@inproceedings{4191, abstract = {{We study optical second-harmonic generation from planar arrays of magnetic split-ring resonators at 1.5 microns resonance wavelength. We obtain by far the largest signals when exciting the magnetic-dipole resonance. }}, author = {{Klein, Matthias W. and Enkrich, Christian and Wegener, Martin and Förstner, Jens and Moloney, Jerome V. and Hoyer, Walter and Stroucken, Tineke and Meier, Torsten and Koch, Stephan W. and Linden, Stefan}}, booktitle = {{Photonic Metamaterials: From Random to Periodic}}, isbn = {{155752808X}}, keywords = {{tet_topic_meta}}, publisher = {{OSA}}, title = {{{Optical Experiments on Second-Harmonic Generation with Metamaterials Composed of Split-Ring Resonators}}}, doi = {{10.1364/meta.2006.tuc5}}, year = {{2006}}, } @article{43272, abstract = {{Optical interband transitions in a series of In0.23Ga0.77As–GaN𝑥As1−𝑥 quantum well samples are investigated. For changing nitrogen content, a type I-type II transition is identified by a detailed analysis of photoluminescence and photoreflectance spectra. Experimental results are compared systematically with spectra calculated by a microscopic theory. A valence band offset parameter of (1.5±0.5)eV is extracted for this heterostructure system.This work was supported by the Deutsche Forschungsgemeinschaft (Research Group on Metastable Compound Semiconductors and Heterostructures), by AFOSR (F49620-02-1-0380) and the Max-Planck Research Prize of the Max-Planck Society and Humboldt Foundation. We thank Stanko Tomić (Daresbury Laboratory) for fruitful discussions. }}, author = {{Schlichenmaier, C. and Grüning, H. and Thränhardt, A. and Klar, P.J. and Kunert, B. and Volz, K. and Stolz, W. and Heimbrodt, W. and Meier, Torsten and Koch, S.W.}}, journal = {{Applied Physics Letters}}, number = {{8}}, publisher = {{American Institute of Physics}}, title = {{{Type I-type II transition in InGaAs–GaNAs heterostructures}}}, doi = {{American Institute of Physics}}, volume = {{86}}, year = {{2005}}, } @article{43271, abstract = {{The optical and electronic properties of semiconductor heterostructures in the vicinity of photonic crystals are discussed. The theoretical approach provides a self-consistent solution of the dynamics of the electromagnetic field and the material excitations. Due to the influence of the structured dielectric environment on the Coulomb interaction, the exciton resonances and the quasiequilibrium carrier densities in the spatially homogeneous semiconductor become space dependent. It is demonstrated that these inhomogeneities lead to distinct modifications of the optical absorption and gain spectra. As an application, numerically calculated density-dependent optical spectra are analyzed for an array of semiconductor quantum wires which are close to a two-dimensional photonic crystal. The spatial inhomogeneities result in novel excitonic absorption features and modification of the optical gain in these structures.}}, author = {{Reichelt, Matthias and Pasenow, B. and Meier, Torsten and Stroucken, T. and Koch, S.W.}}, journal = {{Physical Review B}}, number = {{3}}, publisher = {{035346}}, title = {{{ Spatially inhomogeneous optical gain in semiconductor photonic-crystal structures}}}, doi = {{10.1103/PhysRevB.71.035346}}, volume = {{71}}, year = {{2005}}, } @article{23506, abstract = {{The optical properties of semiconductor quantum wells embedded in one-dimensional photonic crystal structures are analyzed by a self-consistent solution of Maxwell’s equations and a microscopic many-body theory of the material excitations. For a field mode spectrally below the photonic band edge it is shown that the optical absorption and gain are enhanced, exceeding by more than 1 order of magnitude the values of a homogeneous medium. For the photonic crystal structure inside a microcavity the gain increases superlinearly with the number of wells and for more than five wells exceeds the gain of a corresponding vertical-cavity surface-emitting laser.}}, author = {{Pasenow, Bernhard and Reichelt, Matthias and Stroucken, Tineke and Meier, Torsten and Koch, Stephan W. and Zakharian, Aramis R. and Moloney, Jerome V.}}, issn = {{0740-3224}}, journal = {{Journal of the Optical Society of America B}}, number = {{9}}, pages = {{2039--2048}}, title = {{{Enhanced light-matter interaction in semiconductor heterostructures embedded in one-dimensional photonic crystals}}}, doi = {{10.1364/josab.22.002039}}, volume = {{22}}, year = {{2005}}, } @article{23502, abstract = {{Significant aspects of the light–matter interaction can be strongly modified in suitably designed systems consisting of semiconductor nanostructures and dielectric photonic crystals. To analyze such effects, a microscopic theory is presented, which is capable of describing the optoelectronic properties of such hybrid systems via a self-consistent solution of the dynamics of the optical field and the photoexcitations of the material. The theory is applied to investigate the local excitonic resonances, which arise as a consequence of the modified Coulomb interaction in the vicinity of a structured dielectric medium. The excitation of a coherent superposition of the spatially inhomogeneous optical transitions induces an intricate wave packet dynamics. In the presence of dephasing and relaxation processes, the coherent oscillations are damped and the photoexcited carriers relax into spatially inhomogeneous quasi-equilibrium distributions.