相关论文: Femtosecond Resolution Experiments at Third-Genera…
Pump-probe electron energy-loss spectroscopy (EELS) with femtosecond temporal resolution will be a transformative research tool for studying non-equilibrium chemistry and electronic dynamics of matter. In this paper, we propose a new…
The theory for time-resolved photoemission spectroscopy as applied to pump-probe experiments is developed and solved for the generic case of a strongly correlated material. The formal development incorporates all of the nonequilibrium…
Studies of ultrafast dynamics along with femtosecond-pulse metrology rely on non-linear processes, induced solely by the exciting/probing pulses or the pulses to be characterized. Extension of these approaches to the extreme-ultraviolet…
The paper describes a time- and angle-resolved photoemission apparatus consisting of a hemispherical analyzer and a pulsed laser source. We demonstrate 1.48-eV pump and 5.90-eV probe measurements at the >10.5-meV and >240-fs resolutions by…
We present and implement a new scheme for extended multi-channel selective femtosecond coherent control based on symmetry properties of the excitation channels. Here, an atomic non-resonant two-photon absorption channel is coherently…
Through dedicated measurements in the optical regime we demonstrate that ptychography can be applied to reconstruct complex-valued object functions that vary with time from a sequence of spectral measurements. A probe pulse of approximately…
The success of non-linear optics relies largely on pulse-to-pulse consistency. In contrast, covariance based techniques used in photoionization electron spectroscopy and mass spectrometry have shown that wealth of information can be…
The origin of the coherences in two-dimensional spectroscopy of photosynthetic complexes remains disputed. Recently it has been shown that in the ultrashort-pulse limit, oscillations in a frequency-integrated pump-probe signal correspond…
Saturable absorption is a nonlinear effect where a material's ability to absorb light is frustrated due to a high influx of photons and the creation of electron vacancies. Experimentally induced saturable absorption in copper revealed a…
The potential of photon detectors to achieve precise timing information is of increasing importance in many domains, PET and CT scanners in medical imaging and particle physics detectors, amongst others. The goal to increase by an order of…
Pump-probe experiments combining pulses from a X-ray FEL and an optical femtosecond laser are very attractive for sub-picosecond time-resolved studies. Since the synchronization between the two independent light sources to an accuracy of…
We have developed an improved method of time-resolved x-ray reflectivity (XRR) using monochromatic synchrotron radiation. Our method utilizes a polycapillary x-ray optic to create a range of incident angles and an area detector to collect…
We describe a setup to study ultrafast dynamics in gas-phase molecules using time-resolved photoelectron and photoion spectroscopy. The vacuum ultraviolet (VUV) probe pulses are generated via strong field high-order harmonic generation from…
Generation of high-repetition-rate, femtosecond, soliton pulse trains through dual-wavelength pumping of a dispersion-decreasing fiber is studied numerically. The achievable shortest pulse width is found to be limited by third-order…
We propose a method for a straightforward characterization of the temporal shape of femtosecond pulses in the extreme-ultraviolet/soft X-ray spectral region. The approach is based on the presence of a significant linear frequency chirp in…
Attosecond photoelectron spectroscopy is often performed with interferometric experimental setups that require outstanding stability. We demonstrate and characterize in detail an actively stabilized, versatile, high spectral resolution…
Singly ionized nitrogen molecules in ambient air pumped by near-infrared femtosecond laser give rise to superradiant emission. Here we demonstrate coherent control of this superradiance by injecting a pair of resonant seeding pulses inside…
We have developed a single-shot imaging technique that can capture ultrafast events occurring on femtosecond to picosecond time scales. The technique is based on an optical pump-probe method, in which multiple time-delayed femtosecond…
Femtosecond optical pump-probe technique is used to study charge carrier dynamics in few-layer MoS2 samples fabricated by mechanical exfoliation. An ultrafast pump pulse excites carriers and differential reflection of a probe pulse tuned to…
Several ways to electronically synchronize different types of amplified femtosecond laser systems are presented, based on a single freely programmable electronics hardware: Arbitrary-detuning asynchronous optical sampling, as well as…