Exploration of Advanced Ceramic Gain Media with Broadband for the Application to High Energy Laser

Abstract : Practical laser generation from polycrystalline ceramic materials has become available; furthermore, it is expected that ceramic laser technology will completely surpass the conventional glass and single crystal laser technologies in the future. In this work, we fabricated advanced ceramic gain media for broadband such as CLNGG (Ca3LixNb1.5-xGa(3.5-2x)O12), CLNTGG (Ca3(LiNbTaGa)5O12)) and YSAG (Y3Sc1Al4O12), and investigated their spectroscopic properties such as emission spectrum and fluorescence lifetime. Among them, we screened the best candidate compositions for high energy laser and developed into high optical quality ceramic gain media. Nd doped Y3ScxAl5-xO12 (x = 0 to 2) ceramics was confirmed as one of the candidates for high energy laser with broadband. A composite structure with three compositions in Nd doped Y3ScxAl5-xO12 (x = 0 to 2) ceramics was successfully fabricated for the first time to obtain a broadband spectrum. The emission spectrum of multi-layered YSAG composite was more than 5 times broader compared to that of 1at% Nd:YAG. The laser oscillation test showed that multi-layered composite made of Nd:YSAG ceramics reached laser grade optical quality. Based upon the results of this work, we will apply advanced ceramic materials for high energy laser application in the future.