Accession Number : AD0782419

Title :   Elastic Surface Waves in the Presence of a Fluid Layer.

Descriptive Note : Final rept. 1 Apr 72-30 Sep 73,


Personal Author(s) : Das,P.

Report Date : MAY 1974

Pagination or Media Count : 290

Abstract : The is a comprehensive report on the theoretical and experimental performance of devices using elastic surface waves in layered structures. The following are the main achievements of this effort: (1) Space charge coupled convolvers and correlators using surface waves and layer waves; experimental demonstration of lowest insertion loss, a few orders of magnitude lower than the previous state-of-the-art devices; and development of a detailed theory. (2) A new technique for optical probing of surface waves and layer waves: experimental determination of the decay parameter of a surface wave in the direction normal to the propagation surface; and the complete elastic fields in the layer wave structure; demonstration of 25% diffraction efficiency for each first order with only 500 mw of electrical power driving the surface wave transducers. Other important contributions in this report are the theoretical analysis of the layer wave propagation including loss or gain, and the observation of streaming phenomena in a liquid layer due to layer waves. (Author)

Descriptors :   *Surface waves, *Acoustooptics, Elastic waves, Correlators, Space charge, Signal processing, Piezoelectric crystals, Semiconductors, Layers, Computer programs, FORTRAN, Ultrasonic radiation, Rayleigh waves, Lithium compounds, Niobates, Cadmium sulfides

Subject Categories : Line, Surface and Bulk Acoustic Wave Devices
      Acoustooptic and Optoacoustic Devices
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE