Patent ID: 7087902

Claim:
A method for tomographic imaging of an object, the method comprising the steps of: (a) aligning in a path a radiation source adapted to emit radiation to which the object is essentially transparent, a binary lens having a frequency-dependent focal length, and a sensor for sensing radiation modified by the object, the sensor positioned to capture an image projected by said lens with frequency-dependent focal length onto a fixed image plane; wherein said frequency, said lens and said fixed image plane are selected such that: i. said lens is positioned substantially perpendicular to said propagation path; ii. said fixed image plane is located at a distance z′ from said lens along said propagation path also substantially perpendicular to said propagation path and a plane substantially perpendicular to said propagation path at a first distance z from said lens is imaged by said lens on said fixed image plane; iii. said frequency v i is selected such that a plurality of planes z i along said propagation path imaged on said fixed image plane cover a selected segment along said propagation path sufficient to encompass a desired thickness of an object placed in said radiation path; and iv. said binary lens is selected such that: z o =[ r p 2 *z′*v ]/[2 c z′−r p 2 *v ] where r p 2 is the lens zone period with the area dimension, c is the speed of light, z o is the distance of the object from the lens and v is a radiation frequency imaging said object origin on said imaging plane, (b) placing the object in the path between the radiation source and the lens at z=z o; (c) creating an nth frequency-dependent image of an nth slice of the object in a plane perpendicular to the path using radiation at an nth frequency and capturing the nth frequency-dependent image with the sensor, for n equal to 1 through m, inclusive, where m equals an integer greater than or equal to 2; and (d) reconstructing a 3 dimensional tomographic image of said object by assembling the m frequency-dependent images of the object according to their magnification factors.