F Henneberger

Publications (92)230.85 Total impact

• Article: Noninvasive optical control of complex semiconductor laser dynamics

  T. Dahms, V. Flunkert, F. Henneberger, P. Hövel, S. Schikora, E. Schöll, H.-J. Wünsche
  [show abstract] [hide abstract]
  ABSTRACT: Time-delayed feedback control (TDFC) is transferred to the optical domain and applied to complex multisection semiconductor lasers as used in optical communication. Pyragas-type control is provided by purely optical feedback from an external Fabry-Pérot interferometer. This all-optical setup needs no time-consuming signal processing and, thus, has practically no speed limit. Proof-of-principle experiments demonstrate noninvasive stabilization of unstable steady states, chaos control, and suppression of noise-induced oscillations on picosecond time scales. A Lang-Kobayashi type model with optical TDFC is investigated taking into account the dynamic details of the device as well as all-optical time-delayed feedback. The parameter regimes that allow for stabilization of stationary emission are mapped out in good agreement with the experiments. Including noise, an analytical expression for the power spectral density is derived, which is confirmed by the experimental all-optical suppression of noise-induced relaxation oscillations.
  The European Physical Journal Special Topics 04/2012; 191(1):71-89. · 1.56 Impact Factor
• Chapter: Diluted Magnetic Quantum Dots

  F. Henneberger, J. Puls
  [show abstract] [hide abstract]
  ABSTRACT: Epitaxial quantum dots either made of DMS or placed in an environment made of DMS are subjects of this chapter. Emphasis is put on (Cd,Mn)Se- and (Cd,Mn)Te-based heterostructures. The growth by self-assembly is discussed. Dynamic aspects of the interaction between carriers and magnetic ions are reviewed and a close analogy between DMS quantum dots and bound magnetic polarons is pointed out. Single dot spectroscopy and, in particular, spectroscopy of a single dot containing a single magnetic ion is described and discussed.
  11/2011: pages 161-190;
• Source

  Available from: photonik.physik.hu-berlin.de

  Article: Strong exciton-photon coupling in a monolithic ZnO/(Zn,Mg)O multiple quantum well microcavity

  S. Halm, S. Kalusniak, S. Sadofev, H.-J. Wünsche, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We report on strong exciton-photon coupling in an epitaxially grown (Zn,Mg)O-based λ-microcavity (MC) containing four 3.5 nm wide ZnO quantum wells (QWs) as active layers. At 5 K, the observed Rabi splitting in absorption is 26 meV, while the inhomogeneous linewidth of A and B excitons in similar QWs without a MC is about 10 meV. The strong coupling regime (SCR) is lost between 150 K and 200 K due to additional homogeneous broadening. From transfer matrix calculations, we deduce that increasing the number of QWs per cavity length can extend the SCR up to room temperature.
  Applied Physics Letters 11/2011; 99(18):181121-181121-3. · 3.84 Impact Factor
• Source

  Available from: ArXiv

  Article: Electrostatic-field-driven alignment of organic oligomers on ZnO surfaces.

  F Della Sala, S Blumstengel, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We study the physisorption of organic oligomers on the strongly ionic ZnO(1010) surface by using first-principles density-functional theory and nonempirical embedding methods. It turns out that the in-plane variation of the molecule-substrate interaction energy and the bonding dipole in the vertical direction are linked up by a linear relationship originating from the electrostatic coupling of the molecule with the periodic dipolar electric field generated by the Zn-O surface dimers. Long oligomers with a highly axial π-electron system such as sexiphenyl become well oriented with alignment energies of several 100 meV along rows of a positive electric field, in full agreement with recent experiments. These findings define a new route towards the realization of highly ordered self-assembled arrays of oligomers or polymers on ZnO(1010) and similar surfaces.
  Physical Review Letters 09/2011; 107(14):146401. · 7.37 Impact Factor
• Source

  Available from: hu-berlin.de

  Article: Odd-number theorem: optical feedback control at a subcritical Hopf bifurcation in a semiconductor laser.

