摘要
The f→f electronic emission of Eu<sup>2+</sup> with configuration of 4f<sup>7</sup> can bring about laser generation. Some of Eu<sup>2+</sup>-activated crystals which can produce sharp line emission, are candidates for visible solid-state laser at shorter wavelengths because their threshold is low and accumulated energy high.
基金
Project supported by the National Natural Science Foundation of China.
