@article{4237, abstract = {{We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO2 layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the þz side.}}, author = {{Mackwitz, P. and Rüsing, Michael and Berth, Gerhard and Widhalm, A. and Müller, K. and Zrenner, Artur}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{15}}, publisher = {{AIP Publishing}}, title = {{{Periodic domain inversion in x-cut single-crystal lithium niobate thin film}}}, doi = {{10.1063/1.4946010}}, volume = {{108}}, year = {{2016}}, } @article{4240, abstract = {{Cubic gallium nitride (GaN) films are analyzed with highresolution X-ray diffraction (HRXRD) and Raman spectroscopy. Several cubic GaN layers were grown on 3C-SiC (001) substrate by radio-frequency plasma-assisted molecular beam epitaxy. The layer thickness of the cubic GaN was varied between 75 and 505 nm. The HRXRD analysis reveals a reduction of the full-width at half-maximum (FWHM) of omega scans for growing layer thicknesses, which is caused by a partial compensation of defects. The Raman characterization confirms well-formed c-GaN layers. A more detailed examination of the longitudinal optical mode hints at a correlation of the FWHM of the Raman mode with the dislocation density, which shows the possibility to determine dislocation densities by Ramanspectroscopy on a micrometer scale, which is not possible by HRXRD. Furthermore, this Raman analysis shows that normalized Raman spectra present an alternative way to determine layer thicknesses of thin GaN films.}}, author = {{Rüsing, Michael and Wecker, T. and Berth, Gerhard and As, Donat Josef and Zrenner, Artur}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, keywords = {{cubic gallium nitride, dislocation density, HRXRD, Raman spectroscopy}}, number = {{4}}, pages = {{778--782}}, publisher = {{Wiley}}, title = {{{Joint Raman spectroscopy and HRXRD investigation of cubic gallium nitride layers grown on 3C-SiC}}}, doi = {{10.1002/pssb.201552592}}, volume = {{253}}, year = {{2016}}, } @article{10026, abstract = {{Congruent lithium niobate and lithium tantalate mixed crystals have been grown over the complete compositional range with the Czochralski method. The structural and vibrational properties of the mixed crystals are studied extensively by x-ray diffraction measurements, Raman spectroscopy, and density functional theory. The measured lattice parameters and vibrational frequencies are in good agreement with our theoretical predictions. The observed dependence of the Raman frequencies on the crystal composition is discussed on the basis of the calculated phonon displacement patterns. The phononic contribution to the static dielectric tensor is calculated by means of the generalized Lyddane-Sachs-Teller relation. Due to the pronounced dependence of the optical response on the Ta concentration, lithium niobate tantalate mixed crystals represent a perfect model system to study the properties of uniaxial mixed ferroelectric materials for application in integrated optics.}}, author = {{Rüsing, Michael and Sanna, Simone and Neufeld, Sergej and Berth, Gerhard and Schmidt, Wolf Gero and Zrenner, Artur and Yu, H. and Wang, Y. and Zhang, H.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, title = {{{Vibrational properties of LiNb1−xTaxO3 mixed crystals}}}, doi = {{10.1103/physrevb.93.184305}}, year = {{2016}}, } @article{13920, abstract = {{We investigate the transient optical response in high-quality Cd0.88Zn0.12Te crystals in the regime of slow light propagation on the lower exciton-polariton branch. Femtosecond photoexcitation leads to very substantial transmission changes in a ∼10-meV broad spectral range within the transparency window of the unexcited semiconductor. These nonlinear optical signatures decay on picosecond time scales governed by carrier thermalization and recombination. The temporal and spectral dependence indicate the dynamical optical response as arising from excitation-induced dephasing and perturbed free induction decay. Model simulations for the optical response taking into account the actual exciton-polariton dispersion and excitation-induced dephasing of a nonlinearly driven two-level system support this interpretation.}}, author = {{Lohrenz, J. and Melzer, S. and Ruppert, C. and Akimov, I. A. and Mariette, H. and Reichelt, Matthias and Trautmann, Alexander and Meier, Torsten and Betz, M.