Laser-induced plasmonic colours on metals.

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Metallic nanoparticles exhibit plasmonic resonances, historically used for coloring glass.
• Recent advancements in plasmonics have renewed interest in metal nanostructures for surface coloration.
• Existing top-down coloration methods face limitations for large-scale industrial use.

Purpose of the Study:

• To develop a scalable, bottom-up approach for creating a full spectrum of non-iridescent colors on metal surfaces.
• To investigate the relationship between laser parameters and resulting colors.
• To demonstrate the industrial applicability of the developed coloration technique.

Main Methods:

• Utilized picosecond laser pulses for a bottom-up approach to color metal surfaces.
• Applied the technique to silver, gold, copper, and aluminum, including large-scale objects like 5kg silver coins with significant topographic variations.
• Conducted statistical image analyses of laser-irradiated surfaces to determine nanoparticle size distributions.

Main Results:

• Achieved a full palette of non-iridescent colors on various metals.
• Established that color is controllable via a single parameter: total accumulated fluence.
• Demonstrated suitability for high-throughput industrial applications.
• Correlated nanoparticle size distributions with observed color phenomena.

Conclusions:

• The picosecond laser-based bottom-up method offers a scalable and controllable approach to metal surface coloration.
• The process leverages plasmonic resonances in laser-induced nanoparticles for color generation.
• This technique is well-suited for industrial applications requiring high throughput and precise color control.