Quasi-three-level continuous wave Nd:Na2La4(WO4)7 lasers at 0.9 μm

• The single-wavelengths at 889 nm and 912 nm were obtained for the first time. • The single-wavelengths at 890 nm and 905 nm were realized for the first time. • The dual-wavelengths at 889 & 912 nm and 890 & 905 nm were achieved for the first time. A diode-pumped continuous wave (CW) Nd:Na 2 La 4 (WO 4 ) 7 (Nd:NLW) laser operating at 0.9 μm on 4 F 3/2 → 4 I 9/2 transition was demonstrated. Four single- wavelengths (the 889 nm and 912 nm in σ-polarization, the 890 nm and 905 nm in π-polarization) were obtained by rotating an intracavity birefringent filter (BF). At an absorbed pump power of 17.4 W at 808 nm, the highest output power of single-wavelength at 912 nm was 3.4 W. Furthermore, the dual-wavelength at 889 and 912 nm in σ-polarization and the dual-wavelength at 890 and 905 nm in π-polarization were also achieved, respectively. At an absorbed pump power of 17.4 W, the maximum total output powers of the dual-wavelengths at 889 and 912 nm was 2.12 W. To the best of our knowledge, this is the first quasi-three-level Nd:NLW laser operating at 0.9 μm.