Systems and methods for sub-aperture based aberration measurement and correction in interferometric imaging

Patent metadata

Field	Value
Publication number	US-9247874-B2
Application number	US-201414164955-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Feb 1, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present invention, a fast and simple way to correct for defocus aberration is described. A variety of applications for the inventive method are presented.

First claim

What is claimed is:

1. A method for characterizing a wavefront in collected interferometric data on a sample, wherein the interferometric data is generated using a broad bandwidth light source and wherein the data contains information about lateral structure within the sample, said method comprising:
dividing the interferometric data into subsections at a plane where the wavefront should be characterized;
generating images of the structure for at least two of the subsections by transforming each subsection of the data to an image plane in the sample containing the structure;
determining a correlation between the at least two images;
characterizing the wavefront using the correlation; and
storing, displaying, or using as input to a subsequent process the resulting wavefront characterization.

2. A method as recited in claim 1 , wherein the interferometric data is holoscopic imaging data.

3. A method as recited in claim 2 , wherein the holoscopic data is collected off-axis.

4. A method as recited in claim 1 , wherein the interferometric data is transformed to the plane where the characterization of the wavefront should be determined prior to the dividing step.

5. A method as recited in claim 4 , wherein the interferometric imaging data is full-field optical coherence tomography imaging data.

6. A method as recited in claim 4 , wherein the interferometric data is line-field optical coherence tomography imaging data.

7. A method as recited in claim 4 , wherein the interferometric data is flying spot optical coherence tomography imaging data.

8. A method as recited in claim 1 , wherein the broad band light source is a frequency swept laser.

9. A method as recited in claim 1 , wherein the subsections overlap.

10. A method as recited in claim 1 , wherein the characterizing of the wavefront includes a derivation of the local wavefront orientation from the image correlation between any of the subsection images.

11. A method as recited in claim 1 , wherein the characterizing of the wavefront includes a derivation of the wavefront surface from the subsection local wavefront orientation.

12. A method as recited in claim 1 , wherein the characterizing of the wavefront includes Taylor monomials.

13. A method as recited in claim 1 , wherein the characterizing of the wavefront includes Zernike polynomials.

14. A method as recited in claim 1 , further comprising using the characterization of the wavefront as input to a wavefront compensation device to create a compensated wavefront.

15. A method as recited in claim 14 , wherein the wavefront compensation device is a deformable mirror.

16. A method as recited in claim 14 , wherein the wavefront compensation device is a liquid crystal modulator.

17. A method as recited in claim 1 , further comprising using the wavefront characterization to correct the interferometric imaging data and generating an image from the interferometric data from aberrations.

18. A method as recited in claim 17 , further comprising repeating the dividing, generating, determining and characterizing steps until a desired level of correction is achieved.

19. A method as recited in claim 1 , wherein the transformed data is divided into two subsections and the wavefront characterization is used to determine defocus.

20. A method as recited in claim 1 , further comprising using the characterizing of the wavefront as an input to a manufacturing process.

21. A method as recited in claim 20 , wherein the object is an eye and the output product of the manufacturing process is aberration corrected eyeglasses.

22. A method as recited in claim 1 , further comprising using the characterizing of the wavefront as an input to a surgical process.

23. A method as recited in claim 22 , wherein the object is an eye and the surgical process is refractive correction.

24. A method as recited in claim 1 , wherein the object is an eye and the characterizing of the wavefront is used as input for custom selection of an intraocular lens.

25. A method as recited in claim 1 , wherein the interferometric data is three dimensional.

26. A method as recited in claim 1 , wherein the interferometric data is two-dimensional.

27. A method as recited in claim 1 , wherein the measurement area on the sample is non-isoplanatic.

28. A method as recited in claim 1 , wherein the characterized wavefront is used to compensate for aberrations in a high intensity beam of radiation.

29. A method as recited in claim 1 , wherein multiple regions in the sub-aperture images have different correlation values.

30. A method as recited in claim 1 , wherein the characterized wavefront is used to compensate for aberrations in a probe beam for a non-coherent measurement.

31. The method of claim 1 , wherein the image correlation is made using a flow field where different points in the subsection images have different correlations.

32. An interferometric imaging device for imaging a light scattering object comprising:
a broadband light source arranged to generate a beam of radiation;
a beam divider for separating the beam into reference and sample arms, wherein the sample arm contains the light scattering object to be imaged, wherein the light scattering object has structure in the transverse direction to the propagation direction of the beam;
optics to direct said beam of radiation on the light scattering object to be imaged and for combining light scattered from the object and light returning from the reference arm;
a detector for recording the combined light, wherein said detector is located at an imaging plane of the object; and
a processor for generating an aberration corrected image in response to signals generated by the detector, said processor transforming the signals generated by the detector to a plane where the aberration is to be characterized, dividing the transformed data into subsections, generating images for at least two of the subsections by transforming the subsection data to an image plane in the sample containing the structure, determining a correlation between the at least two images, and using the correlation to correct for an aberration.

33. A method for characterizing a wavefront in optical coherence tomography imaging data on a sample:
collecting optical coherence tomography (OCT) imaging data of a sample, wherein said sample has structure in the transverse direction;
transforming the data to generate image data at a particular depth in the sample where the transverse structure is visible;
transforming the image data to a plane where the wavefront is to be characterized;
dividing the transformed data into subsections;
generating images of the structure for at least two of the subsections by transforming each of the subsections of the data to an image plane in the sample containing the structure;
determining a correlation between the at least two images;
characterizing the wavefront using the correlation; and
storing, displaying, or using as input to a subsequent process the resulting wavefront characterization.

34. A method as recited in claim 33 , wherein the OCT data is collected using a flying spot or line field imaging system.

35. A method as recited in claim 34 , further comprising applying a phase adjustment to the OCT imag

Assignees

• Zeiss Carl Meditec Inc

Inventors

• Kumar Abhishek
• Tumlinson Alexandre R
• Leitgeb Rainer

Classifications

• A61B3/14

  Arrangements specially adapted for eye photography · CPC title

• A61B3/0025

  characterised by electronic signal processing, e.g. eye models · CPC title

• A61B3/1015

  for wavefront analysis · CPC title

• G01N2021/1787

  Tomographic, i.e. computerised reconstruction from projective measurements · CPC title

• G03H2222/14

  Broadband source, e.g. sun light · CPC title