Bismuth/Yttria co-doped aluminosilicate fiber: impact of electron irradiation on optical properties

We report on changes in absorptive, emissive and waveguiding properties of Bismuth doped yttria-aluminosilicate (Bi-Al-Y-Si) fiber under the action of high-energy electrons. In addition to the drastic rise of induced absorption in the fiber as a result of bombardment with electrons (measured by similar to 800 dB m-1 in the VIS range at the maximal irradiation dose of similar to 200 KGy(SiO2) or 1 x 1014 cm-2), we reveal prominent (similar to 20 fold at the maximal dose) growth of the fiber emissive potential in NIR (similar to 1.2 mu m) at its pumping in VIS (at 730 nm), an effect never reported before; both phenomena are inferred to arise due to strong growth of the content of Bi-related active centers, mostly of the Bi(Al) type, at irradiation. We also report for Bi-Al-Y-Si fiber notable radiation-induced changes in the photo-bleaching behavior of the centers throughout the VIS/NIR range. Another point deserving attention is that the Stokes shift of the cutoff wavelength after irradiation is insignificant (similar to 25 nm at the maximal dose) in this type of fiber.