Ulf Peschel - Profile on Academia.edu (original) (raw)
Papers by Ulf Peschel
Advanced Materials, 2011
Institute. He authored a number of pioneering results in the physics of regular ensembles of nano... more Institute. He authored a number of pioneering results in the physics of regular ensembles of nanostructures templated in porous matrices. He also promoted this approach for the realization of low-dimensional materials working at universities in Glasgow, Wuppertal, Cork, and Erlangen. His current research focus is the design of complex photonic crystal architectures on colloidal crystal platforms. Alexander Korovin received his PhD in solid state physics from the Kiev Institute of Semiconductor Physics of National Academy of Science of Ukraine in 2002. His thesis was devoted to simulations of nonlinear effects in low-dimensional semiconductors and metals. Since 2004 he is involved in theoretical studies of plasmon excitations in periodic and irregular ensembles of metal nanostructures. Currently, his interests are focused on ultrafast interactions of plasmons with femtosecond high-power laser pulses in transparent dielectrics.
Superfluid motion of coupled light in a fiber transmission line
2011 Conference on Lasers and Electro Optics Europe and 12th European Quantum Electronics Conference, 2011
A unique feature of superfluidity is the frictionless flow below a critical velocity. This was fi... more A unique feature of superfluidity is the frictionless flow below a critical velocity. This was first pointed out by L. D. Landau who argued that only above the speed of sound the excitations of linear or sound waves is energetically favoured (1) leading to a finite drag and to a break down of superfluidity. The superfluid motion of a dilute
Superfluid motion of coupled light in a fiber transmission line
2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC), 2011
A unique feature of superfluidity is the frictionless flow below a critical velocity. This was fi... more A unique feature of superfluidity is the frictionless flow below a critical velocity. This was first pointed out by L. D. Landau who argued that only above the speed of sound the excitations of linear or sound waves is energetically favoured (1) leading to a finite drag and to a break down of superfluidity. The superfluid motion of a dilute
Induced soliton explosions in modulated waveguide arrays
Quantum Electronics and Laser Science Conference Technical Digest Postconference Edition Tops Vol 40, May 12, 2000
Summary form only given. Waveguide arrays are regarded as key components in future steering and r... more Summary form only given. Waveguide arrays are regarded as key components in future steering and routing schemes, because they allow us to distribute signals between many different channels. Therefore several present experimental activities have focused on the formation and dynamics of discrete solitons. AlGaAs samples were operated below half the bandgap to employ the focusing Kerr nonlinearity. For single-mode waveguides
A simple approach for identifying discrete cavity solitons
Nonlinear Guided Waves and Their Applications, 2004
ABSTRACT We introduce an analytical approach which permits to identify domains of existence in pa... more ABSTRACT We introduce an analytical approach which permits to identify domains of existence in parameter space of discrete cavity solitons. We demonstrate the performance of the approach for solitons in an array of quadratically nonlinear cavities.
Dissipative Quadratic Lattice Solitons
Nonlinear Guided Waves and Their Applications, 2005
ABSTRACT We report for the first time on the existence of dissipative lattice solitons in a quadr... more ABSTRACT We report for the first time on the existence of dissipative lattice solitons in a quadratically nonlinear cavity with a periodic modulation of the refractive index. We observe various localized structures, in particular multiband solitons.
Physical Review Letters, 2004
Optics Letters, 1998
We show that, in vectorial intracavity second-harmonic generation, symmetry breaking occurs if th... more We show that, in vectorial intracavity second-harmonic generation, symmetry breaking occurs if the input amplitude exceeds a critical value. The resulting asymmetric stationary solutions are characterized by a second harmonic that is independent of the input amplitude. The solutions can destabilize through Hopf bifurcations, leading to self-oscillations with pronounced antiphase dynamics. We demonstrate that symmetry breaking can be exploited for f lip-f lop operation.
