The high optical quality 5 at% doped Yb:YAG single crystals with diameter of 3 inches have been grown by temperature gradient technology (TGT). The segregation coefficient of Yb ions in TGT-grown 5 at% doped Yb:YAG crystals determined by ICP-AES method is equal to 1.1. The absorption spectra in the range of 190-1200 nm of TGT-grown Yb:YAG crystals were also measured at the room temperature. The absorption peaks of trivalent Yb ions and the unknown color centers were found in the absorption spectra. (C) 2003 Elsevier Science B.V. All rights reserved.