Criteria for the Formation of Laser-Induced Periodic Surface Structures in Phase-Change Materials under Femtosecond Irradiation

The possibility of forming periodic surface structures in amorphous GeTe and Sb 2 Te 3 thin films irradiated by 1030-nm femtosecond laser pulses has been studied. The inclusion of nonlinear absorption and photoinduced electron generation within the framework of the surface electromagnetic wave excitation theory allows the prediction of the formation or absence of surface gratings in these materials induced by ultrashort laser pulses. The simulation results are consistent with experimental data.