Generation of Optical Activity by Bilayered Chiral Metamaterials and Planar Metamaterials in the Visible Spectrum

Abstract: Chiral metamaterial are a class of metamaterials that show optical activity, ellipticity and negative refraction. Optical activity and ellipticity generally occurs together. The aim of this thesis is to obtain a high optical activity with low ellipticity. A bi-layered structure comprising of both a negative and a positive structure was used for this purpose. These structures were fabricted by using focussed ion beam (FIB). The transmission spectrum for the structures is measured by a light microscope equipped with a spectrometer. The bi-layered structures were attempted to be fabricated by using FIB and by micromanipulators. Also, different arrangements of the bi-layered structures were modelled by the finite difference time domain (FDTD) method. From the modelled structures, an optical activity of 61° was obtained with zero ellipticity.