Optical spectroscopy of Dy3+-doped CaGdAlO4 single crystal for potential use in solid-state yellow lasers

The crystal growth, optical spectra and lifetime of Dy:CaGdAlO4 crystal were investigated for the first time to our best knowledge. Single Dy:CaGdAlO4 crystal with size of Φ4 × 40 mm3 was grown by floating zone method. The peak absorption cross-sections were calculated to be 2.43 × 10−21cm2 and 1.28 × 10−21 cm2 at 453 nm for σ and π polarizations. The Judd-Ofelt (JO) parameters of Ω2, Ω4 and Ω6 were calculated to be 1.8 × 10−20cm2, 1.0 × 10−20cm2 and 0.5 × 10−20cm2, respectively. The emission cross-sections were calculated to be 0.51 × 10−20cm2 and 0.55 × 10−20cm2 for σ and π polarizations. The fluorescence decay time is 222 μs. The results indicate that the Dy:CaGdAlO4 crystal is a potential candidate for yellow laser operation.