Nonlinear Joint Transform Processor

Abstract

A nonlinear joint transform image correlator is investigated. The Fourier transform interference intensity is threshold to provide higher correlation peak intensity and better defined correlation spot. Analytical expressions for the threshold joint power spectrum is provided. The effects of the nonlinearity at the Fourier plane on the correlation signals at the output plane is investigated. The correlation signals are determined in terms of the nonlinear characteristics of the spatial light modulator (SLM) at the Fourier plane. We show that thresholding the interference intensity results in a sum of infinite harmonic terms. Each harmonic term is envelope modulated due to the nonlinear characteristics of the device, and phase modulated by m times the phase modulation of the nonthresholded joint power spectrum. The correct phase information about the correlation signal is recovered for the first order harmonic of the threshold interference intensity. (RH)

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1990
Accession Number
ADA225091

Entities

People

  • Bahram Javidi

Organizations

  • Georgia Tech Research Corporation

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Charge Coupled Devices
  • Computational Science
  • Computer Simulations
  • Computer Vision
  • Engineering
  • Fourier Series
  • Image Processing
  • Image Recognition
  • Information Processing
  • Mathematical Analysis
  • Modulation
  • Modulators
  • Optical Correlators
  • Optical Modulators
  • Pattern Recognition
  • Power Spectra
  • Signal Processing

Fields of Study

  • Engineering
  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Optical Physics and Photonics.