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{7}}, title = {{{Ultrafast dynamical response of the lower exciton-polariton branch in CdZnTe}}}, doi = {{10.1103/physrevb.93.075201}}, volume = {{93}}, year = {{2016}}, } @article{10024, abstract = {{The influence of electronic many-body interactions, spin-orbit coupling, and thermal lattice vibrations on the electronic structure of lithium niobate is calculated from first principles. Self-energy calculations in the GW approximation show that the inclusion of self-consistency in the Green function G and the screened Coulomb potential W opens the band gap far stronger than found in previous G0W0 calculations but slightly overestimates its actual value due to the neglect of excitonic effects in W. A realistic frozen-lattice band gap of about 5.9 eV is obtained by combining hybrid density functional theory with the QSGW0 scheme. The renormalization of the band gap due to electron-phonon coupling, derived here using molecular dynamics as well as density functional perturbation theory, reduces this value by about 0.5 eV at room temperature. Spin-orbit coupling does not noticeably modify the fundamental gap but gives rise to a Rashba-like spin texture in the conduction band.}}, author = {{Riefer, Arthur and Friedrich, Michael and Sanna, Simone and Gerstmann, Uwe and Schindlmayr, Arno and Schmidt, Wolf Gero}}, issn = {{2469-9969}}, journal = {{Physical Review B}}, number = {{7}}, publisher = {{American Physical Society}}, title = {{{LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects}}}, doi = {{10.1103/PhysRevB.93.075205}}, volume = {{93}}, year = {{2016}}, } @article{10025, abstract = {{The phonon dispersions of the ferro‐ and paraelectric phase of LiTaO3 are calculated within density‐functional perturbation theory. The longitudinal optical phonon modes are theoretically derived and compared with available experimental data. Our results confirm the recent phonon assignment proposed by Margueron et al. [J. Appl. Phys. 111, 104105 (2012)] on the basis of spectroscopical studies. A comparison with the phonon band structure of the related material LiNbO3 shows minor differences that can be traced to the atomic‐mass difference between Ta and Nb. The presence of phonons with imaginary frequencies for the paraelectric phase suggests that it does not correspond to a minimum energy structure, and is compatible with an order‐disorder type phase transition.}}, author = {{Friedrich, Michael and Schindlmayr, Arno and Schmidt, Wolf Gero and Sanna, Simone}}, issn = {{1521-3951}}, journal = {{Physica Status Solidi B}}, number = {{4}}, pages = {{683--689}}, publisher = {{Wiley-VCH}}, title = {{{LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles}}}, doi = {{10.1002/pssb.201552576}}, volume = {{253}}, year = {{2016}}, } @article{13910, author = {{Ma, Xuekai and Driben, Rodislav and Malomed, Boris A. and Meier, Torsten and Schumacher, Stefan}}, issn = {{2045-2322}}, journal = {{Scientific Reports}}, title = {{{Two-dimensional symbiotic solitons and vortices in binary condensates with attractive cross-species interaction}}}, doi = {{10.1038/srep34847}}, volume = {{6}}, year = {{2016}}, } @article{4185, abstract = {{Semiconductor quantum-dot cavity systems are promising sources for solid-state-based on-demand generation of single photons for quantum communication. Commonly, the spectral characteristics of the emitted single photon are fixed by system properties such as electronic transition energies and spectral properties of the cavity. In the present work we study cavity-enhanced single-photon generation from the quantum-dot biexciton through a partly stimulated nondegenerate two-photon emission. We show that frequency and linewidth of the single photon can be fully controlled by the stimulating laser pulse, ultimately allowing for efficient all-optical spectral shaping of the single photon.}}, author = {{Breddermann, D. and Heinze, D. and Binder, R. and Zrenner, Artur and Schumacher, Stefan}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{16}}, publisher = {{American Physical Society (APS)}}, title = {{{All-optical tailoring of single-photon spectra in a quantum-dot microcavity system}}}, doi = {{10.1103/physrevb.94.165310}}, volume = {{94}}, year = {{2016}}, } @article{13919, author = {{Sternemann, E. and Jostmeier, T. and Ruppert, C. and Thunich, S. and Duc, H. T. and Podzimski, R. and Meier, Torsten and Betz, M.