Hannover 2003 – scientific programme

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Q: Quantenoptik

Q 49: Poster: Photonik

Q 49.15: Poster

Thursday, March 27, 2003, 16:30–18:30, Lichthof

Modulation of Photonic Crystals by Surface Acoustic Waves — •Mauricio de Lima, Francesc Alsina, Werner Seidel, and Paulo Santos — Paul-Drude-Institut für Festk*örperelektronik, Berlin

The modulation of the optical properties of photonic crystals (PC’s) using surface acoustic waves (SAW’s) has been proposed as an effective mechanism for controling light propagation in these structures[1]. The combination of the periodic modulation by the SAW with the artificial periodicity of the PC’s allows for interaction configurations between the SAW and optical beams, which are not found in unstructured materials. Furthermore, in addition to the conventional modulation of the refractive index through the elasto- and electro-optic effect, the acoustic vibrations also modulate the dimensions of the photonic structures, an effect which can be employed to obtain increased modulation efficiencies. We discuss active structures such as light modulators and switches based on the interaction between SAW’s and light beams in PC’s. The pratical realization of these structures requires strong SAW beams propagating through acousto-optical waveguides containing photonic structures. We demonstrate the generation of strong and collimated SAW beams on GaAs multilayer structures with frequencies in the GHz range using focusing interdigital transducers. These beams can be coupled into acousto-optical waveguides, where they propagate without attenuation over distances of the order of 1 mm. Experimental results are presented for the acousto-optical modulation of photonic structure by SAW beams. [1] P. V. Santos, J. Appl. Phys. 89, 5060 (2001)