Resumen de Metamaterials òptics: disseny, fabricació a gran escala i caracterització
Metamaterials are artificially structured materials, thoroughly designed for achieving electromagnetic properties not observed in nature such as the negative refractive index. The purpose of this thesis is the development of up-scalable optical metamaterials that can be easily incorporated into actual devices. By combining colloidal lithography and electrodeposition, we report an entirely bottom-up fishnet metamaterial made of gold and air layers. A proper theoretical and experimental design gives rise to tunable refractive index, from positive to negative values in the near infrared. This structure is extended to multilayered fishnet metamaterials made by nanoimprint lithography and electrodeposition. We thoroughly analyze the optical response of the structures, which lead to strong negative index from the visible to near infrared. Their performance as optical sensors is studied when infiltrating different liquids through the air cavities. These techniques are used to fabricate nanostructured metallic substrates for studying the collective spontaneous emission of fluorescent molecules.
