Snapshot spectral imaging based on digital cameras

Patent metadata

Field	Value
Publication number	US-9459148-B2
Application number	US-201514661682-A
Country	US
Kind code	B2
Filing date	Mar 18, 2015
Priority date	Jan 29, 2012
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Snapshot spectral imagers comprise an imaging lens, a dispersed image sensor and a restricted isometry property (RIP) diffuser inserted in the optical path between the source image and the image sensor. The imagers are used to obtain a plurality of spectral images of the source object in different spectral bands in a single shot. In some embodiments, the RIP diffuser is one dimensional. An optional disperser may be added in the optical path, to provide further dispersion at the image sensor. In some embodiments, all imager components except the RIP diffuser may be part of a digital camera, with the RIP diffuser added externally. In some embodiments, the RIP diffuser may be included internally in a digital camera.

First claim

What is claimed is:

1. An optical element for use in a spectral imaging system comprising: a patterned structure that modifies a point spread function (PSF) of the spectral imaging system at each wavelength in a spectral range such that a resulting linear transformation of a source object into a diffused and dispersed image at an image sensor satisfies a restricted isometry property (RIP) condition.

2. The optical element of claim 1 , wherein the PSF is related to a block-sensing matrix in which a sub-matrix of each block includes a plurality of rows, wherein each row in a single block comprises pixels of a single-wavelength PSF at a given position within the source object.

3. The optical element of claim 2 , wherein the block-sensing matrix is a random matrix and wherein a random sub-matrix of each block corresponds to a single wavelength λ or to a band chosen around a single wavelength λ in a spectral range of interest.

4. The optical element of claim 2 , wherein the block-sensing matrix is a block-Toeplitz matrix and wherein a Toeplitz sub-matrix of each block corresponds to a single wavelength λ or to a band chosen around a single wavelength λ in a spectral range of interest.

5. The optical element of claim 2 , wherein the block-sensing matrix is a deterministic matrix and wherein a deterministic sub-matrix of each block corresponds to a single wavelength λ or to a band chosen around a single wavelength λ in a spectral range of interest.

6. The optical element of claim 3 , wherein the patterned structure includes a phase level pattern.

7. The optical element of claim 6 , wherein the phase level pattern includes a pattern of grooves in the form of stripes extending in one direction, each groove characterized by a width and a random depth h, the width and depth varying along one or two orthogonal spatial coordinates.

8. The optical element of claim 7 , wherein each groove depth h is designed to cause a corresponding phase shift

φ
λ

=

2
⁢

⁢
π
⁢

⁢

h
⁡

[

n
⁡

(
λ
)

-
1

]

λ

where n(λ) is a wavelength dependent refractive index.

9. The optical element of claim 5 , wherein the patterned structure includes a phase level pattern.

10. The optical element of claim 9 , wherein the phase level pattern includes a pattern of grooves in the form of stripes extending in one direction, each grove characterized by a width and a deterministic depth h, the width and depth varying along one or two orthogonal spatial coordinates.

11. The optical element of claim 1 , included in an optical lens block.

12. The optical element of claim 1 , included in a digital camera.

13. An optical element for use in a spectral imaging system comprising: a transparent substrate with a groove structure with random or deterministic groove depths, wherein a block-sensing matrix of the spectral imaging system obeys a mathematical restricted isometry property (RIP) condition with the groove structure.

14. The optical element of claim 13 , wherein each block of the block-sensing matrix is a random sub-matrix.

15. The optical element of claim 13 , wherein each block of the block-sensing matrix is a Toeplitz sub-matrix.

16. The optical element of claim 13 , wherein each block of the block-sensing matrix is a deterministic sub-matrix.

17. The optical element of claim 14 , wherein the groove structure is in the form of stripes extending in one direction, each groove characterized by a width and a depth h, the width and depth varying along one or two orthogonal spatial coordinates.

18. The optical element of claim 17 , wherein each groove depth h is designed to cause a corresponding phase shift

φ
λ

=

2
⁢

⁢
π
⁢

⁢

h
⁡

[

n
⁡

(
λ
)

-
1

]

λ

where n(λ) is a wavelength dependent refractive index.

19. An optical element for use in a spectral imaging system comprising: a patterned groove structure that modifies a point spread function (PSF) of the spectral imaging system at each wavelength in a spectral range such that a resulting linear transformation of a source object into a diffused and dispersed image at an image sensor satisfies a restricted isometry property (RIP) condition, wherein the groove pattern is in the form of stripes extending in one direction, each groove characterized by a width and a random depth h, the width and depth varying along one or two orthogonal spatial coordinates.

Assignees

• Golub Michael
• Nathan Menachem
• Averbuch Amir
• Kagan Asaf
• Zheludev Valery
• Malinsky Roman
• Ramot At Tel-Aviv Univ Ltd

Inventors

• Golub Michael
• Nathan Menachem
• Averbuch Amir
• Kagan Asaf
• Zheludev Valery
• Malinsky Roman

Classifications

• G02B5/02

  Diffusing elements; Afocal elements · CPC title

• H04N9/045

  Electricity · mapped topic

• G01J3/0208

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title

• G02B5/1842

  Gratings for image generation (G02B5/1847 takes precedence) · CPC title

• G01J3/0205

  Optical elements not provided otherwise, e.g. optical manifolds, diffusers, windows · CPC title