WITHDRAWN: Transient optical absorption in pure-silica-core optical fibers from ultraviolet to near-infrared wavelengths

The damage threshold of fused silica in vacuum and air before or after 355nm laser irradiation is measured. The structure and defects of fused silica has been studied by means of FTIR (Fourier transform infrared), Raman and Fluorescence spectroscopy. The primary defect species are oxygen vacancies (such as Si–Si bonds), non-bridging oxygen hole center (NBOHC), oxygen interstitials (peroxy radicals, or O2 molecules). The damage threshold of fused silica in air after pre-irradiation increased, while the threshold of fused silica in vacuum after pre-irradiation decreased. The damage mechanisms are discussed. PACS: 42.70.Ce 61.72.Ji 61.80.Ba