Femtosecond Laser Modification of Antimony-Containing Lithium-Aluminum-Silicate Glass and Transparent Sitall Obtained from It

The particulars of the action of a femtosecond laser beam on antimony-containing lithium-aluminum-silicate glass and the close to zero CLTE sitall obtained from this glass by heat-treatment were studied in a wide temperature range. In both the non-thermal and thermal laser action regimes local refractive index reduction is demonstrated in the laser modified regions of the sitall, reaching 0.002 in the non-thermal regime. The main reason for refractive index reduction is, by all appearances, partial amorphization of the crystal phase of β-eucryptite.