KrF-Excimer-Laser Induced Absorption in Synthetic Fused Silica

KrF-excimer-laser (5.0 eV) induced absorption in synthetic fused silica synthesized by flame hydrolysis of SiCl 4 (type-III-fused silica) was measured. Induced absorption is a Gaussian absorption band peaking at 5.8 eV, which is different from that of ArF-excimer-laser induced absorption consisting of five absorption bands at 6.5, 5,8, 5.4, 5.0 and 4.8 eV. Peak intensities of the absorption band decrease with increasing OH content. When the OH content exceeds ≈1000 ppm in mass, the internal absorption at 5.0 eV approach a constant value ≈1 ×10 -4 cm -1