With the aim of fabricating centimetric size periodically poled KTiOPO4 crystals (PPKTP) with a controlled and regular grating period, we proposed a process based on a flux homo-epitaxial growth process using seeds made of thin PPKTP plates previously obtained by electric field poling. By this way, it is possible to take advantage of the regular grating periodicity obtained by electric field poling and to the possibility of obtaining large size crystals from a high temperature solution growth. The large aperture size crystals obtained may then be used in high energy quasi-phase-matched (QPM) frequency conversion devices.
The optimal growth conditions for obtaining high quality PPKTP thick layers (≈ 1mm) have been determined. The quality of the interface, the propagation of the domains and their regularity have been characterized by MEB, PFM and QPM second harmonic generation [1, 2].
Growth of larger PPKTP crystals are in progress. Such a process may be used for the growth of other periodically poled non linear crystals for infra-red (IR) as well as ultra-violet (UV) applications.
 A. Peña, B. Ménaert, B. Boulanger, F. Laurell, C. Canalias, V. Pasiskevicius, P. Segonds, C. Félix, J. Debray, S. Pairis, “Template-growth of periodically domain-structured KTiOPO4”, Optical Materials Express, Invited Paper, 2011, 1(2), 185-191.
 A. Peña, B. Ménaert, B. Boulanger, F. Laurell, C. Canalias, V. Pasiskevicius, L. Ortega, P. Segonds, J. Debray, C. Félix, “Bulk PPKTP by crystal growth from high temperature solution”, Journal of Crystal Growth, 2011, doi:10.1016/j.jcrysgro.2011.11.081.
Collaboration : F. Laurell, C. Canalias, V. Pasiskevicius, Royal Institut of Technology (KTH), Stockholm, Sweden