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Claims  |
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What is claimed is:
1. An interferometer, comprising:
a transmitting portion that directs differently polarized portions of a
coherent light beam to a reference element and an object, combines the
differently polarized portions returned from the reference element and
object into a combined wavefront, and outputs the combined wavefront;
a multiple phase shift image generating portion arranged to input the
combined wavefront, the multiple phase shift image generating portion
comprising at least a first polarizer array arranged along at least a
first optical path, the first polarizer array comprising a plurality of
first polarizing portions having a first polarization direction and a
plurality of second polarizing portions having a second polarization
direction, the first and second polarizing portions arranged in a pattern
within the first polarizer array; and
a detector portion comprising at least a first detector array arranged
along the first optical path, wherein:
the first polarizer array receives at least a sub-wavefront of the combined
wavefront including the differently polarized portions;
the first polarizing portions transmit the differently polarized portions
of the sub-wavefront to produce at least first interference portions, the
first interference portions comprising interference light having a first
unique phase relationship;
the second polarizing portions transmit the differently polarized portions
of the sub-wavefront to produce at least second interference portions, the
second interference portions comprising interference light having a second
unique phase relationship; and
the multiple phase shift image generating portion outputs interleaved
multiple phase-shifted interference image information from at least the
first polarizer array, the interleaved multiple phase-shifted interference
image information from the first polarizer array comprising at least the
first interference portions and the second interference portions, at least
the first interference portions and the second interference portions
interleaved at a spatial frequency determined at least partially by the
pattern of the first polarizing portions and the second polarizing
portions in the first polarizer array.
2. The interferometer of claim 1, wherein the interleaved multiple
phase-shifted interference image information from the first polarizer
array is output to form an interleaved image on the first detector array.
3. The interferometer of claim 2, wherein the at least first interference
portions and the at least second interference portions each have nominal
extents in the interleaved image on the first detector array, and the
nominal extents are nominally aligned to coincide with the boundaries of a
coextensive set of pixels of the first detector array.
4. The interferometer of claim 3, wherein the coextensive set of pixels on
the first detector array is N pixels wide and M pixels high, where M and N
are integers.
5. The interferometer of claim 4, wherein M is at most equal to 16 and N is
at most equal to 16.
6. The interferometer of claim 5, wherein M at most equal to 8 and N is at
most equal to 8.
7. The interferometer of claim 1, wherein the first unique phase
relationship corresponds to zero degrees relative phase shift in the
corresponding interference light and the second unique phase relationship
corresponds to 180 degrees relative phase shift in the corresponding
interference light.
8. The interferometer of claim 1, wherein the pattern of the plurality of
first polarizing portions and the plurality of second polarizing portions
in the first polarizer array comprises a checkerboard pattern.
9. The interferometer of claim 1, wherein the first polarizer array is
positioned in proximity to a detector surface of the first detector array.
10. The interferometer of claim 1, wherein the multiple phase shift image
generating portion further comprises a first retarder element arranged
along the first optical path to receive the sub-wavefront of the combined
wavefront including the differently polarized portions and to transmit the
sub-wavefront to the first polarizer array.
11. The interferometer of claim 10, wherein the first retarder element
comprises at least one of at least one null phase-shift element and at
least one quarter wave phase-shift element.
12. The interferometer of claim 11, wherein the first polarizer array is
fabricated on a surface of the first retarder element which faces the
first detector array and the first polarizer array is positioned in
proximity to a detector surface of the first detector array.
13. The interferometer of claim 10, wherein at least the first retarder
element, the first polarizer array, and the first detector array form an
integrated monolithic phase-shift imaging element.
