In position detection using matched filtering one is faced with the challenge of determining the best position in the presence of distortions such as defocus and diffraction noise. This work evaluates the performance of simulated defocused images as the template against the real defocused beam. It was found that an amplitude modulated phase-only filter is better equipped to deal with real defocused images that suffer from diffraction noise effects resulting in a textured spot intensity pattern. It is shown that the there is a tradeoff of performance dependent upon the type and size of the defocused image. A novel automated system was developed that can automatically select the right template type and size. Results of this automation for real defocused images are presented.

Date Published: 4 November 2004
PDF: 10 pages
Proc. SPIE 5556, Photonic Devices and Algorithms for Computing VI, (4 November 2004); doi: 10.1117/12.563653

Published in SPIE Proceedings Vol. 5556:
Photonic Devices and Algorithms for Computing VI
Khan M. Iftekharuddin; Abdul Ahad S. Awwal, Editor(s)