Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to optical fibers, and, more particularly, to an optical fiber ribbon with a passive layer.
BACKGROUND
[0002] Generally, an optical fiber has a glass core, a cladding, a primary coating, and then a secondary coating. Further, a color layer is generally disposed over the secondary coating and an Intermittently Bonded Ribbon [IBR] is made by bonding adjacent optical fibers intermittently using Ultraviolet (UV) curable resin applied on the color coating. When an optical fiber is stripped from an IBR, the secondary coating gets damaged, which is not desirable. Further, scrap generation is high due to splitting during bunching if bond strength is kept low and high bond strength can cause more damage to the secondary coating during stripping. As per industry generic requirements and characteristics of single-mode and multimode optical fibers, optical fiber ribbons, and optical fiber cables, there should not be any damage to fiber coatings (i.e., the primary and secondary coatings) during stripping.
[0003] The reference US2022155540A1 discloses about a sacrificial layer above a secondary coating of an optical fiber and above further the sacrificial layer disposed above the color layer in another embodiment. Moreover, ribbon bonds are present on the sacrificial layer. The reference IN202014049225A discloses a sacrificial layer above the secondary coating and that the ink can be added to the sacrificial layer.
[0004] Thus, there is a need for an optical fiber ribbon that overcomes the above stated disadvantages of conventional optical fiber ribbons.
OBJECTIVE OF THE DISCLOSURE
[0005] As mentioned, there is a need for a technical solution that overcomes the aforementioned problems such as damage caused to a coating of an optical fiber when the optical fiber is stripped from an IBR. Thus, an objective of the present disclosure is to provide an optical fiber ribbon (i.e., an IBR). The IBR has a plurality of optical fibers such that each optical fiber of the plurality of optical fibers has a passive layer. Further, an objective of the present disclosure is to provide an optical fiber ribbon (i.e., an IBR) that is manufactured in a way such that there is no damage to coatings (e.g., primary and secondary coatings) of an optical fiber when the optical fiber is stripped from the optical fiber ribbon.
SUMMARY
[0006] In an aspect of the present disclosure, an optical fiber ribbon is disclosed. The optical fiber ribbon having a plurality of optical fibers arranged substantially parallel to one another. Each optical fiber of the plurality of optical fibers has an outer coating, a passive layer that surrounds and is in contact with the outer coating, and a color layer that surrounds and is in contact with the passive layer. The optical fiber ribbon further has a plurality of resin joints applied intermittently contacting the color layer of each pair of adjacent optical fibers of the plurality of optical fibers to form bonded portions of the optical fiber ribbon.
BRIEF DESCRIPTION OF DRAWINGS
[0007] The following detailed description of the preferred aspects of the present disclosure will be better understood when read in conjunction with the appended drawings. The present disclosure is illustrated by way of example, and not limited by the accompanying figures, in which like references indicate similar elements.
[0008] FIG. 1A illustrates a perspective view of an optical fiber ribbon.
[0009] FIG. 1B illustrates a cross-sectional view of an optical fiber of the optical fiber ribbon of FIG. 1A.
DETAILED DESCRIPTION
[0010] The detailed description of the appended drawings is intended as a description of the currently preferred aspects of the present disclosure, and is not intended to represent the only form in which the present disclosure may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different aspects that are intended to be encompassed within the spirit and scope of the present disclosure.

