Meta-lens enabled light-field camera with extreme depth-of-field

Patent metadata

Field	Value
Publication number	US-12520051-B2
Application number	US-202318181966-A
Country	US
Kind code	B2
Filing date	Mar 10, 2023
Priority date	Mar 11, 2022
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

A chiral light-field optical imaging camera incorporating an array of photonic spin-multiplexed bifocal metalenses. Combined with a novel deep learning-based neural network reconstruction algorithm, the system provides distinct aberration-free photographic capabilities, including the ability to achieve a polarization controllable extremely large depth-of-field optical imaging across a range of distances within a range covering at least five orders of magnitude in absence of moving a part of the camera and based on a single exposure of an optical detector while maintaining high spatial lateral resolution.

First claim

What is claimed is:

1 . An article of manufacture comprising:
a chiral metalens including an array of pluralities of spatially-limited material elements,
wherein every plurality of the pluralities of spatially-limited material elements is configured to converge a substantially planar wavefront incident thereon to a first focal point for a first state of polarization of said wavefront and to a second focal point for a second state of polarization of said wavefront, the first and second states of polarizations being orthogonal to one another, the first focal point being spatially different from the second focal point,
and a primary lens axially separated from the chiral metalens and co-axial with the chiral metalens, wherein a combination of the primary lens and the chiral metalens is configured as a bi-focal light-field optical imaging system defining an image plane, wherein an F-number of the primary lens is not smaller than an F-number of the chiral metalens to avoid spatial overlap of multiple images at the image plane.

2 . An article of manufacture according to claim 1 , wherein the F-number of the primary lens is not smaller than the F-number of the chiral metalens that corresponds to a longer of a first focal length and a second focal length of said chiral metalens.

3 . An article of manufacture according to claim 1 ,
(a) wherein each of the spatially-limited material elements is configured as a half-wave plate for each of the first and second states of polarization and/or wherein each of the spatially-limited material elements is shaped as a pillar protruding from a surface of an optical substrate,
and/or
(b) wherein all of first focal points at which said substantially planar wavefront in converged are in a first focal plane and each of second focal points at which said substantially planar wavefront is converged are in the second focal plane, the first and second focal planes being substantially parallel to one another.

4 . An article of manufacture according to claim 1 , wherein:
(a) a first structural condition is satisfied in that the primary lens includes more than one lens element, said more than one lens element being substantially co-axial with one another; and/or (b) a second structural condition is satisfied in that the article of manufacture further comprises a relay optics positioned at the image plane and configured to define a final image plane.

5 . An article of manufacture according to claim 1 , wherein:
(a) said bi-focal light-field optical imaging system is configured to form in said image plane or, (b) when an auxiliary structural condition is satisfied in that the article of manufacture further comprises a relay optics positioned at the image plane and configured to define a final image plane, the relay optics is configured to form in said final image plane:
first multiple images of a first portion of an object space only with the use of a first component of light incident onto the combination of the primary lens and the chiral metalens,
and
second multiple images of a second portion of the object space only with the use of a second component of the light incident onto said combination,
wherein the first component of the light incident onto the combination has the first state of polarization and the second component of the light incident onto the combination has the second state of polarization and/or wherein the first portion of the object space and the second portion of the object space are necessarily different from one another.

6 . An article of manufacture according to claim 5 , wherein:
(a) when the light incident onto said combination is substantially monochromatic, the first portion of the object space is optically conjugate with the image plane and is axially separated from the combination by a first distance while the second portion of the object space is optically conjugated with the image plane and is axially separated from the combination by a second distance, the first and second distances being necessarily different from one another,
and/or
(b) when the light incident onto said combination of the primary lens and the chiral metalens is substantially polychromatic,
at least a part of the first portion of the object space and/or at least a part of the second portion of the object space is not optically conjugate with the image plane in light at one of multiple wavelengths present in the light incident onto the combination of the primary lens and the chiral metalens.

7 . An article of manufacture according to claim 5 ,
wherein the bi-focal light-field optical imaging system is configured to form said first multiple images with the use of only substantially a half of a first fraction of the light incident onto said combination that has the first state of polarization while converging the other half of said first fraction to a first plane different from the image plane, and wherein the bi-focal light-field optical imaging system is configured to form said second multiple images with the use of only substantially a half of a second fraction of the light incident onto said combination that has the second state of polarization while converging the other half of said second fraction to a second plane different from the image plane.

8 . An article of manufacture according to claim 7 , wherein the first and second planes are axially separated from one another by the image plane.

9 . An article of manufacture according to claim 5 , wherein the bi-focal optical imaging system is configured to form said first and second multiple images in a single exposure of an optical detector of said bi-focal optical imaging system and necessarily without axial repositioning of an optical component of said bi-focal optical imaging system.

10 . An article of manufacture according to claim 5 , further comprising:
a programmable processor (a) that is configured to transform optical data acquired by an optical detector positioned in the image plane or, when the second auxiliary structural condition is satisfied, in the final image plane to determine a spatial characteristic and/or a spectral characteristic of a third portion of the object space that is not optically conjugate with the image plane based at least on values of a point spread function (PSF) of the bi-focal optical imaging system empirically determined at multiple wavelengths for a multiplicity of different object distances for each of the first and second states of polarization; and/or (b) that is configured to determine said spatial and/or spectral characteristic of the third portion of the object space that is separated from the combination of the primary lens and the chiral metalens by a distance within a range spanning at least five orders of magnitude or longer.

11 . An article of manufacture according to claim 10 , wherein a lower limit of said range is about a centimeter and/or an upper limit of said range is about 10 kilometers.

12 . An article of manufacture according to claim 10 , wherein the programmable processor is additionally configured:
to transform optical images represented by said optical data to correct said optical images for aberrations including at least third order aberrations and chromatic aberrations, and/or to transform said optical images to estimate disparity thereof and/or to perform refocusing of said optical images at different depths of field, and/or to transform said optical images by spatially stitching different of said optical images with one another,
thereby generating output images that are substantially fully focused for each depth of field corresponding to each distance in said ran

Assignees

• Univ Maryland
• Government Of The Us Secretary Of Commerce

Inventors

• Zhu Wenqi
• Agrawal Amit Kumar
• Chen Lu
• Lezec Henri J

Classifications

• H04N13/232

  using fly-eye lenses, e.g. arrangements of circular lenses · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N25/60

  Noise processing, e.g. detecting, correcting, reducing or removing noise · CPC title

• H04N23/957 Primary

  Light-field or plenoptic cameras or camera modules · CPC title