Recently, laser activity has been achieved in the low-phonon-energy, moisture-resistant bromide host crystals: neodymium-doped potassium lead bromide (Nd3+:KPb2Br5) and rubidium lead bromide (Nd3+:RbPb2Br5). Laser activity at 1.07 µm was observed for both crystalline materials. Laser operation at the new wavelengths of 1.18 and 0.97 µm resulting from the <sup>4</sup>F<sub>5/2</sub> + <sup>2</sup>H<sub>9/2</sub> → <sup>4</sup>I<sub>J</sub> transitions (J=13/2 and 11/2) in Nd:RbPb2Br5 was achieved for the first time in a solid-state laser material. We present cw pump-probe spectra and discuss excited-state absorption and reabsorption processes due to the long-lived lower laser levels, as well as possible depopulation mechanisms feasible for more efficient laser operation in these crystals. The bromides are compared with potassium lead chloride (Nd3+:KPb2Cl5).
© 2005 Optical Society of America
Katja Rademaker, Stephen A. Payne, Günter Huber, Ludmila I. Isaenko, and Eugen Osiac, "Optical pump-probe processes in Nd3+-doped KPb2Br5, RbPb2Br5, and KPb2Cl5," J. Opt. Soc. Am. B 22, 2610-2618 (2005)