Novel bulk acoustic-wave high-Q resonators and acoustically coupled resonator filters have been fabricated and operated at their fundamental half-wavelength mode in the 200-500-MHz frequency range. These structures are fabricated on thin ZnO/silicon diaphragms with dimensions small enough to be incorporated within integrated circuits. Resonator Q’s near 2600 at the fundamental mode have been obtained and strong inter-resonator acoustic coupling has been achieved yielding filters having insertion loss (untuned) as low as 5.5 dB.

The guided acoustooptical interaction on the (100) plane of GaAs is investigated as a function of waveguide thickness type of mode, acoustic frequency, direction of acoustic wave propagation, and substrate refractive index Our calculated results indicate that best efficiency is obtained for TE(0) ? TE(0) optical modes and for acoustic surface wave propagating along the ?01l? direction at a waveguide thickness close to cut-off Under these conditions, approximately 75 mW of acoustic power is required for 100% diffraction. For a transducer aperture giving 50 Omega of radiation resistance, the rf bandwidth of the diffraction is limited essentially by the frequency bandwidth of the interdigital transducer. A comparison of the calculated results with experimental data at 1.06-microm optical wavelength is also given.

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Compensation for the first-order temperature coefficient of phase delay (TCD) of GaAs surface acoustic wave delay lines has been experimentally achieved using a two-layer Au/SiO2 film coating. The negative TCD of SiO2 provides temperature compensation, while the mass loading effect of the gold layer provides nonleaky Rayleigh wave propagation.

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