Yellow pumped Pr³⁺-doped ZBLAN fiber laser at 1015 nm

To date, lasing in the visible to near-infrared wavelengths has been studied for praseodymium-doped fluoride fibers with the upper energy level of ³P₀. In this Letter, a fiber laser operating at 1015 nm has been realized for the first time, to the best of our knowledge, which confirms a new mechanism where ¹D₂ can be the upper energy level. A maximum output power of 241 mW, with a slope efficiency of 30%, was achieved by using a 150-cm-long active fiber pumped at a maximum pump power of 823 mW. Furthermore, the broad emission spectra of Pr³⁺-doped fibers in the near-infrared band have been exploited as new, to the best of our knowledge, spectral sources.