High-efficiency, yellow-light Dy-doped fiber laser with wavelength tuning from 568.7 to 581.9 nm.

We report, to the best of our knowledge, the first demonstration of a wavelength-tunable and highly efficient Dy-doped fiber laser operating in the yellow spectral region. A 2-m-long Dy:ZBLAN fiber pumped by a 447-nm GaN laser diode provides a strong down-conversion gain around 575 nm. A fiber end-facet mirror and a visible reflective grating in the Littrow configuration construct the resonant cavity and introduce the wavelength tunability. A stable yellow laser with a <0.05-nm narrow linewidth is achieved and continuously tuned from 568.7 nm to 581.9 nm, covering more than half of the yellow spectral range. The slope efficiency is as high as 34.9%, and the maximum output power is 142 mW at 576.44 nm, which is 13 times higher than previously reported. It is, to the best of our knowledge, the highest power and conversion efficiency of a yellow-light Dy-doped fiber laser with wavelength tunability.