Dresden 2009 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 14: Photonic Dielectrics III

DF 14.4: Talk

Thursday, March 26, 2009, 11:20–11:40, WIL A317

UV-assisted domain patterning of MgO-doped lithium niobate crystals — •Hendrik Steigerwald, Niklas Waasem, Fabian Luedtke, and Karsten Buse — Institute of Physics, University of Bonn, Wegelerstrasse 8, 53115 Bonn, Germany

Periodically-poled lithium niobate (LiNbO₃) with domain structures in the micrometer regime is of great relevance, e.g. for nonlinear optics. Efficient frequency conversion in this material is usually hampered by optical damage, i.e., undesired index and absorption changes. MgO-doping increases the optical damage threshold, but makes the poling process more challenging, especially for small domain structures in bulk crystals. We obtain such patterns in MgO-doped near-stoichiometric LiNbO₃ using structured UV-illumination, which reduces the coercive field for electric field locally. Bulk domain gratings with a period length of 10 µ m are realized. Another mechanism that lowers the coercive field strength is heating. We show that for combination of UV-illumination and heating of the crystal both effects add up and the coercive field strength is reduced by a factor of four.

*Financial support from the Deutsche Telekom AG is gratefully acknowledged.