Mode interference in dual-core photonic crystal fibers

The modal characteristics of dual-core photonic crystal fibers are analyzed by a full vector supercell method. The fundamental and second order modes of dual-core PCF consist of a pair of even and odd modes with different polarization, the parity properties of the modal electric field are illuminated. Based on the analysis of parity of modal electric fields, we investigated the vector modal interference in dual-core PCF. The power transfer induced by interference of different mode pair is investigated. It is the interference between two same polarized modes that contribute to the inter-core coupling of power. It is shown that the optical power will oscillate from one core to the other. The dependence of the coupling coefficients on wavelength and structural parameter for different polarization is discussed.