DESIGN AND MODELLING OF STEP-INDEX OPTICAL FIBRE FOR GENERATION OF SLOW-LIGHT

Abstract

In the past decade, great research effort was inspired by the need to realise purely optical communication systems, so came the need and application of active optical functionalities. This thesis focuses on a numerical modelling for slow light generation based on stimulated Brillouin scattering for bismuth oxide step index fibre for single mode operation. We have selected a wave-length of 1550nm for our thesis. The approach to acquiring slow light in optical fibre is based on the phenomena of stimulated Brillouin scattering. Slow light phenomenon is to drastically decrease the velocity of light as it travels through certain media. Slow light can be generated via various methods like stimulated Raman scattering (SRS), stimulated brillouin scattering (SBS), electromagnetically induced transparency (EIT), coherent population oscillation (CPO), etc but here we are focusing on stimulated brillouin scattering. For the proposed optical fibre structure, we have obtained affective mode area and confinement loss. A time delay of 104.45 ns has been achieved for the maximum permissible pump power of 976 mW with the Brillouin gain of 90.38 dB and figure of merit of 45.29 at 500 mW pump power. It is observed that time delay can be tuned with input pump power and length of the proposed ridge waveguide. Such tunable features of the slow light can have potential applications in realization of an all-optical network. The proposed structure is analysed by the finite element method using software COMSOL Multiphysics and MATLAB.