Room temperature CW tunable green upconversion holmium fibre laser

Abstract
CW tunable green laser emission between 540 and 553nm (5S2 → 5I8) has been achieved in Ho3+-doped fluorozirconate fibre by upconversion pumping at room temperature, with output powers in excess of 10mW. Laser emission at 0.75μm (3S2 → 5I7) was also observed at the same excited level.