An overview on Yb-doped ceramic laser materials

In the last decade one of the most important goals in diode-pumped solid state laser field was the fabrication of suitably doped transparent polycrystalline materials, i.e. ceramics, used as active materials. Many experiments report on good performances achieved by laser sources relied on ceramics. This success is addressed, first, to their high optical quality and, secondly, to their good thermo-mechanics properties, which are comparables with the more widespread crystals. In particular, it is worth to note that ceramics have a shorter processing time and lower processing temperature which are crucial in the growth of materials because of they can affect the doping homogeneity. An interesting case are the sequioxides as Y2O3, Sc2O3 and Lu2O3, which have a melting point above 2400 °C. Until now only crystals with small sizes have been grown, which unfortunately can not be used in a large number of applications where long rods or larger samples are required. Contrary, sesquioxides ceramics with reasonable size are nowadays available from many laboratories. In this seminar we present an overview on the infrared laser source prototypes designed in our laboratories in the last years which exploit YAG, Sc2O3, Lu2O3, LuAG, and LuYAG ceramics doped with Yb3+ ions. We discuss their main spectroscopic characteristics by showing the absorption and emission cross sections, the photoluminescence excitation and emission spectra. Finally we present their laser performances in term of output power, slope efficiency, laser threshold, beam spatial quality.