Design of a dual-core liquid-filled photonic crystal fiber coupler and analysis of its optical characteristics

Abstract

The photonic crystal fiber coupler (PCFC) is one of the peculiar devices that play a major role in the future of optical networks. Dual-core PCFCs have many advantages over the conventional optical couplers such as more flexible design and shorter coupling length. In this paper we propose a silica-based PCFC with a hexagonal lattice structure, and important properties such as dispersion, effective refractive index, propagation characteristics, and coupling length are analyzed in comparison with benzene and chloroform liquid-filled PCFCs. The above properties are investigated under different geometrical parameters such as hole-to-hole spacing and different air hole diameter within a wide range of wavelengths. By proper adjustment of the dual-core PCFCs, the coupling lengths of 0.0006, 0.007, and 0.0008 m are achieved in the silica-, benzene-, and chloroform-filled PCFCs, respectively. Likewise, the dispersion values of −6987, −7055, and −6684 ps/(nm km) and the propagation constants of 10.9, 11.08, and 10.6 (×106) rad/m are achieved in silica-, benzene-, and chloroform-filled PCFCs, respectively.