Light driven structuring of glasses

Abstract

Theoretical and experimental evidence of light driven structuring of glasses is presented. We show that light overcomes Coulomb repulsion and effective electron-electron interaction in glasses under strong light pumping becomes attractive. As the result homogenious distribution of trapped electrons gets unstable and macroscopic electron bunches are grown. At different conditions ordered structures with period 2µm ± 0.2µm determined by internal properties of the material are formed These structures were observed in ablation: surface profile after laser treatment reveals ordered pattern corresponding to the light induced electron domains.

Light driven self-ordering in fused quartz

“…figure 9 (respectively, in the horizontal and the vertical direction). In all cases the period of the self-organized structure, figures 5-9, was 2 AE 0:2 mm and coincided with periods found in our other experiments [10,11]. The period is a characteristic of the matter but not the light and the fact confirms the self-organized nature of the ordering discussed.…”

“…As a result static polarization directed against the external electric field is established. This polarization amplifies the initial field and the process is stopped at the value of the field 10 5 to 10 7 V cm À1 (for details see [10,11]). At the achieved field of saturation, lightinduced transitions are in the dynamical equilibrium with contraflow due to the ordinary electron mobility.…”

Self-organization driven by broad band light

“…The third electron is transported to the bielectron and so on. We observed this light driven bunching [6,7] under laser pumping in ablation due to Franz-Keldysh effect [12,13]. We found that for different light parameters-power, beam size, coherent length-ordered structure of electron-hole bunches with the same period is formed.…”

“…In the latter case light amplitude has been modulated in time and space, which was crucial for the organization to occur. Our investigations [5][6][7][8] have shown that steady light flow through a system can provide ordering either. This light is a driving force which bunches the electrons together.…”

Development of an extremely thin grinding-tool for grinding microgrooves in optical glass

“…In addition, due to the poor thermal properties of most glass the fabrication of finely machined features such as micro-grooves and micro-holes has been a challenging task. Antonyuk et al (2008) applied an ArF laser beam to effectively act as a drill to produce a micron radius channel up to 1 cm long in fused quartz (the diameter of the light spot was a few millimeters). Nikumb et al (2005) utilized the short pulse solid-state lasers with pulse duration in the nano-to femto-second range to process different types of glass materials.…”