Short Oral Presentations

Wednesday

Presentations From Sponsors:

• Sp01: " Carrier-envelope phase control and stabilization by an acousto-optic programmable dispersive filter "
  N. Forget, L. Canova, X. Chen, A. Jullien, R. Lopez-Martens We demonstrate arbitrary control of the carrier-envelope (CE) phase using an acoustooptic programmable dispersive filter (AOPDF) inserted in a chirped-pulse amplification (CPA) Ti:S laser. We also demonstrate, for the first time, closed-loop CEP stabilization using an AOPDF to correct for the CEP slow drifts.
• Sp02: " CEP stabilization of a 3.5mJ, 5kHz femtosecond laser based on gratings stretcher/compressor and regenerative amplifier "
  A. Cotel, A. Soujaeff, R. Czarny, L. Heng, V. Moro We demonstrate the CEP stabilization of a 3.5mJ at 5kHz (17W average power) femtosecond laser system composed of an CEP-stabilized oscillator, a compact Öffner stretcher, regenerative and cryogenic amplifiers, and a gratings compressor. A CEP drift of 200 mrad is routinely obtained.
• Sp03: " Photonics Industries’s Ultrafast Attosecond Pump Lasers "
  Joyce Kilmer, Andrew Iadevaia, Yusong Yin Photonics Industries manufactures a variety of pump lasers for ultrafast and attosecond research.
• Sp04: " A new method for carrier-envelope phase stabilization of high power regenerative amplifier "
  Chengquan Li, William Tulloch, Alan Fry A new method is proposed to stabilize the carrier-envelope phase of femtosecond laser pulse from a high power regenerative amplifier with a water-cooled Ti:sapphire rod. This method introduces dispersion in the amplifier system to compensate the phase drift and keeps the pulse duration unchanged.
• Sp05: " Advances in long term CEP-stabilization of amplified Ti:S based systems "
  Andreas Assion, Andreas Isemann, Gabriel Tempea, Andreas Stingl Femtolasers has been the leader in commercial Ti:S based CEP-stabilized oscillator and amplifier systems. We will review the advantages of our DFG-based approach to CEP-stabilize an oscillator as well as the scheme for independent stabilization of the amplified system allowing for several hours of continuous CEP-stabilized operation. At the same time, we will introduce our new commercial CEP-stabilized 2 stage amplified system allowing for 5mJ of pulse energy with a pulse duration of < 25 fs incorporating the latest technology from Femtolasers and present data from our Femtopower familiy of amplifiers.
• Sp06: " Institute of Physics and IOP Publishing: An overview of peer-review and journals "
  Julia Dickinson This talk will give an overview of the work of IOP and the journals and services available from IOP Publishing. In particular, management of the peer-review process for Journal of Physics B: Atomic, Molecular and Optical Physics will be discussed.

Fifteen-minute Selected Poster Talks:

