U.S. patent application number 16/398671 was filed with the patent office on 2019-08-22 for rollable optical fiber ribbon.
The applicant listed for this patent is CORNING OPTICAL COMMUNICATIONS LLC. Invention is credited to Bradley Jerome Blazer, Dana Craig Bookbinder, Ming-Jun Li, Alan Todd Parsons, Pushkar Tandon.
Application Number | 20190258013 16/398671 |
Document ID | / |
Family ID | 57882514 |
Filed Date | 2019-08-22 |
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United States Patent
Application |
20190258013 |
Kind Code |
A1 |
Blazer; Bradley Jerome ; et
al. |
August 22, 2019 |
ROLLABLE OPTICAL FIBER RIBBON
Abstract
An optical ribbon is provided. The optical ribbon includes a
plurality of optical transmission elements. The ribbon includes a
ribbon body coupled to and supporting the plurality of optical
transmission elements. The ribbon body is formed from a flexible
polymeric material such that the plurality of optical transmission
elements are reversibly movable between an aligned position in
which the plurality of optical transmission elements are
substantially parallel with each other and a curved position.
Inventors: |
Blazer; Bradley Jerome;
(Granite Falls, NC) ; Bookbinder; Dana Craig;
(Corning, NY) ; Li; Ming-Jun; (Horseheads, NY)
; Parsons; Alan Todd; (Newton, NC) ; Tandon;
Pushkar; (Painted Post, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CORNING OPTICAL COMMUNICATIONS LLC |
Hickory |
NC |
US |
|
|
Family ID: |
57882514 |
Appl. No.: |
16/398671 |
Filed: |
April 30, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15920706 |
Mar 14, 2018 |
10310202 |
|
|
16398671 |
|
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15216757 |
Jul 22, 2016 |
9939599 |
|
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15920706 |
|
|
|
|
62199281 |
Jul 31, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 6/4404 20130101;
G02B 6/4434 20130101; G02B 6/443 20130101 |
International
Class: |
G02B 6/44 20060101
G02B006/44 |
Claims
1. An optical fiber ribbon comprising: a plurality of optical
fibers; a ribbon body coupled to and supporting the plurality of
optical fibers, the ribbon body formed from a first polymeric
material; and a separation region, wherein the separation region is
formed from a second polymer material having a lower modulus of
elasticity than the first polymeric material.
2. The optical fiber ribbon of claim 1, wherein each of the
plurality of optical fibers includes a central axis extending
through a center point of an optical core such that when the
optical ribbon is in an unrolled position, at least 90% of the
first polymeric material of the ribbon body is located on one side
of central axes of the plurality of optical fibers.
3. The optical fiber ribbon of claim 1, wherein when the optical
ribbon is in the unrolled position, all of the first polymeric
material of the ribbon body is located on one side of central axes
of the plurality of optical fibers.
4. The optical fiber ribbon of claim 1, wherein the second polymer
material has a modulus of elasticity that is between 0.5 and 1000
MPA.
5. The optical fiber ribbon of claim 1, wherein the first polymeric
material has a modulus of elasticity greater than 85 MPa and less
than 1500 MPa.
6. The optical fiber ribbon of claim 1, wherein the separation
region is thinner than adjacent portions of the ribbon body.
7. The optical fiber ribbon of claim 1, wherein the separation
region extends an entire length of the optical fiber ribbon.
8. The optical fiber ribbon of claim 1, wherein the separation
region is located only along portions of an entire length of the
optical fiber ribbon providing differing accessibility to the
plurality of optical fibers along the entire length.
9. The optical fiber ribbon of claim 1, wherein the separation
region is a plurality of separation regions that separate the
optical fiber ribbon into distinct groups of optical fibers.
10. The optical fiber ribbon of claim 9, wherein the plurality of
separation regions separates a twelve-fiber ribbon into three
groups of four optical fibers.
11. The optical fiber ribbon of claim 1, wherein the separation
region is colored differently from the ribbon body.
12. An optical fiber ribbon comprising: a plurality of optical
fibers; a ribbon body coupled to and supporting the plurality of
optical fibers, the ribbon body formed from upper webs and lower
webs, each of the upper and lower webs comprising a polymer
material that couples outer surfaces of adjacent fibers, wherein
the upper webs and the lower webs are formed on alternating sides
of the ribbon such that in a horizontal direction of the ribbon one
of the upper or lower webs is positioned between an adjacent pair
of the other of the upper or lower webs on the alternate side of
the ribbon.
13. The optical fiber ribbon of claim 12, wherein the upper and
lower webs have a thickness between 5 and 150 microns.
14. The optical fiber ribbon of claim 12, wherein the upper and
lower webs are contiguous in a lengthwise direction and each of the
upper and lower webs extends over at least two optical fibers.
