Physics and Astronomy › Atomic and Molecular Physics, and Optics

Laser-Matter Interactions and Applications

Works Count: 70001

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This cluster of papers represents the cutting-edge research in attosecond physics and optics, focusing on topics such as high-harmonic generation, ultrafast laser pulses, nonlinear optics, molecular dynamics, quantum control, femtosecond science, X-ray spectroscopy, optical parametric amplifiers, and electron dynamics.

Keywords

Attosecond Physics; High-Harmonic Generation; Ultrafast Laser Pulses; Nonlinear Optics; Molecular Dynamics; Quantum Control; Femtosecond Science; X-ray Spectroscopy; Optical Parametric Amplifiers; Electron Dynamics

Spectral phase interferometry for direct electric-field reconstruction of ultrashort optical pulses

1998-05-15

C. Iaconis , Ian A. Walmsley

We present a novel, self-referencing interferometric technique for measuring the amplitude and the phase of ultrashort optical pulses. The apparatus uses a collinear geometry that requires no moving components. The … We present a novel, self-referencing interferometric technique for measuring the amplitude and the phase of ultrashort optical pulses. The apparatus uses a collinear geometry that requires no moving components. The phase-retrieval procedure is noniterative and rapid and uses only two one-dimensional Fourier transforms. We apply the technique to characterize ultrashort pulses from a mode-locked Ti:sapphire oscillator.

Measuring ultrashort laser pulses in the time-frequency domain using frequency-resolved optical gating

1997-09-01

Rick Trebino , Kenneth W. DeLong , D. N. Fittinghoff +4 more

We summarize the problem of measuring an ultrashort laser pulse and describe in detail a technique that completely characterizes a pulse in time: frequency-resolved optical gating. Emphasis is placed on … We summarize the problem of measuring an ultrashort laser pulse and describe in detail a technique that completely characterizes a pulse in time: frequency-resolved optical gating. Emphasis is placed on the choice of experimental beam geometry and the implementation of the iterative phase-retrieval algorithm that together yield an accurate measurement of the pulse time-dependent intensity and phase over a wide range of circumstances. We compare several commonly used beam geometries, displaying sample traces for each and showing where each is appropriate, and we give a detailed description of the pulse-retrieval algorithm for each of these cases.

High-order harmonic generation from atoms and ions in the high intensity regime

1992-06-15

Jeffrey L. Krause , Kenneth J. Schäfer , K. C. Kulander

We present calculated optical harmonic spectra for atoms and ions in the high intensity regime to current short-pulse experiments. We find that ions can produce harmonics comparable in strength to … We present calculated optical harmonic spectra for atoms and ions in the high intensity regime to current short-pulse experiments. We find that ions can produce harmonics comparable in strength to those obtained from neutrals, and that the emission extends to much higher order. Simple scaling laws for the strength of the harmonic emission and the maximum observable harmonic are suggested. These results imply that the photoemission observed in recent experiments in helium and neon contains contributions from ions as well as neutrals.

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Observation of a Train of Attosecond Pulses from High Harmonic Generation

2001-06-01

P. Paul , E. S. Toma , P. Breger +5 more

In principle, the temporal beating of superposed high harmonics obtained by focusing a femtosecond laser pulse in a gas jet can produce a train of very short intensity spikes, depending … In principle, the temporal beating of superposed high harmonics obtained by focusing a femtosecond laser pulse in a gas jet can produce a train of very short intensity spikes, depending on the relative phases of the harmonics. We present a method to measure such phases through two-photon, two-color photoionization. We found that the harmonics are locked in phase and form a train of 250-attosecond pulses in the time domain. Harmonic generation may be a promising source for attosecond time-resolved measurements.

Observation of high-order harmonic generation in a bulk crystal

2010-12-05

Shambhu Ghimire , Anthony D. DiChiara , Emily Sistrunk +3 more

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Free-Free Transitions Following Six-Photon Ionization of Xenon Atoms

1979-04-23

Pierre Agostini , F. Fabre , G. Mainfray +2 more

The energy spectrum of electrons produced by multiphoton ionization of xenon atoms has been analyzed with a retarding potential technique. We have shown that the discrete absorption of photons above … The energy spectrum of electrons produced by multiphoton ionization of xenon atoms has been analyzed with a retarding potential technique. We have shown that the discrete absorption of photons above the six-photon ionization threshold was observable under specified conditions. A simple model based upon inverse bremsstrahlung gives a resonable agreement with the experiments.

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High-harmonic generation by resonant plasmon field enhancement

2008-06-01

Seungchul Kim , Jonghan Jin , Young‐Jin Kim +3 more

Atomic transient recorder

2004-02-01

Reinhard Kienberger , E. Goulielmakis , M. Uiberacker +7 more

Intense few-cycle laser fields: Frontiers of nonlinear optics

2000-04-01

Thomas Brabec , Ferenc Krausz

The rise time of intense radiation determines the maximum field strength atoms can be exposed to before their polarizability dramatically drops due to the detachment of an outer electron. Recent … The rise time of intense radiation determines the maximum field strength atoms can be exposed to before their polarizability dramatically drops due to the detachment of an outer electron. Recent progress in ultrafast optics has allowed the generation of ultraintense light pulses comprising merely a few field oscillation cycles. The arising intensity gradient allows electrons to survive in their bound atomic state up to external field strengths many times higher than the binding Coulomb field and gives rise to ionization rates comparable to the light frequency, resulting in a significant extension of the frontiers of nonlinear optics and (nonrelativistic) high-field physics. Implications include the generation of coherent harmonic radiation up to kiloelectronvolt photon energies and control of the atomic dipole moment on a subfemtosecond $(1{\mathrm{f}\mathrm{s}=10}^{\mathrm{\ensuremath{-}}15}\mathrm{}\mathrm{s})$ time scale. This review presents the landmarks of the 30-odd-year evolution of ultrashort-pulse laser physics and technology culminating in the generation of intense few-cycle light pulses and discusses the impact of these pulses on high-field physics. Particular emphasis is placed on high-order harmonic emission and single subfemtosecond extreme ultraviolet/x-ray pulse generation. These as well as other strong-field processes are governed directly by the electric-field evolution, and hence their full control requires access to the (absolute) phase of the light carrier. We shall discuss routes to its determination and control, which will, for the first time, allow access to the electromagnetic fields in light waves and control of high-field interactions with never-before-achieved precision.

