Research on the characteristics of high-efficiency microwave-induced plasma jet based on optical processing

Reactive plasma is an promising approach for machining of fused glass substrates. However, the machining accuracy and efficiency need to be improved. In this study, a spline curve-based internal electrode structure for a microwave plasma jet was proposed, which increased the internal electric field strength by 54%. The discharge dynamic simulation results show that the plasma is excited at the inner electrode tip and the bottom of the resonant cavity, then it expands to form a linear discharge region and eventually forms a jet. It was revealed by CCD images that with the increase of carrier gas flow rate, turbulent flow state appears in the tail of the jet. OES data shows that microwave Ar plasma can effectively dissociate CF
4
, and due to the oxidation effect of oxygen, $\mathrm{CF}_{\mathrm{x}}$ and C
2
content decrease significantly with the addition of oxygen. The machining experiment on fused silica shows that the material removal stability of this torch reaches 3.69%, and the removal rate increases nonlinearly with dwell time due to thermal effect. Finally, the machining performance of the atmospheric pressure microwave plasma jet was verified by figuring of a planar fused silica surface reducing the form error from 108.1 nm RMS to 16.5 RMS.