All-Dielectric Two-Dimensional Metamaterial Claddings for Evanescent Field Engineering of Quasi-TM Modes

Abstract

The engineering of evanescent fields from optical waveguides can increase the density level of integrated optical devices. The replacement of an all-isotropic cladding by an all-dielectric metamaterial one provides greater control of the evanescent fields. This study investigates the performance of an all-dielectric two-dimensional metamaterial cladding in strip waveguides. The waveguide core and higher refractive index of the metamaterial cladding are composed of the same material, and for sake of numerical demonstration, Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> was used as a higher refractive index embedded in SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> (lower refractive index). The advantages of such an approach are investigated in waveguide bends. By comparing the metamaterial cladding proposal to a conventional cladding (all-isotropic one), the quasi-TM mode presented a reduction of about 61.5% of bending loss per 180° turn.