Study And Analysis Of Dispersion, Effective Area And Nonlinear Properties Of Photonic Crystal Fiber (Pcf) At Different Doping Concentration

Abstract

Intriguing design of Photonic Crystal Fiber (PCF) with nearly zero dispersion at operating wavelength with high nonlinear coefficient has been exploited. Several optical materials including SiO2, GeO2 doped silica and pure Si has been studied for optimizing a structure for a certain range of operating wavelengths. Design and optical characteristics of defected GeO2 doped SiO2 square core with regular hexagonal air hole cladding have been studied extensively. Modal analysis of the proposed geometries has been performed for a wide range of wavelengths including visible range (400 -700 nm), short-wavelength infrared band (1.4-3 μm) and mid-wavelength infrared band (3-8 μm). A good number of defected core structure such as ellipse, square and some other irregular structures constructed from Bezier curves have also been investigated to achieve nearly zero dispersion. Achieving smaller effective mode area is an important feature of our proposed structure. High nonlinear gain can be mentioned as the eligibility of the proposed fiber as a powerful candidate of Super Continuum Generation (SCG), Four Wave Mixing (FWM) and Polarization effect of PCF. In this thesis, different properties of defected GeO2 doped SiO2 square core like dispersion, effective mode area, nonlinear parameter etc. are investigated numerically using Full Vector Finite Element method(FEM). Several challenging issues in the field of nonlinear photonics have been identified which will help also to optimize an optical waveguide for nonlinear applications from different perspectives.