@article{4264, abstract = {{We demonstrate that the temporal pulse phase remains essentially unaltered before separate phase characteristics are developed when propagating high-intensity pulses coherently on the exciton resonance of an optically thick semiconductor. This behavior is a clear manifestation of self-induced transmission and pulse breakup into solitonlike pulses due to Rabi flopping of the carrier density. Experiments using a novel fast-scan cross-correlation frequency-resolved optical gating (XFROG) method are in good agreement with numerical calculations based on the semiconductor Bloch equations.}}, author = {{Nielsen, N. C. and zu Siederdissen, T. Höner and Kuhl, J. and Schaarschmidt, M. and Förstner, Jens and Knorr, A. and Giessen, H.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, keywords = {{tet_topic_qd}}, number = {{5}}, publisher = {{American Physical Society (APS)}}, title = {{{Phase Evolution of Solitonlike Optical Pulses during Excitonic Rabi Flopping in a Semiconductor}}}, doi = {{10.1103/physrevlett.94.057406}}, volume = {{94}}, year = {{2005}}, } @article{4270, abstract = {{The adiabatic driving of the resonant electron dynamics in a one-dimensional resonant photonic band gap is proposed as an optical mechanism for nonlinear ultrafast switching. Pulsed excitation inside the photonic gap results in an ultrafast suppression and recovery of the gap. This behavior results from the adiabatic carrier dynamics due to rapid radiative damping inside the band gap.}}, author = {{Schaarschmidt, Martin and Förstner, Jens and Knorr, Andreas and Prineas, John P. and Nielsen, Nils C. and Kuhl, Jürgen and Khitrova, Galina and Gibbs, Hyatt M. and Giessen, Harald and Koch, Stephan W.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, keywords = {{tet_topic_qw}}, number = {{23}}, publisher = {{American Physical Society (APS)}}, title = {{{Adiabatically driven electron dynamics in a resonant photonic band gap: Optical switching of a Bragg periodic semiconductor}}}, doi = {{10.1103/physrevb.70.233302}}, volume = {{70}}, year = {{2004}}, } @article{4274, abstract = {{We present a theory of the optical line shape of coherent intersubband transitions in a semiconductor quantum well, considering non-Markovian LO-phonon scattering as major broadening mechanism. We show that a quantum kinetic approach leads to additional polaron resonances and a resonance enhancement for gap energies close to the phonon energy.}}, author = {{Butscher, S. and Förstner, Jens and Waldmüller, I. and Knorr, A.}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, keywords = {{tet_topic_qw}}, number = {{11}}, pages = {{R49--R51}}, publisher = {{Wiley}}, title = {{{Polaron signatures in the line shape of semiconductor ;intersubband transitions: quantum kinetics of the electron–phonon interaction}}}, doi = {{10.1002/pssb.200409053}}, volume = {{241}}, year = {{2004}}, } @article{4277, abstract = {{We investigate the temporal and spectral properties of subpicosecond pulses transmitted on the heavy-hole exciton transition through a multiple-quantum-well Bragg structure, exhibiting a one-dimensional photonic band gap. At low light intensities, a temporal propagation beating is observed. This beating is strongly dependent on the optical dephasing time T2 which is dominated by the radiative interwell coupling. In an intermediate intensity regime, the Pauli-blocking nonlinearity leads to gradual suppression of the photonic band gap and vanishing of the linear propagation beating. For highly nonlinear excitation, we find signatures of selfinduced transmission due to Rabi flopping and adiabatic following of the carrier density. Numerical simulations using the semiconductor Maxwell-Bloch equations are in excellent agreement with the experimental data up to intensities for which higher many-particle correlations become more important and self-phase modulation occurs in the sample substrate.}}, author = {{Nielsen, N. C. and Kuhl, J. and Schaarschmidt, M. and Förstner, Jens and Knorr, A. and Koch, S. W. and Khitrova, G. and Gibbs, H. M. and Giessen, H.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, keywords = {{tet_topic_qw}}, number = {{7}}, publisher = {{American Physical Society (APS)}}, title = {{{Linear and nonlinear pulse propagation in a multiple-quantum-well photonic crystal}}}, doi = {{10.1103/physrevb.70.075306}}, volume = {{70}}, year = {{2004}}, } @inproceedings{4280, abstract = {{Theoretically and experimentally, we investigate temporal phase evolution during Rabi-flopping on the A-exciton resonance in CdSe using a novel fast-scanning XFROG method and observe phase changes smaller than π/2 compared to the slightly-chirped input pulse.