Yb:LuAG laser ceramics: a promising high power laser gain medium

Transparent Ceramics

“…A simple and feasible repeated annealing process was available to obtain transparent PLZT(9/65/35) ceramics [226]. The experiment was started from nanosized powder of PLZT, which was synthesized directly from commercially available constituent oxides by using a high-energy ball milling at near room temperature.…”

“…A series of works have been reported on preparation of YAG based phosphor powders by using spray pyrolysis method, with spray solutions of different fluxes [226][227][228][229]. It has been demonstrated that spray pyrolysis method can be used to control the morphologies and sizes of the YAG based phosphor powders in a very feasible way.…”

“…For instance, impregnation of the green body with epoxy resin, followed by sectioning, polishing, and observation with SEM, could provide quasi-three-dimensional information of the green body microstructure. A liquid immersion technique can be used to characterize the internal structure of granules [93] and green bodies [226]. In this technique, the specimens are made transparent by immersion in a liquid with a matching refractive index and observed in an optical microscope under transmitted light.…”

“…In this respect, Lu 3 Al 5 O 12 (LuAG) has been acknowledged to be a promising host for Yb, because its thermal conductivity is not strongly affected by the doping of Yb [225][226][227]. For example, diode laser pumping at 940 nm of a 5 at.% Yb: LuAG ceramic laser exhibited 1030 nm CW laser emission, with a slope efficiency of 63 %, which was influenced by the residual absorption [227].…”

Potassium double tungstate waveguides with high ytterbium concentration for optical amplification

“…Power dependent non-exponential decay behavior similar to the observation in current work had been reported in YbAG crystals [140] and it was attributed to cooperative energy transfer from two Yb 3+ ions to an Yb 2+ ion. Nevertheless, the presence of Yb 2+ has not been reported in KRE(WO4)2:Yb 3+ till date, although it is known to exist in certain as-grown crystals such as YAG:Yb 3+ [128] and LuAG:Yb 3+ [141]. The observed ETU could be caused by cooperative upconversion luminescence, where the combined energy of the two excited ions leads to emission of visible photon, and possibly also cooperative or cumulative energy transfer to the impurities [142].…”