}}, issn = {{0946-2171}}, journal = {{Applied Physics B}}, title = {{{Quantum interference control of electrical currents in GaAs microstructures: physics and spectroscopic applications}}}, doi = {{10.1007/s00340-015-6310-y}}, volume = {{122}}, year = {{2016}}, } @article{1454, author = {{Grynko, Yevgen and Zentgraf, Thomas and Meier, Torsten and Förstner, Jens}}, issn = {{0946-2171}}, journal = {{Applied Physics B}}, keywords = {{tet_topic_meta, tet_topic_shg}}, number = {{9}}, pages = {{242}}, publisher = {{Springer Nature}}, title = {{{Simulations of high harmonic generation from plasmonic nanoparticles in the terahertz region}}}, doi = {{10.1007/s00340-016-6510-0}}, volume = {{122}}, year = {{2016}}, } @article{1456, author = {{Ye, Weimin and Zeuner, Franziska and Li, Xin and Reineke, Bernhard and He, Shan and Qiu, Cheng-Wei and Liu, Juan and Wang, Yongtian and Zhang, Shuang and Zentgraf, Thomas}}, issn = {{2041-1723}}, journal = {{Nature Communications}}, publisher = {{Springer Nature}}, title = {{{Spin and wavelength multiplexed nonlinear metasurface holography}}}, doi = {{10.1038/ncomms11930}}, volume = {{7}}, year = {{2016}}, } @article{1459, author = {{Chen, Shumei and Zeuner, Franziska and Weismann, Martin and Reineke, Bernhard and Li, Guixin and Valev, Ventsislav Kolev and Cheah, Kok Wai and Panoiu, Nicolae Coriolan and Zentgraf, Thomas and Zhang, Shuang}}, issn = {{0935-9648}}, journal = {{Advanced Materials}}, number = {{15}}, pages = {{2992--2999}}, publisher = {{Wiley-Blackwell}}, title = {{{Giant Nonlinear Optical Activity of Achiral Origin in Planar Metasurfaces with Quadratic and Cubic Nonlinearities}}}, doi = {{10.1002/adma.201505640}}, volume = {{28}}, year = {{2016}}, } @article{1457, author = {{Li, Guixin and Zentgraf, Thomas and Zhang, Shuang}}, issn = {{1745-2473}}, journal = {{Nature Physics}}, number = {{8}}, pages = {{736--740}}, publisher = {{Springer Nature}}, title = {{{Rotational Doppler effect in nonlinear optics}}}, doi = {{10.1038/nphys3699}}, volume = {{12}}, year = {{2016}}, } @article{1458, author = {{Probst, Heike and Zentgraf, Thomas}}, issn = {{0031-9252}}, journal = {{Physik in unserer Zeit}}, number = {{2}}, pages = {{84--89}}, publisher = {{Wiley-Blackwell}}, title = {{{Designermaterialien für nichtlineare Optik}}}, doi = {{10.1002/piuz.201601427}}, volume = {{47}}, year = {{2016}}, } @article{4331, abstract = {{We report about the fabrication and analysis of high Q photonic crystal cavities with metallic Schottky-contacts. The structures are based on GaAs n-i membranes with an InGaAs quantum well in the i-region and nanostructured low ohmic metal top-gates. They are designed for photocurrent readout within the cavity and fast electric manipulations. The cavity structures are characterized by photoluminescence and photocurrent spectroscopy under resonant excitation. We find strong cavity resonances in the photocurrent spectra and surprisingly high Q-factors up to 6500. Temperature dependent photocurrent measurements in the region between 4.5K and 310K show an exponential enhancement of the photocurrent signal and an external quantum efficiency up to 0.26.}}, author = {{Quiring, W. and Al-Hmoud, M. and Rai, A. and Reuter, Dirk and Wieck, A. D. and Zrenner, Artur}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{4}}, publisher = {{AIP Publishing}}, title = {{{Photonic crystal cavities with metallic Schottky contacts}}}, doi = {{10.1063/1.4928038}}, volume = {{107}}, year = {{2015}}, } @article{6520, abstract = {{We investigate the response of a polariton laser driven slightly off-resonantly using light fields differing from the routinely studied coherent pump sources. The response to driving light fields with thermal and displaced thermal statistics with varying correlation times shows significant differences in the transmitted intensity, its noise, and the position of the nonlinear threshold. We predict that adding more photons on average may actually reduce the transmission through the polariton system.