Claims:WE CLAIM

1. An optical fiber comprising:

a core region defined by a region around a central longitudinal axis of the optical fiber;

a cladding region surrounding the core region;

a first coating layer surrounding the cladding region, wherein the first coating layer is formed from a material selected from a group of acrylates and polyimides and wherein the first coating layer has a first diameter in a range of 200 µm – 300 µm; and

a second coating layer surrounding the first coating layer, wherein the second coating layer is formed of a polyimide material, wherein the second coating layer has a second diameter in a range of 300 µm – 400 µm and wherein the range of diameter and a type of material used for the first coating layer and the second coating layer provides strength greater than or equal to 5GPa to the optical fiber.

2. The optical fiber as recited in claim 1, wherein the optical fiber is a bend insensitive fiber.

3. The optical fiber as recited in claim 1, wherein the optical fiber meets the requirements of ITU-T G657 A2.

4. The optical fiber as recited in claim 1, wherein the optical fiber meets the requirements of ITU-T G657 B3.

5. The optical fiber as recited in claim 1, wherein the optical fiber complies with IEC 60794-2 standard.

6. The optical fiber as recited in claim 1, wherein the cladding region has a diameter in a range of 124 µm – 126µm.

7. The optical fiber as recited in claim 1, wherein the optical fiber has a cladding non-circularity of less than equal to 1 %.

8. The optical fiber as recited in claim 1, wherein the optical fiber has a core concentricity error of less than equal to 0.5 µm.
, Description:OPTICAL FIBER FOR INDOOR APPLICATIONS

TECHNICAL FIELD
[0001] The present disclosure relates to a field of fiber optic transmission. More specifically, the present disclosure relates to an optical fiber for indoor applications.

BACKGROUND
[0002] Over the years, optical fibers has acquired an increasingly important role in the field of telecommunications. Nowadays, these optical fibers are widely utilized in fiber-to-the-home applications. These optical fibers are available for residential and commercial consumers to meet their growing demands for bandwidth and high performance. In order to meet the growing demands of these optical fibers having high performance capabilities, these optical fibers are typically coated with multiple coating layers. These multiple coating layers are a rather significant component that determines physical fiber optic characteristics such as bending, chemical resistance, and mechanical strength. For example, these multiple coating layers protect the optical fibers from mechanical damage and preserve the ability of the optical fibers to transmit signals.

[0003] In one of the prior art with patent numberUS7539383 B2, a buffered optical fiber is provided. The buffered optical fiber includes a primary coating layer and a secondary coating layer around a circumference of the buffered optical fiber. Also, the buffered optical fiber includes a tertiary coating layer around the circumference of the buffered optical fiber. Both the primary coating layer and the secondary coating layer are formed of UV cured acrylate material. Moreover, the diameter of the primary coating layer is 180 µm - 200 µm and the diameter of the secondary coating layer is 350 µm – 450 µm. However, the above mentioned prior art bear several drawbacks. The UV cured acrylate is a low modulus soft, cushioning material which is considered to be a suitable material for inner coating layer. The utilization of UV cured acrylate material for manufacturing the secondary coating of the optical fibers do not provide required strength and degrades the performance of the optical fibers. In addition, the cabling, buffering or jacketing of these optical fibers is done for providing enough strength. This increases the manufacturing cost as well as the installation cost.

[0004] In light of the above stated discussion, there exists a need for a cost effective optical fiber having required strength for indoor applications.

OBJECT OF THE DISCLOSURE
[0005] A primary object of the present disclosure is to provide a dual-coated optical fiber for indoor applications.

[0006] Another object of the present disclosure is to provide the dual-coated optical fiber having high strength.

[0007] Yet another object of the present disclosure is to provide the dual-coated optical fiber which has small diameter.

[0008] Yet another object of the present disclosure is to eliminate a need of cabling the dual-coated optical fiber.

[0009] Yet another object of the present disclosure is to enable fast deployment of the dual-coated optical fiber.

