US0082592.12B2(12) United States Patent(10) Patent No.:

Brady et al.
(54) MULTISCALE OPTICAL SYSTEM

Sep. 4, 2012

7,499,094 B2 * 3/2009 Kuriyama ..................... 348/340

7,728,901 B2 *(75) Inventors: David Jones Brady, Durham, NC (US);

6/2010 Onozawa et al. ..

... 348/340

8,049,806 B2 * 1 1/2011 Feldman et al. .............. 348/340

Nathan Adrian Hagen, Durham, NC(US); Scott Thomas McCain, Durham,
NC (US(US)(Continued)
FOREIGN PATENT DOCUMENTS
EP

0809124 A2(73) Assignee: Peted Qants Technologies, Inc.,(*) Notice:

US 8,259,212 B2(45) Date of Patent:

11/1997(Continued)

Subject to any disclaimer, the term of thispatent is extended or adjusted under 35
U.S.C. 154(b) by 376 days.

OTHER PUBLICATIONS
Quertemont, Eric, “PCT Application No. PCT/US2011/034156
International Search Report Sep. 23, 2011”, , Publisher: PCT, Published in: PCT.

(21) Appl. No.: 12/6S1,894(22) Filed:(Continued)

Jan. 4, 2010

(65)

Primary Examiner — Kelly L Jerabek

Prior Publication Data
US 2010/0171866A1(74) Attorney, Agent, or Firm — Kaplan Breyer Schwartz &Jul. 8, 2010

Ottesen LLP

Related U.S. Application Data

(57)(60) Provisional application No. 61/142,499, filed on Jan
5, 2009

A means of enabling an imaging lens system that overcomess -1 - 9Some of the costs and disadvantages of the prior art is dissclosed. A lens system in accordance with the present inven(51) Int. Cl

tion reduces or eliminates one or more aberrations of antion s/225(2006.01)

optical input by separating image collection functionality

GO2B 13/16
GO2B 27/10(200601)(2006,015

from image processing functionality. As a result, each function can be performed without compromising the other func
tion. An embodiment of the present invention comprises a.

o c - - - - -ificati- - - - - -s(58) Field o lity
S

(56)

ABSTRACTs slication file f

4. 348/335; S.

collection optic that provides a first optical field, based onsplurality of lenslets. The processing optic tiles the first opticalfield into a plurality of second optical fields. Each lenslet

4.350619 622 624.
slight from a scene, to a processing optic that comprises a

3 59.f626 62s
hhi
s

1

ee application file for complete search history.
References Cited

receives a different one of the plurality of second opticalfields, reduces at least one localized aberration in its received
second optical field, and provides the corrected optical field toa different one of plurality of photodetectors whose collective
output is used to form a spatially correlated Sub-image of that

U.S. PATENT DOCUMENTS
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400

corrected optical field. The sub-images are readily combined
into a spatially correlated image of the scene.

34 Claims, 7 Drawing Sheets

A.

402

404

418-1 406

408-1

A20-1

410

424

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Collector

Optic

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408-4
418-5

408-5

422-5

US 8,259,212 B2Page 2

2004/0257460 A1* 12/2004 Kuriyama ..................... 348/340

Lam, EdmundY. "Compact and Thin Multi-lens System for Machine
Vision Applications”. “Image Processing: Machine Vision Applica
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Duparre et al., “Microoptical telescope compound eye”, “Optics
Express', Feb. 7, 2005, vol. 13, No. 3, Publisher: Optical Society of

2007/0109438 A1* 5/2007 Duparre et al.

Brady et al. “Multiscale lens design”, “Optics Express 10659, Jun.
22, 2009, vol. 17, No. 13, Publisher: Optical Society of America,

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Christensen et al., “Multiscale Optical Design for Global Chip-to
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Mar/Apr. 2003, vol. 9, No. 2, Publisher: IEEE.
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Hylla, Winfried, “PCT Application No. PCT/US2010/020077 International Search Report May 4, 2010”. Publisher: PCT, Published in:

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lisher: PCT, Published in: PCT.

* cited by examiner

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1.

2
erating significant aberration across the image with approxi
mately equal primary and secondary apertures. Conventional
CROSS REFERENCE TO RELATED
lens design, therefore, normally requires trade-offs between
APPLICATIONS
desired performance metrics. For example, telescopes
achieve high angular resolution by sacrificing field-of-view,
This case claims priority of U.S. Provisional Patent Appli wide-field imagers achieve large angular fields-of-view by
cation U.S. 61/142,499, which was filed on Jan. 5, 2009, andsacrificing diffraction-limited angular resolution, and com
which is incorporated herein by reference.
pound-optics cameras achieve high quality by expanding sys
tem Volume to include more aberration-correction optics.
10
FIELD OF THE INVENTION
MULTISCALE OPTICAL SYSTEM

