Research Progress of Rare-earth Doped Laser Crystals in Visible Region

Visible laser has been widely used in data storage, optical communication, laser display, laser medical treatment, laser printing, and scientific research. With the development of commercial blue light LD, the direct pumping of rare-earth ions doped laser crystals have attracted a lot of interests. Currently, visible ions mainly concentrat on Pr 3+ , Dy 3+ , Tb 3+ , and Sm 3+ . Trivalent praseodymium (Pr 3+ ) is a famous rare-earth ion with extensive laser transitions in visible region such as blue, green, red and orange light. However, there is still a region in yellow emission which is not covered by Pr 3+ . Dy 3+ and Tb 3+ have attracted much attention because of their yellow laser transitions. In addition, Sm 3+ and Eu 3+ are also typical visible rare-earth ions. In this paper, we mainly reviewed properties of rare-earth ions doped laser crystals for visible lasers, especially Pr 3+ , Dy 3+ , Tb 3+ and Sm 3+ -doped YAlO 3 (YAP), SrAl 12 O 19 (SRA) crystals. A design criterion for Pr 3+ doped oxide materials was summarized. The crystal growth, structure, thermal properties, polarization spectroscopic and laser characteristics were analyzed in detail.