Polarized spectral properties of Sm:CaGdAlO4 crystal for reddish-orange laser

Abstract

The crystal growth, polarized spectral properties, Judd-Ofelt (JO) analysis and lifetime of Sm:CaGdAlO4 (Sm:CGA) crystal were reported for the first time. Sm:CGA crystal with size of Φ4 × 33 mm3 was grown by the floating zone (FZ) method. The peak absorption cross-sections at 407 nm were calculated to be 3.41 × 10−20cm2 and 3.20 × 10−20cm2 for the σ and π polarization, and the largest stimulated emission cross-sections at 601 nm were 5.10 × 10−21cm2 and 4.66 × 10−21cm2, respectively. The absorption and emission cross-sections were several times larger than that of Sm:LiYF4. The JO intensity parameters of Ω2, Ω4 and Ω6 were calculated to be 3.0 × 10−20cm2, 6.1 × 10−20cm2 and 6.5 × 10−20cm2, respectively. The lifetime of the 4G5/2 level was obtained to be 0.69 ms. All the results indicate that Sm:CGA crystal is a potential laser host for the reddish-orange laser operation.