14. The interferometer of claim 10, wherein:
the first retarder element comprises a first phase-shifting array:
the first phase-shifting array comprises a plurality of first phase-shift
portions providing a first phase shift and a plurality of second
phase-shift portions providing a second phase shift, the pluralities of
the first and second phase shift portions arranged in a pattern within the
first phase-shifting array;
the first phase-shifting array is aligned relative the first polarizer
array such that each of the first and second polarizing portions are
nominally aligned with a single one of the first and second phase-shift
portions such that:
for the first polarizing portions that are aligned with the first
phase-shift portions, the first polarizing portions transmit the
differently polarized portions of the sub-wavefront to produce the first
interference portions comprising interference light having the first
unique phase relationship;
for the second polarizing portions that are aligned with the first
phase-shift portions, the second polarizing portions transmit the
differently polarized portions of the sub-wavefront to produce the second
interference portions comprising interference light having the second
unique phase relationship;
for the first polarizing portions that are aligned with the second
phase-shift portions, the first polarizing portions transmit the
differently polarized portions of the sub-wavefront to produce a third
interference portion comprising interference light having a third unique
phase relationship;
for the second polarizing portions that are aligned with the second
phase-shift portions, the second polarizing portions transmit the
differently polarized portions of the sub-wavefront to produce a fourth
interference portion comprising interference light having a fourth unique
phase relationship; and
the multiple phase shift image generating portion outputs interleaved
multiple phase-shifted interference image information from at least the
first polarizer array, the interleaved multiple phase-shifted interference
image information from the first polarizer array comprising the first,
second, third and fourth interference portions, the first, second, third
and fourth interference portions interleaved at a spatial frequency
determined at least partially by the pattern of the first polarizing
portions and the second polarizing portions in the first polarizer array
in combination with the pattern of the plurality of first phase shift
portions and the plurality of second phase-shift portions in the first
phase-shifting array.
15. The interferometer of claim 14, wherein:
the pattern of the plurality of first polarizing portions and the plurality
of second polarizing portions in the first polarizer array comprises a
striped polarization pattern;
the pattern of the plurality of first phase shift portions and the
plurality of second phase-shift portions in the first phase-shifting array
comprises a striped retarder pattern; and
the striped retarder pattern is nominally orthogonal to the striped
polarization pattern.
16. The interferometer of claim 14, wherein the pattern of the plurality of
first polarizing portions and the plurality of second polarizing portions
in the first polarizer array comprises a checkerboard polarization pattern
and the pattern of the plurality of first phase shift portions and the
plurality of second phase-shift portions in the first phase-shifting array
comprises a striped retarder pattern.
17. The interferometer of claim 14, wherein the pattern of the plurality of
first polarizing portions and the plurality of second polarizing portions
in the first polarizer array comprises a checkerboard polarization pattern
and the pattern of the plurality of first phase shift portions and the
plurality of second phase-shift portions in the first phase-shifting array
comprises a checkerboard retarder pattern that is coarser than the
checkerboard polarization pattern.
18. The interferometer of claim 14, wherein the plurality of first
phase-shift portions comprise a plurality of null phase-shift portions and
the plurality of second phase-shift portions comprise a plurality of
quarter wave phase-shift portions.
19. The interferometer of claim 14, wherein the first unique phase
relationship corresponds to zero degrees relative phase shift in the
corresponding interference light, the second unique phase relationship
corresponds to 180 degrees relative phase shift in the corresponding
interference light, the third unique phase relationship corresponds to 90
degrees relative phase shift in the corresponding interference light, and
the fourth unique phase relationship corresponds to 270 degrees relative
phase shift in the corresponding interference light.