15. The optical fiber ribbon of claim 12, wherein the optical fiber
ribbon defines a central fiber plane, and wherein the upper and
lower webs are spaced from the central fiber plane such that
outermost, planar surfaces of the upper and lower webs are
substantially parallel to the fiber plane and are positioned
tangentially to an outer surface of adjacent fiber pairs.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 15/920,706, filed on Mar. 14, 2018,
which is a continuation application of U.S. patent application Ser.
No. 15/216,757, filed on Jul. 22, 2016, now U.S. Pat. No.
9,939,599, which claims the benefit of priority to U.S. Provisional
Application No. 62/199,281, filed on Jul. 31, 2015, the content of
which is relied upon and incorporated herein by reference in
entirety.
BACKGROUND
[0002] The disclosure relates generally to optical fibers and more
particularly to optical communication or fiber ribbons. Optical
fibers have seen increased use in a wide variety of electronics and
telecommunications fields. Optical fiber ribbons may hold multiple
optical fibers together in a group or array. The optical fiber
ribbon includes a body formed from a material that holds the
optical fibers together and/or that provides structure that assists
in the handling and connecting of the optical fibers of the ribbon
to various components or devices.
SUMMARY
[0003] One embodiment of the disclosure relates to a rollable
optical fiber ribbon including a plurality of optical transmission
elements. Each optical transmission element includes an optical
core surrounded by a cladding of a different refractive index than
the optical core, and the cladding is surrounded by a fiber coating
layer. The fiber coating layer has an inner surface contacting the
cladding and an outer surface defining an exterior surface of the
optical transmission elements. The ribbon also includes a ribbon
body coupled to and supporting the plurality of optical
transmission elements in an array. The ribbon body is contiguous
lengthwise for at least 10 cm along the length of the plurality of
optical transmission elements and is contiguous widthwise over the
plurality of optical transmission elements. The ribbon body is
formed from a flexible polymeric material such that the plurality
of optical transmission elements are reversibly movable from an
unrolled position in which the plurality of optical transmission
elements are substantially aligned with each other to a rolled
position.
[0004] An additional embodiment of the disclosure relates to an
optical ribbon that includes a plurality of optical transmission
elements, and each optical transmission element includes an optical
core and an exterior surface. The ribbon includes a ribbon body
coupled to and supporting the plurality of optical transmission
elements. The ribbon body is contiguous lengthwise for at least 10
cm along the length of the plurality of optical transmission
elements. The ribbon body is formed from a flexible polymeric
material such that the plurality of optical transmission elements
are reversibly movable between an aligned position in which the
plurality optical transmission elements are substantially parallel
with each other and a curved position. Each of the plurality of
optical transmission elements includes a central axis extending
through a center point of the optical core. In the aligned position
at least 90% of the polymeric material of the ribbon body is
located on one side of central axes of the plurality of optical
transmission elements.
[0005] An additional embodiment of the disclosure relates to an
optical fiber ribbon that includes a plurality of optical fibers
and a flexible ribbon body coupled to and supporting the plurality
of optical fibers. The ribbon body is contiguous lengthwise for at
least 10 cm along the length of the plurality of optical fibers.
The ribbon body is formed from a flexible polymeric material such
that the plurality of optical fibers are bendable around a
longitudinal axis of the ribbon. Each of the plurality of optical
fibers includes a central axis, and at least 90% of the polymeric
material of the ribbon body is located on one side of the central
axes of the plurality of optical fibers. The ribbon body partially
surrounds the plurality of optical fibers such that an outer
surface of the ribbon body defines an outermost surface on a first
side of the ribbon, and exterior surfaces of the optical fibers
define an outermost surface on a second side of the ribbon opposite
the first side of the ribbon.
[0006] Additional features and advantages will be set forth in the
detailed description which follows, and in part will be readily
apparent to those skilled in the art from the description or
recognized by practicing the embodiments as described in the
written description and claims hereof, as well as the appended
drawings.
[0007] It is to be understood that both the foregoing general
description and the following detailed description are merely
exemplary, and are intended to provide an overview or framework to
understand the nature and character of the claims.
[0008] The accompanying drawings are included to provide a further
understanding, and are incorporated in and constitute a part of
this specification. The drawings illustrate one or more
embodiment(s), and together with the description serve to explain
principles and operation of the various embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a perspective view of a rollable optical fiber
ribbon according to an exemplary embodiment.
[0010] FIG. 2 shows a cross-sectional view of the optical fiber
ribbon of FIG. 1 in an unrolled or aligned position according to an
exemplary embodiment.
[0011] FIG. 3 shows a cross-sectional view of the optical fiber
ribbon of FIG. 1 in a rolled or curved position according to an
exemplary embodiment.
[0012] FIG. 4 shows a perspective view of a rollable optical fiber
ribbon according to another exemplary embodiment.
[0013] FIG. 5 shows a cross-sectional view of a rollable optical
fiber ribbon according to another exemplary embodiment.
[0014] FIG. 6 shows a cross-sectional view of the rollable optical
fiber ribbon of FIG. 5 in a rolled or curved position according to
an exemplary embodiment.
