为了得到HF化学激光器的增益发生器较佳的模块尺寸，研究了增益模块长高比对输出功率及放大级提取效率的影响。使用基于变换坐标系的有限差分方法,计算了主振荡功率放大器(MOPA)结构HF激光器不同增益模块长高比条件下的主振荡器输出功率、放大级提取效率及经放大后的输出功率。计算结果表明：对于MOPA结构HF激光器而言，当增益体积一定、小信号增益曲线相同时，随着增益模块长高比的减小，主振荡器输出功率和经放大级放大后的输出功率将有所增加，但放大级的能量提取效率将降低;当增益模块长高比已经较小(小于５)时，进一步降低长高比对激光器输出功率和放大级提取效率的影响微弱。

The paper studies the influence of gain module aspect ratio on output power and extraction efficiency in MOPA-structured HF chemical laser. A finite difference method based on coordinate system transformation is used to calculate the output power of master oscillator, the extraction efficiency of amplifier and the total output power of the HF laser under different gain module aspect ratio. The results show that for the MOPA-structured HF chemical laser, when the gain volume and the small-signal gain curve are fixed, with the decrease of the aspect ratio, the output power of master oscillator and the output power amplified by amplifier will increase, but the extraction efficiency of amplifier will reduce. When the aspect ratio is less than 5, its change has little influence on the extraction efficiency and the total output power.