Surface discharge optical pumping source for XeF blue-green laser

The surface discharge optical pumping source is a key unit of high power XeF blue-green laser with pulse repetition mode. To increase the lifetime of the high power XeF blue-green laser, it is very important to develop a kind of surface discharge optical pumping source which emit strong UV radiation with a long lifespan. In this paper, three kinds of sectioned surface discharge optical pumping sources, which are made from Al2O3 ceramic substrate, BN ceramic substrate and Teflon substrate, are developed respectively, and the electrical, radiation and ablation characteristics of them are examined. Based on discharge current waveform, the equivalent inductance, resistance and energy deposition efficiency of these sources are calculated. UV radiation intensities of the sources are compared by their discharge emission spectrum. Anti-ablative performances of the material are estimated by average line ablation rate which is calculated after 1000 shots. By comparing experimental results from three kinds of surface discharge optical pumping sources, it is found that the best energy deposition efficiency, which is above 82%, is obtained from surface discharge optical pumping source with Al2O3 ceramic substrate, and the UV radiation enhancement is observed in its radiation spectra, with an average line ablation rate less than 0.15 m/shot. The normal working condition is as follows: the charge voltage ranges from 13.5 kV to 26.8 kV, the discharge gap length is 8 cm, and 60%Ar-40% N2 mix gas pressure is 100 kPa. It is believed that Al2O3 ceramic substrate may be utilized to obtain long lifetime XeF blue-green laser.