}}, author = {{Pasenow, B. and Reichelt, Matthias and Stroucken, T. and Meier, Torsten and Koch, S. W.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{19}}, pages = {{195321}}, title = {{{Excitonic wave packet dynamics in semiconductor photonic-crystal structures}}}, doi = {{10.1103/physrevb.71.195321}}, volume = {{71}}, year = {{2005}}, } @article{23504, abstract = {{The coherent optical injection and temporal decay of spin and charge currents in semiconductor heterostructures is described microscopically, including excitonic effects, many-body Coulomb correlations, and the carrier LO-phonon coupling on the second-order Born-Markov level, as well as nonperturbative light-field-induced intraband and interband excitations. A nonmonotonic dependence of the currents on the intensities of the laser beams is predicted. Enhanced damping of the spin current relative to the charge current is obtained as a consequence of Coulomb scattering.}}, author = {{Duc, Huynh Thanh and Meier, Torsten and Koch, S. W.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, number = {{8}}, title = {{{Microscopic Analysis of the Coherent Optical Generation and the Decay of Charge and Spin Currents in Semiconductor Heterostructures}}}, doi = {{10.1103/physrevlett.95.086606}}, volume = {{95}}, year = {{2005}}, } @article{23507, abstract = {{A microscopic model is used to analyze gain and loss properties of (GaIn)(NAs)∕GaAs quantum wells in the 1.3–1.55μm range, including Auger and radiative recombination. The calculations show that, as long as good material quality can be achieved, growing highly compressively strained samples is preferable due to their specific band structure properties. Optimum laser operation is possible slightly above a peak gain of 1000cm−1 ⁠.}}, author = {{Schlichenmaier, C. and Thränhardt, A. and Meier, Torsten and Koch, S. W. and Chow, W. W. and Hader, J. and Moloney, J. V.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{26}}, title = {{{Gain and carrier losses of (GaIn)(NAs) heterostructures in the 1300–1550 nm range}}}, doi = {{10.1063/1.2149371}}, volume = {{87}}, year = {{2005}}, } @inbook{43275, author = {{Meier, Torsten and Koch, S.W.}}, booktitle = {{Encyclopedia of Modern Optics}}, editor = {{Guenther, B. and Bayvel, L. and Steel, D.G.}}, pages = {{163--173}}, publisher = {{Elsevier}}, title = {{{COHERENT TRANSIENTS | Foundations of Coherent Transients in Semiconductors}}}, doi = {{10.1016/B0-12-369395-0/00754-5}}, year = {{2005}}, } @inproceedings{44121, abstract = {{Theory/experiment comparisons of optical properties of dilute nitride heterostructures are presented. A type I - type II transition in In0.23Ga0.77As/GaNxAs1−x heterostructures is identified. The model is used for a study of lasing in the 1.3-1.5μm range.}}, author = {{Meier, Torsten and Schlichenmaier, C. and Thränhardt, A. and Grüning, H. and Klar, Peter J. and Heimbrodt, Wolfram and Koch, S.W. and Chow, Weng W. and Hader, J. and Moloney, Jerome V.}}, booktitle = {{ Quantum Electronics and Laser Science Conference}}, isbn = {{1-55752-770-9}}, location = {{Baltimore, Maryland United States}}, publisher = {{Optical Society of America}}, title = {{{Analysis of dilute nitride semiconductor laser gain materials in the 1.3-1.5/spl mu/m range}}}, year = {{2005}}, } @article{23501, abstract = {{A set of (Ga0.77In0.23)As/Ga(NxAs1−x) heterostructures is studied by time-resolved photoluminescence. Four samples with nitrogen concentrations from x=0.48% up to x=2.2% are investigated at different temperatures and with different excitation densities. The experiments suggest that the heterostructure band offset is type I for x=0.48% and type II for x=2.2%. The situation is more complex for x=0.72% and x=1.25%, since these samples are close to the transition from type I to type II. The experimental findings are analyzed using a detailed microscopic theory. Numerical calculations describe the measured data well. In particular, the interpretation of the experimental results concerning the band alignment is confirmed by the theoretical analysis.}}, author = {{Hantke, K. and Heber, J. D. and Schlichenmaier, C. and Thränhardt, A. and Meier, Torsten and Kunert, B. and Volz, K. and Stolz, W. and Koch, S. W. and Rühle, W. W.