@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}}, } @article{25995, abstract = {{The early stages of ZnS nanoparticle growth from supersaturated solution are investigated in situ by stopped-flow UV absorption spectroscopy with a time resolution of 1.28 ms. A model for data analysis is suggested which makes it possible to study both the average particle radius and the concentration. The average radii lie in the sub-nanometer range. During the first 40 ms, growth is predominantly governed by ripening.}}, author = {{Tiemann, Michael and Weiß, Özlem and Hartikainen, Juha and Marlow, Frank and Lindén, Mika}}, issn = {{1439-4235}}, journal = {{ChemPhysChem}}, pages = {{2113--2119}}, title = {{{Early Stages of ZnS Nanoparticle Growth Studied by In-Situ Stopped-Flow UV Absorption Spectroscopy}}}, doi = {{10.1002/cphc.200500163}}, year = {{2005}}, } @article{25994, abstract = {{Periodically ordered mesoporous magnesium oxides were synthesized by utilization of mesoporous CMK-3 carbon as exotemplate. The products exhibit high thermal stability and basic properties, which makes them promising for application in heterogeneous basic catalysis.}}, author = {{Roggenbuck, Jan and Tiemann, Michael}}, issn = {{0002-7863}}, journal = {{Journal of the American Chemical Society}}, pages = {{1096--1097}}, title = {{{Ordered Mesoporous Magnesium Oxide with High Thermal Stability Synthesized by Exotemplating Using CMK-3 Carbon}}}, doi = {{10.1021/ja043605u}}, 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}}, } @inbook{56461, author = {{Thiel, Ansgar and Teubert, Hilke and Cachay, Klaus}}, booktitle = {{Fußball in Geschichte und Gesellschaft}}, editor = {{Krüger, Michael and Schulze, Bernd}}, pages = {{195--210}}, publisher = {{Czwalina}}, title = {{{Verbundsysteme in der Nachwuchsförderung – Effiziente Kopplung von Spitzensport und Schule als Abstimmungs- und Akzeptanzprobleme}}}, year = {{2005}}, } @article{56462, author = {{Teubert, Hilke and Borggrefe, Carmen and Cachay, Klaus and Thiel, Ansgar}}, journal = {{Sportunterricht}}, pages = {{292--296}}, title = {{{Spitzensport und Schule – Möglichkeiten der strukturellen Kopplung}}}, volume = {{54}}, year = {{2005}}, } @article{56463, author = {{Borggrefe, Carmen and Teubert, Hilke and Cachay, Klaus and Thiel, Ansgar}}, journal = {{Sportunterricht}}, pages = {{297--302}}, title = {{{Spitzensport als Schulprofil?}}}, volume = {{54}}, year = {{2005}}, } @inbook{56465, author = {{Teubert, Hilke and Thiel, Ansgar and Kleindienst-Cachay, Christa}}, booktitle = {{Qualität im Schulsport}}, editor = {{Gogoll, André and Menze-Sonneck, Andrea}}, pages = {{148--153}}, publisher = {{Czwalina}}, title = {{{Die „Bewegte Schule“ auf dem Prüfstand – Qualitätsmerkmale einer grundschulpädagogischen Innovation.}}}, year = {{2005}}, } @article{56460, author = {{Thiel, Ansgar and Teubert, Hilke and Cachay, Klaus}}, journal = {{European Journal for Sport and Society}}, number = {{2}}, pages = {{121--138}}, title = {{{Linking Top Sports and Schools to Foster the Next Generation of Athletes in Competitive Sports – Considerations on the Example of the Integrated Systems}}}, volume = {{2}}, year = {{2005}}, } @inbook{56473, author = {{Teubert, Hilke and Thiel, Ansgar and Halle, Arne and Cachay, Klaus}}, booktitle = {{Spitzensport im Jahr der olympischen Sommerspiele 2004 – Strukturen und Wissen}}, editor = {{Mester, J and Knuth, S}}, pages = {{120--153}}, publisher = {{Meyer & Meyer}}, title = {{{Abstimmung und Akzeptanz der Verbindung von Schule und Leistungssport – Zu den Basisvoraussetzungen effizienter Verbundsysteme}}}, year = {{2005}}, }