• F16 O01: "Controlling the Carrier-Envelope Phase of Single-Cycle Waveforms Synthesized from Raman Generated Frequency Combs"
  Zhi-Ming Hsieh, Chien-Jen Lai, Han-Sung Chan, Sih-Ying Wu, Chao-Kuei Lee, Wei-Jan Chen, Ci-Ling Pan, Fu-Goul Yee, A. H. Kung We proposed and experimentally verified that the carrier-envelope phase of single-cycle waveforms synthesized from Raman generated frequency combs can be precisely set and controlled by generating the comb using an infrared laser tuned near a Raman resonance and the second harmonic of the laser to drive the Raman coherence.
• F44 O02: "Ultrafast electronic dynamics in Helium nanodroplets studied by femtosecond time-resolved EUV photoelectron imaging"
  Oliver Gessner, Oleg Kornilov, Stephen R. Leone, and Daniel M. Neumark We have performed the first femtosecond EUV-pump, IR-probe experiment to study the photoionization dynamics of pure Helium nanodroplets below the atomic Helium IP in real-time. Using Velocity-Map Imaging (VMI) photoelectron spectroscopy we were able to discern processes with associated timescales ranging from tens of femtoseconds to tens of picoseconds. The results will be discussed in the light of complementary energy-domain studies and theoretical models of the droplet’s electronic and nuclear dynamics.
• T38 O03: "Auger decay in krypton induced by attosecond pulse trains and twin pulses"
  Christian Buth, Kenneth J. Schafer Using attoscience, we study the electron correlations responsible for Auger decay in krypton atoms. The Auger decay is induced by a pulse train or a twin pulse composed of subpulses of attosecond duration. During the Auger decay an optical dressing laser may be present. Interference effects between the ejected Auger electron wave packets are predicted.
• F18 O04: "Generation of high-order harmonics with ultra-short pulses from filamentation"
  E. Schulz, D. S. Steingrube, T. Vockerodt, U. Morgner, and M. Kovacev We obtain 7-fs-pulses with 0.3 mJ after filamentation and pulse compression by double-chirped-mirrors (DCM). We use these pulses to generate high-order harmonics in a semi-infinite gas cell setup. Spectral broadening of the harmonics in different gases is observed. Especially in neon an extended continuous cut-off region down to 10 nm (124 eV) can be realized. This opens up the way to attosecond-pulse generation from filamented pulses.
• F36 O05: "Towards Disentangling High Harmonic Generation: Multiple Active Electrons in Strong Field Ionization of Polyatomic Molecules"
  Arjan Gijsbertsen, Andrey E. Boguslavskiy, Jochen Mikosch, Michael Spanner, Niklas Gador, Marc J. J. Vrakking, Olga Smirnova, Serguei Patchkovskii, Misha Y. Ivanov, and Albert Stolow We investigate Strong Field Ionization - the first step in High Harmonic Generation - of polyatomic hydrocarbon molecules. By utilizing a novel covariance technique we show that multiple bound electrons respond simultaneously to the strong laser field. The driven sub-cycle ionization process cannot be described within a single continuum approximation.
• T29 O06: "Counterintuitive angular shifts in the photoelectron momentum distribution for atoms in strong few-cycle circularly laser pulses"
  C. P. J. Martiny, M. Abu-samha, L. B. Madsen We have recently developed a method for solving the time-dependent Schro127 odinger equation for a diatomic molecule (atom) interacting with a strong few-cycle elliptically polarized laser pulse. Here we present the first fully ab initio calculations of the photoelectron momentum distributions for a circularly polarized laser pulse interacting with an atom. Furthermore, we provide a precise quantum mechanical explanation of counterintuitive shifts in the dominant direction of electron ejection, observed in a recent experiment (P. Eckle et.al. Science 322, 1525 (2008)). Our results underline the importance of including both the laser field and the Coulomb interaction in the description.
• F43 O07: "Attosecond Transient Absorption of High Order Harmonics in Helium"
  Mirko Holler, Florian Schapper, Johan Mauritsson, Kenneth J. Schafer, Lukas Gallmann and Ursula Keller We experimentally observe IR-assisted absorption of an attosecond pulse train in a helium gas target. We find that the transmitted photon yield not only modulates on the timescale of the envelope of the IR pulse but also detect oscillations with twice the fundamental laser frequency. We consider our experiment a first step to all-optical experiments in the attosecond domain.
• T17 O08: "Attosecond Hard X-Ray Scattering Spectroscopy"
  G. L. Yudin, D. I. Bondar, S. Patchkovskii, P. B. Corkum, A. D. Bandrauk We formulate an analytic, semi-relativistic theory of laser-assisted attosecond Compton scattering by a weakly bound electron. We (i) present the evidence of the feasibility of measuring the ground-state electron momentum density in the attosecond regime and (ii) investigate the attosecond Compton streak camera and spectral phase interferometry - proposing two new methods of measuring the duration of a hard x-ray pulse without fundamental restrictions on the measurement accuracy.
• T35 O09: "Electron localization in molecular fragmentation with CEP stabilized laser pulses"
  Bettina Fischer, Manuel Kremer, Bernold Feuerstein, Vitor L.B. de Jesus, Artem Rudenko, Claus Dieter Schröter, Robert Moshammer, Joachim Ullrich Fully differential data on dissociating H2 molecules in ultrashort (~6 fs), linearly polarized, intense (~0,4 PWcm-2) laser pulses with stabilized carrier-envelope-phase (CEP) have been measured using a reaction microscope. Depend-ing on the CEP of the laser pulses we see a clear asymmetry in the emission direction of the created protons. Con-trary to earlier measurements by Kling et al. [1] we observe the largest asymmetry in a kinetic energy release (KER) range between 0-3 eV. This excludes the recollision mechanism suggested in [1] and requires another explanation.
• S22 O10: "Probing Doubly Excited Helium with Isolated Attosecond Pulses"
  Steve Gilbertson, Ximao Feng, Sabih Khan, Michael Chini, He Wang, and Zenghu Chang Single attosecond pulses generated with a neon gas target were used to probe two electron excitation and autoionization in a helium gas target. By adding an intense near infrared laser beam, the population of the excited atoms in the 2s2p1P0 state was modified in a controllable manner for the first time.