20. The interferometer of claim 1, wherein:
the multiple phase shift image generating portion further comprises:
a beam-splitting surface,
a first retarder element useable to provide at least a first phase shift,
a second retarder element useable to provide at least a second phase shift,
and
a second polarizer array arranged along a second optical path, the second
polarizer array comprising a plurality of first polarizing portions having
the first polarization direction and a plurality of second polarizing
portions having the second polarization direction, the first and second
polarizing portions arranged in a pattern within the second polarizer
array;
the detector portion further comprises a second detector array arranged
along the second optical path,
the beam-splitting surface is arranged to receive the combined wavefront
and to transmit a first sub-wavefront of the combined wavefront including
the differently polarized portions along the first optical path and a
second sub-wavefront of the combined wavefront including the differently
polarized portions along the second optical path;
the first retarder element is arranged along the first optical path to
receive the first sub-wavefront and transmit the first sub-wavefront to
the first polarizer array;
the second retarder element is arranged along the second optical path to
receive the second sub-wavefront and transmit the second sub-wavefront to
the second polarizer array;
the first polarizing portions of the first polarizer array transmit the
differently polarized portions of the first sub-wavefront to produce at
least the first interference portions that comprises the interference
light having the first unique phase relationship;
the second polarizing portions of the first polarizer array transmit the
differently polarized portions of the first sub-wavefront to produce at
least the second interference portions that comprises the interference
light having the second unique phase relationship;
the first polarizing portions of the second polarizer array transmit the
differently polarized portions of the second sub-wavefront to produce at
least third interference portions, the third interference portions
comprising interference light having a third unique phase relationship;
the second polarizing portions of the second polarizer array transmit the
differently polarized portions of the second sub-wavefront to produce at
least fourth interference portions, the fourth interference portions
comprising interference light having a fourth unique phase relationship;
and
the multiple phase shift image generating portion further outputs
interleaved multiple phase-shifted interference image information from the
second polarizer array, the interleaved multiple phase-shifted
interference image information from the second polarizer array comprising
the at least third interference portions and the at least fourth
interference portions, the at least third interference portions and the at
least fourth interference portions interleaved at a spatial frequency
determined at least partially by the pattern of the first polarizing
portions and the second polarizing portions in the second polarizer array.
21. The interferometer of claim 20, wherein:
the interleaved multiple phase-shifted interference image information from
the first polarizer array is output to form a first interleaved image on
the first detector array;
the interleaved multiple phase-shifted interference image information from
the second polarizer array is output to form a second interleaved image on
the second detector array; and
the second interleaved image corresponds to the first interleaved image.
22. The interferometer of claim 21, wherein the first, second, third and
fourth interference portions each have nominal extents in corresponding
interleaved images on the corresponding detector arrays, and the nominal
extents are nominally aligned to coincide with the boundaries of
coextensive sets of pixels of the corresponding detector arrays, and the
coextensive set of pixels are each N pixels wide and M pixels high, where
M and N are integers at most equal to 16.
23. The interferometer of claim 20, wherein the first unique phase
relationship corresponds to zero degrees relative phase shift in the
corresponding interference light, the second unique phase relationship
corresponds to 180 degrees relative phase shift in the corresponding
interference light, the third unique phase relationship corresponds to 90
degrees relative phase shift in the corresponding interference light, and
the fourth unique phase relationship corresponds to 270 degrees relative
phase shift in the corresponding interference light.
24. The interferometer of claim 20, wherein:
the first retarder element comprises a null phase-shift element; and
the second retarder element comprises a quarter wave phase-shift element.
25. The interferometer of claim 24, wherein:
the pattern of the plurality of first polarizing portions and the plurality
of second polarizing portions in the first polarizer array comprises a
checkerboard pattern; and
the pattern of the plurality of first polarizing portions and the plurality
of second polarizing portions in the second polarizer array comprises a
similar checkerboard pattern.
26. The interferometer of claim 20, wherein:
the multiple phase shift image generating portion further comprises a first
reflective surface and a second reflective surface;
the first reflective surface is arranged to receive the first sub-wavefront
from the beam splitting surface and reflect the first sub-wavefront along
a portion of the first optical path that extends along a first direction;
the second reflective surface is arranged to receive the second
sub-wavefront from the beam splitting surface and reflect the second
sub-wavefront along a portion of the second optical path that is parallel
to the first direction;
the first retarder element and the second retarder element are nominally
coplanar;
the first polarizer array and the second polarizer array are nominally
coplanar; and
the first detector array and the second detector array are nominally
coplanar.
27. The interferometer of claim 26, wherein at least one of a) the set of
the first retarder element and the second retarder element, b) the set of
the first polarizer array and the second polarizer array, and c) the set
of the first detector array and the second detector array comprise first
and second portions of the same element.
