Pang Xiangyang

Online detection of airborne molecular contamination and its influence on the sol-gel coating

Cleanliness management is essential for the safe operation of high power laser systems. In order to maintain the transmittance and minimize the optics damage, we should protect the optics surface with coatings from contamination. Large aperture optics in the vacuum is easily contaminated by airborne molecular from material outgas. In this paper, we introduce the techniques of cleanliness management in SG-II-UP laser facility. The online monitoring of surface airborne molecular contaminant is carried out with quartz crystal microbalance. We investigated the influence of the airborne molecular contaminant on the 351nm transmittance of fused silica optics with sol-gel coatings.

Effect of surface treatment technology on laser damage resistance of aluminium alloy

The effect of surface treatment technology on laser damage resistance of aluminum alloy is studied. Results show that, under the same nanosecond laser irradiation, the laser-induced damage threshold of nickel-plated metal surface, black anode oxidated surface, or hard anode oxidated surface is lower, while that of inactivated or micro arc oxidized surface is higher, if compared with that of mechanically polished surface; surfaces treated by the same treatment process but with different parameters have different damage thresholds. With the comparison among the relevant physical parameters of different technologies, the damage thresholds, morphologies, and patterns are analyzed and the results indicate that the inactivation technology is more suitable for the aluminum alloy surface treatment in high power laser facility. ? 2016, Chinese Lasers Press. All right reserved.