  S Schikora, H-J Wünsche, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: A subcritical Hopf bifurcation is prepared in a multisection semiconductor laser. In the free-running state, hysteresis is absent due to noise-induced escape processes. The missing branches are recovered by stabilizing them against noise through application of phase-sensitive noninvasive delayed optical feedback control. The same type of control is successfully used to stabilize the unstable pulsations born in the Hopf bifurcation. This experimental finding represents an optical counterexample to the so-called odd-number limitation of delayed feedback control. However, as a leftover of the limitation, the domains of control are extremely small.
  Physical Review E 02/2011; 83(2 Pt 2):026203. · 2.26 Impact Factor
• Article: Extreme low-temperature molecular beam epitaxy of ZnO-based quantum structures

  S. Blumstengel, S. Sadofev, H. Kirmse, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We report on extreme low-temperature growth of ZnO by plasma-assisted molecular beam epitaxy. Epilayers and quantum well (QW) structures with very good structural and optical properties are prepared at substrate temperatures as low as 50 °C. The growth proceeds in a single crystalline layer-by-layer mode. ZnO QWs prepared on a-plane sapphire show bright excitonic luminescence with a very narrow linewidth of only 6 meV at 5 K. High-resolution transmission electron micrographs confirm that low-temperature single crystalline growth is not restricted to a particular surface termination of ZnO but works also for crystal growth along a nonpolar direction.
  Applied Physics Letters 01/2011; 98(3):031907-031907-3. · 3.84 Impact Factor
• Source

  Available from: hu-berlin.de

  Article: Random semiconductor lasers: scattered versus Fabry-Perot feedback.

  S Kalusniak, H J Wünsche, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: As a result of growth imperfections, (Zn,Cd)O/ZnO quantum well structures exhibit random laser action. Fabrication of microresonators allows us to study and to compare directly cavity and scattered feedback. Our experimental and theoretical analysis shows that (i) pure random lasing generally requires a larger gain than in the standard Fabry-Perot regime, (ii) the presence of Mie scatterers in the semiconductor-based cavity does not substantially increase the lasing threshold, and (iii) the random feedback creates a subtle modal gain distribution that might be of particular importance for the dynamical properties, both with and without Fabry-Perot cavity.
  Physical Review Letters 01/2011; 106(1):013901. · 7.37 Impact Factor
• Source

  Available from: ArXiv

  Article: Vertical cavity surface emitting laser action of an all monolithic ZnO-based microcavity

  S. Kalusniak, S Sadofev, S. Halm, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We report on room temperature laser action of an all monolithic ZnO-based vertical cavity surface emitting laser (VCSEL) under optical pumping. The VCSEL structure consists of a 2{\lambda} microcavity containing 8 ZnO/Zn(0.92)Mg(0.08)O quantum wells embedded in epitaxially grown Zn(0.92)Mg(0.08)O/Zn(0.65)Mg(0.35)O distributed Bragg reflectors (DBRs). As a prerequisite, design and growth of high reflectivity DBRs based on ZnO and (Zn,Mg)O for optical devices operating in the ultraviolet and blue-green spectral range are discussed.
  11/2010;
• Source

  Available from: hu-berlin.de

  Article: Synchronization of quasiperiodic oscillations to a periodic force studied with semiconductor lasers.

  A Loose, H-J Wünsche, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We experimentally study synchronization processes in a system of two different multisection semiconductor lasers. Periodic self-pulsations of laser 1 are injected into laser 2, which is operating in a regime with two-frequency quasiperiodic self-pulsations. The experimental system demonstrates the new type of transitions to synchrony between three frequencies which has been recently revealed using generic coupled phase and van der Pol oscillator models. In particular, resonances of quasiperiodic oscillations at integer winding numbers three and five are shown to break up before locking to the injected periodic signal. Moreover, carefully determining the coherence of the noisy oscillations, we reveal so far unexplored processes of coherence transfer to nonsynchronized oscillations.
  Physical Review E 09/2010; 82(3 Pt 2):035201. · 2.26 Impact Factor
• Article: Electron-nuclear spin control in charged semiconductor quantum dots by electrical currents through micro-coils

