Design of single-polarization elliptical-hole core circular-hole holey fibers with zero dispersion at 1.55 μm

The dispersion properties of single-mode single-polarization elliptical-hole core circular-hole holey fibers (EC-CHFs) are investigated. In these fibers, the single-polarization regime can be easily achieved by the anisotropic fundamental-space filling modes (FSMs) in the core region and isotropic FSMs in the cladding region. We show that there is a remarkable difference between the mode fields of EC-CHFs having two mutually orthogonal directions of elliptical holes, although their dispersion properties are very close to each other. We also demonstrate that, for small air holes, the single-polarization EC-CHFs with zero dispersion at 1.55 mu m are easily designed by the FSMs, whereas, in the case of a large lattice pitch, tuning zero-dispersion wavelength is needed for designed EC-CHFs by using the FSMs. Moreover, our rough bending-loss estimations based on the weakly guiding fiber approximation show that low bending losses can be achieved in the EC-CHFs. (C) 2008 Optical Society of America