Open AccessLaser-plasma coupling for enhanced ablation of GaAs with combined femtosecond and nanosecond pulses
Author(s) -
Haley Kerrigan,
Majid Masnavi,
Robert Bernath,
Shermineh Rostami Fairchild,
Martin Richardson
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.420599
Subject(s) - femtosecond , nanosecond , materials science , plasma , ultrashort pulse , optics , laser , shadowgraph , ablation , femtosecond pulse shaping , laser ablation , pulse (music) , physics , engineering , quantum mechanics , detector , aerospace engineering
The laser-plasma interactions that occur during the ablation of solid materials by a femtosecond filament superimposed with a lower-intensity nanosecond pulse are investigated. Pulses of 50 fs duration with intensities of ∼10 14 W/cm 2 centered at 800 nm are combined with 8 ns pulses at 1064 nm with ∼10 10 W/cm 2 intensity with delays of ±40 ns on crystalline GaAs targets in air. For each delay, the volume of material removed by a single femtosecond-nanosecond dual-pulse is compared to the laser-plasma interactions that are captured with ultrafast shadowgraph imaging of the plasma and shockwave generated by each pulse. Sedov-Taylor analysis of the shockwaves provides insight on the coupling of energy from the second pulse to the plasma. These dynamics are corroborated with radiation-hydrodynamics simulations. The interaction of the secondary pulse with the pre-existent plasma is shown to play a critical role in enhancing the material removal.