28. The interferometer of claim 20, wherein at least the elements of the
multiple phase shift image generating portion and the first detector array
form an integrated phase-shift imaging element.
29. The interferometer of claim 1, wherein the plurality of first
polarizing portions and the plurality of second polarizing portions
comprise wire-grid polarizers.
30. A method for determining a distance using an interferometer,
comprising:
directing differently polarized portions of a coherent light beam to a
reference element and an object;
combining the differently polarized portions returned from the reference
element and object into a combined wavefront;
passing the combined wavefront through at least a first polarizer array
arranged along at least a first optical path, the first polarizer array
comprising a plurality of first polarizing portions having a first
polarization direction and a plurality of second polarizing portions
having a second polarization direction, the first and second polarizing
portions arranged in a pattern within the first polarizer array, to
produce interleaved multiple phase-shifted interference image information,
comprising:
receiving at the first polarizer array at least a sub-wavefront of the
combined wavefront including the differently polarized portions,
transmitting through the first polarizing portions the differently
polarized portions of the sub-wavefront to produce at least first
interference portions, the first interference portions comprising
interference light having a first unique phase relationship,
transmitting through the second polarizing portions the differently
polarized portions of the sub-wavefront to produce at least second
interference portions, the second interference portions comprising
interference light having a second unique phase relationship; and
directing the interleaved multiple phase-shifted interference image
information from at least the first polarizer array to a detector portion
comprising at least a first detector array arranged along the first
optical path;
wherein the interleaved multiple phase-shifted interference image
information comprises at least the first interference portions and the at
least second interference portions interleaved at a spatial frequency
determined at least partially by the pattern of the first polarizing
portions and the second polarizing portions in the first polarizer array.
31. The method of claim 30, wherein directing the interleaved multiple
phase-shifted interference image information from at least the polarizer
array to a detector portion comprises forming an interleaved image on the
first detector array.
32. The method of claim 31, wherein:
the at least first interference portions and the at least second
interference portions each have nominal extents in the interleaved image
on the first detector array; and
forming the interleaved image on the first detector array comprises
projecting at least the interleaved first and second interference portions
onto the first detector array such that the nominal extents nominally
coincide with the boundaries of a coextensive set of pixels of the first
detector array.
33. The method of claim 32, wherein the coextensive set of pixels on the
first detector array is N pixels wide and M pixels high, where M and N are
integers and M is at most equal to 16 and N is at most equal to 16.
34. The method of claim 30, wherein the pattern of the plurality of first
polarizing portions and the plurality of second polarizing portions in the
first polarizer array comprises a checkerboard pattern.
35. The method of claim 30, wherein:
the multiple phase shift image generating portion further comprises a first
retarder element arranged along the first optical path;
passing the combined wavefront through at least a first polarizer array
arranged along at least the first optical path further comprises:
receiving at the first retarder element the sub-wavefront of the combined
wavefront including the differently polarized portions, and
transmitting the sub-wavefront to the first polarizer array and
receiving at the first polarizer array at least the sub-wavefront of the
combined wavefront comprises receiving the sub-wavefront transmitted from
the retarder element.
36. The method of claim 35, wherein the first retarder element comprises at
least one of at least one null phase-shift element and at least one
quarter wave phase-shift element.
