Abstract

Blue upconversion lasing in ZBLAN optical fiber is an attractive approach for developing laser diode pumped coherent blue sources. While recent laser diode frequency doubling experiments, using bulk KnbO₃^l-2 nonlinear quasi-phasematched waveguides³, and resonant nonlinear cavities⁴ have resulted in CW blue power levels up to 41 mW, upconversion laser pumping greatly relaxes the wavelength stability requirements on the laser diode. Using solid state lasers to pump Tm-doped ZBLAN upconversion fibers lasers, up to 60 mW of blue output power has been demonstrated.⁵ In this paper, we report on the first laser diode pumped high power blue upconversion fiber laser, and demonstrate up to 106 mW of blue laser output power. To the best of our knowledge, this is the highest reported blue laser power level for any upconversion fiber laser and for any direct laser diode frequency conversion technique.

© 1995 Optical Society of America