Laser microprocessing of metal surfaces using a tightly focused radially polarized beam

Area of Science:

• Physics
• Materials Science
• Optical Engineering

Background:

• Ultrafast laser microprocessing is crucial for advanced material fabrication.
• Controlling laser-matter interactions at the nanoscale is a key challenge.
• Radially polarized beams offer unique focusing properties.

Purpose of the Study:

• To investigate the role of the longitudinal electric field in laser ablation of metals.
• To analyze the influence of material properties on ablation crater morphology.
• To explore potential applications in ultrafast laser microprocessing.

Main Methods:

• Utilizing tight focusing of a radially polarized beam for laser ablation.
• Conducting single-shot ablation experiments on various metal materials.
• Analyzing the resulting surface craters for shape and characteristics.

Main Results:

• A strong longitudinal electric field is generated at the focus.
• Ablation craters exhibit either spot or doughnut shapes, dependent on the metal.
• The longitudinal electric field demonstrably promotes material removal.

Conclusions:

• The longitudinal electric field significantly impacts laser ablation of metals.
• Material-dependent crater morphology offers insights into ablation mechanisms.
• This approach presents a novel scheme for ultrafast laser microprocessing with improved spatial resolution.