Share Email Print
cover

Proceedings Paper

Application of a liquid crystal display as a multi-level quantized phase-mostly filter in a 4-f optical correlator
Author(s): Mark Starzomski; Michael Cada
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 twisted nematic liquid crystal display (TN-LCD) from a video projector was characterized for phase modulation. It was found to have a phase modulation of approximately 1.5 to 2(pi) with consistently flat amplitude. Using this knowledge a fast Fourier transformed complex 2D frequency domain image was encoded with 2, 4, 8, and 16 levels of phase modulation. The LCD was then used to display the phase-mostly computer generated (CG) matched filter, known as a kinoform, in the Fourier plane of a 4-f correlator. An intensity modulated LCD was used to display input information to the correlator. Results showed that a CG multi-level phase filter had similar correlation peaks to a CG binary phase filter, but there was a less likely chance of detecting a character or image that was similar to the inverted image used to generate the matched filter. Further study was done with the autocorrelation of images as well as detecting an image amongst other images using an 8 level phase-mostly matched filter.

Paper Details

Date Published: 4 December 1998
PDF: 6 pages
Proc. SPIE 3491, 1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications, (4 December 1998); doi: 10.1117/12.328693
Show Author Affiliations
Mark Starzomski, Dalhousie Univ. (Canada)
Michael Cada, Dalhousie Univ. (Canada)


Published in SPIE Proceedings Vol. 3491:
1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications
George A. Lampropoulos; Roger A. Lessard, Editor(s)

© SPIE. Terms of Use
Back to Top