Abstract

Several nickel-activated crystals have been lased in the past and have shown tunable output in the near infra-red (1.3-1.7 µm).¹ However, the performance of these lasers is rather poor, and exploratory work including the preparation and spectroscopic characterization of new systems containing this activator must continue since there is so far no adequate material for tunable solid state laser systems in the spectral region where oxide crystals doped with Ni²⁺ emit. Oxide garnets are in general very good laser hosts, and most of them are, from the crystal-chemistry point of view, adequate candidates as crystalline hosts for Ni²⁺. However, several of the best candidates such as Y₃A1₅O₁₂ (YAG) , Gd₃Ga₅O₁₂ (GGG) , and Gd₃Sc₂Al₃O₁₂ (GSAG), have octahedral sites occupied by trivalent ions, and when doping with Ni²⁺ a charge compensator is required to avoid creating undesirable color centers or for the purpose of achieving high doping levels. From ionic size and valence stability considerations, Zr⁴⁺ is the best choice for compensator. In our study of these systems we have concentrated in the development of growth conditions and the understanding of the spectroscopic characteristics of Ni, Zr:GGG and Ni, Zr:GSAG.

© 1989 Optical Society of America