Polarization and leakage properties of large-mode-area microstructured-core optical fibers

A novel kind of highly birefringent large-mode-area optical fiber is proposed in this paper. Birefringence in the fiber is realized by the introduction of an anisotropic microstructured core. The microstuctured core is composed of down-doped silica rods embedded in the background of up-doped silica. Numerical investigations demonstrate that high birefringence on the order of 2x10(-4) and hexagonal profile mode fields with mode areas larger than 300 mum(2) can be achieved in the proposed fiber. The influence of doping levels on the properties of birefringence, confinement losses, and mode-areas of the fiber is also investigated. Based on the design, we also propose a novel kind of single-polarization single-mode optical fiber with a mode area of 725 mum(2) and an operating wavelength range as large as 340 nm.