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Article
Ultrafast superheating and melting of bulk ice
The superheating of a solid above its melting point without actually causing it to melt is easy to achieve in substances that form high-quality crystals. That should be the case for water. But nothing is simpl...
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Chapter and Conference Paper
Novel Time- and Frequency-resolved Double Pump Spectroscopy of Short-lived Precursors: The Solvated Electron in Methanol
A combined investigation of the generation process and relaxation dynamics after reexcitation of intermediates of solvated electrons is presented. The experimental technique provides a much more detailed pictu...
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Chapter and Conference Paper
Novel fs-Precursors of Solvated Electrons in Water in the MIR: A Charge Transfer Process
Two intermediates with peak absorptions at 2.9 μm and 1.6 μm are observed for the first time during the generation of hydrated electrons. A charge transfer process is proposed involving an OH:e--complex and parti...
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Chapter and Conference Paper
Widely Tunable Two-Color Femtosecond Ti:Sapphire Laser with Perfect Pulse Syncronization
The development of the Kerr-lens mode-locked femtosecond Ti:sapphire laser [1] has had a great impact on ultrafast spectroscopy. Special versions have permitted the generation of pulses shorter than 10 fs [2,3...
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Chapter
LO Phonon Emission and Femtosecond Non-Equilibrium Dynamics of Hot Electrons in GaAs
We present the first spectrally and temporally resolved studies of hot electron dynamics in the low density regime (N ≈ 1015cm-3) where LO phonon emission is found to be the dominant process for energy relaxation...
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Chapter
Kerr Lens Mode-Locking of a Sub-Picosecond Optical Parametric Oscillator
Synchronous pum** of singly resonant, optical parametric oscillators (OPO) yields intense, tunable radiation from the VIS to the near IR.1, 2 Especially OPO’s working in the pulsed regime generate light pulses ...
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Chapter and Conference Paper
Femtosecond Kinetics of Freely Relaxing Non-Fermi Carrier Distributions in GaAs
The first energy and time resolved femtosecond study at low excitation densities (N = 1014 – 1017cm-3) is presented. Carrier-carrier and carrier-phonon interactions are separately observed.
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Article
Sum-frequency spectroscopy of physisorbed and chemisorbed molecules at liquid and solid surfaces using band-width-limited picosecond pulses
We studied the vibrational Sum-Frequency (SF) spectra of long chain fatty alcohols and amines physisorbed at liquid/air interfaces and of OctadecylTrichlorSilan (OTS) chemisorbed on glass/air interfaces in situ, ...
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Chapter
Workshop session on experimental investigation of structural and dynamic features in varying conditions
This session centered around the comparison of relaxation times measured by different techniques. First A. Geiger made the point that quadrupolar relaxation is one of the best methods for obtaining reorientati...
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Chapter
Picosecond Holeburning Spectroscopy in the Infrared of Water and other Hydrogen-Bonded Systems
The substructure of the broad absorption bands in the infrared spectrum of hydrogen bonded systems is investigated by photophysical holeburning techniques with tunable picosecond pulses. The OH stretching mode...
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Article
Time domain coherent Raman techniques
Exploiting the polarization properties of coherent Raman scattering in liquids, new techniques of polarization-controlled 3-colour CARS are described. It is shown that the nonresonant, resonant-isotropic and r...
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Chapter
Time-, Frequency- and Polarization- Resolved Infrared Spectroscopy of Hydrogen-Bonded Systems
Using intense ultrashort laser pulses novel spectroscopic information on molecular vibrations is obtained. The OH stretching mode of hydroxilic groups is applied as a spectral probe for the dynamics and struct...
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Article
Efficient amplification of sub-picosecond pulses of a non-CW dye laser
Efficient amplification in a dye laser amplifier is investigated theoretically and experimentally. A five-level rate equation approach is considered including rotational relaxation of the dye molecules. The ef...
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Article
Feedback control of an actively-passively mode-locked Nd:Glass laser
Improved performance of a pulsed solid-state laser by electrooptic amplitude control is reported. A sequence of ≃200 pulses is reproducibly generated with 10 Hz repetition rate, 3 ps duration and 300 μJ total ...
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Article
Collective modes — An analytical model for active mode locking in the transient case
A novel concept is presented for the pulse generation in the linear regime of an actively loss modulated laser. Introducing collective laser modes, the frequency detuning of the modulator and the statistical i...
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Article
Polarization effects of picosecond CARS in liquids
Coherent Raman scattering of delayed probing pulses after ultrafast excitation is investigated under generalized polarization conditions. Three factors are shown to contribute to the scattering signal:
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Chapter and Conference Paper
Time — resolved Infrared Spectroscopy on the Picosecond and Sub Picosecond Timescale Studying Coherent Pulse Propagation
In the past time-resolved coherent Raman scattering techniques have been used for numerous studies of molecular dynamics in the electronic ground state. For investigations in condensed matter at room temperatu...
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Chapter and Conference Paper
Introduction
It has become convenient in recent years to use the term “Time-Resolved Vibrational Spectroscopy” (TRVS) for experiments in which a molecular sample is temporarily perturbed and its consecutive evolution studi...
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Chapter and Conference Paper
High-Resolution Fourier Transform Raman Spectroscopy with Ultrashort Laser Pulses
In the past,considerable progress has been achieved in high resolution Raman spectroscopy /1/. Using several versions of the stimulated Raman scattering process and narrow band laser sources,the limitations of...
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Chapter and Conference Paper
Ultrafast Vibronic Dynamics of Dye Molecules Studied by the Induced Grating Method
In recent years numerous papers have investigated the induced grating method for the study of the ultrafast dynamics of dye molecules /1/. A quantitative understanding of the signal transients observed at shor...
