The resolving power in optical imaging is limited not only by optical diffraction but also by the sampling size, which in turn is determined by the optical magnification and pixel size of the imaging devices such as CCD or CMOS. In order to exceed these limits, we propose a method for improving the optical resolving power by using structured illumination shift and multiple image reconstruction. Theoretical and experimental verifications reveal that the use of structured light illumination together with successive approximation (which provides the extrapolation effect) causes the resolving power of the proposed method to exceed the optical diffraction limit. Furthermore, we focused on subpixel sampling using the structured illumination shift method. Subpixel image processing can improve the resolving power without narrowing the visual field of the imaging optics. In addition, the proposed method can provide subpixel resolving power without necessitating the mechanical displacement of the CCD camera. We investigated the relationship between the CCD pixel size and the resolving power provided by the proposed method. We found that the subpixel spatial shift of the structured illumination not only improves the optical resolving power but also enables sub-pixel sampling for optical imaging.

Date Published: 27 August 2010
PDF: 11 pages
Proc. SPIE 7800, Image Reconstruction from Incomplete Data VI, 78000I (27 August 2010); doi: 10.1117/12.861966

Published in SPIE Proceedings Vol. 7800:
Image Reconstruction from Incomplete Data VI
Philip J. Bones; Michael A. Fiddy; Rick P. Millane, Editor(s)