Quasi-periodic self-assembled sub-micrometer ferroelectric bulk domain gratings in Rb-doped KTiOPO4

Abstract

We present a simple technique for fabricating quasi-periodic bulk sub-μm ferroelectric domain gratings in Rb-doped KTiOPO4 (RKTP) based on self-organized ferroelectric domain formation. One-dimensional ferroelectric domain structures, with an average periodicity of 650 ± 200 nm and extending throughout 1 mm thick crystals, are obtained by etching and subsequent electric field poling using planar electrodes. The sub-μm structures in RKTP were used to demonstrate 5th order non-collinear quasi-phase matched backward second harmonic generation.

Shaping light beams in nonlinear processes using structured light and patterned crystals

“…The typical poling periods are in the range of several microns (for visible and near infrared applications) up to several tens or even hundreds [52] of microns for mid-infrared or type II nonlinear processes, and the typical thickness of the crystals is in the range of 500 nm up to 2 µm. As for the state of the art, the smallest domains, of ~0.7 µm were reached with KTP crystals [53][54][55], whereas the thickest poled crystals of 10 mm were achieved in Mg:LN [56] Fig . 3.…”

Blue SHG Enhancement by Silver Nanocubes Photochemically Prepared on a RbTiOPO4 Ferroelectric Crystal

“…Similar domain sub‐structures have been recently reported in the isostructural Rb‐doped KTP crystal when electrical poling using liquid KCl electrodes after a chemical treatment was performed. The physical reason underlying this sub‐domain formation is out of the scope of this manuscript, though changes in the stoichiometry of the surface layer and ionic conductivity after the photochemical treatment can be suggested as reversal domain nucleation mechanism according to Zukauskas et al Finally, Figures (e) and (f) correspond to the SEM images showing the silver nanostructures on the alternating polarity domain surfaces. Silver is domain‐selective and clearly follows the sub‐μm domain structure formed in the RTP crystal.…”