Optical systems utilizing multiple phase filters to increase misfocus tolerance

Abstract

An optical imaging system includes optics for imaging a wavefront of electromagnetic radiation to form an image at a detector. The system also includes a plurality of optical phase filters. Each of the phase filters alters phase of the wavefront. The phase filters cooperate to make the system less sensitive to misfocus, as compared to the optical imaging system without the phase filters. Another optical imaging system includes a detector and optics having two or more optical elements for imaging a wavefront onto the detector. The optical elements include aspherical surfaces that cooperate to alter phase of the wavefront such that the optics are less sensitive to defocus as compared to the optics without the aspherical surfaces. The system also includes a post processor for reversing phase alteration induced by the aspherical surfaces to produce an in-focus electronic image.

Dependencies are inferred from the claim text.