Relativistic Laser-Solid Interactions Driven by Multiple Wavelengths

This thesis presents an experimental and computational study of relativistically-intense, laser-plasma interactions driven at wavelengths ranging from 400 - 2100 nm. Studying such interactions gives us insight to the complex interplay between high electric fields and relativistically-moving charged particles. The recent development of high peak-power, ultra-fast laser systems has enabled the exploration of relativistic laser-plasma interactions with table-top systems at high repetition rates. In this thesis, relativistically driven harmonics of infrared light sources (1.3μm and 2.1μm)were experimentally observed using solid density targets. The harmonic dependence on the driving laser polarization was measured by polarization measurements of the output harmonics up to the sixth harmonic. The introduction of a second, non-commensurate beam provides additional control over the relativistic harmonics, which are governed by the electron critical surface during the interaction. Finally, copper foils irradiated at intensities>1021W/cm2indicate that thin,<5μm thick targets may be uniformly heated to temperatures exceeding 3 keV while remaining near solid density through the use of K-shell x-ray spectroscopy as part of a LaserNetUS experiment at the ALEPH laser facility