Abatement of Computational Issues Associated with Dark Modes in Optical Metamaterials

Optical fields in metamaterial nanostructures can be separated into bright modes, whose dispersion is typically described by effective medium parameters, and dark fluctuating fields. Such combination of propagating and evanescent modes poses a serious numerical complication due to poorly conditioned systems of equations for the amplitudes of the modes. We propose a numerical scheme based on a transfer matrix approach, which resolves this issue for a parallel plate metal-dielectric metamaterial, and demonstrate its effectiveness.Comment: 7 pages, 6 figure

Designer Metasurfaces for On Demand Optical Responses

Nanostructured materials are one of the leading areas in photonics currently. These structures offer almost limitless possibilities in the manipulation of light. Using two different semi-analytical simulation methods, I show a few of the possible properties that these nanostructures possess, including polarization rotation and coupling with electronics

Project Scratch

Project Scratch explores the manipulation of generative music using a program (patch) I created in Max, a visual programming language for music and multimedia. Generative music uses an algorithm to produce musical gestures that vary with each performance by using certain parameters defined by the programmer. My program uses what Christopher Ariza (2010) calls a Computer Aided Algorithmic Composition (CAAC) system, which “permits the user to manipulate indirect musical representations: [which] may take the form of incomplete musical materials (a list of pitches or rhythms)”, but with an emphasis on manipulation of the set in real time. The patch I have developed can be incorporated in the creative process both as an element in improvisational settings and as a tool for generating ideas for fixed compositions. Project Scratch uses minimalist compositional techniques such as ostinato (a repeating sequence of pitches), augmentation/ diminution (tempo control), addition/ subtraction (of notes from the sequence) and phasing (identical offset musical gestures) to perform these manipulations. It also takes advantage of algorithmic procedures to filter information, for example, randomization of note sequences to create a sense of unpredictability. These methods are triggered manually by a live performer. In addition, I use Max in conjunction with Ableton Live, a digital audio workstation, to configure the nine-note fixed sequence and to provide options for sound design. The next steps for Project Scratch will be to incorporate drones (continuously sustained pitches), timbral variation (change of single note at a time), rhythmic displacement (emphasis on different notes in the sequence), polyphony (multiple voices) and more complex harmony. When considering all the factors of my patch, the possibilities for melodic content are vast, ensuring no two performances will be the same

DC Voltage Created Perpendicularly to Nanostructured Metal Films by Surface Plasmon Polariton Excitation at Visible Frequencies.

Plasmonics is a scientific field, encompassing a plethora of novel phenomena related to electron-photon coupling in metal nanostructures and formation of hybrid electromagnetic waves propagating along various metal surfaces, collectively called surface plasmon polaritons (SPPs). SPPs can be excited in a broad band of frequencies from infrared to UV, including visible. SPPs feature extremely strong localized electric fields at selected locations on the boundaries of metal nanostructures, the so-called plasmonic hot spots. These fundamental properties of SPPs currently attract a lot of attention from optoelectronics community. SPPs have a broad range of applications starting from currently mass-produced SPP resonance biosensors for personalized healthcare to the ultrafast circuits for the computers of the future, involving plasmonic components with anticipated bandwidth of several hundred THz. It has been recently proposed and theoretically demonstrated by Durach and collaborators, that propagating optical SPPs create direct current (DC) in metal nanostructures which could have an immense impact on current nanotechnology. We will describe the new results obtained by Matthew LePain working with Dr. Durach, demonstrating that SPPs in a nanostructured metal film create a rectified DC voltage signal perpendicular to the film, which maps the geometrical profile of the film. We obtained the solutions of Maxwell\u27s equations for a metal film nanostructured by a planar grating, through matching a large number of diffraction waves to a large number of guided waves inside the grating structure, to achieve satisfactory approximation of the exact fields involving infinite expansions. Using the obtained electromagnetic fields of SPPs we calculate the rectified forces exerted upon electrons in the metal at particularly intriguing wavelengths. Using a hydrostatic approximation which we developed for the electrons in the nanostructure we are able to obtain voltages applied perpendicular to the film at normal incidence of external radiation. This work represents an important step toward future integration of plasmonics, electronics and optics