To Study the Effect of Grating Length on Propagating Modes in Bragg Filters with AlXGa 1-X N/GaN Material Composition

Abstract

In this paper, the forward and backward propagating modes in an optical waveguide structure namely the fiber Bragg filter also considered as a one dimensional photonic crystal, is analytically computed as a function of grating length for coupled optical modes. Al x Ga 1-x N/GaN material composition is considered as a unit block of the periodic organization, and refractive index of Al x Ga 1-x N/GaN is taken to be dependent on material composition, bandgap and operating wavelength following Adachi's model. Expressions for propagating wave have been derived using coupled mode theory. Simulated results help us to study the propagation of forward and backward wave propagating modes inside fiber and waveguide devices.