On-Demand Coupling of Electrically Generated Excitons with Surface Plasmons via Voltage-Controlled Emission Zone Position
ACS Photonics, 2016
The ability to confine and manipulate light below the diffraction limit is a major goal of future... more The ability to confine and manipulate light below the diffraction limit is a major goal of future multifunctional optoelectronic/plasmonic systems. Here, we demonstrate the design and realization of a tunable and localized electrical source of excitons coupled to surface plasmons based on a polymer light-emitting field-effect transistor (LEFET). Gold nanorods that are integrated into the channel support localized surface plasmons and serve as nanoantennas for enhanced electroluminescence. By precise spatial control of the near-infrared emission zone in the LEFET via the applied voltages the near-field coupling between electrically generated excitons and the nanorods can be turned on or off as visualized by a change of electroluminescence intensity. Numerical calculations and spectroscopic measurements corroborate significant local electroluminescence enhancement due to the high local density of photonic states in the vicinity of the gold nanorods. Importantly, the integration of plasmonic nanostructures hardly influences the electrical performance of the LEFETs, thus, highlighting their mutual compatibility in novel active plasmonic devices.
Device for Beam Deflection in Optical Wave Guide Structures
Nonlinear Optics: Materials, Fundamentals and Applications, 2000
The stability of bright solitons due to cascading of optical rectification and the electro-optic ... more The stability of bright solitons due to cascading of optical rectification and the electro-optic effect in a quadratic nonlinear medium is investigated. A linear stability analysis explains the observed oscillation and radiation of perturbed solitons. @ZOO0 Optical Society of America OCIS codes: (190.5530) Pulse propagation and solitons; (190.5970) Semiconductor nonlinear optics
Optics in Curved Space
Physical Review Letters, Oct 1, 2010
We experimentally study the impact of intrinsic and extrinsic curvature of space on the evolution... more We experimentally study the impact of intrinsic and extrinsic curvature of space on the evolution of light. We show that the topology of a surface matters for radii of curvature comparable with the wavelength, whereas for macroscopically curved surfaces only intrinsic curvature is relevant. On a surface with constant positive Gaussian curvature we observe periodic refocusing, self-imaging, and diffractionless propagation. In contrast, light spreads exponentially on surfaces with constant negative Gaussian curvature. For the first time we realized two beam interference in negatively curved space.
Microcavity Photonic Crystal OPO
ABSTRACT
Optical Design and Engineering II, 2005
For gaining a deeper understanding of the diffraction processes that take place in deep dielectri... more For gaining a deeper understanding of the diffraction processes that take place in deep dielectric transmission gratings, a phenomenological explanation has been developed on the basis of a modal field, which propagates vertically through the grating region. The excitation of these modes by the incident wave, their propagation constants and how they couple to the diffraction orders determines the diffraction efficiency of the transmitted orders. The explicit modal analysis discloses the description of the highly efficient diffraction for polarized or unpolarized light by a very simple interference mechanism, which will be the subject of this paper.
Lossless propagation of magnetic dipole excitations on chains of dielectric particles with high refractive index
Physical Review B
Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwaveleng... more Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwavelength particles is predicted for a narrow frequency range around the magnetic Mie resonance of the individual particles. Mathematical analogies between dipole and magnetoinductive waves are used to reduce back-reflections thus improving the power transfer efficiency of respective particle waveguides. The proposed technique can be used to optimize the propagation of even more complex particle-based configurations.
Selfguiding of visible light in photonic crystal slabs
Information Sciences, 2005
In this paper, we report that diffractionless propagation is also possible in the visible spectra... more In this paper, we report that diffractionless propagation is also possible in the visible spectral range by downscaling the slab system as well as the PC parameters. The experimentally obtained wavelengths for optimal guidance are in excellent agreement with iso-frequency calculation
Light propagation via coupled defects in photonic crystals
Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 2002
Low-loss waveguiding around sharp bends is a key task in microoptics. A coupled-defect waveguide ... more Low-loss waveguiding around sharp bends is a key task in microoptics. A coupled-defect waveguide is able to perform much better at sharp bends than a channel waveguide. It also can enhance considerably the efficiency of second harmonic generation due to the low effective group velocity. Coupled-defect optical waveguides are a superlattice or superstructure consisting of original and modified unit cells
Strongly localized discrete solitons in photonic crystals
Nonlinear Guided Waves and Their Applications, 2004
Advanced Materials, 2011
Institute. He authored a number of pioneering results in the physics of regular ensembles of nano... more Institute. He authored a number of pioneering results in the physics of regular ensembles of nanostructures templated in porous matrices. He also promoted this approach for the realization of low-dimensional materials working at universities in Glasgow, Wuppertal, Cork, and Erlangen. His current research focus is the design of complex photonic crystal architectures on colloidal crystal platforms. Alexander Korovin received his PhD in solid state physics from the Kiev Institute of Semiconductor Physics of National Academy of Science of Ukraine in 2002. His thesis was devoted to simulations of nonlinear effects in low-dimensional semiconductors and metals. Since 2004 he is involved in theoretical studies of plasmon excitations in periodic and irregular ensembles of metal nanostructures. Currently, his interests are focused on ultrafast interactions of plasmons with femtosecond high-power laser pulses in transparent dielectrics.
