Spectroscopic properties of OH− doped and Bi-rich Bi4Ge3O12 crystals by vertical Bridgman method

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 357 nm, Bi-rich BGO after annealing in Ar at 500 °C for 5 h shows a significant emission band peaking around 1170 nm under 808 nm laser diodes (LDs) excitation, and OH− doped BGO shows a noticeable emission band centered at about 1346 nm under 980 nm LDs excitation. A brief discussion is presented.