Acousto-Optic Interaction in Surface Acoustic Waves and Its Application to Real Time Signal Processing.
Abstract
The theory of the interaction of coherent light with surface acoustic waves and an experimental demonstration of the application of the interaction to new devices are presented. The analysis, based upon classical electromagnetic theory and a phenomenological formulation of the photoelastic effect, is applied to the piezoelectric material LiNbO3, and provides good agreement with previously published experimental data. Explicit account is taken of the linear electro-optic and linear elasto-optic contributions to the interaction. The experimental demonstration of applications is restricted to the side-entry technique, an interaction configuration providing the longest interaction length between a surface acoustic wave and unguided optical wave. The relative merits of this configuration are discussed. New experimental results for the real-time side-entry convolver employing optical heterodyning include autocorrelation of Barker codes, ambiguity function generation, demonstration of a parallel acoustic track geometry to inhibit reflections, and measurement of diffraction characteristics for polarized light. Results are given for the correlation of a time varying light intensity distribution with an electrical signal, and the application to an optical communication system is indicated. The scanning of one and two dimensional black and white transparencies is performed, and the extension to color image scanning is demonstrated. All experiments are performed using Y-cut Z-propagating LiNbO3. Acoustic frequencies employed range from 45 MHz to 100 MHz. Laser sources are HeNe and Ar. Devices are analyzed and discussed with reference to the diffraction integral of scalar diffraction theory.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 1977
- Accession Number
- ADA082752
Entities
People
- D. Schumer
- Protik Das
Organizations
- Rensselaer Polytechnic Institute