Abstract

Lanthanum-magnesium hsxaaluminate LaMg Al₁₁O₁₉ (LNA) with magnetoplumbitelike structure is of considerable interest as a solid-state laser material. Compared to YAG:Nd it presents some advantages,¹ among which are the particular emission wavelengths at 1.054 and 1.082 μm tunable over 3.5 and 8.0 μm, respectively.² The hexaaluminate matrix makes possible the substitution of large amounts of Al or Mg by transition metal ions without modifying the crystal growth abilities.^3,4 This has prompted us to investigate the possibilities of sensitizing the neodymium fluorescence in LNA. Such sensitization has led to a dramatic increase of the laser efficiency in the well-known garnet compound GSGG:Nd:Cr, In the lanthanum aluminate, chromium substitutes aluminum preferentially in a distorted octahedral site close to the lanthanide one. Detailed investigations of the Nd³⁺ fluorescence intensities in LNA and LNA:Gr as well as studies of the fluorescence decay profile of Cr³⁺ and Nd³⁺ in the double-doped hexaaluminates indicate that the chromium-neodymium energy transfer is highly efficient in this material.

© 1988 Optical Society of America