Thursday

Ten-minute Selected Poster Talks:

• T01: "Streaking of shake-up ionization in helium"
  Johannes Feist, Andreas Kaltenbäck, Stefan Nagele, Renate Pazourek, Emil Persson, Barry I. Schneider, Lee A. Collins, Joachim Burgdörfer We investigate whether an apparent ``time delay'' between electrons ionized by an attosecond XUV pulse with and without shake-up excitation of the remaining ion can be extracted using XUV-IR streaking setups. To do so, we solve the full Schrödinger equation for the helium atom including all correlation effects. We discuss whether a time delay extracted from the streaking spectra corresponds to a ``real'' time delay or is induced by other effects, such as the influence of the IR field on the ionization process.
• T02: "Elliptically polarized high-order harmonics from aligned molecules within the strong-field approximation"
  Adam Etches, Christian Bruun Madsen, Lars Bojer Madsen A correction term is introduced in the stationary-point analysis on high-order harmonic generation (HHG) from aligned molecules. Arising from a multi-centre expansion of the electron wave function, this term brings our numerical calculations of the Lewenstein model into qualitative agreement with recent experiments.
• T03: "High harmonics generation using long wavelengths: scaling and scaled systems"
  Gilles Doumy, Anne Marie March, Erik Power, Jonathan Wheeler, Chris Roedig, Emily Sistrunk, Fabrice Catoire, Karl Krushelnick, Pierre Agostini, Louis DiMauro Long wavelength lasers have started to become ubiquitous in studies of high harmonics generation, due to their attractive scaling properties (cutoff extension, better synchronization for shorter pulses). They also enable studies where the whole interaction is scaled compared to the usual situation using 800nm light. I will present both results that verified the wavelength scaling and a complete temporal characterization of the emission in a scaled Cesium 3.6micron system using Cross-correlation frequency resolved optical gating (XFROG).
• T04: "Modeling Attosecond Pulse Formation in Strongly Ionized Gaseous Media"
  V. Tosa,1, K. Kovacs, R. Velotta, C. Altucci, K. T. Kim, and C. H. Nam We present the results obtained in modeling single attosecond pulse (SAP) as well as attosecond pulse trains (APT) formation as a result of femtosecond laser pulse interaction with rare gas atoms. A non-adiabatic model is used for solving the laser and harmonic field propagation, while strong field approximation is used to calculate the single dipole response. Quantum trajectories of the electron are generated and their phases are used in a time-dependent phase matching analysis. The role of the propagation can be beneficial in SAP generation as it contributes to the elimination of spurious bursts. APT characteristics will bear the signature of the distorted laser field, which will generate less, shorter and shifted to earlier time wagons.
• T05: "Benchmark experiment on H3+ in intense ultrashort laser pulses"
  J. McKenna, A. M. Sayler, B. Gaire, Nora G. Johnson, K. D. Carnes, B. D. Esry and I. Ben-Itzhak Using coincidence 3D momentum imaging we have probed, for the first time, the fragmentation dynamics of H3+ and its isotopologues in intense ultrashort laser pulses. As the simplest polyatomic molecule, these measurements on H3+ can serve as a benchmark for future theoretical calculations.
• T06: "Ultrafast high-harmonic imaging of a chemical reaction"
  H. J. W¨orner, J. B. Bertrand, P. B. Corkum and D. M. Villeneuve High-harmonic generation in aligned molecules provides information about their electronic structure and ionization continuum within a fraction of a laser cycle. We exploit the ultrahigh time resolution to experimentally observe a chemical reaction of fixed-in-space molecules. We non-adiabatically align Br2 molecules, launch a photodissociation wave packet and measure the high harmonic yield as a function of time delay and angle between the molecular axis and the polarization of the generating laser field. We develop an interferometric technique to extract the harmonic dipole and phase of the excited state along the photodissociation coordinate. This provides the complete information required for the dynamic tomographic imaging of the chemical reaction.
