Linear and non-linear optical properties of transparent glass-ceramics based on Co2+-doped Zn(Al,Ga)2O4 spinel nanocrystals

• Published in: Journal of non-crystalline solids Vol. 557; p. 120627
• Main Authors: Glazunov, I.V., Malyarevich, A.M., Yumashev, K.V., Dymshits, O.S., Alekseeva, I.P., Tsenter, M.Y., Bogdanov, K.V., Zapalova, S.S., Zhilin, A.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2021
• Subjects: Absorption saturation; Cobalt ions; Gallium oxide; Spinel nanocrystals; Transparent glass-ceramics; Spinel nanocrystals; Transparent glass-ceramics; Cobalt ions; Absorption saturation; Gallium oxide
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2020.120627

•Novel transparent glass-ceramics based on Co2+-doped Zn(Ga,Al)2O4 spinel nanocrystals.•Absorption and luminescence are defined by Co2+ ions in Zn(Al,Ga)2O4 nanocrystals.•Co2+ ions concentration in nanocrystals changes with rise in heat-treatment temperature.•IR absorption band of Co2+ ions is shifted to longer wavelengths with Ga2O3 addition.•Absorption saturation contrast is close to that for the Co:MgAl2O4 single crystal.
Transparent glass-ceramics containing Co2+:Zn(Al,Ga)2O4 spinel nanocrystals with sizes of 6-11 nm were prepared on the basis of the glass of the ZnO-Al2O3-Ga2O3-SiO2 system nucleated by TiO2. The absorption and luminescence properties of these glass-ceramics are defined mainly by tetrahedrally coordinated Co2+ ions located in Zn(Al,Ga)2O4 nanocrystals with spinel structure. Co2+ ions in glass-ceramics exhibit absorption saturation at 1.54 µm (the 4A2(4F)→4T1(4F) transition of Co2+ ions in tetrahedrally coordinated sites). This absorption band is shifted to higher wavelengths by 20 nm as compared with glass-ceramics with no Ga2O3 addition. The concentration of Co2+ ions in Zn(Al,Ga)2O4 nanocrystals changes in a complex way with rise in heat-treatment temperature. Characteristic times of luminescence decay, values of ground-state absorption cross-sections, and absorption saturation recovery time were determined. The developed glass-ceramics are promising as saturable absorbers for 1.6 µm erbium lasers.