New Slab Waveguide Structures as Optical Sensors

Abstract

This work concerns planar optical waveguide sensors with the focus on slab waveguide structures comprising left-handed materials with simultaneously negative electric permittivity and magnetic permeability. In the last two decades planar waveguides have been introduced in the literature in optical sensing as a novel non-communication application of slab waveguides. Slab waveguide sensors have received an increasing interest due to their immunity to electromagnetic interference, have no danger of ignition, are field resistant, small sized, safe when used in aggressive environments, and mechanically stable. In this work, a three layer slab waveguide with a left-handed material guiding layer will be studied for sensing applications. TE and TM polarization will be presented. The dispersion relation of the proposed sensor will be obtained. The sensitivity of the sensor to changes in the cladding refractive index and the power flowing through each layer will be presented. The power confinement factor within each layer will also be considered. Moreover, the penetration depth and the Goos-Hanchen shift will be investigated. Metal-clad planar waveguide sensor with one of the layers is made of left-handed material will be analyzed. Metal-clad waveguide can be operated in two different reflection modes, dip and peak types. Our study will focus on dip type mode.