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{16}}, title = {{{Time-resolved photoluminescence of type-I and type-II (GaIn) As/Ga (NAs) heterostructures}}}, doi = {{10.1103/physrevb.71.165320}}, volume = {{71}}, year = {{2005}}, } @article{23496, abstract = {{The optical and electronic properties of semiconductor heterostructures in the vicinity of photonic crystals are discussed. The theoretical approach provides a self-consistent solution of the dynamics of the electromagnetic field and the material excitations. Due to the influence of the structured dielectric environment on the Coulomb interaction, the exciton resonances and the quasiequilibrium carrier densities in the spatially homogeneous semiconductor become space dependent. It is demonstrated that these inhomogeneities lead to distinct modifications of the optical absorption and gain spectra. As an application, numerically calculated density-dependent optical spectra are analyzed for an array of semiconductor quantum wires which are close to a two-dimensional photonic crystal. The spatial inhomogeneities result in novel excitonic absorption features and modification of the optical gain in these structures.}}, author = {{Reichelt, Matthias and Pasenow, B. and Meier, Torsten and Stroucken, T. and Koch, S. W.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{3}}, title = {{{Spatially inhomogeneous optical gain in semiconductor photonic-crystal structures}}}, doi = {{10.1103/physrevb.71.035346}}, volume = {{71}}, year = {{2005}}, } @article{23498, abstract = {{The ultrafast dynamics of photoexcitations at silicon surfaces is investigated using a surface-sensitive purely optical technique. In the experiments, the diffracted second harmonic generated by sequences of ultrashort laser pulses is detected as a function of the time delay between the pulses. It is demonstrated that this five-wave-mixing technique can be used to measure the temporal evolution of the optical polarization and the photoexcited populations at the surface. The experimental results can be reproduced by numerical solutions of optical Bloch equations. The theoretical analysis allows one to investigate which dephasing times and relaxation processes are compatible with experiment. Furthermore, it is outlined how one can describe optical nonlinearities at surfaces using a microscopic theory within the framework of semiconductor Bloch equations.}}, author = {{Meier, Torsten and Reichelt, Matthias and Koch, S W and Höfer, U}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, number = {{8}}, pages = {{S221--S244}}, title = {{{Femtosecond time-resolved five-wave mixing at silicon surfaces}}}, doi = {{10.1088/0953-8984/17/8/003}}, volume = {{17}}, year = {{2005}}, } @article{23499, abstract = {{The ultrafast dynamics of photoexcitations at silicon surfaces is investigated using a surface-sensitive purely optical technique. In the experiments, the diffracted second harmonic generated by sequences of ultrashort laser pulses is detected as a function of the time delay between the pulses. It is demonstrated that this five-wave-mixing technique can be used to measure the temporal evolution of the optical polarization and the photoexcited populations at the surface. The experimental results can be reproduced by numerical solutions of optical Bloch equations. The theoretical analysis allows one to investigate which dephasing times and relaxation processes are compatible with experiment. Furthermore, it is outlined how one can describe optical nonlinearities at surfaces using a microscopic theory within the framework of semiconductor Bloch equations.}}, author = {{Meier, Torsten and Reichelt, Matthias and Koch, S W and Höfer, U}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, number = {{8}}, pages = {{S221--S244}}, title = {{{Femtosecond time-resolved five-wave mixing at silicon surfaces}}}, doi = {{10.1088/0953-8984/17/8/003}}, volume = {{17}}, year = {{2005}}, } @inproceedings{44297, author = {{Meier, Torsten and Reichelt, Matthias and Pasenow, B. and Stroucken, T. and Koch, S.W.}}, booktitle = {{2005 annual conference of the German Physical Society (DPG) during the World year of physics}}, location = {{Berlin, Germany}}, title = {{{Optical properties of semiconductor photonic-crystal structures: spatially-inhomogeneous excitonic resonances and optical gain}}}, volume = {{40}}, year = {{2005}}, } @article{23503, author = {{Oszwałdowski, R. and Reichelt, Matthias and Meier, Torsten and Koch, S. W. and Rohlfing, Michael}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{23}}, title = {{{Nonlinear optical response of the Si ( 111 ) − ( 2 × 1 ) surface exciton: Influence of biexciton many-body correlations}}}, doi = {{10.1103/physrevb.71.235324}}, volume = {{71}}, year = {{2005}}, } @inbook{43274, abstract = {{Experimental results on the nonlinear optical properties of semiconductors are compared with microscopic calculations which include Coulomb many-body correlations at different levels. One aim of this chapter is to