Yb3+:KGd(WO4)2激光器是近年来得到广泛关注的新型固体激光光源，具有吸收和发射截面大、荧光谱线宽、激光阈值低等突出特点。对此三能级激光系统进行微观动力学理论分析，在探讨了不同的晶体切割方向、抽运光偏振方向和激光偏振方向的吸收和发射特性的基础上研究了Yb3+:KGd(WO4)2激光器输出特性随晶体长度和输出耦合镜反射率的变化规律，得到了Yb3+:KGd(WO4)2激光器的最佳构成条件，即：晶体切割方向平行于g轴，抽运光偏振方向平行于m轴，激光偏振方向平行于p轴。

Yb3+:KGd(WO4)2 laser is a new solid-state laser source which has been paid much attention in the recent years. It is characterized with the high absorption and emission cross-section, broad fluorescent linewidth and low laser threshold. The microcosmic kinetic of three energy-level laser system is theoretically analyzed. After investigating the absorptive and emission features with the different crystal cuttings, pump and laser polarization directions, the relationship between the output characteristics of a Yb3+:KGd(WO4)2 laser and the crystal length as well as the reflectance of the output coupler is analyzed. Finally, the optimum conditions for a real Yb3+:KGd(WO4)2 laser have been obtained as: crystal cut-direction parallel to g axis, pump polarization direction parallel to m axis and laser polarization direction parallel to p axis.