A diode-pumped, mirrorless blue fiber laser

Summary form only given. We report cw laser operation at 493 nm in Pr/Yb-doped fluorozirconate (ZBLAN) optical fiber. A single Ti:sapphire laser was used first as the pump source. No discrete dielectric mirrors were used. Instead, we applied dielectric coatings directly to both ends of the fiber to form the laser cavity. The coating on the HR end of the fiber has a transmission of 98% over the pump wavelength band of 780-880 nm and reflectivity of 99.9% at the laser wavelength of 493 nm. The coating on the OC end has a transmission of 1.5% at 493 nm. The combined reflectivity of OC and HR coating is less than 10% in the wavelength ranges of 635-637, 605-633, and 517-540 nm to suppress laser oscillation in this wavelength region. Two types of Pr/Yb-doped ZBLAN fiber were used in our experiment. The first is doped with 3000 ppm by weight Pr/sup 3+/ and 20,000 ppm by weight Yb/sup 3+/. The second is doped with 2000 ppm by weight Pr/sup 3+/ and 20,000 ppm by weight Yb/sup 3+/. We obtained 16 mW of blue cw output with 850 mW of pump power at 845 nm.