37. The method of claim 35, wherein:
the first retarder element comprises a first phase-shifting array that
comprises a plurality of first phase-shift portions providing a first
phase shift and a plurality of second phase-shift portions providing a
second phase shift, the pluralities of the first and second phase shift
portions arranged in a pattern within the first phase-shifting array;
the first phase-shifting array is aligned relative the first polarizer
array such that each of the first and second polarizing portions are
nominally aligned with a single one of the first and second phase-shift
portions; and
transmitting through the first polarizing portions the differently
polarized portions of the sub-wavefront comprises:
transmitting the differently polarized portions of the sub-wavefront
through the first phase-shift portions and the first polarizing portions
that are aligned with the first phase-shift portions to produce the first
interference portions comprising interference light having the first
unique phase relationship, and
transmitting the differently polarized portions of the sub-wavefront
through the second phase-shift portions and the first polarizing portions
that are aligned with the second phase-shift portions to produce a third
interference portions comprising interference light having a third unique
phase relationship;
transmitting through the second polarizing portions the differently
polarized portions of the sub-wavefront comprises:
transmitting the differently polarized portions of the sub-wavefront
through the first phase-shift portions and the second polarizing portions
that are aligned with the first phase-shift portions to produce the second
interference portions comprising interference light having the second
unique phase relationship, and
transmitting the differently polarized portions of the sub-wavefront
through the second phase-shift portions and the second polarizing portions
that are aligned with the second phase-shift portions to produce a fourth
interference portions comprising interference light having a fourth unique
phase relationship; and
directing the interleaved multiple phase-shifted interference image
information from at least the first polarizer array to the detector
portion comprises directing the first, second, third and fourth
interference portions to the detector portion; wherein at least the first,
second, third and fourth interference portions are interleaved at a
spatial frequency determined at least partially by the pattern of the
first polarizing portions and the second polarizing portions in the first
polarizer array in combination with the pattern of the plurality of first
phase shift portions and the plurality of second phase-shift portions in
the first phase-shifting array.
38. The method of claim 37, wherein the first unique phase relationship
corresponds to zero degrees relative phase shift in the corresponding
interference light, the second unique phase relationship corresponds to
180 degrees relative phase shift in the corresponding interference light,
the third unique phase relationship corresponds to 90 degrees relative
phase shift in the corresponding interference light, and the fourth unique
phase relationship corresponds to 270 degrees relative phase shift in the
corresponding interference light.
39. A method for determining a distance using an interferometer,
comprising:
directing differently polarized portions of a coherent light beam to a
reference element and an object;
combining the differently polarized portions returned from the reference
element and object into a combined wavefront;
splitting the combined wavefronts into at least a first sub-wavefront of
the combined wavefront including the differently polarized portions and a
second sub-wavefront of the combined wavefront including the differently
polarized portions;
directing the first sub-wavefront along a first optical path to a first
retarder element;
directing the second sub-wavefront along a second optical path to a second
retarder element;
passing the first sub-wavefront through the first retarder element and a
first polarizer array to produce first interleaved multiple phase-shifted
interference image information, wherein:
the first retarder element provides at least a first phase shift, and
the first polarizer array comprises a plurality of first polarizing
portions having a first polarization direction and a plurality of second
polarizing portions having a second polarization direction, the first and
second polarizing portions arranged in a pattern within the first
polarizer array,
comprising:
receiving at the first polarizer array the first sub-wavefront of the
combined wavefront including the differently polarized portions having the
first phase shift,
transmitting through the first polarizing portions the differently
polarized portions having the first phase-shift of the first sub-wavefront
to produce at least first interference portions comprising interference
light having a first unique phase relationship, and
transmitting through the second polarizing portions the differently
polarized portions having the first phase shift of the first sub-wavefront
to produce at least second interference portions comprising interference
light having a second unique phase relationship;
passing the second sub-wavefront through the second retarder element and a
second polarizer array to produce second interleaved multiple
phase-shifted interference image information, wherein:
the second retarder element provides at least a second phase shift, and
the second polarizer array comprising a plurality of first polarizing
portions having the first polarization direction and a plurality of second
polarizing portions having the second polarization direction, the first
and second polarizing portions arranged in a pattern within the second
polarizer array,
comprising:
receiving at the second polarizer array the second sub-wavefront of the
combined wavefront including the differently polarized portions having the
second phase shift,
transmitting through the first polarizing portions the differently
polarized portions having the second phase-shift of the second
sub-wavefront to produce at least third interference portions comprising
interference light having a third unique phase relationship, and
transmitting through the second polarizing portions the differently
polarized portions having the second phase shift of the second
sub-wavefront to produce at least fourth interference portions comprising
interference light having a fourth unique phase relationship;
directing the first interleaved multiple phase-shifted interference image
information onto a first detector array; and
directing the second interleaved multiple phase-shifted interference image
information onto a second detector array;
wherein:
the first interleaved multiple phase-shifted interference image information
comprises at least the first interference portions and the second
interference portions interleaved at a spatial frequency determined at
least partially by the pattern of the first polarizing portions and the
second polarizing portions in the first polarizer array; and
the second interleaved multiple phase-shifted interference image
information comprises at least the third interference portions and the
fourth interference portions interleaved at a spatial frequency determined
at least partially by the pattern of the first polarizing portions and the
second polarizing portions in the second polarizer array.
