Patent ID: 6545790
Filing Date: 2003-04-08
Classification: G02B,G03H

Abstract:
A method for recovering information from a wave front corresponding to a substantially monochromatic coherent radiation, comprising:(a) irradiating a specimen of material with the substantially monochromatic coherent radiation, the specimen being positioned in a first plane; (b) filtering radiation modulated by the specimen according to N pre-determined filtering patterns corresponding to one or more filters, wherein said one or more filters are positioned substantially in the first plane; (c) for each of the N filtering patterns, capturing spatial intensity values for the filtered modulated radiation at a second plane to produce N corresponding intensity distributions, wherein the second plane is a conjugate diffraction plane with respect to the first plane; (d) processing the N intensity distributions captured in the second plane to provide an estimate of the wave front at the first plane, the step of processing comprising correcting the effect of the corresponding filtering patterns; (e) filtering the provided wave front estimate using the N different filtering patterns to obtain N filtered estimates; (f) processing the filtered estimates to produce N estimated intensity distributions at the second plane; and (g) repeating steps (d), (e) and (f) until an error measure associated with the captured and the estimated intensity distributions in the second plane reaches a predetermined threshold.