In order to overcome some of the limitations of standard

imaging optics, multi-aperture cameras have been developed.
The present invention relates to imaging optics in general,In multi-aperture systems, a standard camera objective lens isand, more particularly, to imaging lenses.
replaced by an array of lenslets, wherein each lenslet has a
BACKGROUND OF THE INVENTION
15 reduced focal length in comparison to a conventional camera.
In Such approaches, a detector measures a set of Sub-sampled
A trend in digital camera systems has been the shrinking of versions of the object within the field-of-view. Post-process
both optical elements and detector arrays. As these elements ing algorithms are used to generate a high-resolution image
shrink, however, the optical performance of their optical sys from the set of sub-sampled sub-images. The result is reduced
tems suffer since the angular resolution and number of resolv system Volume; however, the reduction in System Volume isable object points both decrease as the diameter of the imag achieved at the cost of significant computational post-pro
cessing and compromised image quality.
ing system is reduced.
A digital imaging system provides light from an object or
In addition, the design space for multi-aperture cameras isscene to an opto-electronic detector array. Each detector pro severely restricted, which has limited their adoption in pracvides an electrical signal whose magnitude is a function of the 25 tical systems. The use of a multi-aperture camera requires that
intensity of the light incident on that detector. As a result, the the size of its detector array and system aperture be approxi
detector array enables the light to be electronically processed mately the same size. As a result, conventional multi-aperturein order to estimate properties of the object. Typically, it is designs are generally restricted to very Small collection aper
desirable for the lens system to (1) collect as much of the light tures. This also limits the number of camera formats that cansignal as possible over as large anaperture as possible; and (2) 30 be designed. Further, a multi-aperture camera typically has aprocess the collected light signal to either form an optical restricted field-of-view due to a need to prevent the overlap
image on the detector array or to encode the light signal for ping of Sub-images on the detector array. Such overlapping
digital image estimation.
can be avoided by introducing a field stop in the opticalLens system design begins by specifying targets for major design; however, this increases system Volume. Alternatively,
performance metrics, such as angular resolution, field-of 35 absorbing barriers can be placed between the Sub-image
view, depth of field, spectral range, sensitivity, dynamic regions of the detector array; however, this significantly
range, system mass and Volume. Angular resolution is gener increases manufacturing cost and complexity.
ally the most significant initial metric. The best angular reso
A lens system that avoids some of the design trade-offs
lution of a lens is given by WA, where w is the operating associated with conventional lens design and that achieves
wavelength and A is the collection aperture diameter. Once 40 high performance cost-effectively is desirable.
the collection aperture size has been determined by this rela
SUMMARY OF THE INVENTION
tionship, a lens is designed to achieve the remaining perfor
mance metrics by judicious choice of materials and Surface
profiles.
The present invention enables optical systems that overIn conventional lens design, the aperture size of an entrance 45 come Some of the disadvantages of the prior art. The present
lens or optical stop (i.e., the primary aperture) often deter invention enables a multi-scale lens system in which lightmines the effective aperture size of all subsequent lens sur collection and light processing functions are separate. As afaces (i.e., the secondary aperture) in the lens system. The use result, each function can be independently designed withoutof multiple lenses and apertures enables a lens system to deleterious impact on the other function. The present inven
simultaneously: (1) create an effective focal length and mag 50 tion enables lens systems that are characterized by one ornification appropriate to the imaging task at hand; (2) reduce more of the following: wide-field imaging with diffraction
image aberrations; and (3) provide correct image orientation. limited resolution; improved optical image resolution at
Secondary apertures are typically matched to the effective higher light collection; lower cost lens systems; reduced sys
cross section of the magnified or demagnified entrance aper tem mass and Volume: 3D imaging capability; improved
ture propagated through the lens system. In systems with low 55 depth-of-field; and lower cost detection systems. Embodi
aberration, the size of the entrance aperture often determines ments of the present invention are particularly suitable forangular resolution of the lens system while the size of the high-performance imaging systems for use in applications
secondary apertures determines the field-of-view of the lens Such as cell phones, cameras, Surveillance systems, teleconsystem.
ferencing systems, satellite systems, and the like.
Simple cameras typically balance field-of-view and reso 60 Prior-art lens systems achieve one performance metric,
lution by using a sequence of lenses having approximately Such as high-resolution, wide field-of-view, single-shot expo
equally sized apertures. Microscopes, on the other hand,Sure, and form-factor, only by sacrificing at least one of theachieve large field-of-view and high angular resolution by others. For example, conventional optical systems achieve
increasing secondary aperture relative to the collection aper high-resolution by sacrificing field-of-view through the useture. Telescopes achieve extra-ordinary angular resolution 65 ofa telescope configuration. In contrast, the present invention
with a limited field-of-view by decreasing secondary aperture enables lens systems that achieve all of these performancesize. Wide-field cameras achieve large field-of-view by tol metrics at the same time. Some embodiments of the present

US 8,259,212 B2
4
3
FIG. 3 depicts a third imaging system in accordance withinvention, for example, attain high resolution, wide field-of
the prior art.
view, single-shot exposure, all in a small form-factor.
FIG. 4 depicts a schematic drawing of an imaging system
The present invention enables optical imaging systems thatcombine single aperture lenses with large diameters and in accordance with an illustrative embodiment of the present
micro-optic, multi-aperture lens arrays. The single-aperture 5 invention.
lens provides high angular resolution, while the micro-optic
FIG. 5 depicts operations of a method suitable for provid
lenses provide aberration correction. Further, the use of ing an image in accordance with the illustrative embodimentmulti-aperture lens arrays enables the use of segmented, high of the present invention.
FIG. 6 depicts a representation of the decomposition ofdensity detector arrays.
Embodiments of the present invention comprise a proces 10 full-field field curvature into more-readily correctable com
sor optic that comprises a plurality of optical elements, such ponent aberrations.
FIG. 7 depicts a cross-sectional view of a processor optic
as lenslets. The processor optic tiles a first optical field, which
is based on light from a scene, into a plurality of second suitable for correcting full-field curvature.
FIG. 8 depicts a schematic diagram of a processor optic in
optical fields. Some or all of the second optical fields arecharacterized by at least one localized aberration. Optical 15 accordance with the illustrative embodiment of the present
elements in the processing optic provide mitigation for local invention.
ized aberrations. This relieves some or all of the need for theFIG.9 depicts a schematic diagram of an aperture array incollector optic to provide correction for these aberrations.
accordance with the illustrative embodiment of the present
Each of the optical elements provides a corrected optical invention.
FIG. 10 depicts a schematic diagram of an imaging systemfield to a different one of a plurality of aperture arrays. In
Some embodiments, each aperture array comprises an array of in accordance with a first alternative embodiment of thephotodetectors that receives one of the corrected optical present invention.
fields. The output signals from each photodetector array are
FIG. 11 depicts a schematic diagram of an imaging systemused to form a Sub-image, spatially correlated with the scene. in accordance with a second alternative embodiment of the
In some embodiments, these Sub-images are combined to 25 present invention.
form a complete spatially correlated image of the scene.
DETAILED DESCRIPTION
In some embodiments, each aperture array is a second
processing optic that comprises another plurality of optical
FIG. 1 depicts a first imaging system in accordance withelements. Each plurality of optical elements further tiles its
received corrected optical field into a plurality of third optical 30 the prior art. System 100 is an integrated computational imag
fields. In some embodiments, each optical element also pro ing system that utilizes a multi-lens array and a reconstruction
vides additional aberration correction for its third optical algorithm to provide high-resolution over a wide field-of
field. Such hierarchical embodiments enable the use of larger view. System 100 comprises imager 104, and processor 118.
Imager 104 is a Thin Observation Module by Bound Optics
collector optics than single-stage embodiments of the present
invention. In some embodiments, the optical properties of at 35 (TOMBO) imager that receives an optical field from scene
102. Imager 104 comprises lens array 106, separation layer
least one lenslet are tunable.
110, and photodetector array 112.
Some embodiments comprise a mosaic of detector arrays,
Lens array 106 comprises a two-dimensional array of Sub
wherein each detector array provides an spatially correlated
Sub-image of a scene. In some of these embodiments, regis stantially identicallenses 108. Each lens 108 in lens array 106
tration of these Sub-images is done digitally. As a result, the 40 and its corresponding array of photodetectors forms a differalignment tolerances between the detector arrays are more ent imaging unit. Separation layer 110 comprises partitions
that mitigate optical crosstalk between the imaging units.
relaxed than for prior-art systems.
In operation, imager 104 provides intermediate image 114.
An embodiment of the present invention comprises amethod comprising: receiving a first portion of a first optical Intermediate image 114 comprises a plurality of images 116.
field at a first optical element, wherein the first portion is 45 each of which is a copy of a low-resolution image of scenecharacterized by a first localized aberration, and wherein the 102 that is provided by a different imaging unit of imager 104.
first optical field is received from a collector optic that col Images 116 are slightly distorted versions of each other,lects light from a scene; providing a second optical field from wherein the distortion is based on the position of its corre
the first optical element, wherein the second optical field is sponding lens 108 within lens array 106.
based on the first portion, and wherein the magnitude of the 50 Intermediate image 114 is received by processor 118. Pro
first localized aberration in the second optical field is less than cessor 118 applies a reconstruction algorithm that converts
the magnitude of the first localized aberration in the first the plurality of low-resolution images into a single highportion; receiving a second portion of the first optical field at resolution image 120. The quality of this reconstruction algoa second optical element, wherein the second portion is char rithm relies upon the accuracy of the parameter estimations
acterized by a second localized aberration; and providing a 55 for the displacement and aberrations in the optics of imager
third optical field from the second optical element, wherein 104.
By providing the same information to each of different
the third optical field is based on the second portion, andwherein the magnitude of the second localized aberration in regions of a single photodetector array, a conventional
the third optical field is less than the magnitude of the second TOMBO system enables the use of digital processing to over
60 come sampling limitations that result from the characteristics
localized aberration in the second portion.
of the photodetector array itself. Unfortunately, a TOMBOBRIEF DESCRIPTION OF THE DRAWINGS
system provides no improvement in the optical resolution of
the image since it is ultimately limited by the aperture sizes of
FIG. 1 depicts a first imaging system in accordance with the individual lenslets, which are typically quite Small.
65
Further, the design space for TOMBO-based imaging sys
the prior art.
FIG.2 depicts a second imaging system in accordance with tems is extremely restricted. For example, the system aperture
the prior art.
and detector array must be approximately the same size. As a

