Open AccessSelf-organized periodic structures on Ge-S based chalcogenide glass induced by femtosecond laser irradiation
Author(s) -
Sandra Helena Messaddeq,
Réal Vallée,
Pascal Soucy,
Martin Bernier,
Mohammed El-Amraoui,
Younès Messaddeq
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.029882
Subject(s) - femtosecond , materials science , optics , laser , irradiation , chalcogenide , sapphire , chalcogenide glass , wavelength , electric field , microscopy , scanning electron microscope , optoelectronics , physics , quantum mechanics , nuclear physics
Self-organized periodic structures have been observed on the surface of the ablation craters of Ge-S based chalcogenide glass produced after irradiation by a focused beam of a femtosecond Ti:sapphire laser (1 kHz, 34 fs, 806 nm). Scanning electron microscopy and atomic force microscopy images of irradiated spots show a periodic structure of ripples with a spatial period of 720 nm (close to the wavelength of fs laser pulses) and an alignment parallel to the electric field of light. With an increasing number of pulses, from 5 to 50 pulses, a characteristic evolution of ripples was observed from a random structure to a series of generally aligned peaks-and-valleys self-organized periodic structures. Additionally, at the center of the ablated spot, micro-domains appear where the ripples are still regular but are assembled in a more complex fashion. The experimental observations are interpreted in terms of strong temperature gradients combined with interference of the incident laser irradiation and a scattered surface electromagnetic wave.