Patent ID: 11896303
Assignee: WAVESENSE ENGINEERING GMBH
Field: Medical technology (Instruments)
Classification: CPC A  G | IPC A  G

Claim 0:
1. An interferometric apparatus to image a point on a sample, comprising:
an optical arrangement configured to produce a sample beam and a reference beam and to produce either 1) an image of an original object field of the point at an image plane illuminated by the sample beam, the field including both amplitude information and phase information or 2) a field of the point at a pupil plane when the point is illuminated by the sample beam, the field including both amplitude information and phase information, the optical arrangement configured to produce a combination of the sample beam after illumination of the point and the reference beam;
a scanner located to receive the combination of the sample beam and reference beam and to direct the combination through focusing optics and onto a pinhole filter, the scanner and focusing optics being arranged to translate overlapping spots corresponding to the reference beam and the sample beam across the pinhole filter,
a photodetector located to receive light from the combination passing through the pinhole filter as the overlapping spots translate across the pinhole filter thereby determining a point spread function of the apparatus; and
a digital adaptive optics arrangement comprising:
(i.) a wavefront sensor configured to calculate (1) a sampled wavefront of the original object field of the point at the image plane or (2) a sampled wavefront of the object field of the point at the pupil plane, using the point spread function; and
(ii.) a computing unit adapted to:
A) generate at least one digital shifted copy of the sampled wavefront of the object at the pupil plane by
(1) using the image of the original object field of the point at the image plane to calculate the field at the pupil plane and shifting the calculated field along a horizontal or a vertical direction or an axis of a defined coordinate system of the pupil plane or
(2) using the field of the point at the pupil plane and shifting the field along a horizontal or a vertical direction or an axis of a defined coordinate system of the pupil plane and

B) determine a wavefront error in the original object field based on a phase difference between (1) a sampled wavefront of the calculated and the at least one digital shifted copy at the pupil plane or (2) the sampled wavefront of the object field of the point at the pupil plane and the at least one digital shifted copy at the pupil plane.