Growth and highly efficient mid-infrared continuous-wave laser of lightly-doped Er:SrF2 single-crystal fibers

Abstract Lightly doped Er:SrF2 single-crystal fibers (SCFs) were grown via temperature gradient technique (TGT) method for the first time, to the best of our knowledge. Laser operations at 2.8 μm in Er:SrF2 SCFs were realized under different pump wavelengths of 972 nm and 976 nm, respectively. We obtained the maximum laser output power of 860 mW and slope efficiency of 34.9% by pumping with a 976 nm laser diode (LD).