Ultrafast laser micro-nano structuring of transparent materials with high aspect ratio

TL;DR

This paper reviews how ultrafast laser techniques enable high aspect ratio micro-nano structuring inside transparent materials, transforming previously harmful effects into beneficial tools for advanced applications like glass separation.

Contribution

It provides a comprehensive overview of the physics, characterization, and applications of ultrafast laser processing in transparent materials, highlighting recent advances and the role of nonlinear effects.

Findings

High aspect ratio structures are achievable via nonlinear propagation.

Filamentation of laser beams is beneficial for energy deposition.

Applications include non-ablative glass separation.

Abstract

Ultrafast lasers are ideal tools to process transparent materials because they spatially confine the deposition of laser energy within the material's bulk via nonlinear photoionization processes. Nonlinear propagation and filamentation were initially regarded as deleterious effects. But in the last decade, they turned out to be benefits to control energy deposition over long distances. These effects create very high aspect ratio structures which have found a number of important applications, particularly for glass separation with non-ablative techniques. This chapter reviews the developments of in-volume ultrafast laser processing of transparent materials. We discuss the basic physics of the processes, characterization means, filamentation of Gaussian and Bessel beams and provide an overview of present applications.