• T07: "Attosecond Electron Interferometry"
  K. Klünder, M. Swoboda, M. Gisselbrecht, M. J. Dahlström, P. Johnsson, T. Remetter, J. Mauritsson, A. L'Huillier We present two different interferometric pump-probe experiments aiming to access state specific phase information after attosecond pulse excitation. The common idea is that when creating the wave packet we introduce simultaneously a reference that allows us to measure the phase evolution. In the first experiment we use isolated attosecond pulses to characterize ultrafast bound electron dynamics. While in the second we apply attosecond pulse trains in a RABITT measurement to access the phase induced by a resonant bound state in a two-photon-ionization process.
• T08: "Electron Wavepacket Interferences pointing to Holographic Imaging with Few Cycle Laser Pulses"
  R. Gopal, A. Rudenko, K. Simeonidis, K.-U. Kühnel, M. Kurka, C. D Schröter, O. Herrwerth, Th.Uphues, M. Schultze, E. Goulielmakis, M. Uiberacker, D. Bauer, M. Lezius, R. Moshammer, M. F. Kling, J. Ullrich Three-dimensional (3D) electron (and ion) momentum (P) spectra have been recorded for carrier-envelope-phase (CEP) stabilized few-cycle (~5 fs), intense (~0.4 PW/cm2) laser pulses (740 nm) impinging on He using a reaction microscope. Preferential emission of low-energy electrons (Ee < 15 eV) to either hemisphere is observed as a function of the CEP. Clear interference patterns emerge in P-space at CEPs with maximum asymmetry, interpreted as holographic images of re-scattered electron wavepackets by means of a simple model and in line with previous theoretical predictions.
• T09: "Asymmetric dissociation of H2 and D2 by a two-color laser field"
  D. Ray, S. De, H. Mashiko, I. Znakovskaya, F. He, U. Thumm, G.G.Paulus, M. Kling, I. Litvinyuk, and C.L. Cocke Two-color (800 nm and 400 nm) short (45 fs) linearly polarized pulses are used to ionize and dissociate H2(D2) into a neutral hydrogen (deuterium) atom and a proton(deuteron). The yields and energies of the ions are measured left and right along the polarization vector. As the relative phase of the two colors is varied, strong yield asymmetries are found in the ion energy regions corresponding to bond softening, above-threshold dissociation and rescattering. A model based on the dynamic coupling by the laser field of the gerade and ungerade states in the molecular ion accounts for many of the observed features.
• T10: "Intensity dependence of strong field double ionization mechanisms of diatomic molecules: from field-assisted electron recollision to recollision-assisted field ionization"
  Agapi Emmanouilidou Given the state of the art in computational capabilities addressing the double ionization of strongly driven diatomic molecules with three-dimensional (3-d) firstprinciple techniques, namely quantum mechanical ones, is an immense task. We study the correlated electron dynamics in the double ionization of diatomic molecules with “frozen” nuclei in the non-sequential regime as a function of the intensity of the laser pulse.
• T11: "Time-resolved core-hole decay and sideband structure in laser-assisted photoemission from metal surfaces"
  C.-H. Zhang, U. Thumm We calculate the photoelectron and Auger electron sideband spectra and the ¯rst sideband intensities from adsorbate-covered metal surfaces
• T12: "Time-resolved Coulomb explosion imaging of CO ultrafast dynamics using fewcycle IR and EUV laser pulses"
  A. S. Alnaser, I. Bocharova, K. Singh, C. Wei, M. Kling, C. L. Cocke, I. V. Litvinyuk We have used few-cycle IR and EUV laser pulses in pump-probe arrangement to trace out the dissociation pathways in CO when exploded by strong laser fields. We present two preliminary sets of data of different pump pulses. In these sets, different excited state of CO cations are populated using (< 10 fs) IR, and EUV pulses respectively. We followed the time evolution of these states using the time-resolved Coulomb explosion imaging technique. We compare the time evolution of IR- and EUV-induced excited states by measuring the KER of the fragment ions as a function of the time delay between the pump and the IR probe pulse.