US 8,259,212 B2
5result, such systems are typically restricted to Small collection
apertures. This also limits the number of available camera
formats for which such a system can be designed. Further, theinclusion of separation layer 110 is typically necessary to
restrict the field-of-view of a typical TOMBO-based system
So as to prevent overlapping of images 116. This increasesystem Volume Substantially. Alternatively, light absorbing
barriers can be used between the detector arrays associated6
correct a localized aberration, therefore, an individual lenslet

requires a prescription unique to its received optical field.

Lenslets 214, 216-1, 216-2, 218-1, and 218-2 are substan

tially identical. As a result, system 200 does not correct for
localized aberrations. For example, optical field 222 can becharacterized by a global aberration that is substantially aslowly varying function across the collective optical fields
224. Each of optical fields 224 can be characterized by one orwith each lens 108; however, this increases the fabrication 10 more localized aberrations that are associated only with thatspecific optical field.
complexity and cost for the system.
FIG.2 depicts a second imaging system in accordance with
An additional disadvantage associated with system 200
the prior art. System 200 is a two-stage imaging system that arises in cases wherein the diameter of some of the lenslets
compensates for the curvature of field aberration. This aber approaches or exceeds the pitch of optoelectronic devices
ration results from the projection of a spherically shaped 15 51O.
image surface onto a plane. System 200 comprises lens 202,
FIG. 3 depicts a third imaging system in accordance withoptoelectronic devices 210-1 through 210-5, and lenslets 214, the prior art. System 300 is a second two-stage imaging
216-1, 216-2, 218-1, and 218-2. System 200 is symmetric system that compensates for the curvature of field aberration.
System 300 comprises lens 202, optoelectronic devices 210-1
about optical axis 204.
Lens 202 is a large-area lens that receives light 208 from a through 210-5, and lenslets 302, 304-1, 304-2, 306-1, andscene and provides optical field 222. Lens 202 is character 306-2.
ized by optical axis 204 and image surface 206. Lens 202
Lenslets 302,304-1,304-2, 306-1, and 306-2 are disposed
receives light 208 and focuses it at image surface 206. Image on the top surface of spacer 308. Spacer 308 comprises steps
surface 206 is a spherically shaped surface that denotes the 310, which enable each of the lenslets to be located at image
focal distance of lens 202.
25 surface 206. As a result, however, spacer 208 separates each
Optoelectronic devices 210-1 through 210-5 (collectively of the lenslets from its respective device 210 by a distance thatreferred to as devices 210) are formed in the top surface of increases with distance from optical axis 204. Each of the
Substrate 212 and are co-planar.
lenslets, therefore, has a focal length that corresponds to its
Lenslets 214, 216-1, 216-2, 218-1, and 218-2 are lenslets,
separation distance between it and its corresponding opto
each of which receives one of optical fields 224-1 through 30 electronic device 210.
224-5 (collectively referred to as optical fields 224) from lensSince system 300 positions each lenslet close to image
202. For example, lenslet 218-1 receives optical field 224-1, surface
the light fields received by the lenslets compriselenslet 214 receives optical field 224-3, and lenslet 218-2 more of206,
the
light
focuses at image surface 206 by lens 202. As
receives optical field 224-5 (not shown for clarity). Each a result, each of thelenslets can have Substantially the same35
lenslet focuses its received light field onto the face of its
diameter;howeverthecurvature of the lenslets increases withcorresponding optoelectronic device 210.
distance from optical axis 204.
Lenslets 214, 216-1, 216-2, 218-1, and 218-2 are also
In should be noted that each of systems 200 and 300
co-planar and are disposed on the top Surface of spacer 220,
which is disposed on substrate 212. Spacer 220 separates each employ a single optoelectronic element 210 per lenslet.
of the lenslets from its respective device 210 by the focal 40 Lenslets 302,304-1, 304-2, 306-1, and 306-2 are substan
distance of the lenslet.
tially identical except for their differences in focal length. In
Because the lenslets are coplanar, the separation distance similar fashion to system 200, therefore, system 300 only
between them and image surface 206 increases with distance provides a degree of compensation for field curvature.
from optical axis 204. As a result, the diameter of optical Multi-scale Imaging
fields 224-1 and 224-5 received at lenslets 218-1 and 218-2 is 45
The present invention relies on an inventive concept
larger than the diameter of the optical fields 224-2 and 224-4 referred to as “multi-scale imaging.” In contrast to prior-art
received at lenslets 216-1 and 216-2, which are, in turn, larger imaging systems, such as those depicted in FIGS. 1-3,
than optical field 224-3 received at lenslet 214. In order to embodiments of the present invention comprise a multi-ap
accommodate the larger size of the optical fields they receive, erture processing optic (e.g., an array of lenslets) that interlenslets 216-1 and 216-2 are larger (i.e., have a larger clear 50 poses a collector lens and a focal plane, wherein each aperture
aperture) than lenslet 214. In similar fashion, lenslets 218-1 in the processing optic provides wavefront correction thatand 218-2 are larger than lenslets 216-1 and 216-2. Further,
localized aberrations within an optical field it
the focal lengths of the lenslets increase with increasing dis mitigatesreceivesfromthe collector lens. This use of a heterogeneoustance from optical axis 204 to accommodate the increasing array of processing
apertures to correct localized aberrations
55
separation from image surface 206.
representsasignificant
difference between embodiments of
It should be noted that system 200 provides a degree ofcompensation for field curvature, which is a global aberra the present invention and multiple aperture imaging systems
tion. For the purpose of this Specification, including the of the prior art.
The multi-scale imaging approach affords embodiments ofappended claims, a 'global aberration' is defined as an aberration that extends, in slowly varying fashion, across multiple 60 the present invention significant advantages over prior-art
optical fields. A “localized aberration is defined as an aber imaging systems. First, the present invention separates lightration, or a portion of a global aberration, that is substantially collection from much of the light processing. This separation
unique to an individual optical field. For example, a plurality enables each of the collecting and processing functions to beof localized aberrations might collectively define a global individually improved without comprising the design of theaberration; however, the magnitude of wavefront distortion 65 other. It also enables a large-scale collector lens to be usedassociated with each localized aberration is substantially with a large-count multi-aperture array, thereby reducing theunique to its associated individual optical field. In order to trade-off between geometric aberration and field-of-view.

