Charge compensation effects of Yb on the Bi: near-infrared emission in PbF crystal.

The use of Yb codoping for enhancing the near-infrared (NIR) emission in Bi, Yb codoped PbF crystal was investigated for the first time, to the best of our knowledge. The NIR and visible fluorescence emission properties of the as-grown crystals were investigated in detail. It was found that the Yb ion can act as an effective charge compensated ion to bring about the conversion from Bi to Bi, enhancing the NIR fluorescence emission in Bi:PbF crystal. Moreover, the NIR fluorescence emission peaking at around 1090 and 1485 nm was demonstrated to be two different Bi related centers, Bi(I) and Bi(II), respectively. These results suggest that Bi, Yb codoped PbF crystal may become an attractive gain material for developing NIR broadband lasers under pumps of different wavelengths.