Femtosecond-laser-induced submicron grating periodic structures on As2S3 and As35Se65 glasses

Submicron periodic structures produced by femtosecond Ti:sapphire laser irradiation (1 kHz, 150 fs, 3-5 μm) on As2S3 and As35Se65 glasses at edges of damage holes are observed. Effects of changes in laser wavelength (λ), pulse number, power, and irradiation time on grating periodicity were studied. Regular groove-like ripples and distinct parallel submicron periodic gratings were seen in damaged areas. The damage grating period (Λ) is approximately λ/2n. The period increases with wavelength but is hardly influenced by irradiation time and pulse number. Samples with high refractive index and low bandgap are more prone to melting, and edge stripes are not obvious.