Attractive Role of Hydrogen in TEA CO2 Lasers: Improving Discharge Stability and Output Characteristics

Hydrogen contained in the gas mixture of transversely excited atmospheric-pressure (TEA) CO2 lasers plays an attractive role in improving the discharge stability and output characteristics of glow discharge by suppressing arc discharge. During the excitation of TEA CO2 lasers, hydrogen effectively relaxes the CO2 (010) level, with the action of inhibiting the O2 production by dissociating CO2 molecules, thus reducing the “bottleneck” in the operation of laser systems. We propose a new method that takes into account the role of hydrogen in the whole process from pumping to output of TEA CO2 lasers. We numerically evaluate the transition from glow to arc discharge in the discharge gap of TEA CO2 lasers. The current and voltage (V–I) differential equations of the pumping circuit in TEA CO2 lasers using corona pre-ionization are solved to determine the O2 concentration produced by the change in electron density. Then, the six-temperature model is combined to simulate the dynamics of high-power TEA CO2 lasers considering the change in gas mixtures with hydrogen. The determined discharge voltage and gas mixture are essential for designing and operating TEA CO2 lasers for suitable applications.