[0015] FIG. 7 shows a cross-sectional view of the rollable optical
fiber ribbon of FIG. 5 in another rolled or curved position
according to an exemplary embodiment.
[0016] FIG. 8 shows a cross-sectional view of a rollable optical
fiber ribbon according to another exemplary embodiment.
[0017] FIG. 9 shows a cross-sectional view of a rollable optical
fiber ribbon according to another exemplary embodiment.
[0018] FIG. 10 shows a cross-sectional view of a rollable optical
fiber ribbon according to another exemplary embodiment.
[0019] FIG. 11 shows a cross-sectional view of a rollable optical
fiber ribbon in a rolled or curved position according to another
exemplary embodiment.
[0020] FIG. 12 shows a cross-sectional view of a rollable optical
fiber ribbon in a rolled or curved position according to another
exemplary embodiment.
[0021] FIG. 13 shows a cross-sectional view of a rollable optical
fiber ribbon in a rolled or curved position located within a buffer
tube according to another exemplary embodiment.
[0022] FIG. 14 shows a cross-sectional view of a rollable optical
fiber ribbon in a rolled or curved position located within a buffer
tube according to another exemplary embodiment.
[0023] FIG. 15 shows a system configured to form a rollable optical
fiber ribbon according to an exemplary embodiment.
[0024] FIG. 16 is a cross-sectional view of cable including
rollable optical fiber ribbons according to an exemplary
embodiment.
DETAILED DESCRIPTION
[0025] Referring generally to the figures, various embodiments of
an optical ribbon are shown. In general, the ribbon embodiments
disclosed herein are configured to allow the ribbon to be bent,
curved or rolled from an unrolled position to a rolled or curved
position. In such embodiments, optical transmission elements (e.g.,
optical fibers) are coupled to and supported by a ribbon body. The
ribbon body is formed from a material and configured to provide
sufficient support, structure and protection to the optical fibers
of the ribbon, while at the same time allowing the ribbon to be
rolled and unrolled as needed.
[0026] Specifically, in various embodiments, the ribbon embodiments
disclosed herein utilize a ribbon body that partially surrounds the
optical fibers. In various embodiments, the ribbon body is
contiguous both lengthwise and widthwise over the optical fibers.
In various embodiments, substantially all of the ribbon body is
located on one side of the central ribbon plane. Applicant believes
the configurations of the ribbon body discussed herein provides
sufficient rollability while still providing sufficient support and
protection to the optical fibers. Further, in various embodiments,
the ribbon body is formed from a polymer material that has an
elasticity and/or thickness that further facilitates the
rollability of the ribbon. Providing a rollable optical fiber
ribbon as discussed herein may provide a number of benefits as
compared to conventional optical fiber ribbons or conventional
loose buffered optical fibers including increased fiber count,
higher packing density, easier connectorization, higher
transmission rates, decreased ribbon size and may eliminate the
need for buffer tubes, in at least some applications.
[0027] Referring to FIG. 1, a rollable optical ribbon, shown as
optical fiber ribbon 10, is shown according to an exemplary
embodiment. Ribbon 10 includes a ribbon body, shown as ribbon
matrix 12, and also includes an array 14 of a plurality of optical
transmission elements, shown as optical fibers 16. Optical fibers
16 are coupled to and supported by the material of ribbon matrix
12. In the embodiment shown, ribbon 10 is shown in an unrolled or
aligned position, and in this position, array 14 is a parallel
array of optical fibers in which the central axes 18 of each fiber
(i.e., the axis of each optical fiber 16 perpendicular to the
cross-section shown in FIG. 2) are substantially parallel to each
other. In other embodiments, the optical fibers may be arranged in
non-parallel arrays within ribbon body 12 (e.g., two by two arrays,
staggered arrays, etc.).
[0028] In the embodiment shown, ribbon 10 includes a single linear
array 14 of optical fibers 14. In some other embodiments, ribbon 10
includes multiple arrays 14 of optical fibers 16. In some
embodiments, ribbon 10 includes at least two linear arrays 14. In
some other embodiments, ribbon 10 includes at least four linear
arrays 14. In still other embodiments, ribbon 10 includes of at
least eight linear arrays 14. In yet still other embodiments,
ribbon 10 includes of at least 16 linear arrays 14. In some
embodiments, each linear array 14 of ribbon 10 has at least two
optical fibers 16. In some other embodiments, each linear array 14
of ribbon 10 has at least four optical fibers 16. In still other
embodiments, each linear array 14 of ribbon 10 has at least 8
optical fibers 16. In yet still other embodiments, each linear
array 14 of ribbon 10 has at least 12 optical fibers 16.
[0029] In the embodiment shown, each optical fiber 16 includes a
central portion 20 that includes an optically transmitting optical
core 22 and a cladding layer 24. Optical fibers 16 also each
include a coating layer 26. Optical core 22 is formed from a
material that transmits light, and optical core 22 is surrounded by
a cladding layer 24 that has a different refractive index (e.g., a
lower refractive index) than the optical core 22 such that the
optical fiber acts as a waveguide that retains a light signal
within optical core 22.
