Fabrication-induced metal contaminations and subsurface damage are generally identified as the laser damage initiators
that are responsible for the laser induced damage in fused silica. In this paper, the removal of those two initiators are
realized by two methods: wet chemical surface cleaning and optimized HF-based etch process. Two kinds of chemical
leaching are used to removing the Ce and other metal impurities respectively. In order prevent the redeposition of the
reactive byproducts during HF etch process, we optimized the traditional HF etch process in two ways: absence of NH4F in etch solution and presence of megasonic and ultrasonic agitation during and after etch respectively. And laser damage tests show that these two treatments greatly improve the laser damage resistance of fused silica.