Effect of the dissolved hydrogen on the densification of synthetic silica glass under ArF excimer laser irradiation

The degree of densification-induced birefringence under ArF excimer laser i rradiation decreases with increasing dissolved hydrogen concentration. The hydrogen concentration at the irradiation site was decreased after irradiat ion. Good correlation between the residual hydrogen and the degree of biref ringence suggests that the birefringence change is due to the change in vol ume caused by the decrease in hydrogen. As with spontaneous decay, the rate at which hydrogen was released was proportional to the remaining hydrogen. (C) 2000 American Institute of Physics. [S0021-8979(00)04408-X].