An Er<sup>3+</sup>-doped lead-free bismuth germanate glass is synthesized. Its 2.7-μm emission property is analyzed, and the efficient 2.7-μm emission from the glass is observed under 980-nm laser diode excitation. The prepared glass possesses high spontaneous transition probability (64.8 s<sup>-1</sup>) and a large calculated emission cross section (6.61 × 10<sup>-21</sup> cm<sup>2</sup>) corresponding to the <sup>4</sup>I<sub>11/2</sub> -> <sup>4</sup>I<sub>13/2</sub> transition. The multiphonon relaxation rate for the excited state <sup>4</sup>I<sub>11/2</sub> is only 236 s<sup>-1</sup>. Therefore, the excellent spectroscopic properties and outstanding thermal stability suggest that this glass is a suitable host for developing solid-state lasers operating in the mid-infrared.
© 2012 Chinese Optics Letters
Guoying Zhao, Ying Tian, Huiyan Fan, Junjie Zhang, and Lili Hu, "Efficient 2.7-μm emission in Er3+-doped bismuth germanate glass pumped by 980-nm laser diode," Chin. Opt. Lett. 10, 091601-091601 (2012)