Refractometric sensor based on slab waveguides of simultaneously negative permittivity and permeability materials

Abstract

"A four-layer slab waveguide is treated analytically for optical sensing purposes. The layers of the waveguide are substrate, thin flm and cladding. Another layer is introduced between the substrate and the flm which is considered to have a negative permittivity or simultaneously negative permittivity (ε) and permeability (μ). The structure is analyzed and the refectance is deduced. The refectance of p-polarized (TM) incident wave is investigated and plotted. A peak is observed in the refectance profle which can be employed for sensing purposes. The refectance peak is optimized to give the optimum parameters corresponding to the sharpest peak. The performances of the structures as optical sensors are examined and compared."