腔内倍频拉曼激光器是获得黄光激光光源的重要途径，目前尚未有直接的表达式描述连续腔内倍频激光器的功率输出对抽运和激光器参数的依赖关系。以速率方程为基础，对腔内倍频连续拉曼激光器的理论模型进行归一化处理，得到平面波近似下连续腔内倍频拉曼激光器的归一化速率方程组。对此方程组进行求解，得到描述激光器输出的表达式各变量以及参量与输出变量之间的归一化表达式，根据表达式获得了描述激光器运行的理论曲线。

In diode pumped Nd:YAG lasers, the quantum defect is the most important parameter determining the thermal load of the laser crystal, which can be dramatically reduced by pumping directly into the upper laser level. A compact folded three-mirror cavity with a length of 105 mm is optimized to obtain a highly effcient 473-nm laser. When the absorbed pump power (with 15.8-W incident pump power) at 885 nm into Nd:YAG is 10 W, a continuous-wave 473-nm blue laser as high as 2.34 W is achieved by LBO intra-cavity frequency doubled. The optical-to-optical conversion effciency is 14.8%. To the best of our knowledge, this is the highest e±ciency at 473 nm by an intra-cavity doubled frequency Nd:YAG laser.

A new kind of resonator for doubly resonant continuous-wave (CW) intracavity sum-frequency mixing (SFM) is presented. A coherent radiation of 327 mW at 555 nm is generated by mixing 1342-nm Nd:YVO4 laser and 946-nm Nd:YAG laser. The M2 beam quality factor of the sum-frequency mixed yellow-green laser is less than 1.7. The low-noise characteristic of the yellow laser is demonitrated.