Multi-colour laser oscillation in Pr3+-doped fluoro-aluminate glass fibre pumped by 442.6 nm GaN-semiconductor laser

The successful drawing of a Pr-doped optical fibre of a waterproof fluoro-aluminate glass in an AlF3-YF3-PbF2 system with low loss (0.1 dB/m) is reported and multi-colour laser oscillation in a Pr3+-doped fluoro-aluminate glass fibre pumped by a 442.6 nm GaN-semiconductor laser is demonstrated. Since the fluoro-aluminate glass in an AlF3-YF3-PbF2 system has a remarkable water resistance advantage compared to ZBLAN glass, Pr-doped fluoro-aluminate glass fibre is expected to contribute to making a visible fire laser with high chemical durability without a frequency doubling technique.