Dual-concentric-core photonic crystal fibers with two layers of outer ring core

To elastically design a dual-concentric-core photonic crystal fiber (DCC-PCF) for dispersion compensation, we use double layers of cladding holes as an outer ring core (ORC), instead of single layer ORC, of the DCC-PCF. For a DCC-PCF with single ORC structure, the design process of maximum dispersion coefficient becomes entangled with that of the compensated wavelength. By using double ORC, the optimum value of chromatic dispersion can be kept when the compensated wavelength is adjusted. The numeric results indicate that the negative chromatic dispersion coefficient for the proposed DCC-PCF is approximately 15 % larger than that of the previous DCC-PCF at around the wavelength of 1.55μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.55\,\upmu \hbox {m}$$\end{document}.