Isolated sub-fs XUV pulse generation in Mn plasma ablation

Area of Science:

• Atomic, Molecular, and Optical Physics
• Ultrafast Laser Science
• Plasma Physics

Background:

• High-order harmonic generation (HHG) is a key process for producing extreme ultraviolet (XUV) and soft X-ray radiation.
• Previous studies with multi-cycle laser pulses did not show significant resonant enhancement in HHG spectra.
• Understanding HHG in different plasma environments is crucial for developing novel light sources.

Purpose of the Study:

• To investigate high-order harmonic generation in laser-produced manganese plasmas.
• To explore the effect of sub-4-femtosecond (fs) drive laser pulses on HHG spectra.
• To analyze the spectral characteristics and intensity contrast of generated harmonics.

Main Methods:

• Generation of manganese plasma using intense laser fields.
• Application of sub-4-femtosecond (fs) laser pulses as the driving source for HHG.
• Spectroscopic analysis of the emitted high-order harmonics.
• Theoretical modeling to interpret the experimental observations.

Main Results:

• Observed resonant enhancement in a narrow spectral region (~2.5 eV) around the 31st harmonic (~50 eV).
• Achieved an intensity contrast exceeding one order of magnitude for the enhanced harmonic region compared to adjacent harmonics.
• Demonstrated a significant difference from results obtained with multi-cycle laser pulses.
• Theoretical modeling indicated the formation of isolated sub-femtosecond pulses from the enhanced harmonic emission.

Conclusions:

• Ultrashort laser pulses enable resonant enhancement in high-order harmonic generation from manganese plasmas.
• The observed resonant enhancement leads to the generation of isolated sub-femtosecond pulses.
• This finding opens new pathways for attosecond pulse generation and probing ultrafast dynamics.