Real-time observation of valence electron motion

2010-08-01

E. Goulielmakis , Zhi-Heng Loh , A. Wirth +7 more

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Isolated Single-Cycle Attosecond Pulses

2006-10-19

G. Sansone , E. Benedetti , Francesca Calegari +7 more

We generated single-cycle isolated attosecond pulses around approximately 36 electron volts using phase-stabilized 5-femtosecond driving pulses with a modulated polarization state. Using a complete temporal characterization technique, we demonstrated the … We generated single-cycle isolated attosecond pulses around approximately 36 electron volts using phase-stabilized 5-femtosecond driving pulses with a modulated polarization state. Using a complete temporal characterization technique, we demonstrated the compression of the generated pulses for as low as 130 attoseconds, corresponding to less than 1.2 optical cycles. Numerical simulations of the generation process show that the carrier-envelope phase of the attosecond pulses is stable. The availability of single-cycle isolated attosecond pulses opens the way to a new regime in ultrafast physics, in which the strong-field electron dynamics in atoms and molecules is driven by the electric field of the attosecond pulses rather than by their intensity profile.

Extremely high-intensity laser interactions with fundamental quantum systems

2012-08-16

A. Di Piazza , Carsten Müller , Karen Z. Hatsagortsyan +1 more

The field of laser-matter interaction traditionally deals with the response of atoms, molecules and plasmas to an external light wave. However, the recent sustained technological progress is opening up the … The field of laser-matter interaction traditionally deals with the response of atoms, molecules and plasmas to an external light wave. However, the recent sustained technological progress is opening up the possibility of employing intense laser radiation to trigger or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding $10^{22}\;\text{W/cm$^2$}$ can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum, and can trigger the creation of particles like electrons, muons and pions and their corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and may even allow for potential discovery of new particles beyond the Standard Model. These are the main topics of the present article, which is devoted to a review of recent investigations on high-energy processes within the realm of relativistic quantum dynamics, quantum electrodynamics, nuclear and particle physics, occurring in extremely intense laser fields.

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The Fourier grid Hamiltonian method for bound state eigenvalues and eigenfunctions

1989-09-15

C. Clay Marston , Gabriel G. Balint‐Kurti

A new method for the calculation of bound state eigenvalues and eigenfunctions of the Schrödinger equation is presented. The Fourier grid Hamiltonian method is derived from the discrete Fourier transform … A new method for the calculation of bound state eigenvalues and eigenfunctions of the Schrödinger equation is presented. The Fourier grid Hamiltonian method is derived from the discrete Fourier transform algorithm. Its implementation and use is extremely simple, requiring the evaluation of the potential only at certain grid points and yielding directly the amplitude of the eigenfunctions at the same grid points.

Femtochemistry: Atomic-Scale Dynamics of the Chemical Bond

2000-05-31

Ahmed H. Zewail

This anthology, which is adapted from the Nobel Lecture, gives an overview of the field of Femtochemistry from a personal perspective, encompassing our research at Caltech and focusing on the … This anthology, which is adapted from the Nobel Lecture, gives an overview of the field of Femtochemistry from a personal perspective, encompassing our research at Caltech and focusing on the evolution of techniques, concepts, and new discoveries. In developing femtochemistrythe study of molecular motions in the ephemeral transition states of physical, chemical, and biological changeswe have harnessed the powerful concept of molecular coherence and developed ultrafast-laser techniques for observing these motions. Femtosecond resolution (1 fs = 10-15 s) is the ultimate achievement for studies of the dynamics of the chemical bond at the atomic level. On this time scale, matter wave packets (particle-type) can be created and their coherent evolution as a single-molecule trajectory can be observed. The field began with simple systems of a few atoms and has reached the realm of the very complex in isolated, mesoscopic, and condensed phases and in biological systems such as proteins and DNA. It also offers new possibilities for the control of reactivity and for structural femtochemistry and femtobiology.

Time-dependent propagation of high energy laser beams through the atmosphere

1976-06-01

J. A. Fleck , J. R. Morris , Michael D. Feit

Self-channeling of high-peak-power femtosecond laser pulses in air

1995-01-01

A. Braun , G. Korn , Xiaohong Liu +3 more

The self-channeling of ultrashort laser pulses through 20 m of air was demonstrated. The channeled pulse was measured to have 0.75 mJ of energy, a diameter of 80 microm FWHM, … The self-channeling of ultrashort laser pulses through 20 m of air was demonstrated. The channeled pulse was measured to have 0.75 mJ of energy, a diameter of 80 microm FWHM, and a modulated spectrum. All these values were measured to be fairly constant during the propagation of the pulse. A preliminary model is shown to explain these results.

Coherence in Spontaneous Radiation Processes

1954-01-01

R. H. Dicke

By considering a radiating gas as a single quantum-mechanical system, energy levels corresponding to certain correlations between individual molecules are described. Spontaneous emission of radiation in a transition between two … By considering a radiating gas as a single quantum-mechanical system, energy levels corresponding to certain correlations between individual molecules are described. Spontaneous emission of radiation in a transition between two such levels leads to the emission of coherent radiation. The discussion is limited first to a gas of dimension small compared with a wavelength. Spontaneous radiation rates and natural line breadths are calculated. For a gas of large extent the effect of photon recoil momentum on coherence is calculated. The effect of a radiation pulse in exciting "super-radiant" states is discussed. The angular correlation between successive photons spontaneously emitted by a gas initially in thermal equilibrium is calculated.

