FORMATION AND PHOTOBLEACHING OF 5 EV BANDS IN ION-IMPLANTED SIO2-GE AND SIO2 GLASSES FOR PHOTOSENSITIVE MATERIALS

Formation and photobleaching of optical absorption bands in the 5 eV r egion were examined in proton-implanted 5Ge0-95SiO(2) glasses and SiO2 glasses implanted with Si, Ge, B or P ions. A conspicuous increase in the intensity of the 5 eV band, which is attributed to oxygen vacanci es, was seen in both substrates after implantation. However, a distinc t difference was observed in bleaching with 5 eV light between the H-i mplanted SiO2:Ge glasses and the implanted SiO2 glasses. In the former the 5 eV band was bleached and intense absorptions above 5 eV emerged , whereas in the latter bleaching occurred in the whole UV region. Thi s distinct bleaching nature provides implanted glasses with the possib ility of modification of refractive index by UV illumination.