Now showing items 1-20 of 35

    • Generation of cylindrical vector beams with few-mode fibers excited by Laguerre–Gaussian beams 

      Volpe, Giovanni; Petrov, D. (Elsevier, 2004-07-01)
      We propose a novel method to efficiently produce light beams with radial, azimuthal, and hybrid polarization, through a few-mode fiber excited by a Laguerre–Gaussian beam. With different input polarization we can selectively ...
    • Spectral negative refraction and focusing analysis of a two-dimensional left-handed photonic crystal lens 

      Güven, Kaan; Aydın, Koray; Alıcı, Kamil Boratay; Soukoulis, C. M.; Özbay, Ekmel (American Physical Society, 2004-11)
      We report the spectral refraction analysis and focusing properties of a two-dimensional, dielectric photonic crystal (PC) slab in freespace. A transverse electric polarized upper band of the crystal is used. The measured ...
    • Negative refraction and subwavelength focusing using photonic crystals 

      Özbay, Ekmel; Aydın, Koray; Alıcı, Kamil Boratay; Güven, Kaan (SPIE, 2005-01)
      We review certain novel optical properties of two-dimensional dielectric photonic crystals (PCs) which exhibit negative refraction behavior. We investigate two mechanisms which utilize the band structure of the PC and lead ...
    • Experimental analysis of true left-handed behaviour and transmission properties of composite metamaterials 

      Güven, Kaan; Aydın, Koray; Özbay, Ekmel (Elsevier, 2005-12)
      We report the true left-handed transmission of a composite metamaterial (CMM) consisting of periodically stacked split-ring resonator (SRR) and wire elements. The negative permeability (μ < 0) gap is demonstrated explicitly ...
    • Surface plasmon radiation forces 

      Volpe, Giovanni; Quidant, R.; Badenes, G.; Petrov, D. (The American Physical Society, 2006-06)
      We report the first experimental observation of momentum transfer from a surface plasmon to a single dielectric sphere. Using a photonic force microscope, we measure the plasmon radiation forces on different polystyrene ...
    • Torque detection using brownian fluctuations 

      Volpe, Giovanni; Petrov, D. (The American Physical Society, 2006-11-24)
      We report the statistical analysis of the movement of a submicron particle confined in a harmonic potential in the presence of a torque. The absolute value of the torque can be found from the auto- and cross-correlation ...
    • Printed multilayer superstructures of aligned single-walled carbon nanotubes for electronic applications 

      Kang, S. J.; Kocabaş, Coşkun; Kim, H.-S.; Cao, Q.; Meitl, M. A.; Khang, D.-Y.; Rogers, J. A. (American Chemical Society, 2007-10)
      We developed means to form multilayer superstructures of large collections of single-walled carbon nanotubes (SWNTs) configured in horizontally aligned arrays, random networks, and complex geometries of arrays and networks ...
    • Molecular scale buckling mechanics in individual aligned single-wall carbon nanotubes on elastomeric substrates 

      Khang, D. -Y.; Xiao, J.; Kocabaş, Coşkun; MacLaren, S.; Banks, T.; Jiang, H.; Huang, Y. Y.; Rogers, J. A. (American Chemical Society, 2008)
      We have studied the scaling of controlled nonlinear buckling processes in materials with dimensions in the molecular range (i.e., ∼1 nm) through experimental and theoretical studies of buckling in individual single-wall ...
    • Comparison of electron and hole charge-discharge dynamics in germanium nanocrystal flash memories 

      Akça, İmran B.; Dâna, Aykutlu; Aydınlı, Atilla; Turan, R. (AIP Publishing, 2008-02)
      Electron and hole charge and discharge dynamics are studied on plasma enhanced chemical vapor deposition grown metal-oxide-silicon germanium nanocrystal flash memory devices. Electron and hole charge and discharge currents ...
    • Electro-optic and electro-absorption characterization of InAs quantum dot waveguides 

      Akça, İmran B.; Dana, Aykutlu; Aydınlı, Atilla; Rossetti, M.; Li, L.; Fiore, A.; Dağlı, N. (Optical Society of America, 2008-03)
      Abstract Optical properties of multilayer InAs quantum dot waveguides, grown by molecular beam epitaxy, have been studied under applied electric field. Fabry-Perot measurements at 1515 nm on InAs/GaAs quantum dot structures ...
    • Stable ℋ∞ controller design for time-delay systems 

