CRYSTAL-GROWTH AND OPTICAL-PROPERTIES OF TI3+YAL3(BO3)(4) AND TI3+GDAL3(BO3)(4)

Large single crystals of Ti3+-doped YAl3(BO3)(4) (YAB) and GdAl3(BO3)( 4) (GAB) have been prepared by top-seeded solution growth (TSSG) from a K2Mo3O10-B2O3 flux, using a cooling rate of 2.4 degrees C/day and ro tation rate of 6 rpm in a pure N-2 atmosphere. The optical properties of Ti3+: RAl3(BO3)(4) where R = Y3+ or Gd3+, are quite similar to thos e of Ti3+ : Al2O3. However, the Ti3+-doped aluminoborates have larger absorption coefficients than Ti3+ : Al2O3 and the peaks in the photolu minescence bands are shifted by ca. 20 nm to longer wavelengths compar ed to Ti3+:Al2O3. The results suggest that Ti3+-doped rare-earth alumi noborates have potential as tunable laser gain media in the near infra red region.