Influence of gain module aspect ratio on output power and extraction efficiency

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.