Friday

Ten-minute Selected Poster Talks:

• F01: "Extending upper limit of laser pulse duration for generating single attosecond pulses"
  Ximao Feng, Steve Gilbertson, Hiroki Mashiko, He Wang, Sabih D. Khan, Michael Chini, Zenghu Chang We propose and demonstrate a technique called generalized double optical gating for generating isolate attosecond pulses with 20 fs lasers. These pulses are measured to be 260 attoseconds by reconstructing the streaked photoelectron spectrogram
• F02: "Electron Localization and Multiple Ionization Bursts in H2+ within a Half Cycle of Near-Infrared Laser Light"
  Norio Takemoto, Andreas Becker We found by numerical simulations that H2+ irradiated by intense near-infrared laser light shows multiple bursts of ionization current within a half cycle of the electric field oscillation, in contrast to the intuition given by the quasi-static tunneling ionization picture. We attribute the origin of the multiple bursts to the dynamical localization of the electron at one of the nuclei on the sub-laser-cycle time-scale. A relation between the timing of the bursts and the vector potential of the laser light is derived analytically based on a perturbative solution of a two-state model.
• F03: "Wavelength Scaling in High Harmonic Tomographic Imaging"
  Jonathan A. Wheeler,Gilles Doumy,Terry Miller,Pierre Agostini,Louis F. DiMauro Increasing the wavelength of the fundamental driving laser at constant intensity in high harmonic generation allows one to significantly increase the upper bound of the harmonic energies produced. This feature of harmonic generation is employed in an effort to improve the spatial resolution achieved in the method of tomographic reconstruction of molecular orbitals from high harmonics. Current experimental measurements and comparison with theoretical work will be presented.
• F04: "Femtosecond Dynamics and Multiphoton Ionization driven with an Intense High Order Harmonic Source"
  J. van Tilborg, T. K. Allison, T. W. Wright, M. P. Hertlein, Y. Liu, H. Merdji, R. W. Falcone, A. Belkacem We have constructed a high intensity high order harmonic source delivering 109 extreme ultraviolet photons/shot on a gas target and used it to observe multiphoton ionization and conduct femtosecond EUV-pump IR-probe experiments. Following excitation by 20-25 eV photons, we observed that the excited ethylene cation (H2C-CH2)+ experienced isomerization to the ethylidene configuration (HC-CH3)+ in 5025 fs, followed by an H2 stretch motion. Experimental data and analysis from several other performed and planned experiments will be presented as well.
• F05: "High Harmonic Generation from Multiple Orbitals in N2"
  Brian K. McFarland, Joseph P. Farrell, Philip H. Bucksbaum, and Markus Gühr Contribution from the HOMO and HOMO-1 orbitals are observed in high harmonics from N2. We discuss the harmonic modulations in the rotational revival structure due to the HOMO and HOMO-1.
• F06: "High accuracy, real time, single-shot measurement of absolute carrier-envelope phase and pulse duration for few-cycle laser pulses"
  A. Max Sayler, T. Rathje, J.V. Hernandez, W. Müller, B.D. Esry, and G.G. Paulus We develop a novel approach which allows for the simultaneous a priori single-shot measurement of carrier-envelope phase (CEP) and pulse duration for each and every few-cycle laser pulse in a kHz pulse train, virtually instantaneously. This technique builds upon the previous work of Wittmann et al. [1], which outlines a technique for determining CEP using a stereographic ionization measurement [2]. However, our approach allows for real-time assessment of these parameters, thereby permitting the signal to be used as a laser-feedback control mechanism or as an auxiliary measurement providing shot-by-shot pulse characterization for other measurements.
