Dy3+:Ca3Gd2(BO3)4 single crystal with disordered structure: A promising yellow laser candidate

Abstract

In this article, a series of DyxCa3Gd2-x(BO3)4 (x = 0.02–0.2) polycrystalline compounds were synthesized by solid-state reaction to select the optimum concentration for single crystal growth, after then a 6.36 at.% Dy3+:Ca3Gd2(BO3)4 (Dy:CGB) single crystal with a disordered structure was successfully grown by the Czochralski method. The spectroscopic properties and Judd-Ofelt analyses of the crystal were carried out. Focusing on the absorption cross-section at 453 nm corresponding to the emission bands of InGaN laser diodes, the Dy:CGB crystal has a comparatively large value of 0.95 × 10-21 cm2 with a full width at half maximum (FWHM) of 10.2 nm. The yellow light emission cross-section at 576 nm is 2.2 × 10-21 cm2 with a FWHM of 14.0 nm. The Judd-Ofelt parameters Ω2, Ω4 and Ω6 were obtained to be 2.79 × 10-20 cm2, 2.10 × 10-20 cm2 and 2.28 × 10-20 cm2, respectively. The fluorescence lifetime of 4F9/2→6H13/2 transition was measured to be 0.26 ms. These results reveal that the Dy:CGB crystal is a promising yellow laser candidate.