The recent development of ceramic laser materials is probably the most important innovation in the field of laser material fabrication technology.
We developed highly transparent YAG ceramics by means of modern ceramic technique including the vacuum sintering and nanocrystalline technology. Scattering losses were greatly reduced in our laser ceramic, and the optical properties of the ceramics are even better than those of the single crystal YAG.
The fabrication method of ceramics involves the following. First, YAG oxide powder was fabricated by wet chemical reaction and calcinating. Next, the power was ball-milled with solvent, and milled slurry was put into a gypsum mold and dried to obtain a desired form. Finally, the materials were sintered in vacuum for several hours. After annealing, highly transparent YAG ceramics were obtained. As a result of this method, great progress has been made on the development of Nd:YAG ceramic lasers. The efficiency of the Nd:YAG ceramic laser has been shown to be comparable to or better than that of single crystals at 100 W level, and the CW laser output power reached up to 1.4 kW. The microstructure and optical properties of these ceramics will be discussed.
Moreover, we fabricated Cr4+:YAG, Er:YAG, Nd:Cr:YAG and Nd:YAG - YAG composite ceramics for saturable absorber and gain medium. The microstructure, optical properties and laser characteristic of these ceramics will be reported.