[0030] Coating layer 26 surrounds both optical core 22 and cladding
layer 24. In particular, coating layer 26 has an inner surface that
contacts and is bonded to the outer surface of cladding layer 24.
Coating layer 26 also has an outer surface 28 that defines the
outer or exterior surface of each optical fiber 16. In the
embodiment shown, coating layer 26 is a single layer formed from a
single material that provides protection (e.g., protection from
scratches, chips, etc.) to optical fibers 16. In various
embodiments, coating layer 26 may be a UV curable acrylate
material, and may have a thickness between 10 .mu.m and 100 .mu.m.
In the embodiment shown, an inner surface of ribbon matrix 12 is
bonded, adhered or coupled to outer surface 28 of each optical
fiber 16.
[0031] Ribbon matrix 12 is configured in various ways to allow
ribbon 10 to be reversibly moved from an unrolled or aligned
position (shown in FIGS. 1 and 2) to a curved or rolled position
shown in FIG. 3, while still providing sufficient support and
structure for fibers 16. It should be understood that FIGS. 2 and 3
only show the end portions of ribbon 10 for convenience, as
represented by the break lines shown in FIGS. 2 and 3.
[0032] In the unrolled or aligned position, shown in FIGS. 1 and 2,
optical fibers 16 of the linear array 14 are substantially aligned
with each other such that the central axes of the optical fiber 16
are parallel to each other and lie along the same central fiber
plane 30. As used herein, substantial alignment between optical
fibers 16 allows for some deviation between the central axes of the
optical fibers and central fiber plane 30, such that the central
axis of each substantially aligned fiber is spaced less than 45
.mu.m, in some embodiments less than 20 .mu.m, in other embodiments
less than 10 .mu.m, and in other embodiments less than 5 .mu.m,
from central fiber plane 30 and/or the maximum vertical distance
(in the orientation of FIGS. 1 and 2) between the center points of
any of the fibers 16 is 90 .mu.m or less. Further, in the unrolled
or aligned position, the horizontal distance (in the orientation of
FIGS. 1 and 2) between the optical fibers 16 at opposing ends of
array 14, shown as first end fiber 32 and second end fiber 34, is
at a maximum.
[0033] To move from the unrolled position of FIG. 2 to the rolled
position shown in FIG. 3, ribbon matrix 12 is bent or curved around
ribbon longitudinal axis 36. Thus, in the curved position, fibers
16 define an arc or curve around longitudinal axis 36, and the
horizontal distance between first end fiber 32 and second end fiber
34 is decreased. In this arrangement, when rolled ribbon 10 is held
straight the central axes of optical fibers 16 are substantially
parallel to longitudinal axis 36. In the embodiment shown in FIG.
3, ribbon 10 in the curved position assumes a substantially
circular arrangement such that first end fiber 32 is brought into
close proximity or into contact with second end fiber 34. In the
embodiment shown, ribbon matrix 12 is configured such that when
ribbon 10 is rolled, ribbon matrix 12 is located on the inside of
the rolled ribbon such that a surface 38 of ribbon matrix 12
opposite of optical fibers 16 faces longitudinal axis 36. In
specific embodiments, the rollable ribbons discussed herein may be
in a rolled configuration with the cable, and an end of the ribbon
may be returned to the unrolled position to be coupled to an
optical connector, such as via use of mass splicing equipment.
[0034] In various embodiments, the structure and/or material
properties of ribbon matrix 12 discussed herein provides for an
improved ribbon that balances rollability with fiber support. In
various embodiments, ribbon matrix 12 only partially surrounds
optical fibers 16. In contrast to non-rollable conventional optical
ribbons in which the ribbon matrix completely surrounds the optical
fibers, it is believed the rollability of ribbon 10 is enhanced by
providing a ribbon matrix 12 that partially surrounds optical
fibers 16. In this arrangement, the partial surrounding of optical
fibers 16 provided by ribbon matrix 12 results in a ribbon 10 in
which the outermost surface of ribbon 10 on one side of the ribbon
(e.g., the upper side in the orientation of FIG. 2) is defined by
surface 38 of ribbon matrix 12, and the outermost surface of ribbon
10 on the opposite side of the ribbon (e.g., the lower side in the
orientation of FIG. 2) is defined by outer surface 28 of optical
fibers 16.
[0035] Further, in this arrangement, ribbon matrix 12 is
substantially located only on one side of ribbon 10. For example,
as shown in FIG. 2, at least 90% of the material of ribbon matrix
12 is located on one side (e.g., above) of central fiber plane 30.
