ION IMPLANTATION-INDUCED STRONG PHOTOSENSITIVITY IN HIGH-PURITY FUSED-SILICA - CORRELATION OF INDEX CHANGES WITH VUV COLOR-CENTERS

We have studied optical changes induced by ArF (6.4 eV/193 nm) excimer laser light illumination of high purity SiO2 implanted with Si2+ (5 M eV) at a fluence of 10(15) ions/cm(2). Optical absorption was measured from 3 eV (400 nm) to 8 eV (155 nm) and showed evidence of several we ll-defined absorption bands. A correlation in the bleaching behavior a ppears to exist between the so-called D band (located at 7.15 eV) and the well-known B-2 alpha band which is attributed to oxygen vacancies. Changes in the refractive index as a function of ArF illumination wer e measured and found to be in good quantitative agreement with a Krame rs-Kronig analysis of the optical absorption data. (C) 1996 American I nstitute of Physics.