show that microscopic theories, which have been developed for bare semiconductor heterostructures, are also able to describe semiconductor microcavities very well. Therefore, there is no need to phenomenologically introduce polariton-polariton interactions and parametric scattering of cavity polaritons to describe microcavity experiments, but instead a fully microscopic theory based on a Fermionic electron-hole Hamiltonian can be used. The treatment of many-body correlations using the second-order Born approximation and the dynamics-controlled truncation scheme are introduced and analyzed for bare heterostructures. These approaches are able to successfully explain a number of important experimental results which originate from the dynamics of many-body correlations. Then measurements of the nonlinear optical properties of a quantum-well microcavity are described. In these experiments the spectrally- and temporally-resolved nonlinear optical response is studied in detail using a pump-probe geometry. In particular, the polarization and intensity dependencies of the spectral probe reflection changes and their temporal evolution are analyzed. The prominent features of these experiments are well accounted for by the microscopic many-body theory.}}, author = {{Meier, Torsten and Sieh, C. and Koch, S.W. and Lee, Y.-S and Norris, T.B. and Jahnke, F. and Khitrova, G. and Gibbs , H.M.}}, booktitle = {{Optical Microcavities}}, editor = {{Vahala, K.}}, pages = {{239--317}}, publisher = {{World Scientific, Chap. 6}}, title = {{{Nonlinear optical properties of semiconductor quantum wells inside microcavities}}}, doi = {{10.1142/9789812565730_0006}}, year = {{2004}}, } @inproceedings{44122, abstract = {{We demonstrate that interference of optical excitations of regularly arranged metallic nanodots on a waveguide shows spectral signatures of Fano resonances. The reason is coupling of localized particle plasmons and waveguide modes with different electronic continua.}}, author = {{Meier, Torsten and Giessen, H. and Linden, S. and Christ, A. and Kuhl, J. and Nau, D. and Thomas, P. and Koch, S.W.}}, booktitle = {{Fano resonances in metallic photonic crystals}}, isbn = {{1-55752-770-9}}, location = {{San Francisco, California United States}}, publisher = {{Optical Society of America}}, title = {{{Fano resonances in metallic photonic crystals}}}, doi = {{10.1364/IQEC.2004.IFC5}}, year = {{2004}}, } @inproceedings{44123, abstract = {{An excitonic blue-shift is observed when a GaAs/AlGaAs superlattice is irradiated with a strong THz field. This observation is compared with a microscopic calculation, and is consistent with the onset of dynamical localization.}}, author = {{Meier, Torsten and Koch, M. and Ciulin, V. and Carter, S.G. and Sherwin, M.S. and Koch, S.W. and Zide, J. and Driscoll, D. and Gossard, A.C.}}, booktitle = {{International Quantum Electronics Conference}}, isbn = {{1-55752-770-9}}, location = {{San Francisco, California United States}}, title = {{{Onset of Dynamical Localization in a Semiconductor Superlattice}}}, doi = {{10.1364/IQEC.2004.IMO3}}, year = {{2004}}, } @article{23512, abstract = {{The optically induced electron dynamics at a Si(001) surface is studied using a five-wave-mixing setup which measures the diffracted second-harmonic intensity induced by three ultrashort (13 fs) laser pulses. Depending on the time ordering of the pulses, this technique is capable of monitoring the temporal evolution of photoexcited one- or two-photon coherences, or populations. For a particular pulse sequence, the experiments show a delayed rise and a decay of the diffracted signal intensity on time scales of 50 and 250 fs, respectively. This response can be described by optical Bloch equations by including rapid scattering of the photoexcited carriers in the D(down)band of Si(001).}}, author = {{Voelkmann, C. and Reichelt, Matthias and Meier, Torsten and Koch, S. W. and Höfer, U.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, number = {{12}}, title = {{{Five-Wave-Mixing Spectroscopy of Ultrafast Electron Dynamics at a Si(001) Surface}}}, doi = {{10.1103/physrevlett.92.127405}}, volume = {{92}}, year = {{2004}}, } @article{23514, abstract = {{A theory is presented which couples a dynamical laser model to a fully microscopic calculation of scattering effects. Calculations for two optically pumped GaInNAs laser structures show how this approach can be used to analyze nonequilibrium and dynamical laser properties over a wide range of system parameters.}}, author = {{Thränhardt, A. and Becker, S. and Schlichenmaier, C. and Kuznetsova, I. and Meier, Torsten and Koch, S. W. and Hader, J. and Moloney, J. V. and Chow, W. W.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{23}}, pages = {{5526--5528}}, title = {{{Nonequilibrium gain in optically pumped GaInNAs laser structures}}}, doi = {{10.1063/1.1831570}}, volume = {{85}}, year = {{2004}}, }