In a specific embodiment, all or substantially all (e.g., greater
than 99%) of ribbon matrix 12 is located on one side of central
fiber plane 30. In such embodiments, without ribbon matrix 12
extending downward between adjacent optical fibers 16, optical
fibers 16 are allowed to abut each other such that outer surface 28
of each optical fiber 16 contacts the outer surface 28 of at least
one other optical fiber 16. As shown in FIG. 2, each of the
interior optical fibers 16 abuts two adjacent optical fibers
16.
[0036] Further, as shown in FIG. 1, ribbon matrix 12 is a
substantially contiguous ribbon matrix. In the embodiment shown,
ribbon matrix 12 is contiguous (e.g., an unbroken, integral unitary
body with no gaps or holes) in the lengthwise direction for at
least 10 cm, specifically for at least 50 cm and more specifically
for at least 1 m. In a specific embodiment, ribbon matrix 12 is
contiguous (e.g., an unbroken, integral unitary body with no gaps
or holes) in the lengthwise direction for the entire length of the
ribbon. In addition, ribbon matrix 12 is contiguous in the
widthwise direction such that ribbon matrix 12 extends over at
least two of the optical fibers 16. In the specific embodiment
shown, ribbon matrix 12 is contiguous in the widthwise direction
such that ribbon matrix 12 extends over all of the optical fibers
16 of ribbon 10. Applicant believes that this arrangement provides
suitable support and protection to optical fibers 16 while also
providing a rollable ribbon 10.
[0037] Ribbon matrix 12 also has a thickness that provides a
balance between suitable support and protection to optical fibers
16 and the rollability of ribbon 10. As shown in FIG. 2, ribbon
matrix 12 has a maximum thickness shown as T1. In various
embodiments, T1 is between 5 .mu.m and 150 .mu.m. In other
embodiments, T1 is less than 125 .mu.m, is less than 100 .mu.m, is
less than 50 .mu.m, is less than 25 .mu.m, and less than 10 .mu.m.
In some embodiments, T1 and the ranges discussed herein relate to
an average thickness of ribbon matrix 12.
[0038] Ribbon matrix 12 is also formed from a material, e.g., a
polymer material, such as a thermoplastic material or a curable
polymer material, having a modulus of elasticity that provides a
balance between suitable support and protection to optical fibers
16 and the rollability of ribbon 10. In various embodiments, the
modulus of elasticity of the material of ribbon matrix 12 is less
than 1500 MPa. In some embodiments, the modulus of elasticity of
the material of ribbon matrix 12 is greater than 1 MPa and less
than 1500 MPa, specifically greater than 10 MPa and less than 1500
MPa, and in some embodiments is greater than 85 MPa and less than
1500 MPa.
[0039] In some embodiments, ribbon matrix 12 is formed from a
single layer of polymer material having a modulus of elasticity
greater than 10 MPa and less than 100 MPa. In other embodiments,
ribbon matrix 12 is comprised of two layers, an inner layer and an
outer layer. In some embodiments, the inner layer is in contact
with optical fibers 16 and the outer layer defines the outer
surface of the ribbon. In specific embodiments, the inner layer has
a modulus of elasticity less than 1.5 MPa, and the outer layer has
a modulus of elasticity greater than 1000 MPa. In specific
embodiments, the total thickness of the two layer ribbon matrix 12
is less than 40 microns, and in other embodiments, is less than 30
microns, or is less than 20 microns in still other embodiments.
[0040] In various embodiments, ribbon matrix 12 and optical fibers
16 may be configured to facilitate identification and
connectorization of ribbon 10. In such embodiments, ribbon matrix
12 and/or optical fibers 16 may include coloring or printed indicia
to identify the type, location, etc., of optical fibers 16 within
ribbon 10.
[0041] Referring to FIG. 4, another optical ribbon, shown as
rollable optical fiber ribbon 50, is shown according to an
exemplary embodiment. Ribbon 50 is substantially similar to ribbon
10 except as discussed herein. Ribbon 50 includes a ribbon body
including a plurality of alternating ribbon bridges, shown as upper
webs 52 and lower webs 54. In general, webs 52 and 54 are bands of
polymer material that are coupled between outer surfaces 28 of
adjacent optical fibers 16. Webs 52 and 54 are contiguous in the
lengthwise direction and each extends over at least two optical
fibers 16. Webs 52 and 54 are spaced from central fiber plane 30
such that outermost, planar surfaces of webs 52 and 54 are
substantially parallel to fiber plane 30 and are positioned
tangentially to the outer surface 28 of adjacent fiber pairs.
[0042] In the embodiment shown, each web 52 and 54 extends over and
is coupled to two optical fibers 16. Webs 52 and 54 are positioned
on alternating sides of ribbon 10 such that in the horizontal
direction one web 54 is located between adjacent pairs of webs 52.
Further, webs 52 and 54 alternately define the uppermost and
lowermost surfaces of ribbon 50 at the positions of webs 52 and 54.
In this embodiment, webs 52 and 54 are relatively thin having a
thickness between 5 microns and 150 microns. Further, it is
believed that the alternating positioning of webs 52 and 54 allows
ribbon 50 to be rolled in either direction, and by offsetting webs
52 and 54 from central fiber plane 30, bending strain on the ribbon
material may be reduced.
