern. The results obtained indicate the viability of a temperature- and strain-independent torsion sensor.
Frazão
Orlando
O
INESC Porto-Instituto de Engenharia de Sistemas e Computadores do Porto, Rua do Campo Alegre 687, 4169-007, Porto, Portugal. ofrazao@inescporto.pt
Silva
Ricardo M
RM
Kobelke
Jens
J
Schuster
Kay
K