EMC design of high power TEA CO2 laser

Abstract

High power TEA CO2 laser belongs to the gas laser with high-voltage (HV) pulse excitation. The strong electromagnetic interference (EMI) are generated mainly from the discharge circuit loop, the pulse spark switch and the HV supply when the laser works. It has a strong interference and destructive effect on the electronic equipments inside and outside the laser system. The mechanism analysis and experimental measurement were carried out in this paper. The shielding design on the HV supply, the main discharge circuit loop and the main control unit restrained the transmission of EMI effectively. The mains filters were designed to restrain the conducing EMI propagation path. As a sensitive device to EMI, the control system was shielded, isolated and mains filtered on hardware, anti-interference on software was designed to improve the ability of noise reduction. Experimental results demonstrated that reducing EMI intensity, shielding EMI, improving the hardware ability on noise suppression are the primary methods to retrain EMI and keep the hardware of laser control system from being destroyed, the anti-interference on software is a support and complement of hardware noise suppression, which improves the reliability of the laser system.