ИСТИНА

Laser-induced periodic surface structures (LIPSSs) formed on chalcogenide vitreous semiconductors open wide prospects to create tunable and polarization-sensitive planar photonic elements. In the present work, a possibility to produce LIPSSs under femtosecond laser irradiation (300 fs, 515 nm) is demonstrated on large areas of arsenic sulfide (As2S3) and arsenic selenide (As2Se3, As50Se50) films. Scanning electron and atomic force microscopy revealed that LIPSSs with various periods (170 – 490 nm) and orientations can coexist within the same irradiated region as a hierarchical structure, resulting from the interference of various plasmon-polariton modes generated under intense photoexcitation of nonequilibrium carriers within the film. The periods and orientations of the formed structures numerically simulated using the Sipe – Drude approach. In addition, femtosecond laser irradiation provides structural transformations of As2Se3 and changes in photoluminescence spectra of the As2S3 films. The structures obtained exhibit birefringence and might be used for designing elements of polarization optics and photonic integrated circuits.