• F07: "Analytic Formulas for High-Order Harmonic Generation"
  M.V. Frolov, N.L. Manakov, T.S. Sarantseva, Anthony F. Starace We present closed-form analytic formulas for high-order harmonic generation (HHG) rates for both negative ions and neutral atoms. These formulas provide a fully quantum justification for the famous classical three-step scenario (TSS) of HHG as well as a correction to the well-known classical law for the HHG plateau cutoff energy.
• F08: "Zero Photon Dissociation of H2+ in Few Cycle Pulses"
  B. Gaire, J. McKenna, A. M. Sayler, M. Zohrabi, Nora G. Johnson, F. Anis, J.J. Hua, K.D. Carnes, B.D. Esry, and I. Ben-Itzhak Evidence for dissociation caused by an intense laser field with the net absorption of zero photons is conflicting. We have measured very low kinetic energy release upon H2+ dissociation in few cycle pulses -- a signature of zero photon dissociation. Comparison with solutions of the time dependent Schro127 odinger equation supports this assertion.
• F09: "Theoretical study of Carrier-envelope phase effects from three-dimensional momentum distribution of H2+ dissociation by ultrashort laser pulses"
  Fatima Anis, B. D. Esry The carrier-envelope phase (CEP) of few-cycle laser pulses can be used to control the strong-field dynamics of atoms and molecules. To study CEP effects in H2+, we have solved the time-dependent Scho127 odinger equation including nuclear vibration and rotation as well as electronic excitation, only ionization is excluded. Including nuclear rotation is essential to obtaining results directly comparable with experiment such as the momentum distribution. We show that the momentum distribution is quite sensitive to the CEP.
• F10: "Two-source double-slit interference in angle-resolved high-energy above-threshold ionization spectra of diatoms"
  M. Okunishi, R. Itaya, K. Shimada, G. Prumper, K. Ueda, M. Busuladzic, A. Gazibegovi Busuladzic, D. B. Milosevic, W. Becker Experimental data are reported and compared with molecular strong-field-approximation calculations that display an interference where four electronic quantum orbits conspire. For random orientation of the molecule, footprints of the destructive interference survive for O2, but not for N2.
• F11: "Ultrafast Science and Development at the Astra-Artemis Facility"
  Turcu, Springate, Froud, Collier, Marangos, Tisch, La Porte, Siegel, El-Taha, Kajumba, Brugnera, Procino, Newell, Williams, Greenwood, Calvert, Bryan, Cavalleri, Dhesi, Underwood, Mercer, Gabrielsen, Cogdell, Poletto, Villoresi, Frassetto, Bonora, Roper Astra-Artemis is a unique, new, ultrafast science facility under development in the UK. The paper will report on the: (a) ultrafast science experimental results obtained with Artemis on: HHG mapping of electronic structure; ultrafast molecular process; HHG with 2-colour laser fields, energy transfer in photosynthesis and (b) Artemis facility development of new ultrafast XUV and laser beamlines and time-resolved science end-stations.
• F12: "Inner and Outer Ionization of Atomic Clusters by an Intense Attosecond Laser Pulse"
  A.V. Gets and V.P. Krainov The dynamics of inner and outer ionization of atomic clusters irradiated by intense attosecond laser pulses has been considered. A comparison with the case of femtosecond pulses has been made.

