CUOS Noon Seminar: High intensity lasers and solids, with pizza!

Title: Extreme-contrast, high-intensity laser pulses and their interactions with solids

Intense, femtosecond laser pulses with extreme contrast, provide the advantage of “instantaneous” excitation of solid-density matter. This facilitates the generation of homogenous high-energy-density matter, laser-driven particle acceleration in ultrathin foil targets and efficient interactions with various structured targets. However, the basic interactions of such extreme-contrast laser pulses with solids are not well explored, especially in experiments.

The laser contrast of state-of-the-art terawatt/petawatt class, ultrahigh-contrast laser systems at the nanosecond to 10s of picosecond scale is in the range of 10^-10 to 10^-12, typically using single/double plasma mirrors. We have produced extreme-contrast (better than 10-12 by a few orders), relativistic laser pulses, using efficient second-harmonic generation in an LBO crystal [1]. I will present the temporal shapes of such pulses, measured using self-diffraction frequency-resolved optical gating (SD-FROG) [2]. I will talk about some special “femtosecond-structures” seen in the temporal profiles, and what impact they have on relativistic laser solid interactions.

1. C. Aparajit et al., Opt. Lett. 46, 3540-3543 (2021)
2. C. Aparajit et al., Appl. Phys. Lett. 123, 141108 (2023)