Light-Matter Interactions and Devices Enabled by Novel Engineered Photonic Media

摘要

With the advancement in modern photonics, it becomes possible to manipulate the optical beams having complex structures with novel properties instead of simple conventional Gaussian beams; or to build materials having complex micro or nanoscale structures that cannot be found in the natural world. The goal of this thesis is to investigate and study the novel properties of structured light, structured material and most importantly, how structured light would interacts with structured materials.;A fascinating example of structured light is optical beams with orbital angular momentum (OAM) (optical vortices) that have significant potential in many areas of modern photonics, including telecommunication systems, optical manipulation and spectroscopy. In this dissertation, a novel design of ultra-compact array nanowaveguides is first proposed and then experimentally used to demonstrate that a conventional laser beam passing through the device can be converted into structured beams with an OAM. In addition to the structured light, the novel properties of structured materials are also explored in the thesis. The emergence of the structured material, especially optical metamaterials, opens new opportunities for spatial pattern compression from the micro- to nanoscale. By exploiting strongly anisotropic optical properties of engineered nanostructures, we perform the first experimental demonstration of demagnifying hyperlens enabling optical patterning below the diffraction limit. We show that it is possible to achieve beam shaping on subwavelength scale by using this novel photonic structured medium.;In the last part, we show that a conventional Gaussian beam can be directly transformed to a subwavelength structured light beam without losing its spatial distribution characteristics. The proposed structures are ultra- compact with the subwavelength structured light de-magnification ability, which thus makes it possible to be used for on-chip optoelectronic signal processing.