Definitions:
[0011] As used herein the term “core” of an optical fiber as used herein is referred to as the inner most cylindrical structure present in the centre of the optical fiber, that is configured to guide the light rays inside the optical fiber.
[0012] The term “cladding” of an optical fiber as used herein is referred to as one or more layered structure covering the core of an optical fiber from the outside, that is configured to possess a lower refractive index than the refractive index of the core to facilitate total internal reflection of light rays inside the optical fiber. Further, the cladding of the optical fiber may include an inner cladding layer coupled to the outer surface of the core of the optical fiber and an outer cladding layer coupled to the inner cladding from the outside.
[0013] The term “refractive index” as used herein is referred to as the measure of change of speed of light from one medium to another and is particularly measured in reference to speed of light in vacuum. More specifically, the refractive index facilitates measurement of bending of light from one medium to another medium.
[0014] FIG. 1A illustrates a perspective view of an exemplary optical fiber ribbon 100. The optical fiber ribbon 100 may be an easy to implement optical fiber ribbon that may be manufactured in a way such that there is no damage to optical fiber’s coatings (e.g., primary and secondary coatings). The optical fiber ribbon 100 may have a plurality of optical fibers 102 arranged substantially in parallel and adjacent to one another to form the optical fiber ribbon 100 that is an intermittently bonded optical fiber. Specifically, each optical fiber of the plurality of optical fibers 102 typically has a substantially circular cross section (as shown later in FIG. 2). As illustrated, the plurality of optical fibers 102 has first through fourth optical fibers 102a-102d. The first through fourth optical fibers 102a-102d may have first through fourth cores 104a-104d, first through fourth claddings 106a-106d, first through fourth set of one or more coatings 108, first through fourth passive layers 112a-112d, and first through fourth color layers 114a-114d, respectively. Specifically, the first optical fiber 102a may have the first core 104a, the first cladding 106a, the first set of one or more coatings 108a (hereinafter interchangeably referred to and designated as “the first one or more coatings 108a”) of which a first inner coating 108aa and a first outer coating 108ab are shown, the first passive layer 112a, and the first color layer 114a.
[0015] Similarly, the second optical fiber 102b may have the second core 104b, the second cladding 106b, the second set of one or more coatings 108b (hereinafter interchangeably referred to and designated as “the second one or more coatings 108b”) of which a second inner coating 108ba and a second outer coating 108bb is shown, the second passive layer 112b, and the second color layer 114b. Similarly, the third optical fiber 102c may have the third core 104c, the third cladding 106c, the third set of one or more coatings 108c (hereinafter interchangeably referred to and designated as “the third one or more coatings 108c”) of which a third inner coating 108ca and a third outer coating 108cb is shown, the third passive layer 112c, and the third color layer 114c. Similarly, the fourth optical fiber 102d may have the fourth core 104d, the fourth cladding 106d, the fourth set of one or more coatings 108d (hereinafter interchangeably referred to and designated as “the fourth one or more coatings 108d”) of which a fourth inner coating 108da and a fourth outer coating 108db is shown, the fourth passive layer 112d, and the fourth color layer 114d. Although FIG. 1 illustrates that the optical fiber ribbon 100 has four optical fibers (i.e., the first through fourth optical fibers 102a-102d), it will be apparent to a person skilled in the art that the scope of the present disclosure is not limited to it. In various other aspects, the optical fiber ribbon 100 may have any number of optical fibers, without deviating from the scope of the present disclosure. In such a scenario, each optical fiber may be structurally and functionally similar to the first through fourth optical fibers 102a-102d as described above. In some aspects of the present disclosure, the first one or more coatings 108a has one of, the first outer coating 108ab and a combination of the first inner coating 108aa and the first outer coating 108ab. Specifically, in one aspect, the first one or more coatings 108a may have only the first outer coating 108ab. In another aspect of the present disclosure, the first one or more coatings 108a may have a combination of the first inner coating 108aa and the first outer coating 108ab. It will be apparent to a person skilled in the art that the second through fourth one or more coatings 108b-108d may be embodied in various aspects in a way that is substantially similar to the first one or more coatings 108a i.e., in one aspect, the second through fourth one or more coatings 108b-108d may have only the second through fourth outer coatings 108bb-108db, respectively, and in another aspect, the second through fourth one or more coatings 108b-108d may have a combination of the second through fourth inner coatings 108ba-108da and the second through fourth outer coatings 108bb-108db, respectively, without deviating from the scope of the present disclosure.
[0016] The optical fiber ribbon 100 may further have a plurality of resin joints 116 of which first through sixth resin joints 116a-116f are shown. The first through sixth resin joints 116a-116f may be applied intermittently contacting the color layers (i.e., the first through fourth color layers 114a-114d) of the adjacent optical fibers of the plurality of optical fibers 102 to form bonded portions of the optical fiber ribbon 100. In some aspects of the present disclosure, the first through fourth optical fibers 102a-102d may be bonded in a bonding pattern such as, but not limited to, a parallel pattern, a criss-cross pattern, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the bonding pattern of the first through fourth optical fibers 102a-102d in the optical fiber ribbon 100, without deviating from the scope of the present disclosure. Specifically, the first and second resin joints 116a and 116b may be applied intermittently contacting the first and second color layers 114a and 114b of the first and second optical fibers 102a and 102b, respectively. Further, the third and fourth resin joints 116c and 116d may be applied intermittently contacting the second and third color layers 114b and 114c of the second and third optical fibers 102b and 102c, respectively. Furthermore, the fifth and sixth resin joints 116e and 116f may be applied intermittently contacting the third and fourth color layers 114c and 114d of the third and fourth optical fibers 102c and 102d, respectively. Although FIG. 1 illustrates that the optical fiber ribbon 100 has six resin joints (i.e., the first through sixth resin joints 116a-116f), it will be apparent to a person skilled in the art that the scope of the present disclosure is not limited to it. In various other aspects, the optical fiber ribbon 100 may have any number of resin joints, without deviating from the scope of the present disclosure. In such a scenario, each resin joint may be structurally and functionally similar to the first through sixth resin joints 116a-116f as described above.
