This paper summarizes the main results we obtained in our laboratories in relation with crystalline layers obtained by Liquid Phase Epitaxial growth of lanthanide doped KLu(WO4)(2) and Nb:RbTiOPO4 grown on KLu(WO4)(2) and RbTiOPO4 substrates, respectively. Macroscopic defect free epitaxial layers were grown and characterized in terms of their compositional homogeneity, structural stress in the layer/substrate interface and laser and waveguiding performances. (C) 2010 Elsevier B.V. All rights reserved.