Investigation on Er³⁺/Ho³⁺ co-doped silicate glass for ~2 µm fiber lasers

A stable Er³⁺/Ho³⁺ co-doped lead silicate glass is developed. Luminescent properties are recorded under pumping with 808 and 1550 nm lasers. Energy-transfer mechanism and efficiency are analyzed. Energy-transfer efficiency from Er³⁺:⁴I_13/2 to Ho³⁺:⁵I₇ reaches 93.8% at 3 mol% Ho₂O₃ doping concentration. Strong luminescence is detected when pumped at 1550 nm because of efficient energy transfer from Er³⁺:⁴I_13/2 to Ho³⁺:⁵I₇. Peak gain coefficient at 2056 nm is detected as 1.62 cm⁻¹. The excellent luminescent property and high stability indicate that Er³⁺/Ho³⁺ co-doped lead silicate glass can be applied in 2 µm fiber lasers. - Highlights: • Er³⁺/Ho³⁺ co-doped silicate glasses with high stability are prepared. • Strong luminescence is detected under pump of 1550 nm lasers owing to efficient energy transfer from Er³⁺ to Ho³⁺. • Transfer efficiency is calculated to be 93.8% when Ho₂O₃ doping concentration is up to 3 mol%. • Gain coefficient peaks at 2056 nm to be 1.62 cm⁻¹