Logo Logo
Help
Contact
Switch language to German
Investigation of the XUV Emission from the Interaction of Intense Femtosecond Laser Pulses with Solid Targets
Investigation of the XUV Emission from the Interaction of Intense Femtosecond Laser Pulses with Solid Targets
The generation of coherent high-order harmonics from the interaction of ultra-intense femtosecond laser pulses with solid density plasmas holds the promise for table-top sources of intense extreme ultraviolet (XUV) and soft x-ray (SXR) radiation. Furthermore, they give rise to the prospect of combining the attosecond pulse duration of conventional gas-harmonic sources with the photon flux currently only available from large-scale free-electron laser or synchrotron facilities. In this thesis a series of experiments studying various aspects of harmonic generation from such a plasma source are presented and the emitted XUV-radiation is characterized spectrally, spatially and temporally. The measurements probe the dynamics of the plasma surface on a sub-laser-cycle time scale and help to increase our understanding of the harmonic generation process. It is shown that, at moderate intensities and laser contrast, the emitted harmonics are indeed phase-locked but chirped and emitted as a train of XUV-bursts of attosecond duration. Measurements with very high contrast relativistically intense driving pulses reveal the generation of harmonics up to the relativistic cutoff in a diffraction-limited beam with constant divergence observed for all wavelength. This implies that the harmonics are generated on a curved surface and travel through a focus after the target possibly opening a route towards extreme intensities in the process. In addition it is found that a target roughness on the scale of the wavelength of the highest generated harmonic does not adversely affect the harmonic beam quality implying that the generation of diffraction-limited keV-harmonic beams should be possible. In a third set of experiments the first demonstration of harmonic generation from solid targets using an 8 fs driving laser opens a route towards the generation of ultra-intense single-as pulses and gives conclusive evidence for the unequal spacing of the harmonic emission. Based on these results the development of ultra-intense sources of single as-pulses from the interaction of intense laser pulses with solid surfaces could advance at a fast pace making XUV-pump XUV-probe type investigations of nonlinear processes with attosecond time resolution feasible in the near future.
Not available
Hörlein, Rainer
2009
English
Universitätsbibliothek der Ludwig-Maximilians-Universität München
Hörlein, Rainer (2009): Investigation of the XUV Emission from the Interaction of Intense Femtosecond Laser Pulses with Solid Targets. Dissertation, LMU München: Faculty of Physics
[img]
Preview
PDF
Hoerlein_Rainer.pdf

9MB

Abstract

The generation of coherent high-order harmonics from the interaction of ultra-intense femtosecond laser pulses with solid density plasmas holds the promise for table-top sources of intense extreme ultraviolet (XUV) and soft x-ray (SXR) radiation. Furthermore, they give rise to the prospect of combining the attosecond pulse duration of conventional gas-harmonic sources with the photon flux currently only available from large-scale free-electron laser or synchrotron facilities. In this thesis a series of experiments studying various aspects of harmonic generation from such a plasma source are presented and the emitted XUV-radiation is characterized spectrally, spatially and temporally. The measurements probe the dynamics of the plasma surface on a sub-laser-cycle time scale and help to increase our understanding of the harmonic generation process. It is shown that, at moderate intensities and laser contrast, the emitted harmonics are indeed phase-locked but chirped and emitted as a train of XUV-bursts of attosecond duration. Measurements with very high contrast relativistically intense driving pulses reveal the generation of harmonics up to the relativistic cutoff in a diffraction-limited beam with constant divergence observed for all wavelength. This implies that the harmonics are generated on a curved surface and travel through a focus after the target possibly opening a route towards extreme intensities in the process. In addition it is found that a target roughness on the scale of the wavelength of the highest generated harmonic does not adversely affect the harmonic beam quality implying that the generation of diffraction-limited keV-harmonic beams should be possible. In a third set of experiments the first demonstration of harmonic generation from solid targets using an 8 fs driving laser opens a route towards the generation of ultra-intense single-as pulses and gives conclusive evidence for the unequal spacing of the harmonic emission. Based on these results the development of ultra-intense sources of single as-pulses from the interaction of intense laser pulses with solid surfaces could advance at a fast pace making XUV-pump XUV-probe type investigations of nonlinear processes with attosecond time resolution feasible in the near future.