US 8,259,212 B2
8processor optic 406 comprises optical elements other thanlenslets, such as prisms, diffraction gratings, filters, and the7Second, the correction of localized aberrations reduces thedesign complexity required for the collector lens. This
enables faster collection optics, which reduces overall system

like.

Volume.

Although system 400 comprises lenslets 408 that are
Third, embodiments of the present invention are capable of 5 located after the image plane of collector optic 404, it will be
improved image resolution.
clear to one skilled in the art, after reading this specification,
Fourth, manufacturing cost and complexity are signifi how to specify, make, and use alternative embodiments of thecantly lower for embodiments of the present invention. present invention wherein lenslets 408 are located prior to the
Smaller lenses are better at providing wavefront correction 10 image plane of collector optic 404.
because: 1) wavefront correction and image formation both
As discussed above, the tiling of optical field 416 into ayield geometric Solutions with less wavelength-scale error pluralityof distinct regions (i.e., optical fields 418-1 throughover Smallerapertures; and 2) manufacturing of complex lens418-5)
enables
image formation and processing to be done
Surfaces is much easier in Smaller scale systems.
primarily
bylenslets
As a result, the present invention
Fifth, in some embodiments of the present invention, the 15 Substantially reduces 408.
oreliminates
the need for the design
processor optics focus at diverse ranges with overlapping
tradeoffs,
such
asangularresolution
field-of-view, reso
fields. This enables tomographic object reconstruction by lution vs. System Volume, etc., that arevs.inherent
to the design
combining multi-scale imaging with multi-dimensional of large lenses.
image capture, such as, for example, in a TOMBO-based
Importantly, the tiling of optical field 416 into a plurality ofsystem.
Finally, multi-scale design enables the use of multiple dis distinct optical fields 418-1 through 418-5 also enables theof individual prescriptions for each lenslet 408 to correct
crete focal plane arrays. As a result, the discrete focal plane use
aberrations centered on its respective field angle. In
arrays can be arranged in any advantageous manner, includ localized
otherwords,
each individual lenslet can be designed with aing non-planar arrangements. Further, the size of the focal prescription suitablecorrection of one or more localized25
plane arrays can be selected at a granularity that reduces aberrations within itsfor
received
optical field 418.
fabrication cost and increases overall reliability. Still further,At
operation
503,
processor
optic reduces localized aber
the Sub-images from the plurality of focal plane arrays can becollectively synthesized into a spatially correlated image of a rations in some of optical fields 418. In some embodiments,
scene without the Stitching and field uniformity issues found 30 each of lenslet 408 is designed to improve localized:
i. spherical aberration; orin prior-art imaging systems. And still further, the complexityof the post-processing required to synthesize the full-scene
ii. coma; orimage is significantly lower for embodiments of the present
iii. astigmatism; orinvention than the computational post-processing required inprior-art imaging systems, such as a TOMBO-based system. 35 iv. field curvature; or
V. distortion; orFIG. 4 depicts a schematic drawing of an imaging system
vi. uniform defocus; orin accordance with an illustrative embodiment of the present
invention. System 400 comprises collector optic 404, procesvii. linear defocus; or
sor optic 406, and aperture array 410.
viii.
quadratic defocus; orFIG. 5 depicts operations of a method suitable for provid 40
ix. any combination of i, ii., iii., iv, V. vi. vii, and viii.
ing an image in accordance with the illustrative embodimentof the present invention. Method 500 begins with operation
In order to provide correction for localized aberrations,
501, wherein light 414 from scene 402 is collected by collec each of lenslets 408 is characterized by an individualized
tor optic 404 and provided to processor optic 406 as optical prescription based on those localized aberrations. In somefield 416.

45

embodiments, one or more localized aberration is based on

the geographic position of optical field 418 within opticalfield 416, and the prescription of each of lenslets 408 is based
upon its geographic position within processor optic 406.
to FIG. 2.
At operation502, optical field 416 is tiled into optical fields
The prescription for each of lenslets 408 can be defined by
418-1, 418-2, 418-3, 418-4, and 418-5. In order to tile optical 50 first-order design principles. The Seidel aberrations (i.e.,field 416, collector optic 404 provides it to processor optic spherical aberrations, coma, astigmatism, field curvature, and406 such that a different portion of optical field 416 (i.e., each distortion) for optical field 416 are based on the use of aof optical fields 418-1, 418-2, 418-3, 418-4, and 418-5) is simple thin lens for collector optic 404 and an idealized lensreceived at the clear aperture of each optical element 408-1 at the location of processor optic 406. The aberration function
through 408-5 of processor optic 406. Optical fields 418-1, 55 of the image at aperture array 410 is then determined by:
418-2, 418-3, 418-4, and 418-5 (collectively referred to as
optical fields 418) are received by lenslets 408-1, 408-2,
WoH cos’p+W, Hip cos (p.
(1)
408-3, 408-4, and 408-5 (collectively referred to as lenslets408), respectively. In some embodiments, collector optic 404
provides some correction of one or more global aberrations of 60 where W is the wavefront aberration coefficient expressedin units of length, H is the normalized field angle, p is the
optical field 416.
Processor optic 406 is an array of lenslets located at a point normalized pupil radius, and p is the azimuth angle of theafter the image plane of collector optic 404. Processor optic pupil coordinate.
The prescription for each lenslet 408 can be developed by
406 comprises lenslets 408-1, 408-2, 408-3, 408-4, and 408
5. Processor optic 406 receives optical field 416 and, among 65 first expanding the expression for wavefront aberration fromother things, tiles optical field 416 into an array of smaller equation (1) above in terms of the central field angle, H., for
optical fields 418-1 through 418-5. In some embodiments, the nth lenslet as follows:
Collector optic 404 is a large aperture lens. Collector optic
404 is analogous to lens 202 described above and with respect

US 8,259,212 B2
910= (Woop") +
-

-

|Whe
ic cost -- "lifeconstant cont -CoStGit coic

W222 Hip cos’d -- 2W222 HH,p'cos d) -- W222 Hip cosid -auadratic distigmatism

linear astiginatisin

W220 Hip

constant astigmatism2

22--2W220 HHot + W220 Hip

quadratic defocus (i.e. FC)

linear defocus

defocus2
W31 Hipcosd) 3W31 Hi H. pcosd) -- 3W, H Hipcosd) - W31 Hipcosd,

cithic distortion

tadiatic distortion

tilt (i.e. nagnification error)

