Self-compression of 2 microm laser filaments

Area of Science:

• Nonlinear Optics
• Laser Physics
• Plasma Physics

Background:

• Filamentation of ultrashort laser pulses is crucial for high-intensity light generation.
• Existing studies often focus on near-visible wavelengths (e.g., 800 nm).
• Mid-infrared (mid-IR) sources offer unique advantages for pulse generation.

Purpose of the Study:

• To numerically investigate ultrashort laser pulse filamentation at a 2-micrometer carrier wavelength.
• To explore pulse self-compression mechanisms in noble gases and air.
• To assess the potential for generating single-cycle pulses in the mid-IR.

Main Methods:

• Numerical simulations of laser-matter interaction.
• Analysis of pulse propagation dynamics in various gaseous media.
• Investigation of self-focusing, pulse steepening, and plasma defocusing effects.

Main Results:

• Mid-IR ultrashort pulses (near single-cycle duration) can be generated near the self-focusing threshold.
• Filamentation mechanism involves a combination of optical self-focusing, pulse steepening, and plasma defocusing.
• On-axis spectra and spectral phases were analyzed.

Conclusions:

• Mid-IR single-cycle pulse generation is achievable in noble gases and air.
• This capability has significant applications in generating high-order harmonics.
• Enables the production of isolated attosecond pulses.