Patent ID: 7436595
Filing Date: 2008-10-14
Classification: G01S,G02B

Abstract:
1. An imaging system characterized at least by an ambiguity function and a point spread function (PSF), which ambiguity function is a function of a normalized spatial frequency parameter u and a vertical variable v related to a misfocus parameter ψ, and which PSF is at least a function of the misfocus parameter ψ, the imaging system comprising: at least one lens and an optical mask that cooperate to image light from an object to form an optical image, which light is characterized by at least phase; and a detector for detecting the optical image over a range of spatial frequencies to generate a stored image, wherein the optical mask is configured for modifying the phase of the light such that a main lobe of the ambiguity function is broader in v for a given value of u and the PSF has a functionally different form for a given value of ψ, in comparison to a main lobe of an ambiguity function and a PSF, respectively, characterizing the imaging system without the optical mask for those given values of u and ψ, over an extended depth of focus larger than a depth of focus formed without the optical mask.