Superfluid motion of coupled light in a fiber transmission line
2011 Conference on Lasers and Electro Optics Europe and 12th European Quantum Electronics Conference, 2011
A unique feature of superfluidity is the frictionless flow below a critical velocity. This was fi... more A unique feature of superfluidity is the frictionless flow below a critical velocity. This was first pointed out by L. D. Landau who argued that only above the speed of sound the excitations of linear or sound waves is energetically favoured (1) leading to a finite drag and to a break down of superfluidity. The superfluid motion of a dilute
Superfluid motion of coupled light in a fiber transmission line
2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC), 2011
A unique feature of superfluidity is the frictionless flow below a critical velocity. This was fi... more A unique feature of superfluidity is the frictionless flow below a critical velocity. This was first pointed out by L. D. Landau who argued that only above the speed of sound the excitations of linear or sound waves is energetically favoured (1) leading to a finite drag and to a break down of superfluidity. The superfluid motion of a dilute
Induced soliton explosions in modulated waveguide arrays
Quantum Electronics and Laser Science Conference Technical Digest Postconference Edition Tops Vol 40, May 12, 2000
Summary form only given. Waveguide arrays are regarded as key components in future steering and r... more Summary form only given. Waveguide arrays are regarded as key components in future steering and routing schemes, because they allow us to distribute signals between many different channels. Therefore several present experimental activities have focused on the formation and dynamics of discrete solitons. AlGaAs samples were operated below half the bandgap to employ the focusing Kerr nonlinearity. For single-mode waveguides
A simple approach for identifying discrete cavity solitons
Nonlinear Guided Waves and Their Applications, 2004
ABSTRACT We introduce an analytical approach which permits to identify domains of existence in pa... more ABSTRACT We introduce an analytical approach which permits to identify domains of existence in parameter space of discrete cavity solitons. We demonstrate the performance of the approach for solitons in an array of quadratically nonlinear cavities.
Dissipative Quadratic Lattice Solitons
Nonlinear Guided Waves and Their Applications, 2005
ABSTRACT We report for the first time on the existence of dissipative lattice solitons in a quadr... more ABSTRACT We report for the first time on the existence of dissipative lattice solitons in a quadratically nonlinear cavity with a periodic modulation of the refractive index. We observe various localized structures, in particular multiband solitons.
Physical Review Letters, 2004
Optics Letters, 1998
We show that, in vectorial intracavity second-harmonic generation, symmetry breaking occurs if th... more We show that, in vectorial intracavity second-harmonic generation, symmetry breaking occurs if the input amplitude exceeds a critical value. The resulting asymmetric stationary solutions are characterized by a second harmonic that is independent of the input amplitude. The solutions can destabilize through Hopf bifurcations, leading to self-oscillations with pronounced antiphase dynamics. We demonstrate that symmetry breaking can be exploited for f lip-f lop operation.
