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DF: Fachverband Dielektrische Festkörper
DF 8: Ferroics - Domains, Domain Walls and Skyrmions I
DF 8.4: Vortrag
Dienstag, 21. März 2017, 10:45–11:00, WIL B321
Constant-current calligraphic domain-inversion in lithium-niobate crystals — •Christoph S. Werner1, Simon J. Herr1, Karsten Buse1,2, and Ingo Breunig1 — 1Department of Microsystems Engineering, University of Freiburg — 2Fraunhofer Institute for Physical Measurement Techniques, Freiburg, Germany
Lithium-niobate is commonly applied as a nonlinear crystal in nonlinear, optical frequency converters. In order to phase-match the interacting waves, a periodic domain inversion of the crystal is often necessary. The standard method to create the necessary domain pattern uses a structured electrode which defines the position of the domains. While this method is good in batch-processing large quantities of crystals, it is unflexible for prototyping domain patterns since every pattern requires an individual photolithographic mask. We present a technique to rapidly create high-quality domain-structures in congruent-melting, MgO-doped lithium-niobate crystals by defining the position of the domain with a metallic needle. Therefore, the needle is moved along the desired position of the domain. A current-control-loop maintains a constant current and adjusts the necessary poling-voltage accordingly while the needle moves across the crystal. This ensures a high-quality domain-formation independent of the crystal orientation. This method is especially useful for creation of radially-poled domains which are suited for whispering-gallery resonators.