A curvature sensor based on a polarization-dependent in-fiber Mach-Zehnder interferometer
(MZI) is proposed. The MZI is fabricated by core-offset fusion splicing one section of
polarization maintaining fiber (PMF) between two single mode fibers (SMFs). Two
independent interference patterns corresponding to the two orthogonal polarization modes
for the PMF are obtained. The couple efficiency between the core mode and the cladding
mode decreased with the increasing of the bending on the MZI part. The curvature variation …

A polarization-dependent humidity sensor based on an in-fiber Mach-Zehnder
interferometer (MZI) coated with graphene oxide (GO) film was proposed. The MZI was
constructed by fusion splicing a∼ 15-mm long polarization maintaining fiber (PMF) between
a waist-enlarged taper and a core-offset. The cladding of the PMF was etched off 10 μm, A
GO film with the maximum thickness of 4–5 μm was coated on the etched cladding by
optically driven deposition. With the strong hydrophilic of the GO and the characteristics of …