Off-centered top-seeded solution growth (TSSG) method is demonstrated as an effective and simple way to generate controlled composition modulation in potassium lithium tantalate niobate (KLTN) single crystals. The changes in concentration were measured by differential interference contrast (DIC) microscopy. Large length with periodic modulations ranging from 1 to 5 mum in period was grown along a KLTN sample with period dispersion lower than 2%. (C) 2004 Elsevier B.V. All rights reserved.