The spatial filters employed to increase the focal depth of an optical system are interpreted as the Fourier spectra of certain objects, which will then exhibit relatively low variance to focus errors. This interpretation is applied to designing grating profiles that produce self-images with high focal depth.
© 1986 Optical Society of America
Original Manuscript: November 29, 1985
Manuscript Accepted: February 13, 1986
Published: May 1, 1986
J. Ojeda-Castañeda, P. Andrés, and A. Díaz, "Objects that exhibit high focal depth," Opt. Lett. 11, 267-269 (1986)