field displacement

The expression of the aberration function localized about techniques. In some embodiments, the lenslets are formed
the central field angle of a given lenslet produces a number of using molding techniques, embossing, or another conven
aberration terms which are not of Seidel form. Beneficially, tional technique. It will be clear to one skilled in the art, after
however, the aberrations with high-order field dependence reading this specification, how to specify, make, and use
are significantly reduced and much of their wavefront erroris lenslets 706, 708-1, 708-2, 710-1, and 710-2. In some
shifted into lower-order terms. Advantageously, these lower embodiments, lenslets 706, 708-1, 708-2, 710-1, and 710-2
order terms are easier to correct optically using an appropriate 25 are characterized by complex surface shapes formed on dif
prescription for each lenslet. The inclusion of non-Seidel ferent Substrates, which are aligned and stacked together toaberrations, however, requires that the surfaces of the lenslet form composite lenslets.
comprises non-cylindrically-symmetric shapes in order to
In some embodiments comprise lenslets having opticalproperties that are tunable. Lenslettunability can be affected
provide suitable aberration correction.
30 through any suitable means including, without limitation,
Example of Full-field Curvature Correction
In order to demonstrate how the inclusion of non-cylindri electrical, mechanical, thermal, magnetic, micro-electro-me
cally-symmetric shapes in a lenslet can provide correction for chanical, electromagnetic, magnetostrictive, and the like.
localized aberrations, an exemplary correction for full-field Optical properties that can be tuned include, without limita
tion, magnification, focal length, change of focal plane, andcurvature is provided here.
FIG. 6 depicts a representation of the decomposition of 35 the like.
Lenslet 706 comprises lens 712, which is a spherically
full-field field curvature into more-readily correctable com
ponentaberrations. Plot 600 depicts the full-field field curva symmetric lens Suitable for imaging a received optical field atture of optical field 416 at a processor optic that comprises a corresponding detector array. The focal length of lens 712 isthree optical elements. From plots 602, 604, and 606, an based on the combined thickness of substrate 702 and slab
estimation of the localized aberrations at each optical element 40 714, which typically defines the separation between lens 712
can be developed. As seen from plot 602, the two off-axis and its corresponding detector array.
optical elements see a uniform defocus of approximately 4 toLenslet 706 is centered on optical axis 424. As a result,
4.5 waves. Plot 604 evinces that each off-axis optical element lenslet 706 requires no correction for linear defocus. Slabalso sees a significant linear variation in defocus. Finally, plot 714, therefore, is Substantially rectangular in shape.
606 depicts the conventional field curvature, which is very 45 Lenslets 708-1 and 708-2 are each separated from opticalaxis 424 by distance d1. As depicted in plots 602 and 604, theSmall, at each optical element.
It is clear from plots 602, 604, and 606 that by splitting optical fields received by these lenslets exhibit both uniform
optical field 416 into optical fields 408, the primary aberra defocus and linear defocus.
tions for off-axis lenslets 408-1, 408-2, 408-4, and 408-5
Linear defocus is a function of lenslet position, however.
become uniform defocus and linear defocus (i.e., image tilt). 50 As the distance from optical axis 424 increases, the amount of
FIG. 7 depicts a cross-sectional view of a processor optic linear defocus correction required increases commensurately.
suitable for correcting full-field curvature. Processor optic Linear defocus is corrected by incorporating prisms 718-1
700 comprises substrate 702 and lenslets 706, 708-1, 708-2, and 718-2 into lenslets 716-1 and 716-2, respectively. The
wedge shape of prisms 718-1 and 718-2 correct for linear
710-1, and 710-2.
Substrate 702 is a glass substrate having a thickness suffi 55 defocus by “untilting their respective images. The angle ofcient to provide mechanical strength. Substrate 702 is also the wedge shape is dictated by the amount of image tilt
sufficiently thick to enable the formation of lenslets 706, correction required at each lenslet, which is based on distance708-1, 708-2, 710-1, and 710-2 in surface 704. In somed1. After correction of uniform and linear defocus, field cur

embodiments, substrate 702 comprises a material other than Vature aberration remains; however, it is greatly reduced fromglass. Suitable materials for use in substrate 702 include, 60 its full-field form.
without limitation, plastics, semiconductors, doped glasses,
Uniform defocus is readily corrected by changing the focal
length of each lenslet to compensate for the defocus at thatdielectrics, and the like. In some embodiments, substrate 702
comprises a material Suitable for forming lenses that operate lenslet. As a result, the focal length of lenslets 716-1 andat wavelength ranges other than visible. Such as ultraviolet, 716-2 is based on distance d1 and the thickness of prisms
65 718-1 and 718-2.
near infrared, mid-infrared, long infrared, and the like.
Lenslets 706, 708-1, 708-2, 710-1, and 710-2 are formed in
In similar fashion, lenslets 710-1 and 710-2 are each sepa
Surface 704 using reactive ion etching and sacrificial resist rated from optical axis 424 by distance d2. As a result, theUS 8,259,212 B2
11optical fields received by these lenslets exhibit greater uni