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Attosecond spectroscopy in condensed matter

2007-10-01

A. L. Cavalieri , Norbert Müller , Thorsten Uphues +7 more

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Control of Chemical Reactions by Feedback-Optimized Phase-Shaped Femtosecond Laser Pulses

1998-10-30

A. Assion , T. Baumert , M. Bergt +5 more

Tailored femtosecond laser pulses from a computer-controlled pulse shaper were used to optimize the branching ratios of different organometallic photodissociation reaction channels. The optimization procedure is based on the feedback … Tailored femtosecond laser pulses from a computer-controlled pulse shaper were used to optimize the branching ratios of different organometallic photodissociation reaction channels. The optimization procedure is based on the feedback from reaction product quantities in a learning evolutionary algorithm that iteratively improves the phase of the applied femtosecond laser pulse. In the case of CpFe(CO)2Cl, it is shown that two different bond-cleaving reactions can be selected, resulting in chemically different products. At least in this case, the method works automatically and finds optimal solutions without previous knowledge of the molecular system and the experimental environment.

Above threshold ionization beyond the high harmonic cutoff

1993-03-15

Kenneth J. Schäfer , Baorui Yang , L. F. DiMauro +1 more

We present high sensitivity electron energy spectra for xenon in a strong 50 ps, 1.053 \ensuremath{\mu}m laser field. The above threshold ionization distribution is smoothly decreasing over the entire kinetic … We present high sensitivity electron energy spectra for xenon in a strong 50 ps, 1.053 \ensuremath{\mu}m laser field. The above threshold ionization distribution is smoothly decreasing over the entire kinetic energy range (0--30 eV), with no abrupt changes in the slope. This is in direct contrast to the sharp cutoff observed in xenon optical harmonic generation spectra. Calculations using the single active electron approximation show excellent agreement with the observed electron distributions. These results directly address the unresolved relationship between the electron and photon emission from an atom in an intense field.

Whither the Future of Controlling Quantum Phenomena?

2000-05-05

Herschel Rabitz , Regina de Vivie‐Riedle , Marcus Motzkus +1 more

This review puts into perspective the present state and prospects for controlling quantum phenomena in atoms and molecules. The topics considered include the nature of physical and chemical control objectives, … This review puts into perspective the present state and prospects for controlling quantum phenomena in atoms and molecules. The topics considered include the nature of physical and chemical control objectives, the development of possible quantum control rules of thumb, the theoretical design of controls and their laboratory realization, quantum learning and feedback control in the laboratory, bulk media influences, and the ability to utilize coherent quantum manipulation as a means for extracting microscopic information. The preview of the field presented here suggests that important advances in the control of molecules and the capability of learning about molecular interactions may be reached through the application of emerging theoretical concepts and laboratory technologies.

Compression of amplified chirped optical pulses

1985-12-01

D. Strickland , G. Mourou

Femtosecond filamentation in transparent media

2007-02-07

A. Couairon , A. Mysyrowicz

Plasma perspective on strong field multiphoton ionization

1993-09-27

P. B. Corkum

During strong-field multiphoton ionization, a wave packet is formed each time the laser field passes its maximum value. Within the first laser period after ionization there is a significant probability … During strong-field multiphoton ionization, a wave packet is formed each time the laser field passes its maximum value. Within the first laser period after ionization there is a significant probability that the electron will return to the vicinity of the ion with very high kinetic energy. High-harmonic generation, multiphoton two-electron ejection, and very high energy above-threshold-ionization electrons are all conssequences of this electron-ion interaction. One important parameter which determines the strength of these effects is the rate at which the wave packet spreads in the direction perpendicular to the laser electric field; another is the polarization of the laser. It will be essential for experimentalists to be aware of these crucial parameters in future experiments.

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Recoil-ion and electron momentum spectroscopy: reaction-microscopes

2003-08-14

J. Ullrich , R. Moshammer , Alexander Dorn +3 more

Recoil-ion and electron momentum spectroscopy is a rapidly developing technique that allows one to measure the vector momenta of several ions and electrons resulting from atomic or molecular fragmentation. In … Recoil-ion and electron momentum spectroscopy is a rapidly developing technique that allows one to measure the vector momenta of several ions and electrons resulting from atomic or molecular fragmentation. In a unique combination, large solid angles close to 4π and superior momentum resolutions around a few per cent of an atomic unit (a.u.) are typically reached in state-of-the art machines, so-called reaction-microscopes. Evolving from recoil-ion and cold target recoil-ion momentum spectroscopy (COLTRIMS), reaction-microscopes—the `bubble chambers of atomic physics'—mark the decisive step forward to investigate many-particle quantum-dynamics occurring when atomic and molecular systems or even surfaces and solids are exposed to time-dependent external electromagnetic fields.

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High harmonic interferometry of multi-electron dynamics in molecules

2009-07-22

Olga Smirnova , Y. Mairesse , Serguei Patchkovskii +4 more

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Ein neuer und fundamentaler Versuch zur Totalreflexion

1947-01-01

F. Goos , H. Hänchen

Abstract Die Maxwellsche Theorie lehrt, daß bei Totalreflexion Lichtenergie in das dünnere Medium eindringt. Experimentell wurde bisher diese Energie immer nur im dünneren Medium selbst nachgewiesen, dadurch Licht abgezapft und … Abstract Die Maxwellsche Theorie lehrt, daß bei Totalreflexion Lichtenergie in das dünnere Medium eindringt. Experimentell wurde bisher diese Energie immer nur im dünneren Medium selbst nachgewiesen, dadurch Licht abgezapft und somit die totale Reflexion zunichte gemacht. Es soll nun hier ein neues Experiment beschrieben werden, bei dem die Lichtbewegung im dünneren Medium nachgewiesen wird durch ein Phänomen, welches sich im dichteren Medium abspielt, nachdem das Licht bereits das dünnere Medium durchlaufen und dieses wieder verlassen hat. Dabei wird die totale Reflexion in keiner Weise gestört. Das Phänomen wird quantitativ in Beziehung gesetzt zur Maxwellschen Theorie.

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Attosecond control of electronic processes by intense light fields

2003-02-05

Andrius Baltuška , Th. Udem , M. Uiberacker +7 more

All-Optical Magnetic Recording with Circularly Polarized Light

2007-07-25

C. D. Stanciu , Fredrik Hansteen , A. V. Kimel +4 more

We experimentally demonstrate that the magnetization can be reversed in a reproducible manner by a single 40 femtosecond circularly polarized laser pulse, without any applied magnetic field. This optically induced … We experimentally demonstrate that the magnetization can be reversed in a reproducible manner by a single 40 femtosecond circularly polarized laser pulse, without any applied magnetic field. This optically induced ultrafast magnetization reversal previously believed impossible is the combined result of femtosecond laser heating of the magnetic system to just below the Curie point and circularly polarized light simultaneously acting as a magnetic field. The direction of this opto-magnetic switching is determined only by the helicity of light. This finding reveals an ultrafast and efficient pathway for writing magnetic bits at record-breaking speeds.

