Related papers: Ab-initio multi-scale simulation of high-harmonic …
High-harmonic generation (HHG) in solids has been touted as a way to probe ultrafast dynamics and crystal symmetries in condensed matter systems. Here, we investigate the polarization properties of high-order harmonics generated in…
We observe a new regime of coherent XUV radiation generation in noble gases induced by femtosecond pulses at very high intensities. This XUV emission has both a reduced divergence and spectral width as compared to high-order harmonic…
High-order harmonic generation (HHG) provides a broad spectral bandwidth for synthesizing attosecond pulses. However, in the current HHG schemes, only part of the harmonics can be phase-locked, which limits the ability to achieve shorter…
We report the enhancement of individual harmonics generated at a relativistic ultra-steep plasma vacuum interface. Simulations show the harmonic emission to be due to the coupled action of two high velocity oscillations -- at the…
Attosecond pulses of coherent extreme ultraviolet (XUV) light are instrumental for investigating subatomic dynamics and can be produced using a free-electron laser (FEL). It has been suggested that an optical FEL, which employs a laser…
Extreme ultraviolet (XUV) interferometry is technically challenging to implement. One approach to generating interference between two XUV pulses relies on driving high-harmonic generation in a gas jet with two collinearly overlapping…
We study the temporal and spatial dynamics of the large amplitude and frequency modulation that can be induced in an intense, few cycle laser pulse as it propagates through a rapidly ionizing gas. Our calculations include both single atom…
It is demonstrated by single-atom simulations that X-ray signals in the 3.4 to 4 keV region from an 8 micron laser driven high harmonic generation can be increased by more than two orders of magnitude when a single-cycle pulse centered at…
We review the main research directions ongoing in the development of high-harmonic generation-based extreme ultraviolet sources for the synthesization and application of trains and isolated attosecond pulses to time-resolved spectroscopy. A…
The long standing issue of separating resonant from non-resonant processes in extreme nonlinear optics is resolved. The theoretical formalism is applied to high harmonic generation (HHG) in solids and reveals a deeper view into the dominant…
We report a systematic investigation into the processes behind a near hundredfold enhanced second harmonic wave generated from a laser-induced air plasma, by examining the temporal dynamics of the frequency conversion processes, and the…
Harmonic generation in atoms and molecules has reshaped our understanding of ultrafast phenomena beyond the traditional nonlinear optics and has launched attosecond physics. Harmonics from solids represent a new frontier, where both…
The optical phase of the driving field in the process of high harmonic generation and the coherence properties of the harmonics are fundamental concepts in attosecond physics. Here, we consider to drive the process by incoherent classical…
We investigate the process of circularly polarized high harmonic generation in molecules using a bicircular laser field. In this context, we show that molecules offer a very robust framework for the production of circularly polarized…
We studied the high-order harmonic generation (HHG) from 2D solid materials in circularly and bichromatic circularly polarized laser fields numerically by simulating the dynamics of single-active-electron processes in 2D periodic…
We report theoretical calculations of high-order harmonic generation (HHG) of Xe with the inclusion of multi-electron effects and macroscopic propagation of the fundamental and harmonic fields in an ionizing medium. By using the…
High-harmonic generation (HHG) is a highly nonlinear optical process that typically requires an intense laser to trigger emissions at integer multiples of the driving field frequency. However, the strong fields required for conventional HHG…
The study of high-harmonic generation in confined quantum systems is vital to establishing a complete physical picture of harmonic generation from atoms and molecules to bulk solids. Based on a multilevel approach, we demonstrate how…
We study theoretically and experimentally High Harmonic Generation (HHG) using two non collinear driving fields focused in gases. We show that these two fields form a non stationary blazed active grating in the generation medium. The…
High-order harmonic generation (HHG) enables the up-conversion of intense infrared or visible femtosecond laser pulses into extreme-ultraviolet attosecond pulses. However, the highly nonlinear nature of the process results in low conversion…