A simplified model for HF chemical laser amplifier

Abstract

HF chemical laser with MOPA configuration is a good solution to achieve high output power with high reliability. Kinetic models for HF amplifier are important for prediction and optimization of the performance of MOPA chemical lasers. In this paper, a simplified model for HF chemical laser amplifier is presented. The main processes which are included in the model are: (a) chemical pumping of HF (v=2) and HF (v=1), (b) stimulated transitions and spontaneous emission. (c) relaxation of vibration excited HF molecule by H 2 ,N 2 and HF. Some assumptions are taken in this model: (a) the density of H 2 , N 2 , HF, translational temperature and velocity of gas mixture are averaged across the laser cross section, (b) only two vibration-rotational transitions (2P6, 1P7) occurs in the amplifier, (c) gas temperature does not change during the lasing process in the amplifier. Based on these assumptions, a set of three-level rate equations is formulated and then solved by an iterative technique. Comparison is made with recent experimentally obtained data from a low power discharge-driven CW HF laser with MOPA configuration. It is shown that experimental results are consistent with the calculation from the simplified model.