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Beiträge zur Optik trüber Medien, speziell kolloidaler Metallösungen

1908-01-01

Gustav Mie

~+ 5 ) ( 2 v + 7 ) '??+ ' * ' ) ~+ 5 ) ( 2 v + 7 ) '??+ ' * ' )

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<i>Colloquium</i>: Aligning molecules with strong laser pulses

2003-04-17

Henrik Stapelfeldt , Tamar Seideman

We review the theoretical and experimental status of intense laser alignment---a field at the interface between intense laser physics and chemical dynamics with potential applications ranging from high harmonic generation … We review the theoretical and experimental status of intense laser alignment---a field at the interface between intense laser physics and chemical dynamics with potential applications ranging from high harmonic generation and nanoscale processing to stereodynamics and control of chemical reactions. After placing the intense laser approach in context with other alignment techniques, we proceed with a discussion of the physics underlying this technique and a description of methods of observing it in the laboratory. The roles played by the laser frequency, the pulse duration, and the system temperature are illustrated numerically and experimentally. Alignment is extended to three-dimensional orientational control, a method of hindering the rotation about all three axes of polyatomic molecules. We conclude with a discussion of potential applications of intense laser alignment.

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Time-resolved atomic inner-shell spectroscopy

2002-10-01

Markus Drescher , Michael Hentschel , Reinhard Kienberger +7 more

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Theory of high-harmonic generation by low-frequency laser fields

1994-03-01

Maciej Lewenstein , Ph. Balcou , Misha Ivanov +2 more

We present a simple, analytic, and fully quantum theory of high-harmonic generation by low-frequency laser fields. The theory recovers the classical interpretation of Kulander et al. in Proceedings of the … We present a simple, analytic, and fully quantum theory of high-harmonic generation by low-frequency laser fields. The theory recovers the classical interpretation of Kulander et al. in Proceedings of the SILAP III Works hop, edited by B. Piraux (Plenum, New York, 1993) and Corkum [Phys. Rev. Lett. 71, 1994 (1993)] and clearly explains why the single-atom harmonic-generation spectra fall off at an energy approximately equal to the ionization energy plus about three times the oscillation energy of a free electron in the field. The theory is valid for arbitrary atomic potentials and can be generalized to describe laser fields of arbitrary ellipticity and spectrum. We discuss the role of atomic dipole matrix elements, electron rescattering processes, and of depletion of the ground state. We present the exact quantum-mechanical formula for the harmonic cutoff that differs from the phenomenological law ${\mathit{I}}_{\mathit{p}}$+3.17${\mathit{U}}_{\mathit{p}}$, where ${\mathit{I}}_{\mathit{p}}$ is the atomic ionization potential and ${\mathit{U}}_{\mathit{p}}$ is the ponderomotive energy, due to the account for quantum tunneling and diffusion effects.

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Measurement of subpicosecond time intervals between two photons by interference

1987-11-02

C. K. Hong , Z. Y. Ou , L. Mandeļ

A fourth-order interference technique has been used to measure the time intervals between two photons, and by implication the length of the photon wave packet, produced in the process of … A fourth-order interference technique has been used to measure the time intervals between two photons, and by implication the length of the photon wave packet, produced in the process of parametric down-conversion. The width of the time-interval distribution, which is largely determined by an interference filter, is found to be about 100 fs, with an accuracy that could, in principle, be less than 1 fs.

Multiple-harmonic conversion of 1064 nm radiation in rare gases

1988-02-14

M. Ferray , A. L’Huillier , X. F. Li +3 more

The authors report the observation of very-high-order odd harmonics of Nd:YAG laser radiation in rare gases at an intensity of about 1013 W cm-2. Harmonic light as high as the … The authors report the observation of very-high-order odd harmonics of Nd:YAG laser radiation in rare gases at an intensity of about 1013 W cm-2. Harmonic light as high as the 33rd harmonic in the XUV range (32.2 nm) is generated in argon. The key point is that the harmonic intensity falls slowly beyond the fifth harmonic as the order increases. Finally, a UV continuum, beginning at 350 nm and extending down towards the short wavelength region is apparent in xenon.

Single-Cycle Nonlinear Optics

2008-06-19

E. Goulielmakis , Martin Schultze , Michael Hofstetter +7 more

Nonlinear optics plays a central role in the advancement of optical science and laser-based technologies. We report on the confinement of the nonlinear interaction of light with matter to a … Nonlinear optics plays a central role in the advancement of optical science and laser-based technologies. We report on the confinement of the nonlinear interaction of light with matter to a single wave cycle and demonstrate its utility for time-resolved and strong-field science. The electric field of 3.3-femtosecond, 0.72-micron laser pulses with a controlled and measured waveform ionizes atoms near the crests of the central wave cycle, with ionization being virtually switched off outside this interval. Isolated sub-100-attosecond pulses of extreme ultraviolet light (photon energy approximately 80 electron volts), containing approximately 0.5 nanojoule of energy, emerge from the interaction with a conversion efficiency of approximately 10(-6). These tools enable the study of the precision control of electron motion with light fields and electron-electron interactions with a resolution approaching the atomic unit of time ( approximately 24 attoseconds).

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Bright Coherent Ultrahigh Harmonics in the keV X-ray Regime from Mid-Infrared Femtosecond Lasers

2012-06-07

Tenio Popmintchev , Ming-Chang Chen , Dimitar Popmintchev +7 more

High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding … High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond laser in a high-pressure gas, ultrahigh harmonics can be generated, up to orders greater than 5000, that emerge as a bright supercontinuum that spans the entire electromagnetic spectrum from the ultraviolet to more than 1.6 kilo-electron volts, allowing, in principle, the generation of pulses as short as 2.5 attoseconds. The multiatmosphere gas pressures required for bright, phase-matched emission also support laser beam self-confinement, further enhancing the x-ray yield. Finally, the x-ray beam exhibits high spatial coherence, even though at high gas density the recolliding electrons responsible for HHG encounter other atoms during the emission process.

