Crystal growth and optical properties of Cr3+, Er3+, RE3+: Gd3Ga5O12 (RE=Tm, Ho, Eu) for mid-IR laser applications

► Systematic spectral analyses of Cr3+, Er3+, RE3+: Gd3Ga5O12 (RE=Tm, Ho, Eu) were presented. ► High energy transfer efficiency (84.4 %) of Er:4I13/2→Eu:7F6 was obtained. ► Three chosen RE3+ ions depopulate lower energy state of ∼3.0 μm Er3+ laser effectively. ► We conclude that Cr,Er,Eu:GGG is relatively more suitable as ∼3.0 μm laser gain medium.