Experimental and theoretical analysis of Dy3+-doped fiber lasers for efficient yellow emission

We report a detailed experimental and theoretical analysis of the F-4(9/2) to H-6(13/2) lasing transition of a dysprosium (Dy3+)-doped ZBLAN fiber, a strong candidate for future compact and highly efficient yellow laser emission. Experimentally, we used a gallium nitride laser diode emitting at 447 nm as a pump source and measured yellow laser output generated with a maximum slope efficiency of 33%, which is less than half of the Stokes limit (of similar to 78%). This result is commensurate with two other reports of yellow emission from Dy3+. As a result, we developed a numerical model to understand and analyze the improvement potential of this fiber laser system. For reliable spectroscopic data input to the numerical model, we measured the absorption and emission cross sections from Dy3+-doped ZBLAN glass. We investigated the potential causes of the low experimental slope efficiency and found contributions from the background loss of the fiber and excited-state absorption (ESA) of the intracavity yellow light. We estimated the signal re-absorption cross section using the emission cross section and the McCumber relation, which was subsequently used in our numerical model to compare successfully with our experimental results. We show that the ESA can be reduced for future Dy3+-doped yellow laser systems by cascade lasing or co-doping with a suitable rare earth ion desensitizer. (C) 2021 Optical Society of America

Automated summary

In this study, the F-4(9/2) to H-6(13/2) lasing transition of dysprosium (Dy3+)-doped ZBLAN fiber for yellow laser emission was experimentally and theoretically analyzed. The experimental results showed a lower slope efficiency than the Stokes limit, which was attributed to background loss of the fiber and excited-state absorption of the yellow light. A numerical model was developed to understand and analyze the potential improvements of the fiber laser system, with suggestions for reducing ESA in future Dy3+-doped yellow laser systems through cascade lasing or co-doping with suitable rare earth ion desensitizer.