40. The method of claim 39, wherein:
directing the first interleaved multiple phase-shifted interference image
information onto the first detector array comprises forming a first
interleaved image on the first detector array;
directing the second interleaved multiple phase-shifted interference image
information onto the second detector array comprises forming a second
interleaved image on the second detector array; and
the second interleaved image corresponds to the first interleaved image.
41. The method of claim 40, wherein:
the at least first interference portions and the at least second
interference portions each have nominal extents in the first interleaved
image on the first detector array;
the at least third interference portions and the at least fourth
interference portions each have nominal extents in the second interleaved
image on the second detector array;
forming the first interleaved image on the first detector array comprises
projecting at least the interleaved first and second interference portions
onto the first detector array such that the nominal extents nominally
coincide with the boundaries of a coextensive set of pixels of the first
detector array;
forming the second interleaved image on the second detector array comprises
projecting at least the interleaved third and fourth interference portions
onto the second detector array such that the nominal extents nominally
coincide with the boundaries of a coextensive set of pixels of the second
detector array and
the coextensive set of pixels are each N pixels wide and M pixels high,
where M and N are integers at most equal to 16.
42. The method of claim 39, wherein the first unique phase relationship
corresponds to zero degrees relative phase shift in the corresponding
interference light, the second unique phase relationship corresponds to
180 degrees relative phase shift in the corresponding interference light,
the third unique phase relationship corresponds to 90 degrees relative
phase shift in the corresponding interference light, and the fourth unique
phase relationship corresponds to 270 degrees relative phase shift in the
corresponding interference light.
43. The method of claim 39, wherein:
the first retarder element comprises a null phase-shift element; and
the second retarder element comprises a quarter wave phase-shift element.
44. The method of claim 43, wherein:
the pattern of the plurality of first polarizing portions and the plurality
of second polarizing portions in the first polarizer array comprises a
checkerboard pattern; and
the pattern of the plurality of first polarizing portions and the plurality
of second polarizing portions in the second polarizer array comprises a
similar checkerboard pattern.
45. The method of claim 39, wherein:
directing the first sub-wavefront along the first optical path to the first
retarder element comprises:
directing the first sub-wavefront to a first reflective surface, and
directing the first sub-wavefront from the first reflective surface to the
first retarder element along a portion of the first optical path that
extends along a first direction;
directing the second sub-wavefront along the second optical path to the
second retarder element comprises:
directing the second sub-wavefront to a second reflective surface, and
directing the second sub-wavefront from the second reflective surface to
the second retarder element along a portion of the second optical path
that that is parallel to the first direction; wherein:
the first retarder element and the second retarder element are nominally
coplanar;
the first polarizer array and the second polarizer array are nominally
coplanar; and
the first detector array and the second detector array are nominally
coplanar. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention is directed to an interferometer that includes improved
polarizing and phase shifting structures.
2. Description of Related Art
U.S. Pat. No. 6,304,330, which is incorporated herein by reference for all
of its relevant teachings, discloses a novel multiple phase-shifting image
generating structure that combines a wavefront-spreading element, a
phase-shifting interference element and a sensing element. By combining
the wavefront-spreading element, the phase-shifting interference element,
and the sensing element, the multiple phase-shifting image generating
structure shown in the 330 patent is able to convert many sources of
potential error in interferometry measurements into common-mode errors.
