Effective enhancement of 2.87 µm fluorescence via Yb3+ in Ho3+:LaF3 laser crystal

A novel Yb3+, Ho3+:LaF3 crystal was successfully grown and analyzed. Intense emission at 2.87 µm was observed in Yb3+, Ho3+:LaF3 crystal for the first time. Yb3+ ions not only provide sensitization mechanism for conventional LD pump, but also reduce self-termination by comparing with Ho3+:LaF3 crystal. The emission cross-section, quantum efficiency and fluorescence branching ratio at 2.87 µm are calculated to be 1.21 ×10-20 cm2, 82.5%, and 27.1%, respectively. The results indicate Yb3+, Ho3+:LaF3 crystal an attractive host for solid-state lasers around 2.87 µm under a 974 nm LD pump.