Saturday

Ten-minute Selected Poster Talks:

• S01: "A robust all-non-optical method for the complete characterization of single-shot few-cycle laser pulses"
  Zhangjin Chen, T. Wittmanny, C. D. Lin We analyse the "left" and "right" asymmetry of high-energy photoelectrons along the polarization axis generated by few-cycle infrared laser pulses from atomic targets. Based on the recently developed quantitative rescattering theory, we show that the carrier-envelope phase, the pulse duration and the peak intensity of each single-shot laser pulse can be accurately and e±ciently retrieved, thus providing a robust all-non-optical method for the complete characterization of single-shot few-cycle laser pulses.
• S02: "Chirp-controlled polarization gating for isolated attosecond pulse generation"
  Florian Schapper, Mirko Holler, Lukas Gallmann, Ursula Keller We generate continuous high harmonic spectra in Argon by a superposition of two time-delayed, crosspolarized 12 fs pulses with a small imbalance of group delay dispersion (GDD) between the pulses. Our technique improves overall harmonic flux compared to traditional polarization gating methods. Recorded spectra indicate that the continuum generation is insensitive to the carrier-envelope offset phase (CEP).
• S03: "Generation of continuum harmonic spectrum using multi-cycle two-color infrared laser fields"
  Eiji J. Takahashi, Pengfei Lan, and Katsumi Midorikawa By mixing two infrared laser pulses of different wavelengths, we generate the continuum harmonic spectrum around a cut-off region. Our obtained harmonic spectra clearly show the possibility of generating isolated attosecond pulses from many-cylse laser pulse of the two color laser fields, 30 fs laser pulses centered at 800 nm and 1300 nm. This scheme makes it possible to easily create a high-energy attosecond pulse with a well-established conventional femtosecond laser system.
• S04: "Control of Electron Localization Using XUV and IR pulses"
  Kamal P. Singh, W. Cao , P. Ranitovic, S. De, D. Ray, H. Mashiko, S. Chen, F. He, A. Becker, U. Thumm, I. Litvinyuk, C. L. Cocke We demonstrate an experimental control of electron localization in the deuterium molecular ion created and dissociated by the combined action of an attosecond pulse train (APT) and a multicycle IR laser pulse. A left-right asymmetric ejection of the deuterium ions, characterized by an asymmetry parameter A, exhibits oscillations with a full IR period when the time-delay between the APT and IR pulses is scanned with 300as resolution.
• S05: "High Harmonic Generation seeded by a XUV pulse train"
  F. Kelkensberg, G. Gademann, W. Siu, P. Johnsson, M.J.J. Vrakking In the process of high harmonic generation multiple interfering quantum paths are responsible for the harmonic emission. In a theoretical study from 2004 it was shown that attosecond pulse trains can be used to select a single quantum path. The first experiment to demonstrate this effect showed an enhancement of harmonics emission by seeding it with an attosecond pulse train. Here we present for the first time the delay dependence of this enhancement demonstrating quantum path control.
• S06: "Mapping attosecond electron wavepacket motion in a molecule by using two-color laser pulses"
  Hiromichi Niikura, D. M. Villeneuve, and P. B. Corkum We measure high harmonic generation spectra of D2, N2, CO2, N2O and hydrocarbons by using simultaneously 800nm and 400 nm laser pulses generated with perpendicular polarization. The intensity of high harmonic spectra is modulated as we change the relative phase of the two pulses. The phase of intensity modulation depends on the symmetry of molecular orbitals from which high harmonics are emitted. We show that this allows us to identity any molecular orbital that can contribute high harmonic generation even randomly aligned molecule. Using this approach, we also show the observation of electron wavepacket motion occurring in a few-hundred attoseconds.
