EUV Microscopy with a Tabletop High Harmonic Generation Source: ..

T1 - Toward spatial and spectral control of waveguided high-harmonic generation

High-order Harmonic Generation from Molecules High …

The second part of the research concerns ion acceleration and high-order harmonic generation from solid-state targets using high-intensity laser pulses with ultra-high contrast.

High-order harmonic generation (HHG) – Ultrafast …

These disturbances exist in numerous forms including transients, sags, swells, over voltages, under voltages, harmonics, outages, frequency variations and high frequency noise.

The scope of this thesis is to present novel investigations and methods towards an enhancement of the flux and maximum energy of the accelerated ions and the harmonic radiation via an improved understanding of the underlying physics and, to provide a more complete identification of the actual requirements of the laser and the target for optimum output.


generation of harmonic currents due to switching action of the ..

Here, a state-of-the-art model is developed that can predict both the evolution of an intense laser pulse propagating through a gas-filled fibre, and the extreme ultraviolet field that it generates. This model is first used to discover a new mechanism for compressing energetic laser pulses to few cycle durations within short gas-filled fibres at pressures where high-order harmonic generation is routinely performed. Next, the fibre design is optimised for enhanced phase-matching using the model. Once fabricated and integrated into the source characterisation apparatus, the conversion efficiency at 30-40 nm is found to be almost an order of magnitude higher than comparable sources. Preliminary simulations also predict that isolated attosecond pulses may emerge from the fibre if parameters are carefully tuned.

Additionally, a 13.5 nm source is developed in an extended gas cell geometry. Filters suitable for this wavelength are tested and a single harmonic is then selected and brought to a focus. This apparatus is now being used by the wider scientific community to image test objects and biological samples.

Introduction to High-Order Harmonic Generation | …

Comparison of the mean, 75th percentile and 90th percentile emissions assessments demonstrate the effectiveness of percentile assessment in eliminating outlying high distortion periods from the assessed results.AFRIKAANSE OPSOMMING: Die vinnige toenemende implementering van grootskaalse sonkragfotovoltaïese (PV) aanlegte wêreldwyd, bied nuwe tegniese uitdagings, insluitende die risiko van onaanvaarbare hoë harmoniese spanningvervorming in die netwerk.

Introduction to High-Order Harmonic Generation

AB - Generating intense radiation in the wavelength band of the extreme ultraviolet (XUV, 100 to 10 nm) remains a very challenging goal in today’s scientific research. In this thesis, we describe a unique XUV source based on high harmonic generation. We have thoroughly investigated a number of intrinsic properties of high harmonic generation in a waveguided geometry. We conclude that using waveguides allows for spatial and spectral control of high-harmonic radiation. Our studies have also shown that waveguided high harmonic generation is particularly suited for producing radiation at XUV wavelengths with excellent beam coherence and unique spectral features. Future work, focused on using higher drive laser energy and larger waveguide diameters offer the potential of achieving higher XUV output energy.

of high-order harmonic generation and high-order ..

APMA 2810Y. Discrete high-D Inferences in Genomics
Genomics is revolutionizing biology and biomedicine and generated a mass of clearly relevant high-D data along with many important high-D discreet inference problems. Topics: special characteristics of discrete high-D inference including Bayesian posterior inference; point estimation; interval estimation; hypothesis tests; model selection; and statistical decision theory.