New radiation colour centre in germanosilicate glass fibres

Research paper by P F Kashaykin, A L Tomashuk, V F Khopin, A N Guryanov, S L Semjonov E M Dianov

Indexed on: 21 Dec '18Published on: 18 Dec '18Published in: Quantum electronics


We have investigated radiation-induced absorption (RIA) of light in five optical fibres with a germanosilicate core and a lightreflecting cladding made of undoped silica glass in the visible and near-IR ranges under γ-irradiation to a dose of 1 kGy at temperatures from –60 to +60 °C. The concentration of GeO 2 in the cores of the studied fibres ranged from 3.5 to 50 mol %. It is found that the RIA dependences on temperature for optical fibres having been lightly or heavily doped by germanium are different. An increase in RIA with increasing temperature for heavily doped fibres is associated with an increase in the absorption intensity of the GeX centre due to thermal decay of Ge(1) centre. It is found that, in fibres lightly doped by germanium, RIA in the near-IR range is determined mainly by a previously unknown radiation colour centre (RCC) called the GeY centre, with a maximum of the absorption band at a wavelength of ≈900 nm (1.38 eV), a half-width of 495 nm (0.71 eV)...