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Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses

2005-05-25

A. V. Kimel , A. Kirilyuk , P. A. Usachev +3 more

Über die Ausbreitung der Wellen in der drahtlosen Telegraphie

1909-01-01

A. Sommerfeld

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Tomographic imaging of molecular orbitals

2004-12-01

Jiro Itatani , J. Lévesque , D. Zeidler +5 more

Ultrafast optical manipulation of magnetic order

2010-09-22

A. Kirilyuk , A. V. Kimel , Th. Rasing

The interaction of subpicosecond laser pulses with magnetically ordered materials has developed into a fascinating research topic in modern magnetism. From the discovery of subpicosecond demagnetization over a decade ago … The interaction of subpicosecond laser pulses with magnetically ordered materials has developed into a fascinating research topic in modern magnetism. From the discovery of subpicosecond demagnetization over a decade ago to the recent demonstration of magnetization reversal by a single $40\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$ laser pulse, the manipulation of magnetic order by ultrashort laser pulses has become a fundamentally challenging topic with a potentially high impact for future spintronics, data storage and manipulation, and quantum computation. Understanding the underlying mechanisms implies understanding the interaction of photons with charges, spins, and lattice, and the angular momentum transfer between them. This paper will review the progress in this field of laser manipulation of magnetic order in a systematic way. Starting with a historical introduction, the interaction of light with magnetically ordered matter is discussed. By investigating metals, semiconductors, and dielectrics, the roles of (nearly) free electrons, charge redistributions, and spin-orbit and spin-lattice interactions can partly be separated, and effects due to heating can be distinguished from those that are not. It will be shown that there is a fundamental distinction between processes that involve the actual absorption of photons and those that do not. It turns out that for the latter, the polarization of light plays an essential role in the manipulation of the magnetic moments at the femtosecond time scale. Thus, circularly and linearly polarized pulses are shown to act as strong transient magnetic field pulses originating from the nonabsorptive inverse Faraday and inverse Cotton-Mouton effects, respectively. The recent progress in the understanding of magneto-optical effects on the femtosecond time scale together with the mentioned inverse, optomagnetic effects promises a bright future for this field of ultrafast optical manipulation of magnetic order or femtomagnetism.

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Coherence Properties of Optical Fields

1965-04-01

L. Mandeļ , E. Wolf

This article presents a review of coherence properties of electromagnetic fields and their measurements, with special emphasis on the optical region of the spectrum. Analyses based on both the classical … This article presents a review of coherence properties of electromagnetic fields and their measurements, with special emphasis on the optical region of the spectrum. Analyses based on both the classical and quantum theories are described. After a brief historical introduction, the elementary concepts which are frequently employed in the discussion of interference phenomena are summarized. The measure of second-order coherence is then introduced in connection with the analysis of a simple interference experiment and some of the more important second-order coherence effects are studied. Their uses in stellar interferometry and interference spectroscopy are described. Analysis of partial polarization from the standpoint of correlation theory is also outlined. The general statistical description of the field is discussed in some detail. The recently discovered universal "diagonal" representation of the density operator for free fields is also considered and it is shown how, with the help of the associated generalized phase-space distribution function, the quantum-mechanical correlation functions may be expressed in the same form as the classical ones. The sections which follow deal with the statistical properties of thermal and nonthermal light, and with the temporal and spatial coherence of blackbody radiation. Later sections, dealing with fourth- and higher-order coherence effects include a discussion of the photoelectric detection process. Among the fourth-order effects described in detail are bunching phenomena, the Hanbury Brown-Twiss effect and its application to astronomy. The article concludes with a discussion of various transient superposition effects, such as light beats and interference fringes produced by independent light beams.

The Quantum Theory of Optical Coherence

1963-06-15

Roy J. Glauber

The concept of coherence which has conventionally been used in optics is found to be inadequate to the needs of recently opened areas of experiment. To provide a fuller discussion … The concept of coherence which has conventionally been used in optics is found to be inadequate to the needs of recently opened areas of experiment. To provide a fuller discussion of coherence, a succession of correlation functions for the complex field strengths is defined. The $n\mathrm{th}$ order function expresses the correlation of values of the fields at $2n$ different points of space and time. Certain values of these functions are measurable by means of $n$-fold delayed coincidence detection of photons. A fully coherent field is defined as one whose correlation functions satisfy an infinite succession of stated conditions. Various orders of incomplete coherence are distinguished, according to the number of coherence conditions actually satisfied. It is noted that the fields historically described as coherent in optics have only first-order coherence. On the other hand, the existence, in principle, of fields coherent to all orders is shown both in quantum theory and classical theory. The methods used in these discussions apply to fields of arbitrary time dependence. It is shown, as a result, that coherence does not require monochromaticity. Coherent fields can be generated with arbitrary spectra.

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Double-slit photoelectron interference in strong-field ionization of the neon dimer

2018-12-27

M. Kunitski , Nicolas Eicke , P. Huber +7 more

Wave-particle duality is an inherent peculiarity of the quantum world. The double-slit experiment has been frequently used for understanding different aspects of this fundamental concept. The occurrence of interference rests … Wave-particle duality is an inherent peculiarity of the quantum world. The double-slit experiment has been frequently used for understanding different aspects of this fundamental concept. The occurrence of interference rests on the lack of which-way information and on the absence of decoherence mechanisms, which could scramble the wave fronts. In this letter, we report on the observation of two-center interference in the molecular frame photoelectron momentum distribution upon ionization of the neon dimer by a strong laser field. Postselection of ions, which were measured in coincidence with electrons, allowed choosing the symmetry of the continuum electronic wave function, leading to observation of both, gerade and ungerade, types of interference.

