Compositionally uniform mixed crystals of In(x)Ga(1-x)As(0.07 < x < 0.35) and Si(0.5)Ge(0.5) were grown by the traveling liquidus-zone (TLZ) method. The TLZ method is a kind of zone-melting method but is different from a conventional method in forming a liquidus-zone at a relatively low temperature gradient of about 10 degrees C/cm. In the paper, the principle of the TLZ method, examples of TLZ-grown crystals and merits and demerits of the TLZ method are described. Finally, application of the TLZ-grown In(0.13)Ca(0.87)As crystals to substrates and successful fabrication of high performance laser diodes are introduced. (C) 2010 Elsevier B.V. All rights reserved.