title: Coupling and decoupling of dual-core photonic bandgap fibers.
abstract: Coupling characteristics of dual-core photonic bandgap fibers with triangular photonic crystal cladding are investigated by use of a vector plane-wave expansion method and a vector finite-element method. We demonstrate the eigenmodes and the coupling length for two orthogonal polarizations. A decoupling phenomenon is found at a certain wavelength in this fiber configuration. The decoupling effect is attributed to the effect of surface modes on the eigenmodes. The decoupling wavelength decreases as the ratio of core radius to cladding air-hole pitch increases from 1.05 to 1.15.
authors.affiliation: Institute of Modern Optics, Nankai University, Tianjin 300071, China. wangzhi@mail.nankai.edu.cn
authors.forename: Zhi
authors.initials: Z
authors.lastname: Wang
authors.forename: Guiyun
authors.initials: G
authors.lastname: Kai
authors.forename: Yange
authors.initials: Y
authors.lastname: Liu
authors.forename: Jianfei
authors.initials: J
authors.lastname: Liu
authors.forename: Chunshu
authors.initials: C
authors.lastname: Zhang
authors.forename: Tingting
authors.initials: T
authors.lastname: Sun
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Weigang
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuzhong
authors.initials: S
authors.lastname: Yuan
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Dong