EXCIMER-LASER-INDUCED EMISSION BANDS IN FUSED QUARTZ

The characteristics of KrF (5.0 eV) and ArF (6.4 eV) -excimer-laser-induced luminescence in type-I ([OH]< 5 ppm) and type-II ([OH]=120 ppm) fused quartz were investigated. These two types of fused quartz have an absorption band near 5 eV, called the B2 band. Comparing the absorption and the emission bands under excitation by these excimer lasers, we found that the B2 bands in these types of fused quartz derived from different origins: In type-II fused quartz, the B2 band is the B2 beta band caused by silicon lone-pair center (=Si:), which can be annealed out in air. The B2 band in type-I silica consisted of two types of B2 bands: the main component of this band is the B2 alpha band caused by an oxygen-deficient center (=Si...Si=) and the other component is a small amount of the B2 beta band. We proposed a model in which these defects are located on the grain boundary, which is a trace of the contact between silica and silica particles.