Now showing items 232-251 of 376

    • On chip complex signal processing devices using coupled phononic crystal slab resonators and waveguides 

      Mohammadi, Saeed; Adibi, Ali (Georgia Institute of TechnologyAmerican Institute of Physics, 2012-03)
      In this paper, we report the evidence for the possibility of achieving complex signal processing functionalities such as multiplexing/demultiplexing at high frequencies using phononic crystal (PnC) slabs. It is shown that ...
    • On the accuracy limits of orbital expansion methods: Explicit effects of k-functions on atomic and molecular energies 

      Valeev, Edward F.; Allen, Wesley D.; Hernandez, Rigoberto; Sherrill, C. David; Schaefer, Henry F. (Georgia Institute of TechnologyAmerican Institute of Physics, 2003-05)
      For selected first- and second-row atoms, correlation-optimized Gaussian k functions have been determined and used in the construction of septuple-ζ basis sets for the correlation-consistent cc-pVXZ and aug-cc-pVXZ series. ...
    • On the polarization of the green emission of polyfluorenes 

      Yang, X. H.; Neher, D.; Spitz, C.; Zojer, Egbert; Brédas, Jean-Luc; Guntner, R.; Scherf, U (Georgia Institute of TechnologyAmerican Institute of Physics, 2003-10)
      An experimental and theoretical study of the anisotropic optical properties of polyfluorenes (PFs) bearing ketonic defects is presented. Polarized emission experiments performed on photooxidized aligned PF layers indicate ...
    • Ontology of temperature in nonequilibrium systems 

      Popov, Alexander V.; Hernandez, Rigoberto (Georgia Institute of TechnologyAmerican Institute of Physics, 2007-06)
      The laws of thermodynamics provide a clear concept of the temperature for an equilibrium system in the continuum limit. Meanwhile, the equipartition theorem allows one to make a connection between the ensemble average of ...
    • Optical and electrical interconnect partition length based on chip-to-chip bandwidth maximization 

      Naeemi, Azad; Xu, Jianping; Mule’, Anthony V.; Gaylord, Thomas K.; Meindl, James D. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2004-04)
      The lengths beyond which board-level optical waveguides are capable of transferring a larger number of bits per second than electrical interconnects are found for various technology generations. As technology scales ...
    • Optical correlation using gated localized holography 

      Karbaschi, Arash; Momtahan, Omid; Adibi, Ali; Javidi, Bahram (Georgia Institute of TechnologySociety of Photo-optical Instrumentation Engineers (SPIE), 2005-08)
      We present a new technique for optical correlation using gated holographic recording by which the holograms are localized in separate slices along the recording medium. We compare the performance of localized holographic ...
    • Optical properties of singly charged conjugated oligomers: A coupled-cluster equation of motion study 

      Ye, A.; Shuai, Zhigang; Kwon, O.; Brédas, Jean-Luc; Beljonne, David (Georgia Institute of TechnologyAmerican Institute of Physics, 2004-09)
      We have implemented a coupled-cluster equation of motion approach combined with the intermediate neglect of differential overlap parametrization and applied it to study the excited states and optical absorptions in positively ...
    • Optical single-angle plane-wave transmittances/reflectances from Schwarzschild objective variable-angle measurements 

      Gaylord, Thomas K.; Kilby, Gregory R. (Georgia Institute of TechnologyAmerican Institute of Physics, 2004-02)
      Photonic crystal structures and other nanoscale and microscale optical structures are centrally important to future device technology. The fundamental infrared single-angle plane-wave experimental characterization of these ...
    • Optical transmission of polymer pillars for chip I/O optical interconnections 

      Bakir, M. S.; Gaylord, T. K.; Ogunsola, O. O.; Glytsis, E. N.; Meindl, J. D. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2004-01)
      In the pursuit of high-density wafer-level input–output optical interconnections, microscopic polymer pillars have recently been fabricated. The optical performance of these pillars is critical for their potential ...
    • Optical-fiber-to-waveguide coupling using carbon-dioxide-laser-induced long-period fiber gratings 

      Bachim, Brent L.; Ogunsola, Oluwafemi O.; Gaylord, Thomas K. (Georgia Institute of TechnologyOptical Society of America, 2005-08)
      Optical fibers are expected to play a role in chip-level and board-level optical interconnects because of limitations on the bandwidth and level of integration of electrical interconnects. Therefore, methods are needed to ...
    • Optics in Energy: the power of optical solutions 