12achieved, given the practical constraints associated with lensform defocus and linear defocus. Lenslets 710-1 and 710-2,
manufacturing and integration. For current lens manufactur
therefore, comprise prisms 722-1 and 722-2, which have ing, aperture size for lenslets 408 within the range of approxi
larger wedge angles than prisms 718-1 and 718-2. Further, the mately 100 to approximately 1000 times the wavelengths offocal length of lenslets 720-1 and 720-2 is based on distance light in its associated optical field 418.
d2 and the thickness of prisms 722-1 and 722-2.
FIG.9 depicts a schematic diagram of an aperture array in
The example above demonstrates correction for substan accordance with the illustrative embodiment of the present
tially linear aberrations of uniform and linear defocus. In invention. Aperture array 410 comprises detector arrays
order to Suppress other aberrations, such as coma, spherical 412-1 through 412-5 (collectively referred to as detector
aberration, astigmatism, distortion, and the like, a more com 10 arrays 412). Each detector array 412 comprises a two-dimenplicated lenslet design is typically required. Such designs can sional arrangement of photodetectors 902, which are dis
be readily accomplished using numerical methods and com posedon the surface of a substrate 904. For example, detector
putational lens design techniques.
array
412-3
comprises a 6x3 two-dimensional array of pho
FIG. 8 depicts a schematic diagram of a processor optic in todetectors 902
that are formed on a surface of substrate15
accordance with the illustrative embodiment of the present
904-3.
The
sizeofeach detector array 412 is based upon theinvention. Processor optic 406 comprises lenslets 408-1
aperture
size
of
its
corresponding
lenslet 408, which is based,through 408-5 and frame 802. Processor optic 406 is analo
gous to processor optic 700 described above, and with respect in turn, upon the degree of aberration correction the lenslet
provides, as discussed above and with respect to FIG. 8. In
to FIG. 7. As such, lenslets 408 and frame 802 are formed
using the materials and methods described above, vis-a-vis Some embodiments, at least one of detector array 412 is adifferent size and/or comprises a different number of photo
substrate 702 and lenslets 706, 708-1, 708-2, 710-1, and710-2.
detectors 902 than at least one other detector array 412. In
Frame 802 is an unaltered portion of a substrate. Frame 802 Some embodiments, detector arrays 412 are monolithicallyprovides mechanical strength and Stability to processor optic integrated on a single Substrate. In some embodiments, detec
406. Frame 802 also provides a convenient mounting surface 25 tor arrays 412 are co-planar.
for processor optic 406.
At operation 504, optical fields 418-1 through 418-5 areLenslet 408-3 is centered on optical axis 424; therefore, received by processor optic 406. Each lenslet 408 of proces
lenslet 408-3 is axially symmetric.
sor optic 406 images its received optical field onto aperture
Lenslets 408-1, 408-2, 408-4, and 408-5 are off-axis lensarray 410 as one of individual optical fields 420-1, 420-2,
lets and, therefore, incorporate “wedge-like' features, as 30 420-3, 420-4, and 420-5 (collectively referred to as opticalfields 420). For example, lenslets 408-2 and 408-5 image
shown. Further, each of lenslets 408-1, 408-2, 408-4, and408-5 comprises a surface having a shape for mitigating an optical fields 418-2 and 418-5 onto apertures 412-2 and 412-5
aberration other than uniform defocus and linear defocus. In
as tiled optical fields 420-2 and 420-5 of scene 402. Collec
tively, optical fields 420 represent a complete, spatially corsome embodiments, each of lenslets 408-1, 408-2, 408-4, and408-5 comprises a complex Surface for mitigating an addi 35 related image of scene 402.
tional localized aberration. By segmenting the processing
Each lenslet 408 and its corresponding detector array 412
aperture into Sub-apertures, diverse localized aberrations may collectively define a different one of a plurality of sub-imag
be independently corrected in received optical field 418. FIG. ing units. These Sub-imaging units Sub-divide optical field
8 depicts aberration correction that is stronger in optical ele 416 into a plurality of mosaicked Sub-images. Mosaicking ofments 408-1 and 408-5. The increased aberration correction 40 the Sub-images affords embodiments of the present invention
accommodates for the failure of Small angle approximations with several advantages over imaging systems of the prior art.
for lenslets located at the edges of the image field. The design First, it enables overlapping fields-of-view to be used, whichanticipates aspheric optical elements for complex wavefront relieves a significant constraint for prior-art imaging systems
correction at off-axis field points and diversity in forms for wherein the focal plane array that receives an image of a scene
45 must comprise photodetectors that are immediately adjacentlenslets for diverse field points.
Each localized aberration of an individual optical field 418 to one another. As a result, each of detector arrays 412 can besized to optimize cost, yield, etc. It also enables the use ofis characterized by a magnitude of wavefront distortion.
Wavefront correction capability is proportional to lens aper detector arrays that are different sizes, if desired. Second,
ture size, since wavefront correction capability is based on the detector arrays 412 can be spaced to allow for the inclusion of
maximum phase delay achievable between two points on the 50 electronics between them. Third, Mosaicking of the sublens. As a result, there exists a relationship between the mag images enables multiple-aperture cameras that jointly opti
nitude of wavefront distortion for a localized aberration andmize physical filtering, sampling, and digital processing of
the aperture size necessary for correcting that localized aber the resultant images.
Each of detector arrays 412-1 through 412-5 provides anration. In some embodiments, therefore, the size of each oflenslets 408 is individually determined based on the magni 55 electrical signal from each of its photodetectors 902 to pro
tude of the wavefront distortion associated with one or morecessor 424. These electrical signals are provided as electrical
localized aberrations of its received optical field 418. In some signal arrays 422-1 through 422-5 (collectively referred to as
embodiments, the manner in which optical field 416 is tiled electrical signal arrays 422). For example, detector array
into optical fields 418 is determined by the manner in which 412-1 provides electrical signal array 422-1, which is based
the magnitude of wavefront distortion varies across optical 60 on optical field 420-1, to processor 424.
At operation 505, processor 424 forms a composite image
field 416. In other words, the arrangement of lenslets 408, as
well as the size of each of the lenslets, is based on howof scene 402 based on electrical signal arrays 422, which are
effectively correction of wavefront distortion can beachieved based on optical fields 420.
Processor 424 is a general purpose processor that receives
over each portion of optical field 416.
The inventors of the present invention recognized that the 65 electrical signal arrays 422. Processor 424 digitally processes
optimal aperture size for each of lenslets 408 is the largest electrical signal arrays 422-1 through 422-5 to develop sub
aperture over which nearly diffraction limited imaging can be images representative of optical fields 420-1 through 420-5,

US 8,259,212 B2
14
13
ByarrangingSub-imaging
units 1002 to more closely
respectively. Processor 424 stitches these Sub-images into acomposite image that represents scene 402.
match the image field of collector optic 1006, the present
In some embodiments, the magnification factor of lenslets invention enables collector optic 1006 to have a simpler
408 is less than 1; therefore, optical fields 420 are separated design than would be needed for a system wherein detector
from one another are substantially independent of one arrays 412 are coplanar. Further, the curved arrangement
another. As a result, packaging tolerances for detector arrays depicted mitigates field-curvature aberrations in the system.
Although system 1000 comprises lenslets 1008 that are
412 can be quite relaxed as compared to typical requirements
locatedafter image field 1004, it will be clear to one skilled infor prior art imaging systems. For example, detector arrays in
the
art,
after
reading this specification, how to specify, make,accordance with the present invention can be physically dis 10
andusealternativeof the present invention
placed from one another, include conditioning electronics wherein lenslets 1008embodimentsarelocatedprior
to image field 1004.
between arrays, and the like. As a result, the present invention
11 depicts a schematic diagram of an imaging systemenables a significant manufacturing cost reduction compared in FIG.
accordance with a second alternative embodiment of theto the prior art.
present invention. System 1100 comprises collector optic
FIG. 10 depicts a schematic diagram of an imaging system 15 404, pre-processor optic 1100, processor optic 406, and aperin accordance with a first alternative embodiment of theture array 410.
present invention. System 1000 comprises Sub-imaging units
System 1100 is a hierarchical imaging system that “steps
1002-1 through 1002-5, and collector optic 1006.
down optical field 414, in stages, from optical field 416
Collector optic 1006 forms image 1010 of scene 402 at provided by collector optic 404 to optical fields 420 received
image field 1004. Collector optic 1006 is analogous to col by aperture array 410.
Pre-processor optic 1102 is analogous to processor optic
lector optic 404.
Sub-imaging units 1002-1 through 1002-5 (collectively 406. Pre-processor optic 1102 and processor optic 406 colreferred to as Sub-imaging units 1002) are arranged in an lectively enable a greater degree of aberration correction. As
arrangement that Substantially matches the shape of image a result, system 1100 enables the use of larger aperture colfield 1004. Each of sub-imaging units 1002 comprises one 25 lector optics. Although the characteristics of system 1100 are
a matter of design choice, an exemplary two-processor-stage
lenslet 1008 and one detector array 412.
Each of lenslets 1008 is a substantially identicallenslet that arrangement includes: a collector optic comprising a collec
relays a portion of image 1010 onto its corresponding detec tor lens having a diameter of approximately 1 meter, a pre
tor array 412. In other words, lenslets 1008 act as relay lenses processor optic comprising a plurality of lenslets, each havingthat collectively relay the image formed by collector optic 30 a diameter of approximately 5 millimeters; and a processor
1006 at image field 1004. In system 1000, each of lenslets optic comprising a plurality of lenslets, each having a diam1008 demagnifies its received image portion onto its corre eter of approximately 1 millimeter. It will be clear to one
sponding photodetector array 412. Demagnification of each skilled in the art, after reading this specification, how toreceived image portion mitigates the potential for loss of specify, make, and use alternative embodiments of the present
image information at segmented photodetector arrays 1102. 35 invention that comprise:i. more than two processor stages; orIn some embodiments, each of lenslets 1008 magnifies its
received image portion while relaying it onto its respectiveii. aberration correction is provided by only one of preprocessor optic 1102 and processor optic 406; orphotodetector array. In some embodiments, lenslets 1008 do
iii. a pre-processor optic comprising a plurality of lenslets
not magnify or demagnify their received image portions. It
should be noted that, as described above, in some embodi 40

