Silica fiber laser emitting moderate power-stable visible output

A high slope efficiency of 12%, a stabilized output power of 250 mW at a wavelength of 581.8 nm, and what we believe to be a record peak output power of 450 mW have been achieved from a diode-pumped high concentration Dy³⁺:BaF₂ nanoparticle (NP)-doped silicate fiber laser. The performance is primarily attributed to a reduction in the overall background loss within the cavity and a higher Dy³⁺ concentration in the pre-synthesized NPs. Almost 60% of the initial laser power remains in the steady state after several hours of the fiber being pumped by high-power 450 nm radiation, suggesting a modified local rare-earth ion environment. Such an environment likely leads to moderate photodarkening resistance, which results from the reduced energization of nearby precursor defects in the aluminosilicate glass, typically forming strongly absorbing defect centers. The result opens the door to a new class of lasers that exploits the remarkable material properties of silicate glass for the efficient generation of visible light.