That is, these errors, in view of the multiple phase-shifting image
generating structure disclosed in the 330 patent, equally affect all of
the interferometry measurements. As a result, the magnitude and direction
of these common-mode errors can be ignored when making high-precision
measurements using an interferometer that includes the multiple
phase-shifting image generating structure disclosed in the 330 patent.
SUMMARY OF THE INVENTION
However, the multiple phase-shifting image generating structure disclosed
in the 330 patent introduces new sources of non-common-mode errors that
can adversely affect high-precision interferometry measurements. Achieving
an error insensitivity similar to that obtained with the particular form
of the multiple phase-shifting image generating structure disclosed in the
330 patent while avoiding such new non-common-mode error sources, or
converting them into common-mode errors, would be desirable.
This invention provides an imaging element for an interferometer that
converts non-common-mode error sources of various multiple phase-shifting
image generating structures into common-mode errors.
This invention separately provides an imaging element for an interferometer
that is relatively insensitive to path length changes between an upstream
optical element and the imaging element.
This invention further provides an imaging element that is less sensitive
to path length changes than the multiple phase-shifting image generating
element disclosed in the 330 patent.
This invention provides an imaging element that is usable in one or more
ways that are relatively insensitive to variations over the sensing
element with regard to the relation between input image intensity values
and output signal values.
This invention further provides an imaging element that usable in one or
more ways that are less sensitive to variations between the input image
intensity values and output signal values over the sensing element than
the multiple phase-shifting image generating structure disclosed in the
330 patent.
This invention separately provides an imaging element having a high-density
polarizing array.
This invention separately provides an imaging element having a high-density
polarizing array and a high-density retarder plate array.
This invention separately provides an imaging element for an interferometer
that divides an input light beam into a plurality of different portions
based on polarization, where the different portions of like-polarization
are interleaved across an imaging array on a pixel cell-by-pixel cell
basis.
This invention further provides an imaging element where the pixel cells
are single pixels in size.
This invention separately provides an imaging element for an interferometer
that splits an input light beam into two similar portions, introduces a
phase difference between the portions and applies the two portions to
different regions of an imaging array, where each of the first two
portions is further divided into at least two portions based on
polarization differences, where for each of the first two portions, the at
least two second portions based on polarization differences are
interleaved on a pixel cell-by-pixel cell basis across the corresponding
portions of the imaging array.
These and other features and advantages of this invention are described in,
or are apparent from, the following detailed description of various
exemplary embodiments of the systems and methods according to this
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Various exemplary embodiments of the systems and methods of this invention
will be described in detail, with reference to the following figures,
wherein;
FIG. 1 illustrates one exemplary embodiment of an interferometer apparatus
with which the various exemplary embodiments of the phase-shift array
imaging element according to this invention are usable;
FIG. 2 illustrates the particular form of a multiple phase-shifted image
generating apparatus disclosed in the 330 patent;
FIG. 3 illustrates in greater detail the phase-shifting element of FIG. 2
of the 330 patent;
FIG. 4 illustrates the relative phase shift between the four portions of
light generated using the multiple phase-shifted image generating
structure disclosed in the 330 patent;
FIG. 5 illustrates how the four portions of light are distributed over an
imaging array when using the multiple phase-shifted image generating
structure disclosed in the 330 patent;
FIG. 6 illustrates a portion of one exemplary embodiment of a high-density
polarizer array according to this invention;
FIG. 7 is a plan view that illustrates a first exemplary phase-shift
imaging element including a first exemplary embodiment of a multiple
phase-shift generating structure incorporating a high-density polarizer
array according to this invention;
FIG. 8 is an exploded view of the phase-shift imaging element shown in FIG.
7, including the first exemplary embodiment of the multiple phase-shift
generating structure shown in FIG. 7;
FIGS. 9 and 10 are plan views that illustrate a second exemplary
phase-shift imaging element including a second exemplary embodiment of a
multiple phase-shift generating structure incorporating a high-density
polarizer array according to this invention;
FIG. 11 is an exploded view illustrating a third exemplary embodiment of a
phase-shift imaging element including a third exemplary embodiment of a
multiple phase-shift generating struct | | |