wherein at least one lenslet has a diameter that is differ

ments, each individual lenslet 1008 within sub-imaging units
ent from at least one other lenslet of the plurality; oriv. a pre-processor optic comprising a plurality of lenslets
1002 comprises features that mitigate localized aberrations in
wherein at least one lenslet has a diameter that is differ
its received optical field 418, such as is described above andwith respect to FIGS. 4-9.
ent from at least one other lenslet of the plurality; or
The fact that detector arrays can be mosaicked, as 45 V. a collector optic, pre-processor optic, and/or processor
described above, enables several advantages for system 1000
optic having diameters different than 1 meter, 5 milli
as compared to other imaging systems. First, Sub-imagining
meters, and 1 millimeter, respectively; orunits 1002 are substantially identical and can, therefore, be
vi. any combination of i, ii., iii., iv, and V.
readily mass manufactured at relatively low cost.
It is to be understood that the disclosure teaches just one
Second, an additional lens, whose prescription is uniquely 50 example of the illustrative embodiment and that many varia
based on the Sub-imaging units position in System 1000, can tions of the invention can easily be devised by those skilled inbe easily added to each of otherwise identical Sub-imaging the art after reading this disclosure and that the scope of theunits 1002. Such arrangements separate the image relay aber present invention is to be determined by the following claims.
ration correction functions of lenslets 1008. As a result, such

systems can be manufactured at low cost yet still provide 55
correction of localized aberration correction.

Third, Sub-imaging units 1002 can be arranged in any
practical arrangement that exploits the optical system, Such as
the curved arrangement depicted in FIG.10. Although system
1000 is depicted as comprising a one-dimensional arrange 60
ment of sub-imaging units 1002, it will be clear to one skilledin the art, after reading this specification, how to specify,
make, and use embodiments of the present invention wherein
Sub-imaging units 1002 are arranged in other one-dimensional arrangements and multi-dimensional arrangements, 65
Such as spherical arrangements, elliptical arrangements, andthe like.

What is claimed is:

1. A method comprising:receiving light from a scene at a collector optic, wherein thecollector optic is characterized by an image field;
providing a first optical field from the collector optic,
wherein the first optical field is based on the light fromthe scene;

receiving a first portion of the first optical field at a first
optical element, wherein the first portion is character
ized by a first localized aberration;
providing a second optical field from the first optical ele
ment, wherein the second optical field is based on thefirst portion of the first optical field, and wherein themagnitude of the first localized aberration in the second

US 8,259,212 B2
15
optical field is less than the magnitude of the first local
ized aberration in the first portion of the first optical