[0017] In some aspects of the present disclosure, the plurality of resin joints may be made up of a curable resin material. Specifically, the curable resin material may be an Ultraviolet (UV) curable resin material. In some aspects of the present disclosure, the curable resin may be selected from one of, but not limited to, a polyester resin, a phenolic resin, an alkyd resin, a polycarbonate resin, a polyamide resin, a silicone resin, an epoxy resin, an acrylate polymer, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the curable resin, including known, related, and later developed curable resins, without deviating from the scope of the present disclosure.
[0018] FIG. 1B illustrates a cross-sectional view of the first optical fiber 102a (hereinafter interchangeably referred to and designated as “the optical fiber 102”). It will be apparent to a person skilled in the art that the first through fourth optical fibers 102a-102d has substantially identical structural and functional aspects, therefore, for sake brevity, FIG. 1B explains the structural and functional aspects of the first optical fiber 102a only and such explanation should be considered for the second through fourth optical fibers 102b-102d as well. The optical fiber 102 may be, but not limited to, a single mode optical fiber, a multimode optical fiber, a single core optical fiber, a multicore optical fiber, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the the optical fiber 102, including known, related, and later developed technologies. In some aspects of the present disclosure, the optical fiber 102 may have a diameter in a range of 130 micrometres (µm) to 260 µm. As discussed above, the optical fiber 102 may have the first core 104a (hereinafter interchangeably referred to and designated as “the core 104”), the first cladding 106a (hereinafter interchangeably referred to and designated as “the cladding 106”), the first one or more coatings 108a (hereinafter interchangeably referred to and designated as “the one or more coatings 108”) of which the first inner coating 108aa (hereinafter interchangeably referred to and designated as “the inner coating 108aa”) and the first outer coating 108ab (hereinafter interchangeably referred to and designated as “the outer coating 108ab”) are shown, the first passive layer 112a (hereinafter interchangeably referred to and designated as “the passive layer 112”), and the first color layer 114a (hereinafter interchangeably referred to and designated as “the color layer 114”).
[0019] Specifically, the core 104 may be arranged concentric to a central axis CX of the optical fiber 102 such that the core 104 runs longitudinally, (i.e., concentric to the central axis CX). The core 104 can be designed to guide one or more of optical signals. The core 104 may be a cylindrical structure that may run along a length of the optical fiber 102. The core 104 may be made up of a material such as, but not limited to, a plastic, a pure silica glass, a doped silica glass, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the material for the core 104 including known, related and later developed materials, without deviating from the scope of the present disclosure. The core 104 may define a spatial path to facilitate in carrying the one or more optical signals. In some aspects of the present disclosure, the core 104 can have a circular cross-sectional shape. It will be apparent to a person skilled in the art that the core 104 is shown to have the circular shape to make the illustrations concise and clear and should not be considered as a limitation of the present disclosure.
[0020] Further, the optical fiber 102 has the cladding 106 that may concentrically surround an outer circumferential surface of the core 104. In some aspects of the present disclosure, the cladding 106 may be made up of a material such as, but not limited to, a plastic, a pure silica glass, a doped silica glass, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the material for the cladding 106 including known, related and later developed materials, without deviating from the scope of the present disclosure. In some aspects of the present disclosure, the refractive index of the cladding 106 may be manipulated to ensure restriction of the light signal well within the core 104 of the optical fiber 102.
[0021] The optical fiber 102 further has the inner coating 108aa and the outer coating 108ab. It will be apparent to a person skilled in the art that the optical fiber 102 is shown to have the inner and outer coatings 108aa and 108ab to make the illustrations concise and clear and should not be considered as a limitation of the present disclosure. In various other aspects, the optical fiber 102 may have any number of inner and outer coatings, without deviating from the scope of the present disclosure. In some aspects of the present disclosure, the inner and outer coatings 108aa and 108ab can be made up of an ultraviolet (UV) light curable resin which is formed of, for example, a single material. In another aspect, the inner and outer coatings 108aa and 108ab can have the UV light curable acrylate mixture of monomers, oligomers, photo initiators, and additives, such that the mixtures are cured separately.
[0022] The optical fiber 102 further has the passive layer 112. The passive layer 112 may concentrically surround and may be in contact with the outer coating 108ab. Specifically, the passive layer 112 may be disposed on the outer coating 108ab such that the passive layer 112 surrounds concentrically, an outer circumferential surface of the outer coating 108ab and the passive layer 112 may be in contact with the outer coating 108ab. In some aspects of the present disclosure, the passive layer 112 may be provided to protect the outer coating 108ab when the optical fiber 102 is stripped from the optical fiber ribbon 100. In other words, the passive layer 112 may substantially limit damage to the outer coating 108ab and the inner coating 108aa when the optical fiber 102 is stripped from the optical fiber ribbon 100. In some aspects of the present disclosure, the passive layer 112 may be made up of an Ultraviolet (UV) curable acrylate polymer. In some aspects of the present disclosure, the passive layer 112 may be cured at least 85 %.
