Preparation and Optical Properties of Transparent Spinel-Based Glass-Ceramics Containing Fe(II) Ions

Transparent glass-ceramics of magnesium, lithium-gallium, lithium, and zinc aluminosilicate systems based on $\mathrm{Fe}^{2+}-$ doped nanosized $(4-20 \mathrm{~nm}$) crystals with spinel structure are developed by secondary heat-treatments of glasses melted in reducing conditions using TiO
2
or a mixture of TiO
2
and ZrO
2
as nucleating agents. Their structure and optical properties are studied. The prepared glass-ceramics are promising as saturable absorbers for lasers operating at $\sim 2 \mu \mathrm{m}$.