~1 µm laser output based on heterogeneous fiber with Yb3+-doped fluorophosphate core and phosphate cladding

Abstract

A broad Stark splitting of Yb3+-doped fluorophosphate (FP) core glass and phosphate cladding glass with outstanding thermal and mechanical performance were prepared in this work. Yb3+-doped FP core and phosphate cladding heterogeneous fiber with hexagonal-shape inner cladding was fabricated by the stack-and-draw method. A maximum output power of 2W was obtained with slope efficiency of 25.6% from a 35cm fiber. The laser spectrum had a full width at half maximum (FWHM) of 1.5nm with the central wavelength at 1013nm. Therefore, FP glass fiber might be a good alternative for gain medium in short-linear-cavity single-frequency fiber laser.