Fabrication and spectral properties of Y3+ and Gd3+ ions co-doped transparent Yb:CaF2 ceramics

Abstract

Transparent Yb:CaF₂ ceramics have recently emerged as a promising ultra-fast laser medium with broad emission bandwidth, long lifetime and suitable thermal properties. However, Yb³⁺ clustering in the CaF₂ host strongly influences the performance of these materials as solid-state laser gain media, and mitigating this clustering remains a challenge. Herein, we introduced Y³⁺ and Gd³⁺ buffer ions simultaneously for the first time to modulate the fluorescence properties of transparent Yb:CaF₂ ceramics and explore the effect of Y³⁺ and Gd³⁺ ions co-doping on the optical quality and microstructure of the ceramics. It was found that transmittance in the short wavelength was improved and fluorescence properties could be modulated to a larger extent compared to single buffer ion doping. This finding establishes the correlation between the double buffer ions doping and the fluorescence properties in transparent Yb:CaF₂ ceramics, and may lead to innovative techniques of transmitting enhancement, as well as its ultrafast laser applications.