Bonn 2000 – wissenschaftliches Programm

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Q: Quantenoptik

Q 16: Optische Technik

Q 16.7: Vortrag

Dienstag, 4. April 2000, 18:00–18:15, HS VI

Electrically controlled volume holograms in photorefractive LiNbO₃ — •Viktor Petrov, Cornelia Denz, and Theo Tschudi — Institut für Angewandte Physik, Technische Universität Darmstadt, Hochschulstr. 6, D - 64289 Darmstadt

Diffraction from volume holograms obeys the Bragg condition. For the case of recording volume holograms in an electrooptic material, the Bragg condition can be controlled by applying an electric field due to the formation of the electrooptic effect. This results in a high electric field selectivity (EFS), which provides the possibility to record and retrieve many holograms independently at the same location (multiplexing of volume holograms). One of the advantages of electrically controlled volume holograms is that they can be used as tuneable spectral filters with a very high quality factor.

In this report we describe the optimal experimental configuration for EFS in photorefractive LiNbO₃. Then, we present a comparison between theoretical and experimental data for EFS in dependence of the externally applied electric field, the thickness of the hologram, and the regime of recording. We also present investigations of cross-talk between recorded holograms in dependence of the number of holograms and phase distortions in the readout beam. Finally, we proof experimentally that electrically controlled holograms can operate as highly selective tuneable spectral filters with a selectivity of Δ λ = 4.5 pm, a value which is considerably high in comparison with other holographic techniques. Financial support of the Alexander von Humboldt Foundation is gratefully acknowledged.