Lasing at 2.08μm and 1.38μm in a holmium doped fluoro-zirconate fiesre laser

Abstract

We report for the first time a fibre laser operating beyond the 1.55μm communications window. Using a holmium doped fluoro-zirconate fibre, laser emission occurs from the threelevel 2.08μm transition, and also at 1.38μm via a cascading transition.