}}, author = {{Höner zu Siederdissen, Tilman and Nielsen, Nils Christian. and Kuhl, Jürgen and Förstner, Jens and Knorr, Andreas and Giessen, Harald}}, booktitle = {{International Quantum Electronics Conference and Photonic Applications Systems Technologies}}, isbn = {{1-55752-770-9}}, keywords = {{tet_topic_qd}}, location = {{San Francisco, California (USA)}}, publisher = {{OSA}}, title = {{{Temporal phase evolution during excitonic Rabi flopping in semiconductors}}}, doi = {{10.1364/iqec.2004.imb3}}, year = {{2004}}, } @inproceedings{4282, abstract = {{We investigate theoretically the ultrafast nonlinear suppression of the resonant photonic band gap by strong laser pulses in semiconductor multiple qnantum wells. We achieve good agreement with our measurements on reflection samples.}}, author = {{Schaarschmidt, Martin and Förstner, Jens and Knorr, Andreas and Prineas, John P. and Nielsen, Nils C. and Kuhl, Jürgen and Kithrova, Galina and Gibbs, Hyatt M. and Giessen, Harald and Koch, Stephan W.}}, booktitle = {{Conference on Lasers and Electro-Optics/International Quantum Electronics Conference and Photonic Applications Systems Technologies}}, isbn = {{1-55752-778-4 }}, keywords = {{tet_topic_qw}}, location = {{San Francisco, California (USA) }}, publisher = {{OSA}}, title = {{{Nonlinear light pulse propagation in Bragg-periodic multiple semiconductor quantum well samples: ultrafast switching of a resonant photonic band gap}}}, doi = {{10.1364/iqec.2004.iwa3}}, year = {{2004}}, } @inbook{4286, abstract = {{Due to their many-particle character and their application in quantum cascade lasers, optical intersubband excitations in semiconductor quantum wells have become the focus of many recent publications [1,2]. In samples of high quality, intrinsic processes like electron-electron and electron-phonon many particle correlations determine the basic optical and transport properties such as lineshape and ultrafast dynamics. At the same time, intersubband excitations allow the direct investigation of dynamical properties of an important model system of many particle physics - the two-dimensional electron gas. We here present a microscopic theory for the intersubband dynamics and absorption. The calculation of absorption spectra of MQW systems is in principle composed of two parts: the determination of the polarization in a single quantum well within a density matrix approach as the source of electromagnetic radiation (Fig. 1a) and the calculation of the generated fields in the geometry of interest (Fig. 1b) within a Green's function approach [3,4]. We will here focus on the so-called single-pass geometry (cf. Fig. 1b, [5]).}}, author = {{Waldmüller, Ines and Förstner, Jens and Knorr, Andreas }}, booktitle = {{Nonequilibrium Physics at Short Time Scales}}, editor = {{Morawetz, Klaus}}, isbn = {{9783642057458}}, keywords = {{tet_topic_qw}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Self-consistent Projection Operator Theory of Intersubband Absorbance in Semiconductor Quantum Wells}}}, doi = {{10.1007/978-3-662-08990-3}}, year = {{2004}}, } @phdthesis{4319, abstract = {{In dieser Arbeit wird eine Theorie vorgestellt, welche die quantenmechanische Vielteilchenphysik der Licht-Materie Wechselwirkung in Halbleiternanostrukturen beschreibt. Diese mikroskopische Beschreibung wird durch Kombination eines allgemeinen Dichtematrixansatzes mit speziellen Methoden zur Auswertung der Maxwellgleichungen wie der zeitaufgelösten Finite-Differenzen-Methode (FDTD) erreicht. Die Theorie wird auf verschiedene physikalische Situationen angewendet, wie z.B. Lichtausbreitung in Volumenhalbleitern, Interband- und Intersubbandübergänge in Quantenfilmstrukturen und optische Anregung von Quantenpunkten. Der Fokus liegt dabei auf der Beschreibung der linearen und nichtlinearen Antwort des Vielteilchensystems und seiner Ankopplung an das elektromagnetische Feld. In diesem Zusammenhang wird sowohl die Erzeugung als auch der Zerfall von optischen Anregungen untersucht, indem verschiedene Kopplungsmechanismen wie Elektron-Phonon-, Elektron-Photon- und Elektron-Elektron-Wechselwirkung berücksichtigt werden. Im Bereich der linearen Optik, also für Anregung mit geringer Intensität, ermöglicht die Theorie die Berechnung von Absorptionsspektren. Verschiedene Effekte in linearer Optik