IR luminescence in bismuth-doped germanate glasses and fibres

Photoluminescence of Bi12SiO20 crystals

“…The Stokes shift between the spectral bands I PLE (hv) and the components of the I PL (hv) spectra amounts to 1.25-2.0 eV. Such a significant shift has earlier been marked as a feature characteristic for the PL in many Bi-containing compounds [1,13,14]. A narrow peak located at hν max = 3.39 eV, in which practically all the PL is excited, has also been observed in Refs.…”

Origin of near-IR luminescence in Bi_2O_3–GeO_2 and Bi_2O_3–SiO_2 glasses: first-principle study

“…In binary Bi 2 O 3 -GeO 2 systems, however, distinctly different luminescence occurs. The luminescence in the 1.2-1.3 µm range excited at 0.5, 0.8 and 1.0 µm was observed in [12][13][14][15] and x ≈ 0.01 [16] [15]. Annealing glasses in oxidative atmosphere [12][13][14][15] or adding oxidant (CeO 2 ) in glass [19] led to a decrease in the luminescence intensity evidencing convincingly oxygen-deficient character of the luminescence centers.…”

“…The decrease in intensity of the 1.2-1.3 µm luminescence may be explained by a transformation of = Bi · · · Ge ≡ centers into = Bi · · · Bi = ones owing to thermally stimulated migration of O vacancies. The luminescence near 1.1 µm in Bi 2 O 3 -Al 2 O 3 -GeO 2 glasses [13,16,21] and in Al-doped Bi 4 Ge 3 O 12 crystals [22] may be caused by = Bi · · · Ge ≡ center (AlO 4 )…”

“…Annealing glasses in oxidative atmosphere [12][13][14][15] or adding oxidant (CeO 2 ) in glass [19] led to a decrease in the luminescence intensity evidencing convincingly oxygen-deficient character of the luminescence centers. In Bi 2 O 3 -Al 2 O 3 -GeO 2 glasses [20,21], in Bi 2 O 3 -GeO 2 glass prepared in alumina crucible [16] 2 and SiO 2 (namely, O vacancy and twofold coordinated Si or Ge atoms), but as well similar ODCs containing Bi atoms (BiODCs), namely, = Bi · · · Ge ≡, = Bi · · · Si ≡, = Bi · · · Bi = vacancies and twofold coordi-nated Bi atoms. According to [8], in SiO 2 twofold coordinated Bi atoms bound by bridging O atoms with Si atoms can be considered as Bi 2+ centers, while in GeO 2 such Bi atoms are unstable.…”

First-principle study of the near-IR luminescence centers in Bi2O3-GeO2 andBi2O3-SiO2 glasses

“…In binary Bi 2 O 3 -GeO 2 systems, however, distinctly different luminescence occurs. The luminescence in the 1.2-1.3 µm range excited at 0.5, 0.8 and 1.0 µm was observed in [12][13][14][15] and x ≈ 0.01 [16]), in Bi 12 GeO 20 crystals quenched in N 2 atmosphere [17], and in Mg-or Ca-doped Bi 4 Ge 3 O 12 crystals [18]. The luminescence in the 1.8-3 µm range was observed in…”