8,416 research outputs found
Mesoscopic transport and control of light through disordered nanowire mats
No full textIn this thesis the transport of light through disordered, densely packed semiconductor nanowire mats is studied. It is found that the extremely high photonic strength of these samples leads to corrections to the traditional diffusion picture of light transport due to mesoscopic interference. Such effects are characterized by large intensity fluctuations and correlations, and it is found the transport is dominated by only a few independent transmission channels, close to the Anderson localisation regime. In addition to the strongly scattering nanowire samples, comparatively weakly scattering samples of ZnO are investigated, demonstrating mesoscopic effects in a less exotic, isotropic multiple scattering material. Control is obtained over the transmission by a combination of shaping the incident wavefront and harnessing the intrinsic nonlinearity of the semiconductor with ultrafast optical excitation. Through these techniques, a bright focus at an arbitrary point through the nanowires is created which can be modulated by up to 60% in a demonstration of a reconfigurable photonic switch
An ultrafast reconfigurable nanophotonic switch using wavefront shaping of light in a nonlinear nanomaterial
No full textWe demonstrate a new concept for reconfigurable nanophotonic devices exploiting ultrafast nonlinear control of shaped wavefronts in a multimode nanomaterial consisting of semiconductor nanowires. Femtosecond pulsed laser excitation of the nanowire mat is shown to provide an efficient nonlinear mechanism to control both destructive and constructive interference in a shaped wavefront. Modulations of up to 63% are induced by optical pumping, due to a combination of multimode dephasing and induced transient absorption. We show that part of the nonlinear phase dynamics can be inverted to provide a dynamical revival of the wavefront into an optimized spot with up to 18% increase of the peak to background ratio caused by pulsed laser excitation. The concepts of multimode nonlinear switching demonstrated here are generally extendable to other photonic and plasmonic systems and enable new avenues for ultrafast and reconfigurable nanophotonic devices
An ultrafast reconfigurable nanophotonic switch using wavefront shaping of light in a nonlinear nanomaterial
No full textWavefront shaping of light fields has opened up a wealth of new applications in imaging and communication in highly multimode environments [1-11]. By mixing of the modes with optimized phases and amplitudes it is possible to focus light through - or even inside - opaque scattering media [1,2]. Here we present work demonstrating ultrafast control of such an optimized wavefront transmitted through a dense disordered mat of semiconductor nanowires by exploiting their inherent nonlinearity. Modulations of the peak intensity of up to 63% (4.3 dB) are induced by optical pumping as a result of a combination of multimode dephasing and induced absorption. Next to ultrafast dephasing of the shaped field, we show that it is possible to dynamically rephase the light fields into an optimized spot by means of pulsed nonlinear excitation of the medium. We obtain an enhancement of the peak to background ratio of the optimized spot resulting from rephasing of up to 18%. While our results are obtained for three dimensional media, the concepts of multimode nonlinear switching are generally extendable to other systems, including plasmonic and photonic waveguides, thus enabling new avenues for ultrafast and reconfigurable nanophotonic devices
Michael Rodriguez interviews author Tom Springer
No full textAuthor Tom Springer is interviewed about his writing career and his newest book "Looking for hickories". Springer talks about his career following after earning an Environmental Journalism degree from Michigan State University. He calls his genre "creative non-fiction" and explains how he weaves his memories into his books about life in rural and wild Michigan. Part of the Michigan State University Libraries' Michigan Writers Series. Springer is interviewed by Librarian Michael Rodriguez
Performing the archive: following in the footsteps
No full textUsing documentation of Mike Pearson's performance 'Bubbling Tom', Deirdre Heddon attempts to step into his shoes and re-perform it
CRE Author Tom Franklin
No full textCommon Reading Experience author and UM creative writing instructor Tom Franklin talks about his novel, Crooked Letter, Crooked Letter. Video by Mary Stanton.https://egrove.olemiss.edu/umvideo/1334/thumbnail.jp
Tom Kubancik
No full textTom is the Vice President of Advanced Programs at Applied Defense Solutions (ADS).
Tom’s entire career has been focused on advanced technology with over 30 years in Space Systems, High Performance Computing, and Microelectronics. With a background in Operations Management, Tom has enjoyed broad success when pioneering companies in rapidly evolving markets and shaping today’s high technology landscape.
Tom is a recognized international expert in Space Situational Awareness (SSA), participating in research, development, and deployment programs since the 1980’s. At Applied Defense Solutions (ADS), Tom has led the transition away from military-only SSA, establishing a broad portfolio of research and development, commercialization, and operational support programs. ADS is a recognized leader in civilian, commercial, and government space exploration, focusing on all phases from mission analysis, operations support, and space protection. Leading the ADS Advanced Programs’ team, Tom coordinates a highly talented group of technical experts working alongside program managers, operational experts, and capture professionals. Their focus is to create and develop opportunities for ADS to apply its innovations and expertise to the most challenging space systems development tasks. His team harnesses a company-wide passion for problem-solving by leveraging a world class research portfolio with exquisite analytical capabilities and deep operational experience. ADS has constructed the most interesting mission portfolio in the industry as Tom and his team love their role in defining the next generation of safe space operations.
Tom is an active participant in NATO Science and Technology panels and activities leading to better understanding of global approaches for effective coalition and collaborative SSA. Tom is a published author on global SSA and is a frequent speaker at domestic and international conferences.
Tom has a wealth of experience with leadership positions. He is a graduate of Bowling Green University. Tom and his family live in Boulder, Colorado.https://commons.erau.edu/stm-images/1097/thumbnail.jp
Tom Lawson
No full textTom Lawson is Professor of History and Pro Vice Chancellor for Arts, Design and Social Sciences at Northumbria University. He is the author and editor of several books including Debates on the Holocaust (2010) and most recently The Last Man: a British Genocide in Tasmania (2014).https://commons.erau.edu/genocide-bios/1044/thumbnail.jp
Compliance Update with Tom Fox
No full textJoin us for lunch with Tom Fox, compliance professional, author and creator of the Compliance Podcast Network, hosting a variety of compliance related podcasts, including a succinct daily compliance tip
First person – Tom Carruthers.
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Tom Carruthers is first author on ‘ exTREEmaTIME: a method for incorporating uncertainty into divergence time estimates’, published in BiO. Tom conducted the research described in this article while a PhD student in Professor Robert Scotland's lab in the Department of Plant Sciences, University of Oxford. He is now a postdoc in the lab of Dr William Baker at the Royal Botanic Gardens, Kew, working on determining the extent to which large molecular phylogenies provide information about evolutionary history
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