Abstract

Sub-Wavelength Grating (SWG) periodic media are comprised of alternative dielectric layers with a pitch Λ small enough in comparison to the wavelength to supress any diffraction or interference effect. As a good first approximation, SWG media can be considered as uniform and lossless ones, with an averaging effect over the dielectric permittivity [1]. The use of SWG media as core and/or cladding materials of optical waveguides was first proposed and demonstrated in 2010 [2] as a way to realize easy engineering of the refractive guided index of light with simple lithographic patterning. Since then, SWG waveguides have found various applications such as waveguide crossing, multimode interferometers, optical filters, mid-infrared waveguides, or even optical biosensing [3].

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