      Gümüşsoy, S.; Özbay, Hitay (Taylor & Francis, 2008-04)
      This paper investigates stable suboptimal [image omitted] controllers for a class of single-input single-output time-delay systems. For a given plant and weighting functions, the optimal controller minimizing the mixed ...
    • Spectroscopic ellipsometric study of Ge nanocrystals embedded in SiO 2 using parametric models 

      Basa, P.; Petrik, P.; Fried, M.; Dâna, Aykutlu; Aydınlı, Atilla; Foss, S.; Finstad, T. G. (Wiley, 2008-05)
      Ge-rich SiO2 layers on top of Si substrates were deposited using plasma enhanced chemical vapour deposition. Ge nanocrystals embedded in the SiO2 layers were formed by high temperature annealing. The samples were measured ...
    • A 500 MHz carbon nanotube transistor oscillator 

      Pesetski, A. A.; Baumgardner, J. E.; Krishnaswamy, S. V.; Zhang, H.; Adam, J. D.; Kocabaş, Coşkun; Banks, T.; Rogers, J. A. (American Institute of Physics, 2008-09)
      Operation of a carbon nanotube field effect transistor (FET) oscillator at a record frequency of 500 MHz is described. The FET was fabricated using a large parallel array of single-walled nanotubes grown by chemical vapor ...
    • Slowing down surface plasmons on a Moiré surface 

      Kocabaş, Aşkın; Şenlik, S. Seçkin; Aydınlı, Atilla (The American Physical Society, 2009-02)
      We have demonstrated slow propagation of surface plasmons on metallic Moiré surfaces. The phase shift at the node of the Moiré surface localizes the propagating surface plasmons and adjacent nodes form weakly coupled ...
    • High-frequency performance of submicrometer transistors that use aligned arrays of single-walled carbon nanotubes 

      Kocabaş, Coşkun; Dunham, S.; Cao, Q.; Cimino, K.; Ho, X.; Kim, H.-S.; Dawson, D.; Payne, J.; Stuenkel, M.; Zhang, H.; Banks, T.; Feng, M.; Rotkin, S. V.; Rogers, J. A. (American Chemical Society, 2009-04-08)
      The unique electronic properties of single-walled carbon nanotubes (SWNTs) make them promising candidates for next generation electronics, particularly in systems that demand high frequency (e.g., radio frequency, RF) ...
    • Quantitative assessment of non-conservative radiation forces in an optical trap 

      Pesce, G.; Volpe, Giovanni; De Luca, A. C.; Rusciano, G.; Volpe, G. (Institute of Physics Publishing, 2009-05)
      The forces acting on an optically trapped particle are usually assumed to be conservative. However, the presence of a non-conservative component has recently been demonstrated. Here, we propose a technique that permits one ...
    • Tunable surface plasmon resonance on an elastomeric substrate 

      Olcum, Selim; Kocabaş, Aşkın; Ertaş, Gülay; Atalar, Abdullah; Aydınlı, Atilla (Optical Society of American (OSA), 2009-05)
      In this study, we demonstrate that periods of metallic gratings on elastomeric substrates can be tuned with external strain and hence are found to control the resonance condition of surface plasmon polaritons. We have ...
    • Grating based plasmonic band gap cavities 

      Şenlik, S. Seçkin; Kocabaş, Aşkın; Aydınlı, Atilla (Optical Society of American (OSA), 2009-08)
      We report on a comparative study of grating based plasmonic band gap cavities. Numerically, we calculate the quality factors of the cavities based on three types of grating surfaces; uniform, biharmonic and Moiré surfaces. ...
    • Alignment controlled growth of single-walled carbon nanotubes on quartz substrates 

      Xiao, J.; Dunham, S.; Liu, P.; Zhang, Y.; Kocabaş, Coşkun; Moh, L.; Huang, Y.; Hwang, K. -C.; Lu, C.; Huang, W.; Rogers, J. A. (American Chemical Society, 2009-09-11)
      Single-walled carbon nanotubes (SWNTs) possess extraordinary electrical properties, with many possible applications in electronics. Dense, horizonally aligned arrays of linearly configured SWNTs represent perhaps the most ...
    • Novel perspectives for the application of total internal reflection microscopy 

      Volpe, Giovanni; Brettschneider, T.; Helden, L.; Bechinger, C. (Optical Society of America, 2009-12)
      Total Internal Reflection Microscopy (TIRM) is a sensitive non-invasive technique to measure the interaction potentials between a colloidal particle and a wall with femtonewton resolution. The equilibrium distribution of ...