Changes in optical absorption and point defect formation in 3 types of synthetic glass were examined by using spectroscopic methods. The glass-types were: wet (120ppmOH), dry (less than 1ppmOH) and F-doped (1mol%). They were irradiated with 3.6 x 105 F2 excimer laser pulses having an energy of 8mJ/cm2. Intense optical absorption (between 4 and 8eV) was produced in the wet and dry silica glasses, whereas the intensity of absorption which was produced in the F-doped silica was smaller by an order of magnitude than that in the F-free glasses. The predominant electron spin resonance-active defect in the irradiated specimens was the non-bridging O-hole center for the wet silica, or the E' center for the dry silica. The concentration of non-bridging O-hole centers or E' centers in the F-doped silica was lower, by an order of magnitude, than that in the wet or dry silica.

Effects of Fluorine Dimer Excimer Laser Radiation on the Optical Transmission and Defect Formation of Various Types of Synthetic SiO2 Glass. H.Hosono, M.Mizuguchi, H.Kawazoe, T.Ogawa: Applied Physics Letters, 1999, 74[19], 2755-7