}}, author = {{Assmann, Marc and Bayer, Manfred}}, issn = {{1050-2947}}, journal = {{PHYSICAL REVIEW A}}, number = {{5}}, title = {{{Stochastic pumping of a polariton fluid}}}, doi = {{10.1103/PhysRevA.91.053835}}, volume = {{91}}, year = {{2015}}, } @article{6522, abstract = {{An electric field applied to a semiconductor reduces its crystal symmetry and modifies its electronic structure which is expected to result in changes of the linear and nonlinear response to optical excitation. In GaAs, we observe experimentally strong electric field effects on the optical second (SHG) and third (THG) harmonic generation. The SHG signal for the laser-light k vector parallel to the [001] crystal axis is symmetry forbidden in the electric-dipole approximation, but can be induced by an applied electric field in the vicinity of the 1s exciton energy. Surprisingly, the THG signal, which is allowed in this geometry, is considerably reduced by the electric field. We develop a theory which provides good agreement with the experimental data. In particular, it shows that the optical nonlinearities for the 1s exciton resonance are modified in an electric field by the Stark effect, which mixes the 1s and 2p exciton states of opposite parity. This mixing acts in opposite way on the SHG and THG processes, as it leads to the appearance of forbidden SHG in (001)-oriented GaAs and decreases the crystallographic THG.}}, author = {{Brunne, D. and Lafrentz, M. and Pavlov, V. V. and Pisarev, R. V. and Rodina, A. V. and Yakovlev, D. R. and Bayer, M.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{8}}, publisher = {{American Physical Society (APS)}}, title = {{{Electric field effect on optical harmonic generation at the exciton resonances in GaAs}}}, doi = {{10.1103/physrevb.92.085202}}, volume = {{92}}, year = {{2015}}, } @article{6524, abstract = {{We use a picosecond acoustics technique to modulate the laser output of electrically pumped GaAs/AlAs micropillar lasers with InGaAs quantum dots. The modulation of the emission wavelength takes place on the frequencies of the nanomechanical extensional and breathing (radial) modes of the micropillars. The amplitude of the modulation for various nanomechanical modes is different for every micropillar which is explained by a various elastic contact between the micropillar walls and polymer environment.}}, author = {{Czerniuk, T. and Tepper, J. and Akimov, A. V. and Unsleber, S. and Schneider, C. and Kamp, M. and Höfling, S. and Yakovlev, D. R. and Bayer, M.}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{4}}, publisher = {{AIP Publishing}}, title = {{{Impact of nanomechanical resonances on lasing from electrically pumped quantum dot micropillars}}}, doi = {{10.1063/1.4906611}}, volume = {{106}}, year = {{2015}}, } @article{6526, abstract = {{We introduce photon-statistics excitation spectroscopy and exemplarily apply it to a quantum-dot micropillar laser. Both the intensity and the photon number statistics of the emission from the micropillar show a strong dependence on the photon statistics of the light used for excitation of the sample. The results under coherent and pseudothermal excitation reveal that a description of the laser properties in terms of mean input photon numbers is not sufficient. It is demonstrated that the micropillar acts as a superthermal light source when operated close to its threshold. Possible applications for important spectroscopic techniques are discussed.}}, author = {{Kazimierczuk, T. and Schmutzler, J. and Aßmann, M. and Schneider, C. and Kamp, M. and Höfling, S. and Bayer, M.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, number = {{2}}, publisher = {{American Physical Society (APS)}}, title = {{{Photon-Statistics Excitation Spectroscopy of a Quantum-Dot Micropillar Laser}}}, doi = {{10.1103/physrevlett.115.027401}}, volume = {{115}}, year = {{2015}}, } @inproceedings{6529, author = {{Yakovlev, D. R. and Warkentin, W. and Brunne, D. and Mund, J. and Pavlov, V. V. and Rodina, A. V. and Pisarev, R. V. and Bayer, M.}}, booktitle = {{Nonlinear Optics and Applications IX}}, editor = {{Bertolotti, Mario and Haus, Joseph W. and Zheltikov, Alexei M.}}, location = {{Prague, Czech Rep}}, publisher = {{SPIE}}, title = {{{Novel mechanisms of optical harmonic generation on excitons in semiconductors}}}, doi = {{10.1117/12.2185309}}, year = {{2015}}, }