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DF: Fachverband Dielektrische Festkörper
DF 6: Poster I
DF 6.12: Poster
Dienstag, 24. März 2009, 09:30–12:30, P5
Ultra-fast detection of multi-wave mixing on optically induced microstructures — •Annika Kruse, Bettina Schoke, and Mirco Imlau — Department of Physics, University of Osnabrück, Germany
The ultra-fast detection of multi-wave mixing on optically induced microstructures was examined with iron-doped lithium niobate (LiNbO3:Fe) for test purposes. The aim of this work is to analyse contributions of index and absorption gratings in short-living mixed diffraction gratings with a decay time below 10 ms. A standard holographic two-beam setup allowing for the recording and simultaneous reading of elementary gratings in LiNbO3:Fe (λrec = 514 nm: θrec=20∘, λread = 633 nm: θB=25∘ ) was applied and expanded by a fast motorized rotationary stage (rotation velocity 720∘/s) for sample rotation. This enabled the determination of the rocking curve from recorded diffraction gratings, i.e. the angular dependence of the diffraction efficiency on the angular deviation from the Bragg angle was measured. Appropriate photo diodes and a digital storage oscilloscope for data collection were used in order to match for the high scan speed. As a result, the rocking curves could be detected with excellent resolution in an angular range of ±0.3∘ within < 1 ms. The results are successfully compared with theoretical expectations of mixed diffraction gratings. The continuative development of this technique for a comprehensive two-beam coupling analysis is discussed. *Financial supported by the Deutsche Forschungsgemeinschaft (Projects IM37/5-1 and GRK 695).