Numerical Study of CO2 MOPA System Using Six-Temperature Model

Chin-Chia Wu^1*, Chun-Tse Wu¹, Shih-Hung Chen¹

¹物理所, 國立中央大學, 桃園市, Taiwan

* Presenter:Chin-Chia Wu, email:jen527738@gmail.com

This paper presents a numerical scheme for studying a CO2 master oscillator power amplifier (MOPA) system by modifying the Teller-Landau six-temperature model for CO2 laser with additionally considering the effect of fast-axial flow and RF-discharge pumping. This model gives an accurate description of every single energy level evolving during lasing processes. In this paper, we will demonstrate the operation temperature ranges (T_3=4000K~8000K, T_0,T_1,T_2=300K~400K ) for most efficient energy exchange between vibrational level of N_2 and upper lasing level of CO2. Moreover, detailed analysis of evolution of population inversion by the adjustment of parameters of RF pump and input seed can help provide a guideline for the optimization or design of a new CO2 MOPA system.

Keywords: CO2 amplifier, fast-axial system, LPP-EUV, 6T model, RF-discharge pump