A tunable filter with collinear acoustooptical TE-TM mode conversion in GaAs/AlAs multilayer

Bruno Bêche (1, 2) , Henri Porte (3) , Jean-Pierre Goedgebuer (4) , Chantal Fontaine (5)

1 IUF - Institut universitaire de France
2 IPR - Institut de Physique de Rennes
3 Photline Technologies - Photline Technologies
4 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
5 LAAS - Laboratoire d'analyse et d'architecture des systèmes

We investigate theoretically an acoustooptic tunable filter (AOTF) based on TE-TM mode conversion by collinear acoustooptic interaction, using the high form birefringence that occurs in a GaAs-AlAs multiquantum-well (MQW) rib waveguide. Mode conversion is achieved using a transverse piezoelectric surface acoustic wave. We propose to use a piezoelectric layer (ZnO or AlN) of 6-mm symmetry, which can be deposited by plasma-enhanced chemical vapor deposition. The c axis is then parallel to the plane of the layer. Under this condition, a transverse piezoelectric surface acoustic wave excited by inderdigital electrodes can propagate within the GaAs-AlAs MQW optical waveguide. TE-TM conversion is then possible with a relatively low acoustic frequency (some tens of megahertz), yielding a high diffraction efficiency and a figure of merit 14 times higher than that of conventional LiNbO/sub 3/ filters based on AOTFs.

Domaines: Optique / photonique; Micro et nanotechnologies/Microélectronique; Matériaux; Physique Générale [physics.gen-ph]

Bruno Bêche, Henri Porte, Jean-Pierre Goedgebuer, Chantal Fontaine. A tunable filter with collinear acoustooptical TE-TM mode conversion in GaAs/AlAs multilayer. IEEE Journal of Quantum Electronics, 1999, 35 (5), pp.820-826. ⟨10.1109/3.760331⟩. ⟨hal-01556255⟩