      Kippelen, Bernard (Georgia Institute of TechnologyOptical Society of America, 2010-04)
    • Optimal sliding correlator channel sounder design 

      Pirkl, Ryan J.; Durgin, Gregory D. (Georgia Institute of TechnologyInstitute of Electrical and Electronics Engineers, 2008-09)
      The sliding correlator technique remains one of the most versatile and effective methods for sounding the radio propagation channel in next-generation wireless systems. Despite their utility, there has never been a ...
    • Optimal sparse solution for fluorescent diffuse optical tomography: theory and phantom experimental results 

      Mohajerani, Pouyan; Eftekhar, Ali Asghar; Huang, Jiandong; Adibi, Ali (Georgia Institute of TechnologyOptical Society of America, 2007-04)
      We present a method to accurately localize small fluorescent objects within the tissue using fluorescent diffuse optical tomography (FDOT). The proposed method exploits the localized or sparse nature of the fluorophores ...
    • Optimization of anisotropically etched silicon surface-relief gratings for substrate-mode optical interconnects 

      Wu, Shun-Der; Gaylord, Thomas K.; Maikisch, Jonathan S.; Glytsis, Elias N. (Georgia Institute of TechnologyOptical Society of America, 2006-01)
      The optimum profiles of right-angle-face anisotropically etched silicon surface-relief gratings illuminated at normal incidence for substrate-mode optical interconnects are determined for TE, TM, and random linear (RL) ...
    • Optimization of finite-length input volume holographic grating couplers illuminated by finite-width incident beams 

      Wu, Shun-Der; Glytsis, Elias N.; Gaylord, Thomas K. (Georgia Institute of TechnologyOptical Society of America, 2005-07)
      A finite volume holographic grating coupler (VHGC) normally illuminated with various incident-beam profiles (such as a Gaussian beam, a flat cosine-squared beam, and an exponential-decay beam) with finite beam widths for ...
    • Optimization of sawtooth surface-relief gratings: effects of substrate refractive index and polarization 

      Wu, Shun-Der; Gaylord, Thomas K.; Glytsis, Elias N. (Georgia Institute of TechnologyOptical Society of America, 2006-05)
      The effect of the refractive index of the substrate together with the incident polarization on the optimization of sawtooth surface-relief gratings (SRGs) is investigated. The global optimum diffraction efficiencies of the ...
    • Optimizing organic photovoltaics using tailored heterojunctions: A photoinduced absorption study of oligothiophenes with low band gaps 

      Schueppel, R.; Schmidt, Karin; Uhrich, C.; Schulze, K.; Wynands, D.; Brier, E.; Reinold, E.; Bu, H.-B.; Baeuerle, P.; Maennig, B.; Pfeiffer, M.; Leo, K.; Brédas, Jean-Luc (Georgia Institute of TechnologyAmerican Physical Society, 2008-02)
      A power conversion efficiency of 3.4% with an open-circuit voltage of 1 V was recently demonstrated in a thin film solar cell utilizing fullerene C60 as acceptor and a new acceptor-substituted oligothiophene with an optical ...
    • Optimum parallel-face slanted surface-relief gratings 

      Maikisch, Jonathan S.; Gaylord, Thomas K. (Georgia Institute of TechnologyOptical Society of America, 2007-06)
      Using a combination of rigorous coupled-wave analysis and simulated annealing, parallel-face slanted surface-relief gratings (PFSSRGs) are optimized. For substrate-mode optical interconnects, profiles are presented for ...
    • Origin of the open-circuit voltage in multilayer heterojunction organic solar cells 

      Potscavage, William J., Jr.; Yoo, SeungHyup; Kippelen, Bernard (Georgia Institute of TechnologyAmerican Institute of Physics, 2008-11-10)
      From temperature dependent studies of pentacene/C₆₀ solar cells in the dark, the reverse saturation current is found to be thermally activated with a barrier height that corresponds to the difference in energy between the ...
    • Oscillations in meta-generalized-gradient approximation potential energy surfaces for dispersion-bound complexes 

      Johnson, Erin R.; Becke, Axel D.; Sherrill, C. David; DiLabio, Gino A. (Georgia Institute of TechnologyAmerican Institute of Physics, 2009-07)
      Meta-generalized-gradient approximations (meta-GGAs) in density-functional theory are exchange-correlation functionals whose integrands depend on local density, density gradient, and also the kinetic-energy density. It has ...