Radiation-induced optical absorption bands in low loss optical fiber waveguides

Abstract The radiation-induced optical absorption of high purity silica and doped silica glass in the visible and near infrared has been studied using the long path length afforded by low loss optical fiber waveguides. This technique has permitted the investigation of previously unobserved bands of low absorption coefficient in this spectral region. Absorption measurements were made during steady state irradiation, after pulsed irradiation and at long times following irradiation over the 0.4–1.7 μ region. Photobleaching of induced bands centered near 700 nm in high purity synthetic silica core fibers has been studied, and the effects of dopants such as Ge, P, B, F, and Cs on the absorption spectra have been investigated.