werden in dieser Arbeit untersucht und beschrieben: Linienaufspaltung durch Polaritonen im Volumenmaterial, Zunahme der Linienbreite bei Intersubbandübergängen verursacht durch Elektron-Elektron- und Elektron- Phonon-Streuung in einzelnen Quantenfilmen, Bildung einer optischen Bandlücke durch starke radiative Kopplung in Vielfilmstrukturen in Bragg-Geometrie, Phononenseitenbänder verursacht durch quantenkinetische Effekte in einzelnen Quantenpunkten und schliesslich Superradianz und Interferenzeffekte in Quantenpunktgittern. Bei nichtlinearer Anregung treten Dichte-Rabiflops als fundamentale Prozesse in allen betrachteten Systemen auf und können als kohärente Be- und Entvölkerung von quantenmechanischen Zuständen beobachtet werden. Der Einfluss von starker Lichtkopplung und verschiedenen Wechselwirkungen auf dynamische Größen wie die Besetzung wird untersucht. Bei nichtlinearer Propagation, bei der sich ein starker Lichtpuls über längere Strecken in einem System bewegt, wird selbstinduzierte Verstärkung der Transmission näher betrachtet. Des weiteren werden von der Coulombwechselwirkung verursachte nichtlineare Effekte wie exzitoninduziertes Dephasieren in Volumenmaterial und verschränkte Zustände in Quantenpunkten untersucht, die einen Zusammenbruch der Hartree-Fock- Näherung darstellen. Zusammenfassend werden in dieser Arbeit verschiedene lineare und nichtlineare optische Effekte in Halbleiternanostrukturen verschiedener Dimensionalität mit Hilfe einer allgemeinen Theorie, die einen Dichtematrixansatz mit den Maxwellschen Gleichungen kombiniert, untersucht.}}, author = {{Förstner, Jens}}, keywords = {{tet_topic_qd, tet_topic_qw, tet_topic_phc}}, title = {{{Light Propagation and Many-Particle Effects in Semiconductor Nanostructures}}}, doi = {{10.14279/depositonce-999}}, year = {{2004}}, } @article{4288, abstract = {{We report the experimental observation and the theoretical modeling of self-induced-transparency signatures such as nonlinear transmission, pulse retardation and reshaping, for subpicosecond pulse propagation in a 2-mm-long InGaAs quantum-dot ridge waveguide in resonance with the excitonic ground-state transition at 10 K. The measurements were obtained by using a cross-correlation frequency-resolved optical gating technique which allows us to retrieve the field amplitude of the propagating pulses.}}, author = {{Schneider, S. and Borri, P. and Langbein, W. and Woggon, U. and Förstner, Jens and Knorr, A. and Sellin, R. L. and Ouyang, D. and Bimberg, D.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, keywords = {{tet_topic_qd}}, number = {{18}}, pages = {{3668--3670}}, publisher = {{AIP Publishing}}, title = {{{Self-induced transparency in InGaAs quantum-dot waveguides}}}, doi = {{10.1063/1.1624492}}, volume = {{83}}, year = {{2003}}, } @article{4290, abstract = {{The nonlinear propagation of subpicosecond pulses resonant to the hh 1s exciton in Bragg-periodic multiple quantum wells is investigated experimentally and theoretically. We show coherent pulse breakup and its suppression for increasing pulse intensity in good agreement with calculations based on the semiconductor Maxwell-Bloch equations. For highly nonlinear excitation, pulse compression is observed which is strongly enhanced by the additional contribution of self-phase modulation in the barrier and substrate material.}}, author = {{Nielsen, N. C. and Kuhl, J. and Schaarschmidt, M. and Förstner, Jens and Knorr, A. and Koch, S. W. and Gibbs, H. M. and Khitrova, G. and Giessen, H.}}, issn = {{1610-1634}}, journal = {{physica status solidi (c)}}, keywords = {{tet_topic_qw}}, number = {{5}}, pages = {{1484--1487}}, publisher = {{Wiley}}, title = {{{Pulse propagation in Bragg-resonant multiple quantum wells: from pulse breakup to compression}}}, doi = {{10.1002/pssc.200303207}}, year = {{2003}}, } @article{4292, abstract = {{We outline a theoretical description of the absorption linewidth of quantum well intersubband transitions by solving Maxwell’s equations for a non-local susceptibility including many particle effects. We show that the intersubband absorption results from a complex interplay between mean-field effects, dephasing contributions and light propagation effects, all being very sensitive to subband dispersion.