Laser-induced breakdown versus self-focusing for focused picosecond pulses in water

Area of Science:

• Optics and Photonics
• Nonlinear Optics
• Laser-Plasma Interactions

Background:

• Nonlinear propagation of intense laser pulses in materials is crucial for applications.
• Understanding the interplay between self-focusing and laser-induced breakdown is essential for controlling laser-matter interactions.

Purpose of the Study:

• To numerically investigate the nonlinear propagation of picosecond laser pulses focused in water.
• To determine the conditions under which self-focusing precedes or follows laser-induced breakdown.
• To derive a predictive criterion for the dominant nonlinear optical effect.

Main Methods:

• Numerical simulations of nonlinear pulse propagation.
• Analysis of picosecond laser pulses in water under varying focusing conditions and input powers.

Main Results:

• Self-focusing and laser-induced breakdown compete during nonlinear propagation.
• The relative timing of these phenomena depends critically on pulse duration and focusing geometry.
• A criterion is established to predict the dominant effect.

Conclusions:

• The derived criterion provides a tool for predicting self-focusing versus laser-induced breakdown in water.
• This understanding is vital for applications involving high-power picosecond lasers in condensed matter.