Ion implantation-induced strong photosensitivity in high-purity fused silica: Correlation of index changes with VUV color centers

Abstract

Si ion implantation-induced damage in fused silica probed by variable-energy positronsWe have studied optical changes induced by ArF ͑6.4 eV/193 nm͒ excimer laser light illumination of high purity SiO 2 implanted with Si 2ϩ ͑5 MeV͒ at a fluence of 10 15 ions/cm 2 . Optical absorption was measured from 3 eV ͑400 nm͒ to 8 eV ͑155 nm͒ and showed evidence of several well-defined absorption bands. A correlation in the bleaching behavior appears to exist between the so-called D band ͑located at 7.15 eV͒ and the well-known B 2 ␣ band which is attributed to oxygen vacancies. Changes in the refractive index as a function of ArF illumination were measured and found to be in good quantitative agreement with a Kramers-Kronig analysis of the optical absorption data.

Photoluminescence and absorption in multi-energy Ge implanted type III silica

“…There was no band calculated at 7.6 eV since they assumed that an exponential function, representing the band edge, was absorbing at energies >7.0 eV. Their calculation did not produce the bands at 5.02 and 5.18 eV that have been reported [4,7,25,29] as intrinsic to the silica defect structures.…”

“…Based on these recent results and the fact that our data only goes to 6.4 eV, we have made the minimal assumption of one band at energies greater than 6.0 eV. This assumption does not preclude the presence of bands at energies >7.0 eV such as the D and E bands [4,5,7,29]. Our assumption of a single band at energies >6.0 eV is the minimal assumption.…”

Effects of B and N implantation on optical absorption and photoluminescence and comparison to the effects of implanting Si, Ge, O, and Ar in silica

“…We used a band at 7.15 eV to represent bands at energies >6.4 eV in the linear fits. This band at 7.15 eV was chosen for these linear fits because its presence was reported in ion implanted samples [30,31]. The linear fits as previously reported [9,11] clearly do not fit the spectra for energies >5.4 eV.…”

“…Here we use those bands detected at energies >4.5 eV since in our samples no bands were detected in the spectra of our samples at energies <4.5 eV. Table 3 provides a list of some of the defects in silica and their energies of maximum absorption and FWHMs reported in the literature [1][2][3][4][5]21,[25][26][27][28][29][30][31]. Because of the widths of the absorption bands and the differences in the energies of the maximum amplitudes of these defect bands, the bands overlap.…”

Photosensitive point defects in optical glasses: Science and applications

“…Such approaches include the use of hydrogen treatments at elevated temperatures [18,22] and pressures [23,24] which increase the density of photoactive defects in the material, the addition of dopants to provide additional optically active sub-band-gap states [25][26][27], ion implantation [28,29] and the manipulation of optical exposure conditions. The latter case …”