CC BY
4*
ALT'23
The 30th International Conference on Advanced Laser Technologies
LM-O-4
Structured laser beams for polarization-sensitive laser material
processing
S. Khonina1, N. Ivliev1, S. Syubaev2, A. Porfirev1
1-Image Processing Systems Institute of RAS—Branch of the FSRC "Crystallography and Photonics " RAS, Samara,
Russia
2- Far Eastern Federal University, Vladivostok, Russia khonina@ipsiras. ru
After their first demonstration sixty years ago, lasers were envisaged to be ideal tools for material processing. In 1967, Peter Houldcroft demonstrated the first experiments in gas-assisted laser cutting with a 300W CO2 gas laser. Since that, a lot of progress in the development and commercialization of laser material processing systems has been achieved, especially regarding the thickness of the processed samples and the processing velocity. Currently, structured laser beams are increasingly used for material processing. Structured laser beams are known as spatially amplitude, phase, and polarization modulated laser radiation shaped with the help of classical optical elements, diffractive optical elements, metasurfaces, or structured screens [1]. These laser beams make it possible to control the morphology of structures formed on the surface and in the volume of materials both at the nano- and micro-levels. For example, polarization makes it possible to set the orientation of laser-induced periodic surface structures (LIPSSs) [2]. Even more opportunities arise when using structured laser radiation in the processing of polarization-sensitive materials, such as various azopolymers and chalcogenide glasses (CGs) [3]. Multilayer structures based on CGs and azopolymers are promising optically sensitive materials used for dynamic systems of optical conversion and signal transmission, data recording, and storage. Such materials are able to change their structure under the influence of illuminating laser radiation - not only depending on the amplitude but also the polarization of the radiation. Recent studies have shown the high sensitivity of such materials to both transverse and longitudinal components of the light field. Their joint consideration should provide an unprecedented level of control over the profiles of nano- and microstructures formed in polymers, which is necessary for the creation of various elements of planar and three-dimensional micro-optics and components of nanophotonics. Here we demonstrate some examples of laser processing of thin metal and polymer films with vector laser beams with the predetermined polarization distributions (see Fig. 1). We use laser beams shaped with the help of such elements as g-plates of different orders and depolarizers. In addition, we demonstrate polarization-sensitive direct laser patterning of azopolymer thin films with vortex beams and the realization of spiral-shaped mass transfer. This work was financially supported by Russian Science Foundation (grant No. 21-7920075).
Figure 1. LIPSSs with radial symmetry formed on the surface of titanium films using cylindrically polarized laser beams with an intensity distribution in the form of a semicircle.
[1] A. Forbes, M. de Oliveira, M. R. Dennis, Structured light, Nat.Photonics, vol. 15, pp. 253-262 (2021).
[2] W. H. Duff and L. V. Zhigilei, Computational study of cooling rates and recrystallization kinetics in short pulse laser quenching of metal targets, J. Phys.: Conference Series, vol. 59, pp. 413 (2007).
[3] Z. Sekkat, S. Kawata, Laser nanofabrication in photoresists and azopolymers, Laser Photon. Rev., vol. 8, pp. 1-26 (2014).
