Self-compression by femtosecond pulse filamentation: experiments versus numerical simulations

Area of Science:

• * Ultrafast optics and nonlinear phenomena.
• * Laser physics and pulse manipulation.

Background:

• * Generating ultrashort laser pulses is crucial for various scientific applications.
• * Self-compression in optical filaments offers a promising avenue for achieving shorter pulse durations.

Purpose of the Study:

• * To experimentally and numerically analyze femtosecond pulse self-compression in filaments.
• * To investigate the efficiency and scalability of this compression technique.

Main Methods:

• * Experimental demonstration of pulse compression using femtosecond filaments.
• * Numerical simulations incorporating dispersion, Kerr nonlinearity, and plasma generation.
• * Quantitative comparison between experimental results and simulation data.

Main Results:

• * Achieved sixfold pulse compression from 45 fs to 7.4 fs at millijoule energies.
• * Observed a characteristic spectrotemporal structure with a compressible blue wing and red pedestal.
• * Validated a comprehensive propagation model for filament self-compression.

Conclusions:

• * Filament self-compression is an efficient and scalable method for generating ultrashort pulses.
• * The observed spectrotemporal structure is explained by underlying physical mechanisms.
• * This technique eliminates the need for external dispersion compensation.