Nanofabrication in transparent materials with a femtosecond pulse laser

• Published in: Journal of non-crystalline solids Vol. 352; no. 6; pp. 646 - 656
• Main Authors: Shimotsuma, Yasuhiko, Hirao, Kazuyuki, Qiu, Jianrong, Miura, Kiyotaka
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2006; Elsevier
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Glasses (including metallic glasses); Laser–matter interactions; Materials science; Nanoscale materials and structures: fabrication and characterization; Optical microscopy; Other topics in nanoscale materials and structures; Physics; Scanning electron microscopy; Silica; Silicates; Soda–lime–silica; Specific materials; Surface treatments; Tellurites; Tellurites; Scanning electron microscopy; Optical microscopy; Laser–matter interactions; Soda–lime–silica; Silicates; Silica; Soda-lime-silica; Particle cluster; Refractive index; Doping; Laser assisted processing; Glass; Silver additions; Nanoparticles; Precipitation; Self organization; Laser matter interactions: Optical microscopy; Laser pulse; Microstructure; Nanotechnology
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2005.11.060

Femtosecond lasers have been applied for materials processing when high accuracy and small structure size are required. Various induced structures have been observed inside glasses after the femtosecond laser irradiation. We report the femtosecond laser induced refractive-index change, space-selective valence state change of active ions, formation of nanograting, and precipitation and distribution of nanoparticles. We systematically studied the morphology of structures that are induced in the bulk of transparent materials by the tightly focused femtosecond laser radiation. Rugby-ball-like asymmetric induced structures were observed inside Ag +-doped silicate glass. These structures are due to the aggregation of Ag nanoparticles at the depth of the focal point. The size of the induced structure depended on the time interval between successive femtosecond laser pulses. In the case of zinc-tellurite glass, TeO 2 rich parts were formed in the center of the focal spot, while zinc migrated to the outside. The mechanisms of the observed phenomena are discussed.