Chromatic Dispersion of an Optical Fiber Based on Photonic Quasicrystals with Twelve-Fold Symmetry and its Application as Directional Coupling

Ádller De O Guimarães,Emmanuel R M Dantas,José P Da Silva

doi:10.1590/2179-10742015v14i2481

Abstract

Optical fibers composed by photonic quasicrystals it is based on aperiodic structures characterized by at least two different symmetrical patterns from the base matrix. In this work, an optical fiber composed by quasi-periodic and symmetric matrix was analyzed using the finite element method in conjunction with cylindrical perfectly matched layers. The structure is composed by pure silica and/or silica doped with germanium, and originated from twelve distributions of air holes symmetrically with a defect caused by the absence of the fiber central hole. The obtained results shown that the structure in analysis exhibits an ultra-flat chromatic dispersion for a range of wavelengths varying from 1.4 to 1.6 µm covering the bands E,S, C and L, with chromatic dispersion, for the silica doped with germanium, varying between 22.1 and 23.01 [ps.km-1.nm-1]. This photonic quasicrystal fiber (PQCF) was used to form a coupler with three identical horizontal cores surrounded by air holes. The signal power launched in the central core is equally divided between the two neighboring cores with 50% of the coupling ratio.

Highlights

Structures composed by Photonics Quasicrystal (PQC) represent a class of structures that has been extensively studied in the last decade, mainly due to their application in the development of optical fibers [1]
The simulations showed that in a Photonic Crystal Fiber (PCF) the air holes cause a decrease in the average refractive index of the cladding region of the fiber and confines light in the solid
The light propagation in PCF occurs due to total internal reflection which describes the light guiding in the central core of solid [3], this characteristics so occurs in the photonic quasicrystal fiber (PQCF) with 12-fold symmetry

Summary

Introduction

Structures composed by Photonics Quasicrystal (PQC) represent a class of structures that has been extensively studied in the last decade, mainly due to their application in the development of optical fibers [1] These types of structures exhibit an important feature, do not contain translational symmetry, normally present in traditional photonic crystals (PCs). The quasicrystals are characterized by a very unusual alignment of the atoms and containing aperiodic structures, they have at least two different symmetrical patterns from the base matrix, which form a structure without gaps, but not regularly repeating [3]. Under these circumstances, it can lead symmetries of 6, 8, 12 and even. The main geometrical parameters of a solid core PQCF with holes distributed from a quasi-periodic matrix with

Methods

Results

Conclusion