Design and Optical Characterization of Anisotropic Plasmonic Metamaterials at Visible and Infrared Wavelengths

Download or read book Design and Optical Characterization of Anisotropic Plasmonic Metamaterials at Visible and Infrared Wavelengths written by Nikolaos Vasilantonakis and published by . This book was released on 2015 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of plasmonics studies the interaction of light and free electrons in metals, giving rise to excitation of surface waves, on a metallodielectric interface. One branch of plasmonics is the design of metamaterials in visible and infrared spectral range which are artificial structures designed to manipulate the propagation of light in a way not possible with conventional materials. This thesis is categorized in 3 main parts. The first part examines the effects of waveguided modes in Au nanorod metamaterial waveguides. It shows, both theoretically and experimentally, that these materials can be designed to control the sign and magnitude of modal group velocity depending on the geometry and polarization chosen exhibiting high effective refractive indices (up to 10) and have an unusual cut-off from the high-frequency side, providing deep-subwavelength (.\0/6 - ,\0/8 waveguide thickness) single-mode guiding. This allows slow light to exist in such waveguides in a controllable environment which is a critical factor for nonlinear and active nanophotonic devices, quantum information processing, buffering and optical data storage components. The second part discusses, analytically and numerically, strategies for biosensing and nonlinearity enhancement with hyperbolic nanorod metamaterials. It shows how the sensitivity of unbound, leaky as well as waveguided modes can be enhanced based on geometrical considerations. Additionally, refractive index variation of the host medium produces 2 orders of magni- 4 5 tude higher sensitivity compared to nanorod or superstrate refractive index changes. In certain configurations, both TE and TM-modes of the metamaterial transducer have comparable sensitivities opening up opportunities for polarization multiplexing in sensing experiments.