Seminar_Rare-earth-doped lasers from the visible to the mid-infrared_Christian Kränkel_September 17, 201517/09 : 13h - 14h15
As part of the Cluster LAPHIA seminars (IdEx Bordeaux), Christian Kränkel (Universität Hamburg) will present his research on "Rare-earth-doped lasers from the visible to the mid-infrared".
The seminar LAPHIA will be held Thursday, September 17, 2015 from 1:15 pm to 2:15 pm in the auditorium of the Institut d'Optique d'Aquitaine (tram B - Arts et Métiers) .
A coffee break is organized at 1:00 pm in the hall of IOA, you are welcome to join us.
The 4f-shells of rare earth ions provide optical transitions from the UV to the mid-IR. Utilizing these transitions for efficient lasers is often not straight-forward and the choice of the host material is crucial in this respect. Besides obvious properties such as transparency range or thermal conductivity also factors like the crystal field strength and the phonon energies of the host lattice have to be taken into account to avoid unwanted parasitic radiative and non-radiative transitions between energy levels of the doping ion.
In my presentation I will treat these requirements and present our latest results on novel, highly efficient rare-earth doped lasers. Pr3+- and Tb3+-doped materials allowed for more than 1 W of continuous wave output power at various visible wavelengths with efficiencies exceeding 50%, while Tm3+- and Er3+-doped laser crystals enabled highly efficient lasing in the 2 ?m and 3 ?m spectral range. The ongoing progress in semiconductor-based pump sources even allowed to increase the efficiency of well-established laser ions such as Yb3+ and allowed fs-lasers with optical-to-optical efficiencies in the order of 70% at 1 ?m.