Improved conversion efficiency of Cr4+ ions in Cr: YAG transparent ceramics by optimization the particle sizes of sintering aids

In this study, fully dense chromium doped Y3Al5O12 ceramics with an average grain size of ∼3 μm were successfully fabricated by a solid state reactive sintering method under vacuum, and the effect of particle sizes of applied divalent dopants (CaO and MgO) on the optical properties, conversion efficiency of Cr4+ ions as well as microstructures of the fabricated Cr doped YAG ceramics were investigated. It was found that the conversion efficiency of Cr4+ ions in Cr: YAG ceramics depended strongly on the particle sizes of divalent dopants. For the sample doped with fine divalent dopants, the absorption coefficient at 1030 nm was 3.7 cm−1, which was 12 times higher than that of the sample doped with coarse divalent dopants.