Single crystals of LiNbO3 co-doped with Er3+ and Yb3+ have been grown by th
e Czochralski technique, from melts having a fixed erbium concentration (0.
5 mol%) and different ytterbium concentrations (0.1, 0.5, 1.0, 1.5 and 2.0
mol%). Optical absorption measurements indicate the efficient incorporation
of the rare-earth ions to the crystal, with the absorption bands character
istic of the 3(+) valence. The co-doping with Yb3+ increases substantially
the absorption band in the 880-1040 nm region compared to Er-doped crystals
. The incorporation of the rare-earth ions to the crystal is better describ
ed by considering both dopants as a single species with a solubility depend
ent on the total impurity concentration. (C) 1999 Elsevier Science B.V. All
rights reserved.