• S07: "Attosecond chirp-encoded dynamics of light nuclei"
  S. Haessler, W. Boutu, S. Weber, J. Caillat, R. Taieb, A. Maquet, P. Brege, B .Carre, P. Salieres We use the attosecond emission from light molecules to probe the ultrafast nuclear dynamics occurring between the ionization and recombination steps. By measuring the phase of the XUV emission, we have direct access to the mapping of harmonic frequency to the excursion time, which represents the delay after which the evolved molecular ion is probed. The small difference in the harmonic phase between H2 and D2 calculated theoretically is consistent with our experimental results.
• S08: "Atomic wavefunctions probed through strong field light-matter interactions"
  D. Shafir, Y. Mairesse, J. Higuet, B. Fabre, E. Mével, E. Constant, D. M. Villeneuve, P. B. Corkum, N. Dudovich The spatial properties of atomic wavefunctions were probed through the strong field process of high harmonic generation. Using elliptically polarized laser fields and two color fields we were able to manipulate the 2D motion of free electrons and probe the atomic wavefunctions from different angles. The atomic orbitals in turn were used as spatial probes to investigate the dynamics of the ionization process.
• S09: "High order harmonic generation with mid-infrared driven pulses"
  Han Xu, Hui Xiong, Yuxi Fu, Jinping Yao, Bin Zeng, Wei Chu, Ya Cheng, Zhizhan Xu We report on coherent water-window radiation by high-order harmonic generation in a gas cell with midinfrared femtosecnd pulses . With optimized parmeters, photon energy upto ~420 eV could be observed.
• S10: "High Harmonic Generation using 1425 nm sub-3 cycles laser pulses"
  F. Légaré, B. E. Schmidt, A. D. Shiner, C. Trallero, H. Worner, M. Giguère, P. B. Corkum, J-C. Kieffer, D. M. Villeneuve 13.1 fs pulses with 400 μJ pulse energy at 1425 nm have been generated using spectral broadening of OPA (Optical Parametric Amplifier) signal beam in an Ar filled hollow core fiber. Chirped mirrors are used for temporal compression and the IR few-optical-cycle pulses are applied to study the extension of the high harmonic cut-off frequency with noble gas.
• S11: "Quantum phase- and population-control in a vibrational wavepacket"
  W. A. Bryan, C. R. Calvert, R. B. King, J. Nemeth, J. B. Greenwood, J. D. Alexander, E. L. Springate, C. A. Froud, I. C. E. Turcu, I. D. Williams, W. R. Newell We present experimental evidence of the manipulation of vibrational phase and population by light-induced dynamic potential surface deformation. A vibrational wavepacket is created in D$_2^+$ in a 10 fs NIR pump pulse; the evolution of the wavepacket is non-destructively modified by a control pulse. Depending on the pump-control delay, population is up- or down-shifted and the relative phase delayed or advanced with respect to the unperturbed motion. The resulting quantum control of the wavepacket is understood in terms of a novel quasi-classical model.
• S12: " Ultrafast electron dynamics at surfaces studied using femtosecond photoelectron spectroscopy techniques "
  J. Yin, L. Miaja-Avila, G. Saathoff, S. Mathias, M. Aeschlimann, M. Bauer, M. M. Murnane, H. C. Kapteyn We directly observed the core-level relaxation dynamics in a complex surface-adsorbate system by combining laser-assisted Auger decay (LAAD) with the laser-assisted photoelectric effect (LAPE). Furthermore, we show that by using longer-wavelength driven pulses, we can more-effectively probe ultrafast dynamics using LAPE. These findings show how complex electron dynamics in solid and surface systems can be observed on femtosecond-to-attosecond time-scales.

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