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Compression of amplified chirped optical pulses

1985-10-01

D. Strickland , G. Mourou

Attosecond physics

2009-02-02

Ferenc Krausz , Misha Ivanov

Intense ultrashort light pulses comprising merely a few wave cycles became routinely available by the turn of the millennium. The technologies underlying their production and measurement as well as relevant … Intense ultrashort light pulses comprising merely a few wave cycles became routinely available by the turn of the millennium. The technologies underlying their production and measurement as well as relevant theoretical modeling have been reviewed in the pages of Reviews of Modern Physics (Brabec and Krausz, 2000). Since then, measurement and control of the subcycle field evolution of few-cycle light have opened the door to a radically new approach to exploring and controlling processes of the microcosm. The hyperfast-varying electric field of visible light permitted manipulation and tracking of the atomic-scale motion of electrons. Striking implications include controlled generation and measurement of single attosecond pulses of extreme ultraviolet light as well as trains of them, and real-time observation of atomic-scale electron dynamics. The tools and techniques for steering and tracing electronic motion in atoms, molecules, and nanostructures are now becoming available, marking the birth of attosecond physics. In this article these advances are reviewed and some of the expected implications are addressed.

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Attosecond science

2007-06-01

P. B. Corkum , Ferenc Krausz

Attosecond metrology

2001-11-01

Michael Hentschel , Reinhard Kienberger , Christian Spielmann +7 more

Frequency-Resolved Optical Gating: The Measurement of Ultrashort Laser Pulses

2000-01-01

Rick Trebino

Dynamic Microcavities Arrays from Colliding Attosecond Pulses in a Medium

2025-06-25

Р. М. Архипов , М. В. Архипов , N. N. Rosanov | Optics Letters

Angular distributions of single-photon and above-threshold detachment of sulfur hexafluoride anions in femtosecond laser fields

2025-06-25

Tian Sun , Yong Liang , D. X. Liu +4 more | The Journal of Chemical Physics

We experimentally investigate the photodetachment of sulfur hexafluoride anions (SF6−) in 400 nm 35 fs laser fields using a home-built mass-selective anion source combined with electron velocity map imaging (VMI). … We experimentally investigate the photodetachment of sulfur hexafluoride anions (SF6−) in 400 nm 35 fs laser fields using a home-built mass-selective anion source combined with electron velocity map imaging (VMI). The electron kinetic energy and the photoelectron angular distributions (PADs) are obtained from the VMI measurements. In addition to the single-photon detachment, two-photon above-threshold detachment (ATD), which is induced by strong laser fields with peak intensity higher than &gt;1.0×1013W/cm2, is clearly identified for the first time. By fitting the measured PADs, the partial-wave distributions of the detached electron are achieved, resulting in the coefficiency of the s-orbital (p-orbital) of ∼68.1%(∼31.9%) in the mixed s–p molecular orbital of SF6−, which is in good agreement with the ab initio calculations. The ponderomotive shift in the ATD channel is investigated and different behaviors for the strong-field photodetachment comparing with that in weak laser fields are discussed. The present study adds to our knowledge on the photodeachment of the SF6− anion and sheds some light on the dynamics of the interaction of polyatomic molecular anions with ultrafast strong laser fields.

Attosecond X-ray pulse generation by waveform control of mid-infrared laser

2025-06-25

Bonggu Shim , Zenghu Chang | Optics Express

Phase evolution of strong-field ionization

2025-06-24

Lynda Hutcheson , Maximilian Hartmann , Gergana D. Borisova +6 more | Physical Review Research

We investigate the time-dependent evolution of the dipole phase shift induced by strong-field ionization (SFI) using attosecond transient absorption spectroscopy (ATAS) for time delays where the pump-probe pulses overlap. We … We investigate the time-dependent evolution of the dipole phase shift induced by strong-field ionization (SFI) using attosecond transient absorption spectroscopy (ATAS) for time delays where the pump-probe pulses overlap. We study measured and calculated time-dependent attosecond transient absorption spectra of the ionic <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>4</a:mn><a:mi mathvariant="italic">d</a:mi><a:mo>→</a:mo><a:mn>5</a:mn><a:mi mathvariant="italic">p</a:mi></a:mrow></a:math> in xenon, and present the time-dependent line shape parameters in the complex plane. We attribute the complex dynamics to the contribution of three distinct processes: accumulation of ionization, transient population, and retrapping of excited states arising from polarization of the ground state. Published by the American Physical Society 2025

Simple and efficient high-energy few-cycle pulse generation through hybrid MPC and filamentation

2025-06-24

Yuhao Luo , Chao Li , Xincai Diao +6 more | Optics Express

Energy redistribution of a chaotic injected laser for pulsed random bit generation

2025-06-24

Zhen-Yu Zhao , H. Zhang , Yiying Gu +1 more | Optics Express

Robust implicit quantum control of interacting spin chains

2025-06-23

NULL AUTHOR_ID | Physical review. A/Physical review, A

Phase-dependent Coulomb focusing effect in orthogonally polarized two-color laser fields

2025-06-23

NULL AUTHOR_ID | Physical review. A/Physical review, A

Generation of femtosecond polygonal optical vortices from a mode-locked quasi-frequency-degenerate laser

2025-06-23

Hongyu Liu , Lisong Yan , Liang Wang +7 more | Light Science & Applications

Abstract Polygonal optical vortices—a new subset of optical vortices—uniquely enable numerous applications due to the new degrees of freedom offered and their customizable light intensity structure. So far, their generation … Abstract Polygonal optical vortices—a new subset of optical vortices—uniquely enable numerous applications due to the new degrees of freedom offered and their customizable light intensity structure. So far, their generation has only been reported for continuous wave. Here, we demonstrate the first femtosecond polygonal optical vortex pulses, which is also the first pulsed demonstration of such vortices in general. From a mode-locked Yb:KGW laser oscillator, femtosecond Hermit-Gaussian pulses at the quasi-frequency-degenerate state were generated and subsequently converted by astigmatic mode conversion to femtosecond polygonal optical vortices. They have light intensity distributions of square, pentagonal, and hexagonal shapes and carry orbital angular momentums. In all these variations, the average power and pulse duration are greater than one watt and less than 500 fs. These results open the way to new applications in the fields of femtosecond optical tweezer and three-dimensional microstructure fabrication.