[0043] Referring to FIG. 5, another optical ribbon, shown as
rollable optical fiber ribbon 60, is shown according to an
exemplary embodiment. Ribbon 60 is substantially similar to ribbon
10, except as discussed herein. Ribbon 60 includes a ribbon body
including a plurality of ribbon bridges, shown as webs 62. In
general, webs 62 are bands of polymer material that are coupled
between outer surfaces 28 of adjacent optical fibers 16. Webs 62
are contiguous in the lengthwise direction and each extends between
the outer surfaces of two adjacent optical fibers 16. Webs 62 are
spaced from central fiber plane 30 such that outermost, planar
surfaces of webs 62 are substantially parallel to fiber plane 30,
and webs 62 are located below the outermost portion of surface 28.
In various embodiments, the angular positioning of webs 62 relative
to the central fiber plan 30 is shown by angle A. In various
embodiments, angle A is greater than 0 degrees and less than 90
degrees, specifically is between 5 degrees and 45 degrees, and more
specifically is between 10 degrees and 20 degrees. In a specific
embodiment, angle A is about 15 degrees (e.g., 15 degrees plus or
minus 1 degree). In various embodiments, webs 62 have a thickness
between 5 microns and 75 microns.
[0044] Referring to FIG. 6, ribbon 60 is shown in the rolled or
curved position according to an exemplary embodiment. In this
embodiment, ribbon 60 is rolled such that webs 62 face outward from
rolled ribbon 60. Further, ribbon 60 is rolled defining an angle B
between center points of two adjacent optical fibers 16, as
measured from a horizontal plane 64. In general angle B represents
the degree of bend allowed by webs 62. In various embodiments,
angle B is between 10 degrees and 90 degrees, specifically is
between 15 degrees and 45 degrees and more specifically is about 30
degrees (e.g., 30 degrees plus or minus 1 degree). In an embodiment
in which ribbon 60 includes 6 optical fibers 16, webs 62 allow
ribbon 60 to be rolled into a hexagonal array as shown in FIG.
6.
[0045] Referring to FIG. 7, ribbon 60 is shown in the rolled or
curved position according to another exemplary embodiment. In this
embodiment, ribbon 60 is rolled such that webs 62 face inward
toward the longitudinal axis of rolled ribbon 60. In various
embodiments, webs 62 may be formed from material having elasticity
that allows ribbon 60 to be rolled in both the configuration shown
in FIG. 6 and in FIG. 7.
[0046] Referring to FIG. 8, another optical ribbon, shown as
rollable optical fiber ribbon 70, is shown according to an
exemplary embodiment. Ribbon 70 is substantially similar to ribbon
10 except as discussed herein. Ribbon 70 includes eight optical
fibers 16 supported by ribbon matrix 12. Ribbon 70 includes a
plurality of strength elements, shown as aramid yarn strands 72,
supported from ribbon matrix 12. In the embodiment shown, aramid
yarn strands 72 are located in the center of ribbon 70 such that
two end groups of optical fibers 16 are formed. In other
embodiments, aramid yarn strands 72 may be positioned at any other
positions within ribbon matrix 12. Further, in other embodiments,
ribbon 70 may include other strength elements, such as steel wire,
glass reinforced plastics, other strength yarn types, etc., in
place of aramid yarn strands 72.
[0047] Referring to FIG. 9, another optical ribbon, shown as
rollable optical fiber ribbon 80, is shown according to an
exemplary embodiment. Ribbon 80 is substantially similar to ribbon
10 except as discussed herein. Ribbon 80 includes one or more
regions, shown as regions 82, within ribbon matrix 12 that is
formed from a different material than the rest of ribbon matrix 12.
In some such embodiments, regions 82 are formed from a polymer
material having a lower modulus of elasticity than the rest of
ribbon matrix 12. Further, regions 82 may be formed from a material
that has low bonding with the material forming the rest of ribbon
matrix 12, and in yet other embodiments, regions 82 may be thinner
than adjacent regions of ribbon matrix 12. In such embodiments,
regions 82 act as separation points allowing groups of optical
fibers 16 to be separated from each other. In specific embodiments,
regions 82 are formed from a polymer material having a modulus of
elasticity lower than that of the material forming the rest of
ribbon matrix 12, and the modulus of elasticity of the material of
regions 82 is between 0.5 and 1000 MPa. In other embodiments,
ribbon 80 may include other tear features, ripcords, scores, etc.
in place of or in addition to regions 82. In specific embodiments,
regions 82 may be colored differently from the rest of ribbon
matrix 12 or include printed indicia that provides an indication of
the location of regions 82. In some embodiments, regions 82 may
extend the entire length of ribbon 80, and in other embodiments,
regions 82 may only be located at certain portions along the length
of ribbon 80 providing differing accessibility to optical fibers
16, along the length of ribbon 80.
