Analysis of Novel Chirped Types of Refractive Index Profile Metamaterial Planar Slab Optical Waveguide by Finite-Element Method for Sensor Application

In this paper, a finite-element method (FEM) has been applied to estimate the power confinement properties for a highly complicated linear chirp types of metamaterial planar slab waveguide. The accuracy of the method has been tested with respect to the number of core division into FEM formulations. The solution converges well for only 30 core divisions. In the beginning of this paper, we compute the power confinement factor, power flow in the core/cladding region for the case of normal α-profile and normal chirped type of profile, respectively. Then, we compute the effective refractive index of metamaterial planar slab waveguide for the various cases. We try to establish the relation between leakage power loss factors versus normalized frequency. To obtain the accurate expressions, we derive the higher order polynomials. It has been found while analyzing that metamaterial slab waveguide has a special feature for better sensing capability like flat effective refractive index over the band, large power flow into cladding region, and so on. It is expected that metamaterial planar slab waveguide having chirped types of refractive index profile has a huge application in leaky fibre sensor, gas sensor, chemical sensor for oil and under grounds mining industries.