Effect of Lu content on microstructure and spectral properties of Yb: (LuxSc1-x)2O3 solid-solution sesquioxide transparent ceramics

Yb3+-doped (Lux,Sc1-x)2O3 materials demonstrate superior performance in generating short pulse lasers because of the broader emission spectra than single-component sesquioxide, making them a promising laser gain material for high-power ultrafast lasers. By adjusting the concentration of Lu/Sc, laser gain materials with different widths of emission spectra can be obtained. In this work, 5 at.% Yb:(LuxSc1-x)2O3 nano-powders with varying Lu concentrations (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9)were successfully synthesized by the co-precipitation method. Subsequently, Yb:(LuxSc1-x)2O3 transparent ceramics were produced through a combination of vacuum pre-sintering and hot isostatic pressing (HIP) post-treatment at 1700 degrees C. Influence of Lu content on densification process, microstructure changes and optical transmittance of Yb:(LuxSc1-x)2O3 ceramics was investigated in detail. The average grain sizes of ceramics pre-sintered at 1700 degrees C decrease from 3.42 mu m to 1.43 mu m, and all ceramics have a relatively uniform microstructure. After HIP post-treatment, the optimum in-line transmittance of Yb:(LuxSc1-x)2O3 ceramics reaches 77.6 % at 1100 nm when x value = 0.1. With the increase of Lu content, the emission wavelength experiences a gradual blueshift from 1041 nm to 1034 nm. Notably, the Yb:(Lu0.6Sc0.4)2O3 ceramics exhibited the broadest emission bandwidth of 18 nm, which is 1.5 times of the Yb: Sc2O3, suggesting their immense potential for applications in ultrashort pulse lasers.