}}, author = {{Waldmüller, Inès and Woerner, Michael and Förstner, Jens and Knorr, Andreas}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, keywords = {{tet_topic_qw}}, number = {{3}}, pages = {{474--477}}, publisher = {{Wiley}}, title = {{{Theory of the lineshape of quantum well intersubband transitions: optical dephasing and light propagation effects}}}, doi = {{10.1002/pssb.200303165}}, volume = {{238}}, year = {{2003}}, } @article{4294, abstract = {{The phonon-induced dephasing dynamics of semiconductor quantum dots during nonlinear optical excitation is studied using quantum kinetic equations. We find that despite the decoherence process Rabi oscillations occur even for relatively long pulse durations and that their signatures in pump-probe experiments only get suppressed for high input pulse areas.}}, author = {{Förstner, Jens and Weber, Carsten and Danckwerts, Juliane and Knorr, Andreas}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, keywords = {{tet_topic_qd}}, number = {{3}}, pages = {{419--422}}, publisher = {{Wiley}}, title = {{{Phonon-induced damping of Rabi oscillations in semiconductor quantum dots}}}, doi = {{10.1002/pssb.200303155}}, volume = {{238}}, year = {{2003}}, } @inproceedings{4296, abstract = {{A non-Markovian quantum kinetic theory of the coupled electron-phonon system in semiconductor quantum dots is used to analyze the nonlinear dipole decoherence and light propagation dynamics for arbitrary pulse strengths and lengths.}}, author = {{Förstner, Jens and Weber, C. and Danckwerts, J. and Knorr, A.}}, booktitle = {{Postconference Digest Quantum Electronics and Laser Science, 2003. QELS.}}, isbn = {{1557527490}}, keywords = {{tet_topic_qd}}, location = {{Baltimore, MD, USA, USA }}, publisher = {{IEEE}}, title = {{{Damping of electron density Rabi-oscillations and self-induced-transparency in semiconductor quantum dots}}}, doi = {{10.1109/qels.2003.238120}}, year = {{2003}}, } @inproceedings{4298, abstract = {{The linewidth of intersubband transitions resulting from simultaneous action of many-body contributions and radiative damping is analyzed. The processes are non-additive and a self-consistent treatment is necessary to explain recent experiments.}}, author = {{Waldmuller, I. and Förstner, Jens and Knorr, A. and Woerner, M. and Reimann, K. and Kaindl, R.A. and Hey, R. and Ploog, K.H.}}, booktitle = {{Postconference Digest Quantum Electronics and Laser Science, 2003. QELS.}}, isbn = {{1557527490}}, keywords = {{tet_topic_qw}}, location = {{ Baltimore, MD, (USA)}}, publisher = {{IEEE}}, title = {{{Correlated influence of carrier-carrier/carrier-phonon interaction and radiative damping on semiconductor intersubband transitions}}}, doi = {{10.1109/qels.2003.238217}}, year = {{2003}}, } @article{4322, abstract = {{We present the experimental observation and the theoretical modelling of self-induced transparency signatures such as nonlinear transmission, pulse retardation and reshaping for subpicosecond pulse propagation in a 2 mm-long InGaAs quantum-dot ridge waveguide at 10 K. The measurements were obtained using a cross-correlation frequency resolved optical gating technique which allows us to retrieve the field amplitude of the propagating pulses.}}, author = {{Schneider, S. and Borri, P. and Langbein, W. and Woggon, U. and Förstner, Jens and Knorr, A. and Sellin, R. L. and Ouyang, D. and Bimberg, D.}}, issn = {{1610-1634}}, journal = {{physica status solidi (c)}}, keywords = {{tet_topic_qd}}, number = {{5}}, pages = {{1548--1551}}, publisher = {{Wiley}}, title = {{{Self-induced transparency in InGaAs quantum dot waveguides}}}, doi = {{10.1002/pssc.200303228}}, year = {{2003}}, } @article{671, author = {{Förstner, Jens and Weber, C. and Danckwerts, J. and Knorr, A.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, keywords = {{tet_topic_qd}}, number = {{12}}, pages = {{127401}}, publisher = {{American Physical Society (APS)}}, title = {{{Phonon-Assisted Damping of Rabi Oscillations in Semiconductor Quantum Dots}}}, doi = {{10.1103/physrevlett.91.127401}}, volume = {{91}}, year = {{2003}}, } @inproceedings{4305, abstract = {{On the basis of a density matrix approach including electron-electron scattering, a detailed analysis of the temporal dynamics and the dephasing process after optical excitation in intersubband emitters is presented for a wide range of parameters. }}, author = {{Waldmüller, Ines and Förstner, Jens and Knorr, Andreas}}, booktitle = {{Nonlinear Optics: Materials, Fundamentals and Applications}}, isbn = {{1557527210}}, keywords = {{tet_topic_qw}}, publisher = {{OSA}}, title = {{{Theory of ultrafast dynamics and lineshape of semiconductor quantum well intersubband emitters}}}, doi = {{10.1364/nlo.2002.we34}}, year = {{2002}}, }