Dual-Wavelength Laser Output in Nd3+/Yb3+ Co-Doped Phosphate Glass Fiber Under 970 nm Pumping

We report the demonstration of dual-wavelength laser output originating from excited Nd
³⁺
ions and Yb
³⁺
ions in Nd
³⁺
/Yb
³⁺
co-doped phosphate glass fiber under 970-nm laser diode pumping. Using a free-space coupling method, laser bands at 1028 and 1053 nm were observed in a 35-cm-long fiber with the corresponding lasing thresholds of 4.3 and 31.5 W at room temperature. Emission and lasing spectra under different pump powers were tested by the optical spectrum analyzer. The 1053-nm laser threshold was found to be temperature sensitive. The mechanism of Yb
³⁺
→ Nd
³⁺
energy transfer under 970 nm pumping was explored. It was proposed that Yb
³⁺
→ Nd
³⁺
energy transfer process with the participation of phonon resulted in 1053-nm laser of Nd
³⁺
ions in this co-doped fiber under 970 nm pumping.