Laser induced rear-surface-crack damage properties of HF etched fused silica

The micro subsurface cracks of fused silica etched with HF solution were observed using AFM and optical microscope, and damage characteristics of crack at each etching state were studied. Experimental results show that inclusions in cracks play a important role in cracks' damage behavior. After HF etching, inclusions were eliminated completely, configuration was transformed, and the initial damage threshold (IDT) was greatly improved. Experimental results show that HF etching wouldn't change the damage growth properties of cracks.