Tm3+-doped lead silicate glass sensitized by Er3+ for efficient ~2 μm mid-infrared laser material

It can be seen the overlap between the emission cross section of Er3+ and the absorption section of Tm3+ large indicating the existence of efficient energy transfer from Er3+ to Tm3+. The calculated maximum emission cross section of Ho3+ is 2.689 × 10−21 cm2 at 1863 nm. This suggests that the lead silicate glass is excellent mid-infrared laser material.162