Broadband dispersion measurement of photonic crystal fibers with nanostructured core

Introduction of subwavelength inclusions in the core opens up an additional degree of freedom in shaping of dispersion characteristic in photonic crystal fibers (PCFs). We have developed a PCF with a nanostructured inclusion in the core to verify this concept. To suppress higher order modes, the photonic cladding structure of the developed fiber is composed of a first ring with linear filling factor of 0.95 and the remaining 5 rings with a lower linear filling factor of 0.4 with a lattice constant of 2.6μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$2.6\,\upmu \hbox {m}$$\end{document}. Diameter of the nano-inclusion in the core is 410 nm. For the fiber development, we used a pair of thermally matched soft glasses: Schott SF6 lead glass and an in-house synthesized NC21 borosilicate glass. In this paper, we report on dispersion measurements using a spectral interferomeric technique. A dispersion unbalanced Mach–Zehnder interferometer, combined with a supercontinuum source is used. Dispersion characteristics in wide range of wavelengths extending from 0.65 to 1.6μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.6\,\upmu \hbox {m}$$\end{document}, are measured and verified against calculated results.