Related papers: First-principles approach to ultrafast pump-probe …
Laser treatment has emerged into a cornerstone of industrial manufacturing. This creates the demand to understand in detail the involved physical processes and their dynamics, to control the process, and to keep guard in-situ the laser…
We present a pump-probe technique for monitoring ultrafast polarizability changes. In particular, we use it to measure the plasma density created at the temporal focus of a self-compressing higher-order pump soliton in gas-filled…
Carrying digital information in traditional copper wires is becoming a major issue in electronic circuits. Optical connections such as fiber optics offers unprecedented transfer capacity, but the mismatch between the optical wavelength and…
Femtosecond spectroscopy is applied to study transient electronic and lattice processes in bismuth. Components with relaxation times of 1 ps, 7 ps and ~ 1 ns are detected in the photoinduced reflectivity response of the crystal. To…
The rapidly increasing use of sensors throughout different research disciplines and the demand for more efficient devices with less power consumption depends critically on the emergence of new sensor materials and novel sensor concepts.…
How molecules convert light energy to perform a specific transformation is a fundamental question in photophysics. Ultrafast spectroscopy reveals the kinetics associated with electronic energy flow, but little is known about how absorbed…
We performed ultrafast degenerate pump-probe spectroscopy on monolayer WSe2 near its exciton resonance. The observed differential reflectance signals exhibit signatures of strong many-body interactions including the exciton-exciton…
The Bethe-Salpeter equation (BSE) is a powerful theoretical approach that is capable to accurately treat electron-hole interactions in materials in an excited state. We developed an ab initio framework based on the BSE to describe a…
Developing from the transient absorption (TA) spectroscopy, the two dimensional (2D) spectroscopy with pump-probe geometry has emerged as a versatile approach for alleviating the difficulty on implementing the 2D spectroscopy with other…
We propose the new method of essential decrease of transit-time broadening of Doppler-free absorption resonances on transitions between long-lived quantum levels of atoms (or molecules) of a rarefied gas medium. This method is based on…
Lead halide perovskites show remarkable performance when used in photovoltaic and optoelectronic devices. However, the peculiarities of light-matter interactions in these materials in general are far from being fully explored experimentally…
There are conflicting predictions and reports on the character of the exciton Mott transition (EMT) in monolayer transition metal dichalcogenides. It could be either a discontinuous or a continuous transition from the excitonic to the…
We present an effective linear response approach to pump-probe femtosecond coherence spectroscopy in the well separated pulse limit. The treatment presented here is based on a displaced and squeezed state representation for the…
Standard optical pump-probe methods analyze a system's temporal response to a laser pulse within sub-femtoseconds to several nanoseconds, constrained by the optical delay line's length. While resistance is a sensitive detector in various…
A theory of pump-probe spectroscopy is developed in which optical fields drive two-quantum, Raman-like transitions between ground state sublevels. Three fields are incident on an ensemble of atoms. Two of the fields act as the pump field…
Coherent excitation of materials via ultrafast laser pulses can have interesting, observable dynamics in time-resolved photoemission measurements. The broad spectral width of ultrafast pump pulses can coherently excite multiple exciton…
We report high-pressure photoluminescence, Raman scattering, and x-ray diffraction measurements on a lead-free halide perovskite $Cs_3Sb_2Br_9$. At about 3 GPa, an electronic transition manifests itself through a broad minimum in linewidth,…
Highly intense, sub-picosecond terahertz (THz) pulses can be used to induce ultrafast temperature jumps (T-jumps) in liquid water. A supercritical state of gas-like water with liquid density is established, and the accompanying structural…
Excitons, electron-hole pairs bound by the Coulomb potential, are fundamental quasiparticles of coherent light-matter interaction energizing processes from photosynthesis to optoelectronics. Excitons are observed in semiconductors, and…
Electron motion on the (sub-)femtosecond time scale constitutes the fastest response in many natural phenomena such as light-induced phase transitions and chemical reactions. Whereas static electron densities in single molecules can be…