Ceramic and glass-ceramic lasers

In the field of solid-state lasers, luminescent-ion activated ceramics appear to be interesting challengers for single crystals. They are easier to obtain and higher doping levels can be achieved. These materials have been known since the sixties, but they have gained practical importance only recently, thanks to the improvements in the synthetic procedures, leading to materials with increased transparencies and also because of the strong demand for high power laser materials. Nd:YAG ceramics are the most studied ones and they give the highest power achieved so far ( similar to 1.5 kW continuous-wave). However, ceramic techniques have also been recently applied to other refractory oxides whose single crystals are difficult to grow. Similarly, recent progress in partial and controlled crystallization of glasses has allowed the development of neodymium-doped glass-ceramic fibers. The glass-ceramic properties, which approach those of crystalline materials, allow the achievement of other optical functions, such as passive-Q-switching and second harmonic generation. The ceramic and glass ceramic lasers offer large potentialities and they will develop at the same rate than their synthesis.