Combining Optical Control and Geometrical Optimization for Efficient Control of Competing Molecular Photoinduced Processes Far from the Ground State

2025-06-20

David Veintemillas , Bo Y. Chang , Ignacio R. Solá | Journal of Chemical Theory and Computation

The yield of a photochemical process can be maximized by optimizing the driving fields, such as in optical control, or the initial wave function, as in geometrical optimization. We combine … The yield of a photochemical process can be maximized by optimizing the driving fields, such as in optical control, or the initial wave function, as in geometrical optimization. We combine both algorithms in an iterative process, showing very fast convergence and great improvement in the yields, as applied to driving population to the second excited state of the molecular hydrogen cation through the first excited dissociative state by a pump-pump scheme. The results reveal the impact of the initial vibrational coherences in photoinduced processes that occur at nuclear configurations very far from the ground state, or that are even mediated by processes in the continuum. On the other hand, depending on whether we maximize the total electronic population (that mainly dissociates) or the bound population, the initial wave functions change considerably, involving nodal patterns in the position or in the momentum representations, respectively, that lead to different dynamics.

Bringing weak transitions to light

2025-06-20

Yu He , Xiao‐Min Tong , Shuyuan Hu +7 more | Nature Communications

Abstract Weak transitions between quantum states are of fundamental importance for a broad range of phenomena from analytical biochemistry to precision physics, but generally challenge experimental detection. Due to their … Abstract Weak transitions between quantum states are of fundamental importance for a broad range of phenomena from analytical biochemistry to precision physics, but generally challenge experimental detection. Due to their small cross sections scaling with the absolute square of their transition matrix elements, spectroscopic measurements often fail in particular in the presence of competing background processes. Here we introduce a general concept to break this scaling law and enhance the transition probability by exploiting a stronger laser-coupled pathway to the same excited state. We demonstrate the concept experimentally by attosecond transient absorption spectroscopy in helium atoms. The quasi-forbidden transitions from the ground state 1 s 2 to the weakly coupled doubly excited 2 p 3 d and s p 2,4− states are boosted by an order of magnitude. Enhancing single-photon-suppressed transitions can find widespread applicability, from spectral diagnostics of complex molecules in life and chemical sciences to precision spectroscopy of weak transitions in metastable atomic nuclei in the search for new physics.

Interpretational Pitfalls of Singlet Fission Studies by Impulsively Generated Vibrational Wavepackets

2025-06-20

Marcin Andrzejak , Grzegorz Mazur , Piotr Petelenz | The Journal of Physical Chemistry C

Wavelength-dependent photodissociation of iodomethylbutane

2025-06-20

Valerija Music , Felix Allum , Ludger Inhester +7 more | Scientific Reports

Abstract Ultrashort XUV pulses of the Free-Electron-LASer in Hamburg (FLASH) were used to investigate laser-induced fragmentation patterns of the prototypical chiral molecule 1-iodo-2-methyl-butane ( $$\hbox {C}_5$$ $$\hbox {H}_{11}$$ I) in … Abstract Ultrashort XUV pulses of the Free-Electron-LASer in Hamburg (FLASH) were used to investigate laser-induced fragmentation patterns of the prototypical chiral molecule 1-iodo-2-methyl-butane ( $$\hbox {C}_5$$ $$\hbox {H}_{11}$$ I) in a pump-probe scheme. Ion velocity-map images and mass spectra of optical-laser-induced fragmentation were obtained for subsequent FEL exposure with photon energies of 63 eV and 75 eV. These energies specifically address the iodine 4d edge of neutral and singly charged iodine, respectively. The presented ion spectra for two optical pump-laser wavelengths, i.e., 800 nm and 267 nm, reveal substantially different cationic fragment yields in dependence on the wavelength and intensity. For the case of 800-nm-initiated fragmentation, the molecule dissociates notably slower than for the 267 nm pump. The results underscore the importance of considering optical-laser wavelength and intensity in the dissociation dynamics of this prototypical chiral molecule that is a promising candidate for future studies of its asymmetric nature.

Tuning the Ellipticity of High-Order Harmonics from Helium in Orthogonal Two-Color Laser Fields

2025-06-18

Shushan Zhou , Hao Wang , Yue Qiao +4 more | Symmetry

High-order harmonic generation in atomic systems driven by laser fields with tailored symmetries provides a powerful approach for producing structured ultrafast light sources. In this work, we theoretically investigate the … High-order harmonic generation in atomic systems driven by laser fields with tailored symmetries provides a powerful approach for producing structured ultrafast light sources. In this work, we theoretically investigate the ellipticity control of high-order harmonics emitted from helium atoms exposed to orthogonally polarized two-color laser pulses with a 1:3 frequency ratio. The polarization properties of the harmonics are governed by the interplay between the spatial symmetry of the driving field and the atomic potential. By numerically solving the time-dependent Schrödinger equation, we show that fine-tuning the relative phase and amplitude ratio between the fundamental and third-harmonic components enables selective symmetry breaking, resulting in the emission of elliptically and circularly polarized harmonics. Remarkably, we achieve near-perfect circular polarization (ellipticity ≈ 0.995) for the 5th harmonic, as well as highly circularly polarized 17th (0.945), 21st (0.96), and 23rd (0.935) harmonics, demonstrating a level of polarization control and efficiency that exceeds previous schemes. Our results highlight the advantage of using a 1:3 frequency ratio orthogonally polarized two-color laser field over the conventional 1:2 configuration, offering a promising route toward tunable attosecond light sources with tailored polarization characteristics.

