Regensburg 2007 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 9: Electric, Electromechanical and Optical Properties I
DF 9.7: Talk
Thursday, March 29, 2007, 12:20–12:40, H48
High-temperature-recorded index gratings in periodically-poled lithium niobate* — •Michael Kösters, Ulrich Hartwig, Theo Woike, and Karsten Buse — Institute of Physics, University of Bonn, Wegelerstr. 8, 53115 Bonn, Germany
Holographic index gratings based on a zero-electric-field photorefractive effect are recorded at high temperatures in copper-doped periodically-poled lithium niobate crystals. High-temperature recording causes strong absorption modulations which are linked to index gratings via the Kramers-Kronig relations as it is described in Ref. (1). The gratings do not originate from the electro-optic effect and can be read out regardless of their orientation in the crystal. Subsequently, the interplay between the periodic domain structure (grating vector G) and the index grating (grating vector K) is studied: The fundamental K-grating is strongly suppressed. Pronounced sideband gratings with Ks = K± s G appear, where s is an integer number. The findings are of great importance for applications, where both, index gratings and ferroelectric domain gratings, are needed, e.g. for a DFB-OPO (Distributed-Feedback Optical Parametrical Oscillator).
*Financial support from the Deutsche Forschungsgemeinschaft (FOR 557) and from the Deutsche Telekom AG is gratefully acknowledged.
(1) U. Hartwig, K. Peithmann, B. Sturman, and K. Buse, Appl. Phys. B 80, 227 (2005).