Highly birefringent polymer fibers for hydrostatic pressure sensing

Abstract

We present two polymer birefringent fibers with enhanced polarimetric sensitivity to hydrostatic pressure. In the first fiber, with birefringence induced by the arrangement of holes in the microstructured cladding, an increased sensitivity to pressure was obtained by enlarging selected holes in the cladding. The second is a side-hole fiber with an elliptical core made of polymethyl metacrylate–polystyrene (PMMA/PS) copolymer and pure PMMA cladding. The fiber core is located in a narrow PMMA bridge separating the holes. The transmission and sensing characteristics of both fibers are compared, including spectral losses, birefringence, polarization cross-talk and polarimetric sensitivity to hydrostatic pressure.