  Jungtaek Kim, J. Puls, Y. S. Chen, G. Bacher, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We have fabricated micrometer-sized single-turn coils on top of charged CdSe/ZnSe quantum dot heterostructures by lithographical techniques. Current injection creates magnetic fields in the some 10 mT range, strong enough to modulate the hyperfine interaction. The very low coil inductance allows for generation of fast field transients. We demonstrate local control of the resident electron spin as well as read-out of the nuclear spin state on the 10 ns time scale by electrical current pulses.
  Applied Physics Letters 04/2010; 96(15):151908-151908-3. · 3.84 Impact Factor
• Article: An inorganic/organic semiconductor "sandwich" structure grown by molecular beam epitaxy.

  S Blumstengel, S Sadofev, J Puls, F Henneberger
  Advanced Materials 12/2009; 21(47):4850-3. · 13.88 Impact Factor
• Article: Laser-induced erasure and reversal of the permanent magnetization in a ferromagnet-dilute magnetic semiconductor hybrid structure

  Y.-H. Fan, J. Puls, S. Halm, S. Sadofev, F. Seifert, E. Schuster, G. Bacher, W. Keune, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: Manipulation of the magnetizations via laser pulse heating is studied for a hybrid structure, where the fringe field of a metallic ferromagnet controls remotely the carrier and magnetic ion spins in a diluted magnetic semiconductor quantum well. A single nanosecond pulse with an energy density of 160 pJ/μm2 is found to be sufficient to erase the ferromagnet magnetization. Applying a reversed external bias field about five times below the ferromagnet coercive field, a complete reversal of the magnetization via optical excitation is demonstrated.
  Applied Physics Letters 11/2009; 95(22):223502-223502-3. · 3.84 Impact Factor
• Conference Proceeding: Synchronization of quasiperiodic oscillations in semiconductor lasers

  A. Loose, H.-J. Wunsche, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: Oscillatory behavior is ubiquitous in nature and technology, e.g. as subthreshold oscillations or excitatory and inhibitory interactions of nerve cells. To gain insight in the mechanisms of phase synchronization of chaotic intensity pulsations in lasers, we first investigated the synchronization of quasiperiodic oscillations with two semiconductor lasers in experiment. The devices each are a single-mode distributed feedback (DFB) laser, integrated in a compound cavity with a passive phase-tuning section and an amplifier section. Similar devices have recently been proposed for the generation of high-dimensional optical chaos, used in communication schemes with enhanced privacy.
  Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009. European Conference on; 07/2009
• Source

  Available from: physcon.ru

  Conference Proceeding: Multistability of a semiconductor laser with integrated delayed optical feedback

  A. Loose, B.K. Goswami, H.-J. Wunsche, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: A new regime reveals the operation, where optical feedback enables a semiconductor laser to operate in one of several stable states. An experimental device integrates the delayed optical feedback by using a passive waveguide and an amplifier section on the same chip as the distributed feedback (DFB) laser. Feedback phase and strength can be adjusted by applying a direct current to the passive and amplifier section, respectively. For the laser current I_DFB biased closely above threshold, three continuous wave (cw) states spaced 0.4 nm apart from each other and having a different power were found to coexist for multiple ranges of amplifier I_A and phase current I_P.
  Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009. European Conference on; 07/2009
• Article: Resident electron spin dynamics of II-VI quantum dots

  V. Gapon, J. Puls, F. Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: The spin dynamics of single electrons resident to charged CdSe/ZnSe quantum dots is studied. The spin-orbit mediated spin lifetime is uncovered. It follows a magnetic-field dependence of τ_so=190 ms   T ⁴/B⁴ . Below about B=2 T , the electron-nuclear hyperfine coupling takes over and the electron spin lifetime shortens. We analyze the temperature dependence of the spin transfer via hyperfine interaction and find that the efficiency for the formation of a nuclear dynamical polarization increases up to 100 K.
  Applied Physics Letters 06/2009; · 3.84 Impact Factor
• Source

  Available from: hu-berlin.de

  Article: Tristability of a semiconductor laser due to time-delayed optical feedback.