[0048] Referring to FIG. 10, another optical ribbon, shown as
rollable optical fiber ribbon 90, is shown according to an
exemplary embodiment. Ribbon 90 is substantially similar to ribbon
70 except as discussed herein. In this embodiment, ribbon matrix 12
of ribbon 90 includes a region 92 in which aramid yarn strands 72
are supported. In such embodiments, region 92 may be similar to
regions 82 in that region 92 has a lower modulus of elasticity than
the rest of ribbon matrix 12, which facilitates separation of
aramid yarn strands 72 from optical fibers 16. Such separation of
aramid yarn strands 72 may be desirable during some
connectorization procedures.
[0049] FIGS. 11 and 12 show an optical fiber ribbon 100 in various
curved or rolled configurations. It should be understood that
optical fiber ribbon 100 may be any of the optical fiber ribbon
embodiments discussed herein. As shown in FIG. 11, optical fiber
ribbon 100 may be rolled into a non-circular shape in which optical
fibers 16 surround longitudinal ribbon axis 36. As shown in FIG.
12, optical fiber ribbon 100 may be rolled into a spiral shape in
which most of the optical fibers 16 surround longitudinal ribbon
axis 36 and the innermost end optical fiber 16, resides at or near
longitudinal ribbon axis 36. In some embodiments, the rolled
arrangements shown in FIGS. 11 and 12, may allow ribbon 100 to be
stranded or otherwise located within a cable without first being
located within a buffer tube.
[0050] In various embodiments, when an optical fiber ribbon
containing glass optical fibers, such as ribbon 100, is rolled or
folded into a non-planar array, the minimum bending stiffness tends
to increase significantly because there will no longer exist a bend
axis that allows all of the glass fibers to occupy the neutral
axis. As a result, not only will the rolled ribbon be stiffer than
a planar ribbon, but also the material of the ribbon body may also
be subject to significant shear stress in order to maintain the
rolled ribbon as a coherent composite structure. In some
embodiments, the material of the ribbon bodies discussed herein
have sufficient strength and elasticity to resist the forces
associated with stranding of the rolled ribbon 100 into a cable and
also those forces associated with the bending of the cable as it is
stored, installed and put in use. In other embodiments, the ribbon
bodies discussed herein are designed to intentionally separate at
more moderate stress levels, relieving stress as needed while
remaining intact at sufficient intervals along the length to
provide the intended fiber organization benefit.
[0051] Referring to FIGS. 13 and 14, the various ribbon embodiments
discussed herein may be located within a polymeric buffer tube 110,
which in turn may be incorporated into a fiber optic cable. As
shown in FIG. 13, optical fiber ribbon 70, which includes embedded
aramid yarn strands 72, may be rolled and located within buffer
tube 110 without additional loose strength elements. In another
embodiment, as shown in FIG. 14, an optical fiber ribbon without
embedded strength elements, such as optical fiber ribbon 80, may be
rolled and located within buffer tube 110, and additional loose
strength elements, shown as loose aramid yarn strands 112, may be
included within buffer tube 110. In other embodiments, the rollable
optical fiber ribbons discussed herein may be used within cables
without buffer tubes surrounding the ribbons. In such embodiments,
the rolled optical fiber ribbons may be directly positioned within
a cable jacket and may be stranded around a central strength
member.
[0052] In various embodiments, the ribbon bodies discussed herein
may be formed by applying a polymer material, such as a UV curable
polymer material, around optical fibers 16 in the desired
arrangement to form a particular ribbon body. The polymer material
is then cured forming the integral, contiguous ribbon body while
also coupling the ribbon body to the optical fibers. In other
embodiments, the ribbon bodies discussed herein may be formed from
any suitable polymer material, including thermoplastic materials
and thermoset materials.
[0053] FIG. 15 shows an exemplary tool for forming a ribbon body.
Tool 120 consists of a block of abrasion resistant material bored
with a series of fiber channels 122 to guide an array of optical
fibers 16 that are pulled through tool 120. Resin channels 124
convey liquid resin in a path that intersects fiber channels 122 at
the exit of the tool. UV curable liquid resin as an example could
be applied using the tool and immediately cured by the use of UV
lamps positioned at the tool exit to form the polymer ribbon bodies
discussed herein. In various embodiments, the shape of the
interface between fiber channels 122 and resin channels 124 may be
configured to form any of the ribbon body shapes discussed herein.
Further, to form ribbons (such as ribbons 10, 60, 70, 80 and 90) in
which the ribbon body is only on one side of optical fibers 16,
tool 120 would be operated to supply resin only through either the
upper series or through the lower series of resin channels 124. To
form a ribbon, such as ribbon 50 having ribbon body portions on
both sides of the ribbon resin would be supplied through both the
upper series and through the lower series of resin channels
124.
