High-Energy Q-switched Er:ZBLAN Fibre Laser at 2.79 μm

In recent years most research on fibre lasers has been focused on the 1, 1.5, and 2 μm wavelength ranges using rare-earth ions such as Yb, Er, Tm, or Ho in silicate glass hosts. This approach led to remarkably high power and high energy systems. Regarding direct laser sources emitting around 3 μm with comparable performance only few reports can be found in literature. High peak power lasers emitting here have significant potential for applications in medicine because of the strong absorption peak of water containing substances, e.g. biological tissue [1]. Although ZBLAN glass fibres have poor thermal properties there are several benefits for using ZBLAN based mid-IR lasers, e.g. low phonon energy and high transmission up to 3.5 μm.