Optical Characteristics of Al_2O_3 Ceramics with Highly Doped Cr

概要

論文の詳細を見る
Recently, the need for the solid-state laser is rapidly increased. With this laser, it is required to make a solidstate laser medium with high efficiency. Generally, a single crystal has been used for the solid-state laser medium. The single crystal laser medium is generally limited by its size and the amount of optically active elements. For the solution of these problems, it is proposed to use a poly-crystalline medium for the laser. As a fundamental study, the optical characteristics of Cr doped poly-crystalline Al_2O_3 (sintered ruby) ceramics were investigated. Poly-crystalline Al_2O_3 ceramics in which Cr was doped with high concentrations (2,3 and 4wt.%) was fabricated with an extrusion molding process following by a vacuum sintering method using Al_2O_3 and Cr_2O_3 powders. The crystal structure of the sintered ruby was confirmed with a powder X-ray diffraction method. The microstructure of the sintered ruby was observed by an optical microscope and a SEM. The dispersion of Cr ion within Al_2O_3 matrix was characterized with an EPMA. The optical properties of Cr ions were characterized by using photoluminescence and absorption spectra. It was found that a high concentration of Cr ions was optically activated and the fluorescence spectrum by Cr ions was nearly equal to that of a single crystal.
東海大学の論文