Patent ID: 7659993
Filing Date: 2010-02-09
Classification: G01J,G01N,G03H

Abstract:
1. A method for sensing a wave-front of light totally back-scattered from an illuminated area in a specimen, said method comprising the steps of: focusing illumination light from a laser light source via a focusing optic into the specimen; directing the totally back-scattered light via an imaging optic to a detector device having a plurality of detector elements and sensing light with local resolution wherein said imaging optic images a back focal plane of the focusing optic onto the detector elements; coherence-gating of the totally back-scattered light comprising an interferometric superposition of the totally back-scattered light with reference light split from the illumination light of the laser light source, wherein the reference light is directed through a reference light path from a beam splitting device to the detector elements of the detector device, the reference light path having an optical reference path length identical with an optical sample path length from the beam splitting device via a predetermined sample plane of the specimen to the detector device; measuring the coherence-gated light intensities contained in the totally back-scattered light at each of the detector elements, said coherence-gated light intensities being scattered in the predetermined sample plane of the specimen and being selected by the coherence-gating of the totally back-scattered light; locally resolved measuring phase information based on the coherence-gated light intensities, said phase information being influenced by light scattering in the specimen; modulating at least one of the optical sample and reference path lengths and repeating the steps of selectively detecting coherence-gated light intensities and measuring phase information with various path length differences in the sample and reference paths set by said modulating; and reconstructing the wave-front of the coherence-gated light intensifies on the basis of the phase information obtained with the various path length differences.