[0054] Referring to FIG. 16, in various embodiments, any of the
ribbons discussed herein may be incorporated into a cable, such as
cable 130. Cable 130 includes a polymeric cable jacket 132 and a
elongate strength member 134 (e.g., a GRP rod, metal wire, etc.)
located within cable jacket 132. A plurality of optical fiber
ribbon containing buffer tubes 110 surround strength member 134,
and each buffer tube 110 includes an optical fiber ribbon, such as
ribbon 70 discussed above. It should be understood however that
cable 130 may include any of the ribbon embodiments discussed
herein in any combination. In various embodiments, a binding
element, such as a helically wound binder yarn or thin film binder,
may be located to the outside of buffer tubes 110 and surrounding
buffer tubes 110 and may act to hold buffer tubes 110 in a stranded
pattern (e.g., an SZ stranding pattern) around strength member 134.
In other embodiments, cable 130 includes no binding element. In
various embodiments, cable 130 may include rolled ribbons located
within the cable without buffer tubes 110. In such embodiments, the
ribbons may be rolled and then stranded around strength member 134.
In some such embodiments, cable 130 may optionally include a
binding element surrounding the rolled ribbons, and the binding
element acts to bind the rolled ribbons to strength member 134. In
various embodiments, each rolled ribbon may be surrounded by a
binder element that helps hold the rolled ribbon in the rolled
position, and in some such embodiments, the binder element may be
color-coded to help identify a particular ribbon within cable 130.
In some other embodiments, cable 130 may include one or more
strength member (e.g., a GRP rod, metal wire, etc.) embedded within
jacket 132 in place of or in addition to strength member 134, and
in some such embodiments, the optical fiber ribbons are located
within cable 130 without buffer tubes.
[0055] It should understood that the optical ribbons discussed
herein can include various numbers of optical fibers 16. In various
exemplary embodiments, the optical ribbons discussed herein may
include 2, 4, 6, 8, 10, 12, 14, 16, 24 etc. optical fibers or
transmission elements (e.g., optical fibers 16). While the ribbon
embodiments discussed herein are shown having optical fibers 16
arranged in a substantially parallel, linear array, optical fibers
16 may be arranged in a square array, rectangular array, a
staggered array, or any other spatial pattern that may be desirable
for a particular application. In various embodiments, optical
fibers 16 can include a wide variety of optical fibers including
multi-mode fibers, single mode fibers, bend insensitive/resistant
fibers, etc. In other embodiment, the optical ribbons discussed
herein may include a multi-core optical fiber located within ribbon
matrix 12. In this embodiment, a single, integral optical structure
having multiple optical transmission elements (e.g., multiple
optical cores surrounded by cladding) may be provided, and the
single multi-core optical fiber is embedded in one of the
stress-isolating ribbon matrix embodiments and/or coated with a
coating layer (e.g., coating layer 26) as discussed herein. In
specific exemplary embodiments, optical fibers 16 may be Corning's
Ultra.RTM. SMF-28, ClearCurve.RTM. LBL and ZBL G.652 compatible
optical fibers.
[0056] In various embodiments, the optical fiber ribbon embodiments
discussed herein may include optical fibers that do not include
coating layer 26. In these embodiments, cladding 24 defines the
outer surface of optical fibers 16. In these embodiments, the inner
surface of the innermost ribbon body layer contacts the outer
surface of cladding 24. In another such embodiment, the ribbon body
may include a single inner most layer formed from the high modulus
material of coating layer 26.
[0057] The optical fibers discussed herein may be flexible,
transparent optical fibers made of glass or plastic. The fibers may
function as a waveguide to transmit light between the two ends of
the optical fiber. Optical fibers may include a transparent core
surrounded by a transparent cladding material with a lower index of
refraction. Light may be kept in the core by total internal
reflection. Glass optical fibers may comprise silica, but some
other materials such as fluorozirconate, fluoroaluminate, and
chalcogenide glasses, as well as crystalline materials, such as
sapphire, may be used. The light may be guided down the core of the
optical fibers by an optical cladding with a lower refractive index
that traps light in the core through total internal reflection. The
cladding may be coated by a buffer and/or another coating(s) that
protects it from moisture and/or physical damage. These coatings
may be UV-cured urethane acrylate composite materials applied to
the outside of the optical fiber during the drawing process. The
coatings may protect the strands of glass fiber.
[0058] Unless otherwise expressly stated, it is in no way intended
that any method set forth herein be construed as requiring that its
steps be performed in a specific order. Accordingly, where a method
claim does not actually recite an order to be followed by its steps
or it is not otherwise specifically stated in the claims or
descriptions that the steps are to be limited to a specific order,
it is in no way intended that any particular order be inferred.
[0059] It will be apparent to those skilled in the art that various
modifications and variations can be made without departing from the
spirit or scope of the disclosed embodiments. Since modifications
combinations, sub-combinations and variations of the disclosed
embodiments incorporating the spirit and substance of the
embodiments may occur to persons skilled in the art, the disclosed
embodiments should be construed to include everything within the
scope of the appended claims and their equivalents.
* * * * *