Research Of Discharge Uniformity In Radio-Frequency-Excited Slab Gas Lasers

Radio frequency (RF)-excited gas lasers with electrodes in slab geometry are still developing to higher output power while maintaining excellent beam quality. Consequently, this kind of perspective gas lasers has been widely studied in the recent years. This thesis mainly discussed how to analyze and simulate the electric field configuration between the electrodes in this kind of laser using a novel numerical method—finite element analysis (FEA) to obtain two-dimensional simulation.Firstly the development of RF-excited gas lasers was introduced, and then the source and intention of this task was mentioned.The principle and model of RF gas discharging was described basing on the elements of the gas discharging. Some aspect of the electromagnetic theory and computation was introduced with the classic Maxwell's equation. Two kinds of numerical method and theory were discussed, including finite-difference time-domain(FDTD) method and finite-integration theory(FIT). Then the electric field between the electrodes of the RF-excited gas laser was studied basing on the finite-integration theory.With the discussion of the problem of one-dimensional simulation of the static electric field between the electrodes using the method of FEA, the fundamental theory and elements of FEA were introduced. Then the model of RF-excited gas laser with electrodes in slab geometry whose ends was placed with shunt inductors was established using the function of the universal FEA software ANSYS. With the language APDL provided by ANSYS, the thesis presented the electric fields of two-dimensional simulations for a typical large-area and narrow-gap electrode structure when a single inductor or several shunt inductors placing at different positions along the length of the electrodes. In this way, we found the method to improve the discharge uniformity between the electrodes.At the end of this thesis, the results of the FEA and FIT simulation were compared and discussed. The problem exists during computing was also discussed.