Patent ID: 7463366
Filing Date: 2008-12-09
Classification: G01N,G02B,G03H

Abstract:
1. A digital holographic microscope for obtaining without scanning three-dimensional images of a specimen to be studied, comprising a light source, an interferometer, a recorder defined by a sensitive plane and a processor, said microscope being conceived in such a manner that in operating conditions said light source provides a partially spatially coherent light beam, said interferometer separates said partially spatially coherent light beam into a reference light beam and an object light beam, said object beam illuminates a specimen preliminary placed therein, said object and reference beams are recombined to produce interference patterns in the sensitive plane of said recorder, the recorder records said interference patterns and said processor processes said recorded interference patterns and reconstructs three-dimensional images of the specimen, wherein the interferometer comprises: a movable first subassembly that comprises a beam splitter and a mirror, able to form two parallel beams-an object beam and a reference beam, from the source light beam; a movable second subassembly comprising a beam splitter and a mirror so as to combine said object beam and said reference beam into a recombined light beam; an object cell, to receive the specimen to be studied, said object cell being placed in the optical path of the object beam between the first subassembly and the second subassembly; a first microscope objective located in the optical path of the object beam between the first subassembly and the second subassembly, downstream of the object cell; a compensator to optimize the equalization of the optical path lengths between the object beam and the reference beam, said compensator being located in the optical path of the reference beam between the first subassembly and the second subassembly; a second microscope objective located in the optical path of the reference beam between the first subassembly and the second subassembly, downstream said compensator; wherein the microscope further comprises a focuser defined by a back focal plane, said focuser being placed between the interferometer and the recorder in such a way that the back focal plane of said focuser is in the sensitive plane of the recorder and that an invariant positioning of the recombined light beam on the sensitive plane of the recorder is maintained when the second subassembly is moved in operation.