As-grown Sm:NLBO crystal and schematic of (1 0 0) oriented rectangular crystal plate. (a) Sm:NLBO crystal. (b) Schematic of (1 0 0) oriented crystal plate.

Sm³⁺ doped Na₃La₉O₃(BO₃)₈ (Sm:NLBO) crystal has been grown by the top-seeded solution growth (TSSG) method. The absorption and emission spectra were measured at room temperature by using a (1 0 0) oriented crystal plate. According to the Judd–Ofelt theory, the spontaneous transition probabilities, fluorescence branch ratio, and radiation lifetime of ⁴G_5/2 state were calculated. The unpolarized and polarized emission properties of 564, 601, and 651 nm under the 405 nm excitation were also evaluated. The decay curve of the 601 nm emission assigned to the ⁴G_5/2–⁶H_7/2 transition was also measured. The experimental results have shown that Sm:NLBO would be a promising orange-red laser material, which can be pumped directly by lighting 405 nm laser diodes (LDs).

Optical Materials, 2015