CC BY
10LM-I-18
Non-diffractive ultrafast beams; new opportunities for material
processing
R. Stoian
Laboratoire Hubert Curien, CNRS UMR 5516, Université Jean Monnet, 42000 St Etienne, France
razvan.stoian@univ-st-etienne.fr
Material structuring represents today the base for rapidly growing application areas in emerging technologies. Ultrafast lasers contribute essentially to the development of micro/nanotechnologies, being able to structure materials with utmost precision [1] . Alongside efficiency, the question of resolution is crucial for further industrial insertion and the challenge lies now in pushing the capacity t reach the nanoscale, with resulting morphologies defining upgraded functions to be attached to the structured material. Optical processing being typically limited by diffraction to scales comparable to tl wavelength, an alternative strategy to achieve extreme scales relies on harvesting material reactions to light, experiencing thus not an optical limit but a material organization limit which, for a large range oi material phenomena, lies one order of magnitude below. We will discuss ultrafast laser irradiation concepts, combining beam engineering in space and time, capable of achieving structuring features whit sub-wavelength characteristic sizes in direct irradiation modes as well as in periodic self -organization processes [2,3]. We will show the effects of far and near-field scattering and coherent superposition of wavelets in generating light patterns of various complexity, dynamically coupling electromagnetic and hydrodynamic evolution. We present advanced optical methods to resolve in-situ irradiation nanoscaled patterns and the growth of nanostructures beyond diffraction limit [4,5]. We indicate as well sgnificanl advantages of non-diffractive beams to structure materials with unprecedented resolution as well as wi high efficiency. These advantages pertain to both transparent and nc-transparent matter (Fig.1). A rang of applications will be discussed.
Fig 1. (a) Observing in-situ nanostructure on stainless steel using structured illumination microscopy [4]. (b) Regular patterns of light determining surface corrugation with periodic surface structures [3]. (c) Nanostructuring of transparent material (inset: process dynamics) with non-diffractive beams [2]. (d) Deep drilling in non-transparent materials with non-diffractive beams.
[1] K. Sugioka and Y. Cheng, Ultrafast lasers-reliable tools for advanced materials processing, Light: Sci. Appl. 1, e149 (2014).
[2] R. Stoian, M. K. Bhuyan, A. Rudenko, J.P. Colombier, and G. Cheng, High-resolution material structuring using ultrafast laser non-dif-fractive beams, Adv. Phys. X 4, 1659180 (2019)
[3] A. Rudenko, C. Mauclair, F. Garrelie, R. Stoian, and J. P. Colombier, Self-organization of surfaces on the nanoscale by topography-mediated selection of quasi-cylindrical and plasmonic waves, Nanophotonics, https://doi.org/10.1515/nanoph-2018-0206 (2019).
[4] A. Aguilar, C. Mauclair, N. Faure, J. P. Colombier, and R. Stoian, In-situ high-resolution visualization of laser-induced periodic nanostructures driven by optical feedback, Sci. Rep. 7, 16509 (2017).
[5] M. Somayaji, M. K. Bhuyan, F. Bourquard, P. K. Velpula, C. D'Amico, J. P. Colombier and R. Stoian, Multiscale electronic and thermo-mechanical dynamics in ultrafast nanoscale laser structuring of bulk fused silica" Sci. Rep. 10, 15152 (2020)