Room-temperature high-average-power strong-field terahertz source based on industrial high-repetition-rate femtosecond laser

2025-06-17

Deyin Kong , Yichen Su , Cheng Song +1 more | Photonics Research

Two-octave mid-infrared pulses via chirp-optimized cascaded intra-pulse difference frequency generation

2025-06-17

Tongyu Feng , Hao Yuan , Yahui Ma +7 more | Optics Express

Spatiotemporal Evolution in Femtosecond Second-Harmonic Generation with Back-Conversion

2025-06-17

Jianqiu Xu , Jie Guo , Zichen Gao +5 more | Optics Express

Attosecond virtual charge dynamics in dielectrics

2025-06-16

Gian Luca Dolso , Shunsuke A. Sato , Giacomo Inzani +5 more | Nature Photonics

All-optical controlled multichannel nonlinear holography for switchable beam shaping in atomic vapor

2025-06-16

Pan Churong , Li Huangjie , zhang xuzhe +7 more | Optica

Attosecond Rabi oscillations in high harmonic generation resonantly driven by extreme ultraviolet laser fields

2025-06-16

Alba de las Heras , Carlos Hernández-García , Javier Serrano +4 more | Physical Review Research

High-order harmonic generation driven by intense extreme ultraviolet (EUV) fields merges quantum optics and attosecond science, giving rise to an appealing route for the generation of coherent EUV and soft … High-order harmonic generation driven by intense extreme ultraviolet (EUV) fields merges quantum optics and attosecond science, giving rise to an appealing route for the generation of coherent EUV and soft x-ray light for high-resolution imaging and spectroscopies. We theoretically investigate ultrafast resonant dynamics during the interaction of He atoms with strong extreme ultraviolet pulses. At high driving intensities, we identify record fast attosecond Rabi oscillations imprinting observable signatures in the high harmonic spectrum. At field strengths suppressing the Coulomb potential barrier for all the bound states, we demonstrate the survival of the attosecond two-level dynamics for several Rabi cycles. Consequently, this intense EUV laser-atom interaction reveals a strong-field scenario in which resonant coupling of two-level bound-bound transitions prevails, in contrast to the bound-continuum transitions typically dominant in conventional infrared strong-field regimes. Our findings of a high-frequency up-conversion regime combining two coexisting pathways—a two-level coupling and a bound-continuum coupling—set an interesting perspective for extreme attosecond nonlinear optics with intense short-wavelength laser fields. Published by the American Physical Society 2025

134 W, 1.34 mJ, 209 fs Femtosecond Pulses From a Rod-Type Photonic Crystal Fiber Amplifier

2025-06-16

Meng Su , Hao Meng , Tianmeng Jiao +6 more | Optics Letters

Resolving electron partial waves in multiphoton ionization of molecules

2025-06-13

Ruolin Gong , Yang Li , Shengzhe Pan +7 more | Science Advances

Resolving partial waves, including their amplitudes and phases, is crucial for understanding the intricate structure and dynamics of the photoelectron released. However, the knowledge is limited because of the complexities … Resolving partial waves, including their amplitudes and phases, is crucial for understanding the intricate structure and dynamics of the photoelectron released. However, the knowledge is limited because of the complexities of the multiphoton interactions with molecules in the nonperturbative regime. Here, we address these challenges using an orthogonal two-color (OTC) scheme, which combines different photon energies and polarizations of the laser fields to produce characteristic photoelectron angular distributions (PADs) that vary with the laser phase. By analyzing the phase-dependent PADs, the partial waves, including their individual amplitudes and phases, involved in the nondissociative and dissociative single ionization of H 2 are unambiguously resolved. In addition, the interaction phases accumulated during the absorption of multiple photons of different polarizations are revealed. The OTC scheme works as a powerful tool to achieve a partial-wave decomposition of the photoelectron wave packet launched via multiphoton ionization and explore attosecond electron dynamics in strong laser fields.

Field-resolved attosecond solitons

2025-06-13

Amelie M. Heinzerling , Francesco Tani , Manoram Agarwal +3 more | Nature Photonics

Nonperturbative effects in attosecond four-wave-mixing spectra

2025-06-13

NULL AUTHOR_ID | Physical review. A/Physical review, A

Peculiarities of supercontinuum generation in high-pressure He, N2, Ar, and CO2 gases

2025-06-13

Yu. É. Geints , V. O. Kompanets , Alexander V. Kireev +1 more | Optics & Laser Technology

Electro-Optical Modulation of the Nonlinear Optical Response in a GaAs/AlGaAs Symmetric Multiple Quantum Well System

2025-06-12

C. A. Dagua-Conda , John A. Gil-Corrales , R. V. H. Hahn +3 more | Physics

External fields modify the confinement potential and electronic structure in a multiple quantum well system, affecting the light–matter interaction. Here, we present a theoretical study of the modulation of the … External fields modify the confinement potential and electronic structure in a multiple quantum well system, affecting the light–matter interaction. Here, we present a theoretical study of the modulation of the nonlinear optical response simultaneously employing an intense non-resonant laser field and an electric field. Considering four occupied subbands, we focus on a GaAs/AlGaAs symmetric multiple quantum well system with five wells and six barriers. By solving the Schrödinger equation through the finite element method under the effective mass approximation, we determine the electronic structure and the nonlinear optical response using the density matrix formalism. The laser field dresses the confinement potential while the electric field breaks the inversion symmetry. The combined effect of both fields modifies the intersubband transition energies and the overlap of the wave functions. The results obtained demonstrate an active tunability of the nonlinear optical response, opening up the possibility of designing optoelectronic devices with tunable optical properties.

Some Insights on Kerr Lensing Effects

2025-06-10

Kamel Aı̈t-Ameur , Abdelkrim Hasnaoui | Photonics

The research on high-order transverse modes in lasers was largely abandoned a few years after the invention of the laser in 1960. The main reason for this was that high-order … The research on high-order transverse modes in lasers was largely abandoned a few years after the invention of the laser in 1960. The main reason for this was that high-order beams are more divergent and less bright than the Gaussian beam. In the present paper, we showed that the behaviour of LGp0 beams faced to the optical Kerr effect (OKE) varies considerably depending on the mode order (p = 0 or p≥1). We focused our attention on the properties of LG00 and LG10 beams when subject to OKE, and we found that the LG10 beam keeps its focusability much better than the LG00 beam. This property has at least two applications concerning first the conception of high-intensity laser chains not based on a Gaussian beam but on an LG10 beam and second, the use of an LG10 beam instead of the usual Gaussian beam which can reduce drastically the protection of optical limiters based on OKE; this constitutes a counter-measure against such limiters.

Extra cost of erasure due to quantum lifetime broadening

2025-06-06

NULL AUTHOR_ID | Physical review. A/Physical review, A