Related papers: Table-top Nonlinear Extreme Ultraviolet Spectrosco…
Photoelectron emission from excited states of laser-dressed atomic helium is analyzed with respect to laser intensity-dependent excitation energy shifts and angular distributions. In the two-color XUV (exteme ultra\-violet) -- IR (infrared)…
High-harmonic generation (HHG) is used as a source for various imaging applications in the extreme ultraviolet spectral range. It offers spatially coherent radiation and unique elemental contrast with the potential for attosecond time…
We investigate, by solving the time-dependent Schr\"{o}dinger equation in the single-active-electron approximation in helium, a two-color scheme for tabletop high-order harmonic generation (HHG) that combines a mid-infrared (MIR) driving…
Transient extreme ultraviolet (XUV) spectroscopy probes core level transitions to unoccupied valence and conduction band states. Uncertainty remains to what degree the core-hole created by the XUV transition modifies the measurement of…
High-harmonic generation (HHG) in solids has rapidly emerged as a promising platform for creating compact attosecond sources and probing ultrafast electron dynamics. Resonant metasurfaces are essential for enhancement of the otherwise small…
High-brightness femtosecond-to-attosecond pulses are indispensable for probing electron dynamics on their fundamental temporal scales. X-ray free-electron lasers (XFELs) at high repetition rates will facilitate high-statistics measurements…
The generation of harmonic radiation through a non-linear mechanism driven by bunching at fundamental frequency is an important option in the operation of high gain Free-Electron Lasers (FELs). The use of harmonic generation at a large…
We study high-order harmonic generation (HHG) resulting from the illumination of plasmonic nanostructures with a short laser pulse. We show that both the inhomogeneities of the local electric field and the confinement of the electron motion…
Second-harmonic generation (SHG) is a powerful surface-specific probe for centrosymmetric materials, with broad relevance to energy and biological interfaces. Plasmonic nanomaterials have been extensively utilized to amplify this nonlinear…
The ideal laser source for the emerging research field of nonlinear Terahertz (THz) spectroscopy should offer radiation with a large versatility and deliver both ultra-intense multi-octave spanning single-cycle pulses and user-selectable…
We calculate high-harmonic generation (HHG) by intense infrared lasers in atoms and molecules with the inclusion of macroscopic propagation of the harmonics in the gas medium. We show that the observed experimental spectra can be accurately…
Bright, coherent soft X-ray (SXR) radiation is essential to a variety of applications in fundamental research and life sciences. So far, high photon flux in this spectral region can only be delivered by synchrotrons, free electron lasers or…
Optical-field sampling using second-harmonic generation (SHG) from strong-field ionization enables ultrabroadband terahertz detection, but the microscopic origin of the SHG signal and its ultrabroadband response have been unclear. Here we…
Correlated phenomena occur in quantum materials because of the delicate interplay between internal degrees of freedom, leading to multiple symmetry-broken quantum phases. Resolving the structure of these phases is a key challenge, often…
Second harmonic generation microscopy (SHG) is a powerful imaging modality which has found applications in investigating both biological and synthetic nanostructures. Like all optical microscopy techniques, the resolution of SHG is limited…
We report the observation of optical second harmonic generation (SHG) in single-layer indium selenide (InSe). We measure a second harmonic signal of $>10^3$ $\textrm{cts/s}$ under nonresonant excitation using a home-built confocal…
Time- and angle-resolved photoemission spectroscopy has played an important role in revealing the non-equilibrium electronic structures of solid-state materials. The implementation of high harmonic generation to obtain a higher photon…
Coherent light sources in deep ultra-violet (DUV) is essential for various applications such as biomedical imaging and biosensing. Nonlinear crystals (NLCs) generate DUV light, but limited by its bulky thickness, low transparency, and…
The development of schemes for coherent nonlinear time-domain spectroscopy in the extreme-ultraviolet regime (XUV) has so far been impeded by experimental difficulties that arise at these short wavelengths. In this work we present a novel…
Extending the high-harmonic cutoff with experimentally accessible fields is essential for advancing tabletop coherent extreme ultraviolet (EUV) and soft X-ray sources. Although terahertz (THz) assistance offers a promising route, cutoff…