On-Demand Coupling of Electrically Generated Excitons with Surface Plasmons via Voltage-Controlled Emission Zone Position
ACS Photonics, 2016
The ability to confine and manipulate light below the diffraction limit is a major goal of future... more The ability to confine and manipulate light below the diffraction limit is a major goal of future multifunctional optoelectronic/plasmonic systems. Here, we demonstrate the design and realization of a tunable and localized electrical source of excitons coupled to surface plasmons based on a polymer light-emitting field-effect transistor (LEFET). Gold nanorods that are integrated into the channel support localized surface plasmons and serve as nanoantennas for enhanced electroluminescence. By precise spatial control of the near-infrared emission zone in the LEFET via the applied voltages the near-field coupling between electrically generated excitons and the nanorods can be turned on or off as visualized by a change of electroluminescence intensity. Numerical calculations and spectroscopic measurements corroborate significant local electroluminescence enhancement due to the high local density of photonic states in the vicinity of the gold nanorods. Importantly, the integration of plasmonic nanostructures hardly influences the electrical performance of the LEFETs, thus, highlighting their mutual compatibility in novel active plasmonic devices.
Device for Beam Deflection in Optical Wave Guide Structures
Nonlinear Optics: Materials, Fundamentals and Applications, 2000
The stability of bright solitons due to cascading of optical rectification and the electro-optic ... more The stability of bright solitons due to cascading of optical rectification and the electro-optic effect in a quadratic nonlinear medium is investigated. A linear stability analysis explains the observed oscillation and radiation of perturbed solitons. @ZOO0 Optical Society of America OCIS codes: (190.5530) Pulse propagation and solitons; (190.5970) Semiconductor nonlinear optics
Optics in Curved Space
Physical Review Letters, Oct 1, 2010
We experimentally study the impact of intrinsic and extrinsic curvature of space on the evolution... more We experimentally study the impact of intrinsic and extrinsic curvature of space on the evolution of light. We show that the topology of a surface matters for radii of curvature comparable with the wavelength, whereas for macroscopically curved surfaces only intrinsic curvature is relevant. On a surface with constant positive Gaussian curvature we observe periodic refocusing, self-imaging, and diffractionless propagation. In contrast, light spreads exponentially on surfaces with constant negative Gaussian curvature. For the first time we realized two beam interference in negatively curved space.
Microcavity Photonic Crystal OPO
ABSTRACT
Optical Design and Engineering II, 2005
For gaining a deeper understanding of the diffraction processes that take place in deep dielectri... more For gaining a deeper understanding of the diffraction processes that take place in deep dielectric transmission gratings, a phenomenological explanation has been developed on the basis of a modal field, which propagates vertically through the grating region. The excitation of these modes by the incident wave, their propagation constants and how they couple to the diffraction orders determines the diffraction efficiency of the transmitted orders. The explicit modal analysis discloses the description of the highly efficient diffraction for polarized or unpolarized light by a very simple interference mechanism, which will be the subject of this paper.
Lossless propagation of magnetic dipole excitations on chains of dielectric particles with high refractive index
Physical Review B
Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwaveleng... more Lossless propagation of longitudinal magnetic dipole waves along chains of high-index subwavelength particles is predicted for a narrow frequency range around the magnetic Mie resonance of the individual particles. Mathematical analogies between dipole and magnetoinductive waves are used to reduce back-reflections thus improving the power transfer efficiency of respective particle waveguides. The proposed technique can be used to optimize the propagation of even more complex particle-based configurations.
Selfguiding of visible light in photonic crystal slabs
Information Sciences, 2005
In this paper, we report that diffractionless propagation is also possible in the visible spectra... more In this paper, we report that diffractionless propagation is also possible in the visible spectral range by downscaling the slab system as well as the PC parameters. The experimentally obtained wavelengths for optimal guidance are in excellent agreement with iso-frequency calculation
Light propagation via coupled defects in photonic crystals
Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 2002
Low-loss waveguiding around sharp bends is a key task in microoptics. A coupled-defect waveguide ... more Low-loss waveguiding around sharp bends is a key task in microoptics. A coupled-defect waveguide is able to perform much better at sharp bends than a channel waveguide. It also can enhance considerably the efficiency of second harmonic generation due to the low effective group velocity. Coupled-defect optical waveguides are a superlattice or superstructure consisting of original and modified unit cells
Strongly localized discrete solitons in photonic crystals
Nonlinear Guided Waves and Their Applications, 2004