Now showing items 21-40 of 1136

    • Photo-induced force mapping of plasmonic nanostructures 

      Tumkur, Thejaswi U.; Yang, Xiao; Cerjan, Benjamin; Halas, Naomi J.; Nordlander, Peter; Thomann, Isabell (2016)
      The ability to image the optical near-fields of nanoscale structures, map their morphology and concurrently obtain spectroscopic information, all with high spatiotemporal resolution, is a highly sought-after technique in ...
    • Mid infrared quantum cascade laser operating in pure amplitude modulation for background-free trace gas spectroscopy 

      Bidaux, Yves; Bismuto, Alfredo; Patimisco, Pietro; Sampaolo, Angelo; Gresch, Tobias; Strubi, Gregory; Blaser, Stéphane; Tittel, Frank K.; Spagnolo, Vincenzo; Muller, Antoine; Faist, Jérôme (2016)
      We present a single mode multi-section quantum cascade laser source composed of three different sections: master oscillator, gain and phase section. Non-uniform pumping of the QCL’s gain reveals that the various laser ...
    • Stargazin Modulation of AMPA Receptors 

      Shaikh, Sana A.; Dolino, Drew M.; Lee, Garam; Chatterjee, Sudeshna; MacLean, David M.; Flatebo, Charlotte; Landes, Christy F.; Jayaraman, Vasanthi (2016)
      Fast excitatory synaptic signaling in the mammalian brain is mediated by AMPA-type ionotropic glutamate receptors. In neurons, AMPA receptors co-assemble with auxiliary proteins, such as stargazin, which can markedly alter ...
    • Stability of High-Density Two-Dimensional Excitons against a Mott Transition in High Magnetic Fields Probed by Coherent Terahertz Spectroscopy 

      Zhang, Qi; Wang, Yongrui; Gao, Weilu; Long, Zhongqu; Watson, John D.; Manfra, Michael J.; Belyanin, Alexey; Kono, Junichiro (2016)
      We have performed time-resolved terahertz absorption measurements on photoexcited electron-hole pairs in undoped GaAs quantum wells in magnetic fields. We probed both unbound- and bound-carrier responses via cyclotron ...
    • Investigating irregularly patterned deep brain stimulation signal design using biophysical models 

      Summerson, Samantha R.; Aazhang, Behnaam; Kemere, Caleb (2015-06)
      Parkinson's disease (PD) is a neurodegenerative disorder which follows from cell loss of dopaminergic neurons in the substantia nigra pars compacta (SNc), a nucleus in the basal ganglia (BG). Deep brain stimulation (DBS) ...
    • Circular Differential Scattering of Single Chiral Self-Assembled Gold Nanorod Dimers 

      Wang, Lin-Yung; Smith, Kyle W.; Dominiquez-Medina, Sergio; Moody, Nicole; Olson, Jana M.; Zhang, Huanan; Chang, Wei-Shun; Kotov, Nicholas; Link, Stephan (2015)
      Circular dichroism spectroscopy is essential for structural characterization of proteins and chiral nanomaterials. Chiral structures from plasmonic materials have extraordinary strong circular dichroism effects compared ...
    • New approaches in quartz-enhanced photoacoustic sensing 

      Sampaolo, Angelo; Patimisco, Pietro; Pennetta, Riccardo; Scamarcio, Gaetano; Tittel, Frank K. (2015)
      We report on the design and realization of custom quartz tuning forks with different geometries and sizes aimed to improve the photoacoustic effect in quartz-enhanced photoacoustic (QEPAS) sensor systems. A detailed analysis ...
    • Focused terahertz waves generated by a phase velocity gradient in a parallel-plate waveguide 

      McKinney, Robert W.; Monnai, Yasuaki; Mendis, Rajind; Mittleman, Daniel (2015)
      We demonstrate the focusing of a free-space THz beam emerging from a leaky parallel-plate waveguide (PPWG). Focusing is accomplished by grading the launch angle of the leaky wave using a PPWG with gradient plate separation. ...
    • Decision-Directed Channel Estimation Implementation for Spectral Efficiency Improvement in Mobile MIMO-OFDM 

      Ketonen, Johanna; Juntti, Markku; Ylioinas, Jari; Cavallaro, Joseph R. (2015)
      Channel estimation algorithms and their implementations for mobile receivers are considered in this paper. The 3GPP long term evolution (LTE) based pilot structure is used as a benchmark in a multiple-input multiple-o ...
    • Photoluminescence of a Plasmonic Molecule 

