为定量分析放大自发辐射(ASE)对调Q激光器性能的影响，在调Q激光速率方程中引入放大自发辐射项，并在合理的近似下求解，给出了激光二极管(LD)端面抽运电光调Q运转的固体激光器反转粒子数的建立过程，分析了放大自发辐射对激光上能级储能效率的影响及考虑放大自发辐射时调Q激光器输出脉冲宽度和脉冲能量随抽运功率的变化关系。结果表明，由于放大自发辐射的存在，上能级储能效率降低，且在一定的抽运功率下，调Q输出脉冲宽度变宽,脉冲能量下降。用LGS(La3Ga5SiO14)晶体作电光调Q元件，在激光二极管抽运的Nd∶YVO4激光器上进行了实验，实验结果与理论分析结果基本吻合。

To quantificationally analyse the effect of amplified spontaneous emission (ASE) on Q-switched laser, a term depicting ASE in rate equation is introduced and the buiding-up process of inverted population in four level system is derived under reasonable hypothesis. The effect of ASE on energy storage efficiency in upper level, output pulse width and pulse energy, etc. are analyzed. As a result, upper manifold energy storaged efficiency is decreased, pulse width is broadened and pulse energy is declined when ASE is taken into account. To support it, a laser diode end-pumped Nd∶YVO4 laser with LGS (La3Ga5SiO14) crystal electro-optical (EO) Q-switched was set up, the experiment results are agreed with analysis.