[0023] Specifically, the passive layer 112 may be cured at least 85 %. The curing of the passive layer 112 may be done at least 85 % as below 85 %, bonding between the passive layer 112 and the color layer 114 may be too strong and may lead to damage to the outer coating 108ab of the optical fiber 102. The term “curing” as used herein, refers to a chemical process that produces a toughening and/or hardening of a polymer material by cross-linking of polymer chains. In some aspects of the present disclosure, the passive layer 112 may have a thickness that may be in a range of 4 µm to 12 µm. Specifically, the thickness of the passive layer 112 may be selected to be in the range of 4 µm to 12 µm, as below 4 µm, the coating process of the passive layer 112 may be difficult and further at such thickness (i.e., below 4 µm) the passive layer 112 may not function properly. Further, in case the thickness of the passive layer 112 is selected above 12 µm, the thickness of the optical fiber 102 will increase which is not desirable. In some aspects of the present disclosure, the passive layer 112 may have an elongation at break of at least 20 %. Specifically, the elongation at break of the passive layer 112 may be selected to be 20 % as below 20 %, the passive layer may not break easily and can thus damage the outer coating 108ab of the optical fiber 102. In some aspects of the present disclosure, the passive layer 112 may have a tensile strength in a range of 2 Megapascal (MPa) to 40 MPa. Specifically, the tensile strength of the passive layer 112 may be selected to be in the range of 2 MPa to 40 MPa, as below 2 MPa, mechanical strength may not be enough for handling the optical fiber ribbon 100 and above 40 MPa, the passive layer 112 may damage the outer coating 108ab of the optical fiber 102. In some aspects of the present disclosure, at 30°C, the passive layer 112 may have a viscosity in a range of 0.2 Pascal-Second (Pa.s) to 4.2 Pa.s. Specifically, the viscosity of the passive layer 112 may be selected to be in the range of 0.2 Pa.s to 4.2 Pa.s, as below 0.2 Pa.s, the viscosity may be too less and uniform application of the passive layer 112 may be difficult, on the other hand viscosity above 4.2 Pa.s will make the passive layer 112 too viscous and difficult to handle.
[0024] The optical fiber 102 further has the color layer 114. The color layer 114 may concentrically surround and may be in contact with the passive layer 112. In other words, the color layer 114 may concentrically surround an outer circumferential surface of the passive layer 112 and the color layer 114 may be in contact with the passive layer 112. In some aspects of the present disclosure, the optical fiber 102 may be manufactured by one of, a tandem manufacturing process, a separate manufacturing process. In an exemplary scenario, the passive layer 112 and the color layer 114 may be applied by way of the tandem process that implies that the passive layer 112 and the color layer 114 may be applied in a single process and/or the passive layer 112, the color layer 114, and optical fiber ribbon 100 may be manufactured in a single process.
[0025] In some aspects of the present disclosure, the passive layer 112 and the color layer 114 may have a first strip force there between. The first strip force may be in a range of 3 Newtons (N) to 9 N. In other words, a force (i.e., the first strip force) required to separate the passive layer 112 from the color layer 114 without damage may be in the range of 3 N to 9 N. The first strip force between the passive layer 112 and the color layer 114 may be selected to be in the range of 3 N to 9 N, as below 3 N, the passive layer 112 may not get removed and above 9 N, the passive layer 112 may damage the outer coating 108ab of the optical fiber 102.
[0026] In some aspects of the present disclosure, the passive layer 112 and the outer coating 108ab of the optical fiber 102 may have a second trip force therebetween. The second strip force may be in a range of 1 N to 5 N. In other words, a force (i.e., the second strip force) between the passive layer and the outer coating 108ab required to separate the passive layer 112 from the outer coating 108ab of the optical fiber 102 without damage may be in the range of 1 N to 5 N. The second strip force between the passive layer 112 and the color layer 114 may be selected to be in the range of 1 N to 5 N, as below 1 N, the second strip force may not be enough for handling the optical fiber ribbon 100 and above 5 N, the second strip force may damage the outer coating 108ab of the optical fiber 102 when the passive layer 112 is stripped off from the outer coating 108ab. In some aspects of the present disclosure, the first strip force may be selected such that the first strip force is relatively higher than the second strip force.
[0027] Thus, the optical fiber ribbon 100 of the present disclosure provides the passive layer 112 added in between the outer coating 108ab and the color layer 114. The plurality of resin joints 116 may be applied over the color layer 114. When the optical fiber 102 is stripped from the optical fiber ribbon 100, the damage is restricted to the passive layer 112 and layer beneath (i.e., the inner coating 108aa and the outer coating 108ab) remain intact. Further, the optical fiber ribbon 100 provides the plurality of resin joints 116 having bonds with high strength that prevent the outer coating 108ab from damage. The optical fiber ribbon 100 is a cost-effective optical fiber ribbon as the manufacturing of the optical fiber ribbon 100 would be approximately similar to standard optical fiber ribbon 100 due to reduced color layer 114 thickness.
[0028] Advantages:
? The optical fiber ribbon 100 of the present disclosure is easy to implement as the passive layer 112 can be applied using the same process that is used to apply the color layer 114 and does not require any sophisticated equipment.
? Further, while stripping a fiber (e.g., the optical fiber 102) from the optical fiber ribbon 100, damage to the inner coating 108aa and the outer coating 108ab of the optical fiber 102 is prevented. This further reduces scrap generation and makes handling easy.
[0029] While various aspects of the present disclosure have been illustrated and described, it will be clear that the present disclosure is not limited to these aspects only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the present disclosure, as described in the claims. Further, unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.
, Claims:I/We claim(s)

