High-temperature-recorded index gratings in periodically poled lithium niobate.
Holographic index gratings based on a zero-electric-field photorefractive effect are recorded at high temperatures in copper-doped periodically poled lithium niobate crystals. The interplay between the domain structure and the index grating is studied: the fundamental grating with spatial frequency K is strongly suppressed. Pronounced sideband gratings with K(s)=K+sG appear, where G is the domain grating vector and s is an integer number. After development, an additional grating based on the electro-optic effect shows up. In contrast with the previously mentioned gratings, this grating allows anisotropic diffraction.
Hartwig
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Institute of Physics, University of Bonn, D-53115 Bonn, Germany. hartwig@uni-bonn.de
Kösters
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Woike
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Buse
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