Enhanced ultra-broadband optical amplification in Yb-Bi codoped magnesium germanate glasses

Yb-Bi codoped magnesium germanate glasses were prepared. Their optical properties were investigated by absorption, luminescence spectra and luminescence decay lifetime and compared with single Bi-doped glass. The emission intensity of Yb-Bi codoped glass (MGBY) is ~10 times larger than that of single Bi-doped sample (MGB). The single-pass optical amplification was measured on a traditional two-wave configuration with excitation of single commercially available 980 nm laser diode. Internal optical gain of 4.06 dB at 1310 nm and 0.76 dB at 1550 nm were realized in a 1 mm-thick bulk MGBY sample. It is more than 3 times larger than those of MGB glass. The Yb-Bi codoped glasses are promising for ultrabroadband optical amplification covering almost all the O, E, S, C, and L bands.