1. An optical fiber ribbon (100) comprising:
a plurality of optical fibers (102) arranged substantially parallel to one another, wherein each optical fiber of the plurality of optical fibers (102) comprising:
one or more coatings (108);
a passive layer (112) that surrounds and is in contact with the one or more coatings (108); and
a color layer (114) that surrounds and is in contact with the passive layer (112); and
a plurality of resin joints (116) applied intermittently contacting the color layer (114) of each pair of adjacent optical fibers of the plurality of optical fibers (102) to form bonded portions of the optical fiber ribbon (100).

2. The optical fiber ribbon (100) of claim 1, wherein each optical fiber of the plurality of optical fibers (102) comprising a core (104), a cladding (106) that surrounds the core (104), the one or more coatings (108) that surrounds the cladding (106), wherein the one or more coatings (108) comprises at least one of, (i) a combination of an inner coating (108aa) and an outer coating (108ab) and (ii) the outer coating (108ab).

3. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) is made up of an Ultraviolet (UV) curable acrylate polymer.

4. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) is cured at least 85%.

5. The optical fiber ribbon (100) of claim 1, wherein a thickness of the passive layer (112) is in a range of 4 micrometres (µm) to 12 µm.

6. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) and the color layer (114) is applied in a tandem process.

7. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) has an elongation at break of at least 20 %.

8. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) and the color layer (114) has a first strip force therebetween that is in a range of 3 Newton (N) to 9N.

9. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) and the second coating (108ab) has a second strip force therebetween that is in a range of 1 N to 5 N.

10. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) has a tensile strength in a range of 2 Megapascal to 40 MPa.

11. The optical fiber ribbon (100) of claim 1, wherein the passive layer (112) has a viscosity in a range of 0.2 Pascal-Second (Pa.s) to 4.2 Pa.s at 30 degree Celsius (°C).