Otimização de uma fibra de cristal fotônico para geração de um interferômetro de Mach-Zehnder

Abstract

This work presents the optimization of a photonic crystal fiber model able to produce a Mach-Zehnder Interferometer to obtain a Free Spectrum Range (FSR) according to International Telecommunication Union Telecommunication Standardization Sector (ITU-T) for Wavelength Division Multiplexing (WDM). The interferometer is based on a pair of long-period gratings written in series on fiber. Firstly, it is demonstrated the theoretical basis of the behavior of light in optical fibers and the Coupled Modes Theory, mentioning its purposes for the interferometer construction. Then, it is shown the steps of fiber optimization, evidencing the optimization algorithm development that fulfills the minimization of the given merit function. The optimization was based on numerical analysis using LiveLinkTM for MatLab®, a tool that integrates the software COMSOL Multiphysics® with the software MatLab®. Using the COMSOL Multiphysics® resources through MatLab® code lines, the optimization algorithm was created employing the Nelder-Mead method. With this method we obtained optimized designs of two different types of Mach-Zehnder interferometers that meet the required standards and are robust against manufacturing errors.