      Huang, Da; Byers, Chad P.; Wang, Lin-Yung; Hoggard, Anneli; Hoener, Ben; Chang, Wei-Shun; Landes, Christy F.; Link, Stephan (2015)
      Photoluminescent Au nanoparticles are appealing for biosensing and bioimaging applications because of their non-photobleaching and non-photoblinking emission. The mechanism of one-photon photoluminescence from plasmonic ...
    • Non-intrusive Persistence with a Backend NVM Controller 

      Pu, Libei; Doshi, Kshitij; Giles, Ellis; Varman, Peter (2015)
      By providing instruction-grained access to vast amounts of persistent data with ordinary loads and stores, byte-addressable storage class memory (SCM) has the potential to revolutionize system architecture. We describe a ...
    • Transaction local aliasing in storage class memory 

      Giles, Ellis; Doshi, Kshitij; Varman, Peter (2015)
      This paper describes a lightweight software library to solve the challenges [6], [3], [1], [5], [2] of programming storage class memory (SCM). It provides primitives to demarcate failure-atomic code regions. SCM loads and ...
    • Extraordinary sensitivity enhancement by metasurfaces in terahertz detection of antibiotics 

      Xie, Lijuan; Gao, Weilu; Shu, Jie; Ying, Yibin; Kono, Junichiro (2015)
      We have detected trace amounts of molecules of antibiotics (kanamycin sulfate) dispersed on metasurfaces with terahertz (THz) spectroscopy. Utilizing the extraordinary optical transmission resonance of an array of square-shaped ...
    • Superfluorescence from photoexcited semiconductor quantum wells: Magnetic field, temperature, and excitation power dependence 

      Cong, Kankan; Wang, Yongrui; Kim, Ji-Hee; Noe, G. Timothy II; McGill, Stephen A.; Belyanin, Alexey; Kono, Junichiro (2015)
      Superfluorescence (SF) is a many-body process in which a macroscopic polarization spontaneously builds up from an initially incoherent ensemble of excited dipoles and then cooperatively decays, producing a delayed pulse ...
    • Direct Plasmon-Driven Photoelectrocatalysis 

      Robatjazi, Hossein; Bahauddin, Shah Mohammad; Doiron, Chloe; Thomann, Isabell (2015)
      Harnessing the energy from hot charge carriers is an emerging research area with the potential to improve energy conversion technologies. Here we present a novel plasmonic photoelectrode architecture carefully designed to ...
    • Charge Transfer Plasmons: Optical Frequency Conductances and Tunable Infrared Resonances 

      Wen, Fangfang; Zhang, Yue; Gottheim, Samuel; King, Nicholas S.; Zhang, Yu; Nordlander, Peter; Halas, Naomi J. (2015)
      A charge transfer plasmon (CTP) appears when an optical-frequency conductive pathway between two metallic nanoparticles is established, enabling the transfer of charge between nanoparticles when the plasmon is excited. ...
    • Distinguishing between plasmon-induced and photoexcited carriers in a device geometry 

      Zheng, Bob Y.; Zhao, Hangqi; Manjavacas, Alejandro; McClain, Michael; Nordlander, Peter (2015)
      The use of surface plasmons, charge density oscillations of conduction electrons of metallic nanostructures, to boost the efficiency of light-harvesting devices through increased light-matter interactions could drastically ...
    • From tunable core-shell nanoparticles to plasmonic drawbridges: Active control of nanoparticle optical properties 

      Byers, Chad P.; Zhang, Hui; Swearer, Dayne F.; Yorulmaz, Mustafa; Hoener, Benjamin S.; Huang, Da; Hoggard, Anneli; Chang, Wei-Shun; Mulvaney, Paul; Ringe, Emilie; Halas, Naomi J.; Nordlander, Peter; Link, Stephan; Landes, Christy F. (2015)
      The optical properties of metallic nanoparticles are highly sensitive to interparticle distance, giving rise to dramatic but frequently irreversible color changes. By electrochemical modification of individual nanoparticles ...
    • WATCH: WiFi in Active TV Channels 

      Zhang, Xu; Knightly, Edward W. (2015)
      Today's "white space" model of spectrum sharing applied in the UHF TV band allows channels that are not being used regionally by a TV broadcaster to be re-purposed for unlicensed-style secondary access in 24 hour increments. ...