  A Loose, B K Goswami, H-J Wünsche, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We present an experimental and theoretical study of multistability of a single-mode laser subject to feedback through phase tuning and amplifier sections integrated on the same chip. Closely above threshold, a regime of tristability of continuous-wave (CW) states is found for multiple ranges of amplifier and phase currents. The separation between the tristable wavelengths agrees with the channel spacing of dense wavelength multiplexing in the C band of optical communication making the device interesting for ternary logic applications. Complementary theoretical investigations in the framework of the paradigmatic Lang-Kobayashi model provide a consistent understanding of the experimental findings and additionally yield an analytic formula expressing the maximum number of coexisting stable CW states by the linewidth-enhancement factor alpha . Tristability belongs to the alpha range from 5 to 8 in good agreement with experiment.
  Physical Review E 04/2009; 79(3 Pt 2):036211. · 2.26 Impact Factor
• Article: ZnCdO/ZnO – a new heterosystem for green‐wavelength semiconductor lasing

  S. Kalusniak, S. Sadofev, J. Puls, F. Henneberger
  Laser & Photonics Review 11/2008; 3(3):233 - 242. · 7.39 Impact Factor
• Source

  Available from: hu-berlin.de

  Article: All-optical noninvasive chaos control of a semiconductor laser.

  S Schikora, H-J Wünsche, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We demonstrate experimentally control of a chaotic system on time scales much shorter than in any previous study. Combining a multisection laser with an external Fabry-Perot etalon, the chaotic output transforms into a regular intensity self-pulsation with a frequency in the 10-GHz range. The control is noninvasive as the feedback from the etalon is minimum when the target state is reached. The optical phase is identified as a crucial control parameter. Numerical simulations agree well with the experimental data and uncover global control properties.
  Physical Review E 09/2008; 78(2 Pt 2):025202. · 2.26 Impact Factor
• Article: Manipulation of spin states in a semiconductor by microscale magnets

  S Halm, P E Hohage, J Nannen, E Neshataeva, L Schneider, G Bacher, Y H Fan, J Puls, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: We present the ability to manipulate spin states in a semiconductor on a sub-micrometre length scale via the magnetic fringe fields of microstructured magnets. Fe/Tb multilayers with remanent out-of-plane magnetization induce a remanent, vertical magnetization in an underlying diluted magnetic semiconductor (DMS), which in turn results in an efficient spin polarization of optically excited charge carriers via sp–d exchange interaction. By optically switching the magnetization of the ferromagnet, the DMS magnetization can be manipulated and the limits of a dynamical interaction between the spin states in the ferromagnet and the magnetic semiconductor are discussed. Moreover, magnetic ion spins of the DMS initially aligned along the sample surface are tipped by optically generated, spin polarized holes, which leads to a coherent spin precession around the total magnetic field. We show that the fringe field of in-plane magnetized Co wires can be utilized to locally modify the coherent dynamics of the semiconductor magnetization and demonstrate how the field inhomogeneity influences the coherent response of the Mn spin ensemble in the DMS.
  Journal of Physics D Applied Physics 07/2008; 41(16):164007. · 2.54 Impact Factor
• Article: Electronic coupling of optical excitations in organic/inorganic semiconductor hybrid structures

  S Blumstengel, S Sadofev, F Henneberger
  [show abstract] [hide abstract]
  ABSTRACT: The epitaxial growth of small conjugated molecules on ZnO-based surfaces is studied. A weak substrate interaction allows for the preparation of organic layers with well-defined morphology and electronically intact interfaces without the need for extra passivation. Nonradiative energy transfer from inorganic quantum wells to various molecules is identified by optical spectroscopy. The strength of the dipole–dipole mediated coupling between Wannier and Frenkel excitons is as large as 2 meV. In hybrid structures with type-II energy level alignment, charge separation occurs at the organic/inorganic interface as well. These findings render organic/ZnO hybrid structures interesting for light-emitting as well as photovoltaic applications benefiting from favorable properties of both material classes.
  New Journal of Physics 06/2008; 10(6):065010. · 4.18 Impact Factor