Multi-dimensional imaging using multi-focus microscopy

Patent metadata

Field	Value
Publication number	US-9477091-B2
Application number	US-201313739310-A
Country	US
Kind code	B2
Filing date	Jan 11, 2013
Priority date	Jan 11, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

An optical imaging system includes a first diffractive optical element that receives a multi-wavelength beam of light and separates the received beam of light into diffractive orders. The optical imaging system also includes a second diffractive optical element that includes panels displaced along the second diffractive element in at least one direction, where each panel is positioned to receive and pass the multi-wavelength beam of one of the diffractive orders. A refractive optical element is positioned to receive multi-wavelength beams of the diffractive orders that pass through the second diffractive element, and an optical lens that receives the multi-wavelength beams of the diffractive orders that pass through the refractive element and focuses each of the multi-wavelength beams of the diffractive orders to a different location on an image plane at the same time.

First claim

What is claimed is:

1. An optical imaging system comprising:
a first diffractive element configured to receive a multi-wavelength beam of light and separates the received beam of light into diffractive orders, each diffractive order comprising a multi-wavelength beam of light that propagates away from the first diffractive element in a different direction, the first diffractive element comprising a grating pattern configured to apply a focus shift to the diffractive orders;
a second diffractive element comprising panels displaced along the second diffractive element in at least one direction, each panel positioned to receive and pass the multi-wavelength beam of one of the diffractive orders;
a refractive optical element positioned to receive multi-wavelength beams of the diffractive orders that pass through the second diffractive element; and
an optical lens that receives the multi-wavelength beams of the diffractive orders that pass through the refractive element and focuses each of the multi-wavelength beams of the diffractive orders to a different location on an image plane at the same time, wherein
the grating pattern being configured to apply a focus shift to the diffractive orders comprises the grating pattern being configured to apply a phase shift to the diffractive orders.

2. The optical imaging system of claim 1 , wherein, in use, the first diffractive element is positioned in the Fourier plane of a separate imaging system.

3. The system of claim 1 , wherein the refractive element comprises a prism having a surface that receives the multi-wavelength beams of the diffractive orders that pass through the second diffractive element, the surface comprising facets that are substantially flat.

4. The system of claim 3 , wherein each facet is positioned to receive the multi-wavelength beam of one of diffractive orders that passes through the second diffractive element.

5. The system of claim 3 , wherein the prism is a single piece of material that transmits at least one wavelength in the multi-wavelength beam of light.

6. The system of claim 3 , wherein the prism is formed from multiple pieces.

7. The system of claim 3 , wherein the second diffractive element comprises a blazed diffraction grating.

8. The optical imaging system of claim 3 , wherein the faceted prism comprises a plurality of facets, a number of facets being the same as a number of generated diffraction orders.

9. The optical imaging system of claim 3 , wherein the second diffractive element and the refractive optical element are part of a single physical element, and each facet of the prism comprises a blazed grating.

10. The optical imaging system of claim 3 , wherein the prism is non-monolithic and comprises a plurality separate elements.

11. The system of claim 1 , wherein the second diffractive element comprises panels in a periodic arrangement extending along a surface of the second diffractive element in two directions that are orthogonal to each other.

12. The system of claim 1 , wherein the second diffractive element is a single piece.

13. The system of claim 1 , wherein the second diffractive element comprises multiple-pieces that, in use, are assembled together to form the second diffractive element.

14. The system of claim 1 , wherein the first diffractive element introduces chromatic dispersion onto the diffractive orders, and passing the diffractive orders through the second diffractive element removes substantially all of the chromatic dispersion over a wavelength bandwidth.

15. The system of claim 14 , wherein the wavelength bandwidth is about 30-50 nm.

16. The system of claim 1 , wherein the first diffractive element comprises one of a binary or multi-phase phase-only diffraction grating.

17. The system of claim 1 , further comprising a housing that encloses the first diffractive element, the second diffractive element, the refractive element, and the lens, wherein the housing defines a first opening on a first side, the first opening positioned to allow light to enter the housing and propagate towards the first diffractive element, and the housing defines a second opening on a second side, the second opening positioned to receive light exiting the lens.

18. The system of claim 17 , wherein the housing comprises:
a connection on the first opening to couple the first opening to a camera port of a microscope, followed by an optical lens that forms a Fourier plane where the first diffractive element is positioned, and
a connection on the second opening to couple the second opening to a camera.

19. The system of claim 1 , wherein the multi-wavelength beam of light that the first diffractive element receives comprises light from multiple depths within an imaged volume, and each of the multi-wavelength beams focused at a different location on the image plane corresponds to an image of the volume at one of the depths.

20. The system of claim 19 , wherein the multi-wavelength beam of light comprises an output beam from one of a microscope or a photographic camera.

21. The system of claim 19 , further comprising a multi-element holder with selectable positions, each position comprising a different diffractive element, and wherein selection of a particular diffractive element determines a distance between each of the multiple depths.

22. The system of claim 21 , further comprising a housing that contains the first diffractive element, the second diffractive element, the refractive element, the multi-element holder, and the lens, and wherein the elements of the multi-element holder are selectable from an exterior of the housing.

23. The system of claim 1 , wherein the first diffractive element is inside of an imaging objective.

24. The system of claim 1 , wherein the multi-wavelength beam of light comprises fluorescence from an illuminated biological sample.

25. The system of claim 1 , wherein the multi-wavelength beam of light comprises a wavelength band selected such that the second diffractive element removes all residual chromatic dispersion.

26. The system of claim 1 , wherein the optical lens that focuses each of the multi-wavelength beams of the diffractive orders comprises an array of lenses.

27. The optical imaging system of claim 1 , wherein the first diffractive element comprises a surface positioned to receive the multi-wavelength beam of light, and the grating pattern comprises grooves formed in the surface, the grooves having more than two different groove depths relative to the surface.

28. The optical imaging system of claim 1 , wherein each diffractive order comprises light from a particular depth in a volume sample, and the grating pattern applies a phase shift to each diffractive order that is equal to a depth-induced phase error of the depth associated with the diffractive order.

29. The optical imaging system of claim 1 , wherein the grating pattern is based on the Abbe sine condition.

30. An imaging system comprising:
a dichroic mirror positioned to receive a multi-wavelength beam of light;
a first color channel and a second color channel that receive, respectively, a light beam of a first color from the dichroic mirror and a light beam of a second color from the dichroic mirror; wherein each of the first color channel and the second color channel comprise:
a first diffractive element comprising a diffraction pattern, the

Assignees

• Hughes Howard Med Inst

Inventors

• Abrahamsson Sara
• Gustafsson Mats G L

Classifications

• G02B27/0075

  with means for altering, e.g. increasing, the depth of field or depth of focus · CPC title

• G02B27/4205 Primary

  having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant · CPC title

• G02B27/4211

  correcting chromatic aberrations (G02B27/0056, G02B27/4222, G02B27/4227 take precedence) · CPC title

• G02B27/1086

  operating by diffraction only · CPC title

• G02B21/367 Primary

  providing an output produced by processing a plurality of individual source images, e.g. image tiling, montage, composite images, depth sectioning, image comparison · CPC title