29 May, 2024
New Article: Polarization Singularities For Shaping Of Vector Flat-Top Beams

The article – Polarization singularities for shaping of vector flat-top beams in utilization for high-power laser micromachining of various materials – was published in Optics & Laser Technology, Volume 177, 2024. Written by the authors: Ernestas Nacius, Orestas Ulčinas, Sergej Orlov, Vytautas Jukna.

“Structured light is desired in the micromachining of various materials. As the latest ultrashort laser sources increase the average power by increasing the repetition rate, the efficiency of the process becomes crucial in laser micromachining.

The standard Gaussian beam shape, because of its slow ascending/descending slope, is not the most efficient beam, neither in precise energy deposition nor in heat management.
Flat-top beams are required for precise and even energy distribution and are used in laser ablation or thin-film removal.”

“Polarization singularities provide a unique ability to dynamically shape vector beams using the design of geometric phase elements (GPEs) proposed in this work and based on hollow center space variant waveplates. (…)

The produced GPEs were successfully used to generate high-energy polarization singularities and these were employed in glasswelding, thinfilm removal, and silicon ablation applications.

The experimental results demonstrate the significant impact of the shape of the beam on the material processing results. Polarization singularities with tunable Flat-Top beam profiles offer enhanced control over heat deposition and material modification, enabling the production of more precise and uniform structures compared to Gaussian beams.

These findings underscore the potential of flat-top beams in various material processing applications, including volume modification of transparent materials and selective surface ablation of thin metallic films, as well as for semiconductors.”

Read the full article