16
plane and the second array of photodetectors defines a second
plane, and wherein the first plane and second plane are dif
ferent planes.
field;
7. The method of claim 3 further comprising providing a
receiving a second portion of the first optical field at a pluralityof photodetector arrays, wherein the plurality of
second optical element, wherein the second portion is photodetector
arrays comprises the first array of photodetec
characterized by a second localized aberration; andtors
andsecondarray of photodetectors, and wherein theproviding a third optical field from the second optical ele plurality of photodetector
arrays are arranged in an arrange
ment, wherein the third optical field is based on the ment that substantially matches the shape of the image field of
second portion of the first optical field, and wherein the the collector optic.
magnitude of the second localized aberration in the third 10 8. The method of claim 1 further comprising providing theoptical field is less than the magnitude of the second second optical field Such that the magnitude of a third local
localized aberration in the second portion of the first ized aberration in the second optical field is less than themagnitude of the third localized aberration in the first portion
optical field.
of the first optical field.
2. The method of claim 1 further comprising:15
9. The method of claim 1 further comprising:providing the first optical element as one of a plurality ofreceiving the second optical field at a second optical ele
optical elements, wherein the first optical element
ment, wherein the second optical element tiles the sec
reduces the magnitude of the first localized aberration by
ond optical field into a first plurality of optical sub-fields,
an amount that is based on the position of the first opticaland wherein each of the first plurality of optical sub
element within the plurality of optical elements; andfields is characterized by a third localized aberration;
providing the second optical element as one of the plurality
providing a second plurality of optical Sub-fields, whereineach of the plurality of second optical sub-fields is basedof optical elements, wherein the second optical element
on a different optical sub-field of the first plurality of
reduces the magnitude of the second localized aberra
optical sub-fields, and wherein the magnitude of thetion by an amount that is based on the position of thethird localized aberration in each of the plurality of
second optical element within the plurality of optical 25
second optical Sub-fields is less than the magnitude ofelements.
the third localized aberration in its corresponding optical
3. The method of claim 1 further comprising:
sub-field of the first plurality of optical sub-fields:(1) forming a first Sub-image, wherein the first Sub-image is
receiving the third optical field at a third optical element,
formed by operations comprising:wherein the third optical element tiles the third optical(i) receiving the second optical field at a first array of 30
field into a third plurality of optical sub-fields, andphotodetectors;
whereineach of the third plurality of optical sub-fields is(ii) generating a first plurality of electrical signals,
characterized
by a fourth localized aberration; andwherein the first plurality of electrical signals areproviding a fourth plurality of optical sub-fields, wherein
generated by the first array of photodetectors based oneach of the plurality of fourth optical sub-fields is based35
the second optical field;
on a different optical sub-field of the third plurality of
optical sub-fields, and wherein the magnitude of the(iii) providing the first plurality of electrical signals to afourth localized aberration in each of the plurality ofprocessor; andfourth optical sub-fields is less than the magnitude of the(iv) digitally processing the first plurality of electrical
fourth localized aberration in its corresponding opticalsignals to form the first Sub-image; andof the third plurality of optical sub-fields.
(2) forming a second Sub-image, wherein the second Sub 40 10.sub-field
A method comprising:image is formed by operations comprising:tiling a first optical field into a plurality of second optical(i) receiving the third optical field at a second array offields, wherein the first optical field is based on light
photodetectors;
from a scene;(ii) generating a second plurality of electrical signals,
providing a plurality of third optical fields, wherein each ofwherein the second plurality of electrical signals are 45
the plurality of third optical fields is based on a different
generated by the second array of photodetectors based
one of the plurality of second optical fields, and wherein
the magnitude of a first localized aberration in each ofon the third optical field;
the plurality of third optical fields is less than the mag(iii) providing the second plurality of electrical signals
nitude of the first localized aberration in its correspondto the processor, anding second optical field; and(iv) digitally processing the second plurality of electrical 50
forming a plurality of Sub-images based on the plurality ofsignals to form the second Sub-image.
third optical fields, wherein the plurality of sub-images
4. The method of claim 3 further comprising:and the plurality of third optical fields has a one-to-one
selecting the size of the first array of photodetectors,
correspondence.
wherein the size of the first array of photodetectors is
11.
The method of claim 10 further comprising combining
selected based upon the aperture size of the first optical 55 the pluralityof sub-images to form a first image of the scene,element; andwhereinthe
firstimage is spatially correlated with the scene.
Selecting the size of the second array of photodetectors,
12.
The
methodclaim 10 wherein the plurality of sub
wherein the size of the second array of photodetectors is images is formed byofoperations
comprising:Selected based upon the aperture size of the second opti
receiving a different one of the plurality of third opticalcal element.
60
fields at each of a plurality of photodetector arrays;
5. The method of claim3 further comprising forming a first
generating a plurality of output signal arrays, wherein each
image, wherein the first image is spatially correlated with theof the plurality of output signal arrays is based on thescene, and wherein the first image comprises the first Sub
third optical field received by a different one of theplurality of photodetector arrays; andimage and the second Sub-image.
6. The method of claim 3 further comprising arranging the 65 digitally processing each of the plurality of output signal
first array of photodetectors and second array of photodetec
arrays to form a different one of the plurality of sub
images.
tors, wherein the first array of photodetectors defines a firstUS 8,259,212 B2
17
18
and wherein each of the plurality of Sub-images is based on a
13. The method of claim 12 further comprising:providing the plurality of third optical fields to the plurality different one of the plurality of electrical signal arrays.
22. The apparatus of claim 21 wherein the processor formsof photodetector arrays, wherein each of the third opticalfields is provided by a different optical element of a a first image based on the plurality of Sub-images, andwherein the first image is spatially correlated with the scene.
plurality of optical elements; and23. The apparatus of claim 20 wherein the plurality ofdetermining the size of each of the plurality of photodetec photodetector
arrays are co-planar.
tor arrays based upon the aperture size of its correspond
24. The apparatus of claim 20 wherein the plurality of
ing optical element of the plurality of optical elements.
photodetector arrays are monolithically integrated.
14. The method of claim 12 further comprising providing 10 25. The apparatus of claim 20 whereina first photodetector
the plurality of photodetector arrays, wherein each of the array of the plurality of photodetector arrays is located on aplurality of photodetector arrays lies on a first plane.
first plane, and wherein a second photodetector array of the
15. The method of claim 12 further comprising providing plurality of photodetector arrays is located on a second plane,
the plurality of photodetector arrays in an arrangement and wherein the first plane and second plane are different
planes.
wherein the photodetector arrays are not co-planar.
15
26. The apparatus of claim 20 wherein the plurality of
16. The method of claim 12 further comprising providing
the plurality of photodetector arrays in an arrangement photodetector arrays are arranged in an arrangement that
Substantially matches the shape of the image field.
wherein the photodetector arrays are co-planar.
27. The apparatus of claim 20 wherein each of the plurality
17. The method of claim 12 further comprising:ofphotodetector arrays and a different one of the plurality ofreceiving the light from the scene at a collector optic, opticalcollectively define a Sub-imaging unit, andwherein the collector optic provides the first optical field whereinelements
theplurality
Sub-imaging units are arranged in an
to a processor optic, and wherein the collector optic is arrangement based onoftheshape of the image field.
characterized by an image field;
28.
The
apparatusofclaim
19 further comprising an aperproviding the processor optic, wherein the processor optic ture array, wherein each apertureof the aperture array com
tiles the first optical field, and wherein the processor 25 prises a plurality of optical elements,
and wherein each aper
optic comprises a plurality of optical elements;of the aperture array receives a different one of theproviding the plurality of photodetector arrays, wherein the tureof third optical fields, and further wherein eachplurality of photodetector arrays and the plurality of pluralityof the aperture array tiles its received third optical
optical elements collectively define a plurality of sub aperture
into a plurality of fourth optical fields.
imaging units, and wherein the plurality of Sub-imaging 30 field
29. The apparatus of claim 28 wherein each optical element
units are provided in an arrangement that Substantially is dimensioned
and arranged to reduce the magnitude of thematches the shape of the image field.
first localized aberration.
18. The method of claim 10 further comprising providing
30. The apparatus of claim 19 wherein at least one of thethe plurality of third optical fields such that the magnitude of plurality
optical elements is dimensioned and arranged toa second localized aberration in each of the plurality of third 35 reduce theofmagnitudeof a second localized aberration.
optical fields is less than the magnitude of the second local
31. An apparatus comprising:ized aberration in its corresponding second optical field.
a collector optic, wherein the collector optic receives light
19. An apparatus comprising:from a scene and provides a first optical field that is
a collector optic, wherein the collector optic receives lightbased
on the light, and wherein the collector optic isfrom a scene and provides a first optical field that is 40
characterized by an image field;
based on the light, and wherein the collector optic is
a processor optic comprising a plurality of first opticalcharacterized by an image field; andelements, wherein the plurality of first optical elements
a processor optic comprising a plurality of optical ele
is arranged in an arrangement that Substantially matches
ments, wherein each of the plurality of optical elements
theimage field; and wherein each of the plurality ofis dimensioned and arranged to reduce the magnitude of 45
opticalelements is dimensioned and arranged to reducea first localized aberration;
the magnitude of a first localized aberration; andwherein the processor optic tiles the first optical field into
a plurality of photodetector arrays, wherein each of thea plurality of second optical fields, and wherein each ofplurality of photodetector arrays receives a portion of thethe plurality of optical elements receives a different one
first optical field from a different one of the plurality ofof the plurality of second optical fields and provides a 50
first optical elements, and wherein each of the plurality
third optical field based on its received second opticalof photodetector arrays provides a Sub-image that isfield;
based
on its received portion of the first optical field.
wherein the magnitude of the first localized aberration in
32.
The
apparatus
claim 31 wherein each of the plurality
each of the plurality of third optical fields is less than the of optical elements isofarranged
as a relay lens between themagnitude of the first localized aberration in its corre 55 image field and its optically coupled
photodetector array.
sponding second optical field.
33.
The
apparatus
of
claim
32
whereineach of the plurality
20. The apparatus of claim 19 further comprising an aper of first optical elements further comprises
second optical
ture array, wherein the aperture array comprises a plurality of element that is dimensioned and arranged toareducethe mag
photodetector arrays, and wherein each of the plurality of nitude of a second localized aberration.
60
photodetector arrays receives a different one of the plurality
The apparatus of claim 31 further comprising a procesof third optical fields, and further wherein each of the plural Sor,34.wherein
processor forms a composite image that
ity of photodetector arrays provides an electrical signal array comprises thethe
pluralityof sub-images, and wherein the comthat is based on its received third optical field.
positeimage
isspatiallycorrelated with the scene.
21. The apparatus of claim 20 further comprising a proces
k
k
k
k
k
Sor, wherein the processor forms a plurality of Sub-images,

UNITED STATES PATENT AND TRADEMARK OFFICECERTIFICATE OF CORRECTIONPATENT NO.

: 8,259,212 B2

APPLICATIONNO.

: 12/6.51894

Page 1 of 1

DATED
INVENTOR(S): September 4, 2012
: Brady et al.

It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below:

Title Page
There is an error in the Assignee. It presently lists 1 Assignee: Applied Quantum Technologies, Inc.,but both Assignees should be listed:
Applied Quantum Technologies, Inc.
Durham, NC
andDuke University
Durham, NC

Signed and Sealed thisTwenty-sixth Day of February, 2013

Teresa Stanek Rea

Acting Director of the United States Patent and Trademark Office