Share Email Print
cover

Proceedings Paper

Analysis Of Nonlinear Optical Correlation
Author(s): Bahram Javidi
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

A nonlinear joint transform image correlator is investigated. The Fourier transform interference intensity is thresholded to provide higher correlation peak intensity and better defined correlation spot. Analytical expressions for the thresholded 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 thresholded interference intensity. We show that various types of correlation signals can be produced simply by varying the severity of the nonlinearity and without the need to synthesize the specific matched filter. For example, a phase-only correlation signal is produced by selecting the appropriate nonlinearity.

Paper Details

Date Published: 16 December 1989
PDF: 17 pages
Proc. SPIE 0977, Real-Time Signal Processing XI, (16 December 1989); doi: 10.1117/12.948582
Show Author Affiliations
Bahram Javidi, The University of Connecticut (United States)


Published in SPIE Proceedings Vol. 0977:
Real-Time Signal Processing XI
J. P. Letellier, Editor(s)

© SPIE. Terms of Use
Back to Top