Temperature Stable Surface Acoustic Wave Delay Lines with SiO 2 Film Overlays

In order to obtain efficient operation of the wedge transducer, it is necessary to control the pertubation in the surface wave resulting from the presence of the wedge. Two methods of controling the perturbation by limiting the mechanical coupling between the wedge and substrate are discussed here for the case of Rayleigh waves. One method employs a layer of a compliant material, such as plastic, epoxy, or indium between the wedge and substrate and is found to be effective for a wide range of substrates. These layer materials have the additional advantage of serving to bond the wedge to the substrate. The second method for controling the coupling employs a layer in which the fields are evanescent. This method is limited to relatively dense substrates and involves a more difficult fabrication, although it offers the advantage of extremely wide band performance. The Characteristics of both types of layer materials are illustrated by computing the leaky-wave characteristics, as well as the design and performance of wedge transducers, for various combinations of wedge, layer, and substrate materials.

Coupling layers for efficient wedge transducers

Frequency-modulated signals in the output of a semiconductor laser are generated by applying surface acoustic waves to the device. The SAW modulator is discussed and theoretical and experimental results are compared.

Direct frequency modulation of a semiconductor laser by surface acoustic waves

https://ieeexplore.ieee.org/iel5/10273/32706/01533157.pdf

M.T. Wauk

Papers

Surface Wave Scattering and Loss from Planar Discontinuities in Bonded Acoustic Composites