Berlin 2005 – wissenschaftliches Programm

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Q: Quantenoptik und Photonik

Q 71: Transversale nichtlineare Optik

Q 71.2: Vortrag

Mittwoch, 9. März 2005, 15:15–15:30, HU 1070

Dynamic Fourier control of a photorefractive single-mirror feedback system
— •Christian Ripperda, Philip Jander, and Cornelia Denz — Institut für Angewandte Physik, Westfälische Wilhelms-Universität, Corrensstrasse 2, 48149 Münster

Photorefractive single feedback systems are known to exhibit a variety of transverse patterns [1]. In addition to predominant hexagonal patterns, stripes, squares and squeezed hexagons can be observed to coexist and compete. Fourier control is an established method for statically selecting specific patterns which may be relatively unstable or to inhibit specific pattern geometries or orientations [2].

We experimentally demonstrate dynamic Fourier control in a Michelson feedback geometry. Using this method, patterns can be dynamically selected, inhibited or otherwise controlled. Electronic feedback of the current system state on the control signal is realized, opening a new possibility for minimally invasive control. Additionally, dynamic Fourier control is exploited to investigate the relative stability of two-dimensional patterns with different geometries.

[1] M. Schwab, C. Denz, M. Saffman, Appl. Phys. B 69, 429-433 (1999)

[2] M. Schwab, M. Saffman, C. Denz, T. Tschudi, Opt. Commun. 170, 129-136 (1999)