Pupil ptychography methods and systems

• US 10,568,507 B2
• Filed: 06/12/2017
• Issued: 02/25/2020
• Est. Priority Date: 06/10/2016
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Chung, Jaebum, Yang, Changhuei
• Primary Examiner(s): Pham, Nam D
• Application Number:
  US15/620,674
• Publication Number:
  US 20170354329A1
• Time in Patent Office: 988 Days
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/112 for measuring diameter of pupils
• CPC Class Codes: A61B 3/12 for looking at the eye fundus, e.g. ophthalmoscopes A61B3/13 takes precedence
• CPC Class Codes: A61B 3/13 Ophthalmic microscopes
• CPC Class Codes: A61B 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B

Abstract

Certain embodiments pertain to pupil ptychography methods and systems.

Claims

1. A pupil ptychography system comprising:

an aperture modulator configured to modulate apertures at a Fourier plane of a first imager;

the first imager configured to acquire a full pupil image of a sample being incoherently illuminated by a light source during operation, and configured to acquire a sequence of N limited-aperture images of the sample while the aperture modulator modulates a first aperture to N locations at the Fourier plane of the first imager;

one or more optical components configured to propagate light reflected from the sample to the aperture modulator and propagate light from the aperture modulator to the first imager; and

at least one processor configured to;

use the N limited-aperture images to recover a pupil function of an optical system in an optical path between the sample and the first imager; and

deconvolve the full pupil image of the sample using the recovered pupil function to generate a substantially aberration-free full pupil image of the sample.

2. The pupil ptychography system of claim 1,

further comprising a second imager in communication with the at least one processor,

wherein the optical components are further configured to propagate light reflected from the sample to the second imager,

wherein the second imager is configured to acquire, in parallel with the first imager, one or more unmodulated images of the sample, and

wherein the processor is further configured to modify the N limited-aperture images and the full aperture image to correct for motion based on the one or more modulated images.

3. The pupil ptychography system of claim 1, wherein the first imager is further configured to acquire another limited aperture image while the aperture modulator modulates a second aperture at the Fourier plane of the first imager, wherein the second aperture is larger than the first aperture.

4. The pupil ptychography system of claim 3, wherein the second aperture is at least 10% larger than the first aperture.

5. The pupil ptychography system of claim 3, wherein the second aperture is at least 5% larger than the first aperture.

6. The pupil ptychography system of claim 1,

wherein the at least one processor is further configured to

segment each of the limited-aperture images into tiles regions;

recover a tile pupil function for each of the tile regions; and

combine the recovered tile pupil functions to generate the pupil function of the optical system.

7. The pupil ptychography system of claim 1, further comprising an illumination source configured to provide monochromatic, incoherent illumination to the sample during operation.

8. The pupil ptychography system of claim 1, further comprising an illumination source configured to provide monochromatic, incoherent illumination of each of a red wavelength, a green wavelength, and a blue wavelength to the sample during operation.

9. The pupil ptychography system of claim 1, wherein the at least one processor is further configured to send signals to the first imager and the aperture modulator to synchronize the sampling times of the first imager with times for modulating the apertures at the Fourier plane.

10. The pupil ptychography system of claim 1, wherein the aperture modulator is a spatial light modulator configured to digitally address to shift the first aperture to the N different locations across the Fourier plane.

11. The pupil ptychography method of claim 1, wherein the aperture modulator is a digital micromirror device.

12. A pupil ptychography method comprising:

receiving, from a first imager, a sequence of N limited-aperture images of a sample being incoherently illuminated, the N limited-aperture images are acquired, by the first imager, while an aperture modulator sequentially modulates a first aperture at N different locations at the Fourier plane of the first imager and one or more optical components propagate light reflected from the sample to the aperture modulator and propagate light from the aperture modulator to the first imager;

receiving a full pupil image of the sample from the first imager, the full pupil image acquired while the sample is incoherently illuminated by a light source;

recovering a pupil function of an optical system in an optical path between the sample and the first imager the sequence of N limited-aperture images; and

deconvolving the full pupil image of the sample using the recovered pupil function to generate a substantially aberration-free full pupil image of the sample.

13. The pupil ptychography method of claim 12, sending one or more signals to the aperture modulator and the first imager to synchronize generation of the first aperture by the aperture modulator at N different locations of the Fourier plane of the first imager with the acquisition of N limited aperture images of the sample.

14. The pupil ptychography method of claim 12, further comprising receiving another limited aperture image, from the first imager, the other limited aperture image acquired while a second aperture was modulated, by the aperture modulator, at the Fourier plane of the first imager.

15. The pupil ptychography method of claim 12,

further comprising segmenting each of the sequence of N limited-aperture images into tiles regions;

and

wherein recovering the pupil function comprises recovering a tile pupil function for each of the tile regions and combining the recovered tile pupil functions to generate the pupil function of the optical system.

16. The pupil ptychography method of claim 12, wherein the first imager acquires images while the sample is illuminated by monochromatic, incoherent illumination.

17. The pupil ptychography method of claim 12, comprising:

receiving, from a second imager, one or more unmodulated images of the sample being incoherently illuminated; and

correcting the N limited-aperture images for motion based on the one or more modulated images.

18. The pupil ptychography method of claim 12, comprising:

receiving, from the first imager, another limited aperture image based on a second aperture larger than the first aperture; and

initializing the pupil function based on the other limited aperture image received from the first imager.