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Showing 1 to 20 of 38 for “"high harmonic generation"”.
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Modelling of capillary high harmonic generation
High harmonic generation (HHG) is now an accepted method for laboratory based generation of XUV and soft x-ray light. HHG produces pulses that are highly coherent, with a pulse length in the femtosecond or attosecond timescales. To predict the XUV output from an HHG experiment, both the emission …
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Limits of long wavelength High Harmonic Generation
… pushing for long wavelength driver pulses for High Harmonic Generation (HHG). The advantage of longer wavelengths is that the cut-off of the harmonic spectrum can be increased without the need for large electric fields. Large electric field is undesirable because it leads to large plasma …
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Limits of High Harmonic Generation conversion efficiency
High Harmonic Generation (HHG) is a fascinating phenomenon from both fundamental and technological point of view. It enables the generation of attosecond pulses and can have applications in EUV lithography and bio-microscopy. HHG can be described by the Three Step Model (TSM), due to the three …
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Capturing atomic and electronic motion with high harmonic generation light pulses
Contains fulltext : 90924.pdf (Publisher’s version ) (Open Access)
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High harmonic generation and attosecond dynamics in small organic molecules and biomolecules
… we report on calculations of ionization and high harmonic generation (HHG) in a number of small molecules, using the EDAMAME code, which combines a TDDFT description of electronic dynamics with a classical treatment of ionic dynamics. The work is divided into two main areas.<br/><br/> In the …
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High harmonic generation by short laser pulses: time-frequency behavior and applications to attophysics
High harmonic generation (HHG) is a process in which noble gas atoms excited by an intense laser field at frequency ω<sub>1</sub> emit radiation of higher frequencies that are odd integer multiples of ω<sub>1</sub>. Driven by an infrared laser, high harmonic radiation can span from the optical into …
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Tabletop coherent extreme ultraviolet and soft X-ray sources based on high harmonic generation
High harmonic generation (HHG) is a fascinating strong-field physics phenomenon that occurs when a laser pulse with a moderate intensity interacts with atoms and partially ionizes the atoms. A series of harmonics are generated at similar efficiencies and extend to a few tenth, even thousandth, …
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Adaptive control of coherent soft X-rays
… x-rays through the nonlinear optical process of high-harmonic generation allows for the monitoring of the fastest events ever observed in the laboratory. The attosecond pulses produced are the fundamental tool for the time-resolved study of electron motion in atoms, molecules, clusters, liquids …
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Designing a nanoscale x-ray source: towards single molecule x-ray scattering
… of a femtosecond X-ray source based on high harmonic generation in an argon filled hollow capillary waveguide. The system has demonstrated excellent efficiency at generating harmonics in the range 20-50 eV and is tuneable by exploiting the ionization-induced blue-shift that occurs in the …
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Homodyne High-harmonic Spectroscopy: Coherent Imaging of a Unimolecular Chemical Reaction
At the heart of high harmonic generation lies a combination of optical and collision physics entwined by a strong laser field. An electron, initially tunnel-ionized by the field, driven away then back in the continuum, finally recombines back to rest in its initial ground state via a radiative …
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Modeling of nonlinear ultrashort optical pulse propagation
… nonlinear wave mixing, plasma blue-shifting, and high harmonic generation. I also demonstrate the capabilities of our versatile simulation package, which can handle optical pulse propagation through a host of geometries and guiding structures. Finally, the simulation package is used to investigate …
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Development and spatio-spectral mapping of a capillary high harmonic source
… development and operation of a capillary based High Harmonic Generation (HHG) system. Using this system a coherent beam of soft x-rays is generated, studied and applied. A series of experiments was then undertaken in order to deepen our knowledge of the HHG process and to optimise the …
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High intensity femtosecond enhancement cavities
To produce extreme ultraviolet radiation via high harmonic generation (HHG) in rare gases, light intensities in excess of 1014 W/cm 2 are required. Usually such high intensity are obtained by parametric amplification of laser pulses, which in turn reduces the pulse repetition rate to a few kHz. …
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Extreme ultraviolet polarization optics for polarimetry of structured high harmonics
High Harmonic Generation (HHG) is a leading way to generate table-top coherent extreme ultraviolet (EUV) and attosecond pulses. Polarization characterization in this spectral range is important to understand the phenomena of HHG and quantify the light used for experiments. Furthermore, polarization …
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Nonlinear optical and photoemission spectroscopies of quantum materials
… the input. In this thesis, we discuss how second harmonic generation (SHG) and time and angle-resolved photoemission spectroscopy (tr-ARPES) based on high harmonic generation can offer a unique pathway toward studying quantum materials in the context of broken symmetries and nonequilibrium …
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Characteristics of Multilayer Mirrors in the X-ray and Extreme Ultraviolet Radiation Ranges
… X-ray microprobes, EUVL lithography systems and high harmonic generation sources, i.e. monochromator, broad-angle supermirror, broadband intensity and polarising beamsplitters and order-selecting mirror. The particle swarm optimisation method was successfully applied in a global search of …
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Strong-field physics with ultrafast optical resonators
Light fields from modern high-intensity, femtosecond laser systems can produce electrical forces that rival the binding forces in atomic and solid-state systems. In this strong-field regime, conventional non-linear optics gives way to novel phenomena such as the production of attosecond bursts of …
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Methods for engineering sub-two-cycle mode-locked lasers
… enhancement cavities, such as those used in high harmonic generation. In contrast to the standard approach of dynamic simulation, which converges linearly, our algorithm converges quadratically to the stable solution, typically converging two to three orders of magnitude faster than the …
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The role of near time coherent contrast on ultrafast laser driven radiation sources
… of third order dispersion (spectral phase) on high harmonic generation. The third order dispersion (TOD) changes the shape of the incident pulse creating either leading or trailing satellite pulses which can influence the harmonics generated. A scan of TOD is undertaken, and the harmonics …
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Table-top XUV nanoscope
… imaging. Such radiation can be produced via high harmonic generation (HHG) by focusing a highly intense ultrashort laser pulse into gas. In order to obtain high flux XUV radiation suitable for CDI, various generation conditions are explored. By observing the fluorescence from an argon gas jet …
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