Electromagnetic origin of femtosecond laser-induced periodic surface structures on GaP crystals

The formations of different types of laser-induced periodic surface structures (LIPSS) on the surface of GaP crystals with different laser fluence are researched in experiments. The transition from the high spatial frequency LIPSS (HSFL) to the low spatial frequency LIPSS (LSFL) occurred as the number of the irradiated laser pulse increased. The finite difference time domain method combined with the holographic ablation model is used to simulate the LIPSS firmation under the irradiation of multiple pulses. Different types of ripples are predicted by the electromagnetic approach. Results demonstrate that the electromagnetic origins of HSFL and LSFL are due to the interference of incident field and the scattering field under the multi-pulse irradiation. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This study investigates the formations of different types of laser-induced periodic surface structures (LIPSS) on GaP crystal surfaces under different laser fluences. The transition from high spatial frequency LIPSS (HSFL) to low spatial frequency LIPSS (LSFL) is observed with an increase in the number of laser pulses. The electromagnetic approach predicts different types of ripples. The interference of the incident field and scattering field under multi-pulse irradiation is found to be the origins of HSFL and LSFL.