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Abstract: Spectral properties in Mg and Ca doped Bi4Ge3O12 (BGO) crystals and glasses were investigated. Near-infrared (NIR) photoluminescence was observed in Mg and Ca doped Bi4Ge3O12 (BGO) crystals, while NIR emission in doped BGO glasses was very weak. There is no fundamental difference about NIR emission between Mg2+ and Ca2+ doped BGO crystals, and the emission center is still related to Bi ions, the doped ions can influence energy level of Bi ions. [Copyright &y& Elsevier]

Abstract: OH− and Cl− doped Bi4Ge3O12 (BGO) single crystals had been grown by Vertical Bridgman (VB) method. The structure of these crystals was determined by XRD, the transmittance and emission spectra in near infrared region (NIR) were measured at room temperature. 5% OH− doped BGO shows a significant emission band peaking around 1181nm under 808nm laser diodes (LDs) excitation, and the 5% Cl− doped BGO exhibits a relatively weak emission band as well. 100% and 5% OH− doped BGO show noticeable emission band centered at about 1346nm under 980nm LDs excitation. [Copyright &y& Elsevier]

Abstract: OH− doped and Bi-rich Bi4Ge3O12 (BGO) single crystals were grown by Vertical Bridgman (VB) method. The structure of these crystals was determined by XRD, and the emission spectra in visible and near infrared region (NIR) were measured at room temperature. The emission spectrum of Bi-rich BGO has extra peaks at 385, 367 and 357nm, Bi-rich BGO after annealing in Ar at 500°C for 5h shows a significant emission band peaking around 1170nm under 808nm laser diodes (LDs) excitation, and OH− doped BGO shows a noticeable emission band centered at about 1346nm under 980nm LDs excitation. A brief discussion is presented. [Copyright &y& Elsevier]

Abstract: Red Bi4Ge3O12 (BGO) single crystals had been grown by vertical Bridgman (VB) method. The structure of this crystal was determined by XRD. The absorption and emission spectra of the red BGO in visible and near infrared region (NIR) were measured at room temperature. The emission intensity of the red BGO is weaker than that of ordinary BGO at about 500nm. Interestingly, the red BGO shows a significant emission band centered at about 1495nm. The red BGO faded and its properties recovered after ultraviolet (UV) irradiation or annealing. [Copyright &y& Elsevier]

Abstract: Red Bi4Ge3O12 (BGO) crystals were obtained by the vertical Bridgman method. The absorption/transmittance spectra of red BGO in the visible and near-infrared (NIR) regions were measured at room temperature. The luminescence and decay time in the NIR region were then measured down to a temperature of 8K. A broad emission band was found at approximately 1150nm at T<200K, and the luminescence lifetime was measured at several hundred microseconds. Decreased temperature led to increased luminescence intensity. We report that red BGO is a promising cryogenic scintillator for experimental rare-event research. [Copyright &y& Elsevier]

Abstract: MoO3 and WO3 doped Bi4Ge3O12 (BGO) crystals were grown by the optical floating zone (OFZ) method. The structure of doped crystals was determined by XRD. The fluorescence spectra and fluorescence decay curves of these BGO crystals at room temperature were also studied. The emission intensity of BGO crystals increased with WO3 dopant but decreased with MoO3 dopant. A heavily WO3 doped BGO has shown a much shorter decay time than undoped BGO at about 500nm. [Copyright &y& Elsevier]

Abstract: 2.0mol% (relative to Ba2+) Yb3+ doped α-BaB2O4 (α-BBO) crystal was obtained by the Czochralski method. The doped crystal structure was determined by means of an X-ray diffraction analysis. The absorption, near-infrared (NIR) luminescence spectra and fluorescence decay curve of Yb3+ doped α-BBO crystal were investigated. NIR emission under 940nm and 980nm LDs (laser diodes) excitation was observed in the Yb doped α-BBO crystal. [Copyright &y& Elsevier]

Abstract: We report on the near-infrared (NIR) luminescent properties of Bi2O3–GeO2 glass. Apparent differences of NIR luminescence, decay properties and thermal stability manifest the co-existence of more than one active center in this system. The effects of Al ions introduced both unintentionally and intentionally were investigated. 27Al NMR analysis proposes 4-fold Al coordination as dominant structure which can also provide the environment for active centers. We suggest that Al ions play a crucial role to restrain concentration quenching at higher Bi2O3 concentration instead of assisting to construct Bi centers. [Copyright &y& Elsevier]