Dual-core photonic quasicrystal fiber with high negative dispersion

Abstract

We propose a dual-core photonic quasicrystal fiber with six-fold symmetry that may be useful in compensating chromatic dispersion of a single-mode fiber. The geometry of the proposed photonic quasicrystal fiber is described and then the behaviors of effective index and chromatic dispersion are calculated according to the structural parameters. The dual-core fiber is composed of a pure silica inner core and an outer core that is formed by reducing the diameter of air holes in the third cladding layer. We investigate the dependence of the effective indices of inner core and outer core, the fundamental super mode, and the effect of chromatic dispersion on the structural parameters by using plane wave expansion method. The dual-core photonic quasicrystal fiber has a large negative chromatic dispersion value of approximately -2000 ps nm^-1 km^-1 over optical communication band around 1.5μm. Introducing quasicrystal structures in the dual-core optical fibers can improve the capability of dispersion compensation of the fibers significantly.