Investigating with rectangular and semi-sinusoidal variation of the refractive index

Abstract

In this article, the propagation of electromagnetic waves in a multi-layered cylindrical photonic crystal is considered. We have arranged the plasma and dielectric layers alternatively in two ways of sharply square and semi-sinusoidal refractive index variations that are not studied so far. In our investigations, we have used transfer matrix programming in MATLAB software. We have chosen the cylindrical photonic crystals because they have been studied less than the conventional planar ones. The cylindrical photonic crystals have potential applications in optical communications, optoelectronics, etc. Our numerical results show that the shape of the layers (i.e., sharp or gradual variation of the refractive index in the photonic crystal) has a major impact on the reflection pattern. In the current study, the effect of the increasing starting radius of the photonic crystal, plasma electron density, and the number of layers have been investigated. It was seen that by increasing the dielectric refractive index, the optical gaps do not show a well-defined change.