Experimental investigation of enhancing the subsurface damage threshold of Nd-doped phosphate glass

Experimental investigation was performed with a 1064-nm,10-ns Nd:YAG laser to determine the effects of the surface hydrogen acid etching on laser damage,compared with damage of conventionally polished surface.The investigation was helpful for us to understand the negative effects of Nd-doped phosphate glass surface and subsurface damage（SSD）on laser induced damage threshold（LIDT）.A set of samples was polished,and then chemically etched in a cool buffered 10%HF+20%H;SO;solution at different times.Another set of samples was ground and etched in the hot-buffered solution,and then polished.All the samples were irradiated with Nd:YAG laser and characterized by optical microscopy.Results of LIDT were obtained according to International standard ISO/DIS 11254-1.2.Chemical treatment can remove the contaminants in the polished re-deposition layer and the SSD for improving the laser damage resistance of Nd-doped phosphate glass surfaces.The method of using hot solution was more effective than that of using cool solution.