[0010] Yet another object of the present disclosure is to provide the dual-coated optical fiber having crush resistant properties suitable for indoor staple installation.

[0011] Yet another object of the present disclosure is to provide the dual-coated optical fiber flexible for indoor deployment.

SUMMARY
[0012] In an aspect of the present disclosure, the present disclosure provides an optical fiber. The optical fiber includes a core region. The core region is defined by a region around a central longitudinal axis of the optical fiber. In addition, the optical fiber includes a cladding region. The cladding region surrounds the core region. Further, the optical fiber includes a first coating layer. The first coating layer surrounds the cladding region. Furthermore, the optical fiber includes a second coating layer. The second coating layer surrounds the first coating layer. Moreover, the first coating material is formed from a material selected from a group of a crylates and polyimides. In addition, the first coating layer has a first diameter in a range of 200 µm – 300 µm. The second coating layer is formed of a polyimide material. In addition, the second coating layer has a second diameter in a range of 300 µm – 400 µm. Furthermore, the range of diameter and type of materials used for the first coating layer and the second coating layer provides strength greater than equal to 5GPa to the optical fiber.

[0013] In an embodiment of the present disclosure, the optical fiber is a bend insensitive fiber.

[0014] In an embodiment of the present disclosure, the optical fiber meets the requirements of ITU-T G657 A2.

[0015] In an embodiment of the present disclosure, the optical fiber meets the requirements of ITU-T G657 B3.

[0016] In an embodiment of the present disclosure, the cladding region has a diameter in a range of 124µm to 126µm.

[0017] In an embodiment of the present disclosure, the optical fiber complies with IEC 60794-2 standard.

[0018] In an embodiment of the present disclosure, the optical fiber has a cladding non-circularity of less than equal to 1 %.

[0019] In an embodiment of the present disclosure, the optical fiber has a core concentricity error of less than equal to 0.5 µm.

STATEMENT OF THE DISCLOSURE
[0020] The present disclosure relates to an optical fiber. The optical fiber includes a core region. The core region is defined by a region around a central longitudinal axis of the optical fiber. In addition, the optical fiber includes a cladding region. The cladding region surrounds the core region. Further, the optical fiber includes a first coating layer. The first coating layer surrounds the cladding region. Furthermore, the optical fiber includes a second coating layer. The second coating layer surrounds the first coating layer. Moreover, the first coating material is formed from a material selected from a group of a crylates and polyimides. In addition, the first coating layer has a first diameter in a range of 200 µm – 300 µm. The second coating layer is formed of a polyimide material. In addition, the second coating layer has a second diameter in a range of 300 µm – 400 µm. Furthermore, the combination of the first diameter and the material of the first coating layer and the second diameter and the material of the second coating layer provides strength to the optical fiber greater than or equal to 5GPa.

BRIEF DESCRIPTION OF THE FIGURES
[0021] Having thus described the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0022] FIG.1Aillustratesa cross-sectional view of an optical fiber, in accordance with an embodiment of the present disclosure; and

[0023] FIG. 1B illustrates a perspective view of an optical fiber of FIG. 1A, in accordance with an embodiment of the present disclosure.

[0024] It should be noted that the accompanying figures are intended to present illustrations of exemplary embodiments of the present disclosure. These figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.

DETAILED DESCRIPTION
[0025] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present technology. It will be apparent, however, to one skilled in the art that the present technology can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form only in order to avoid obscuring the present technology.

[0026] Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but no other embodiments.

[0027] Moreover, although the following description contains many specifics for the purposes of illustration, anyone skilled in the art will appreciate that many variations and/or alterations to said details are within the scope of the present technology. Similarly, although many of the features of the present technology are described in terms of each other, or in conjunction with each other, one skilled in the art will appreciate that many of these features can be provided independently of other features. Accordingly, this description of the present technology is set forth without any loss of generality to, and without imposing limitations upon, the present technology.

[0028] FIG. 1A illustrates a cross-sectional view of an optical fiber 100, in accordance with an embodiment of the present disclosure. The optical fiber 100 is a fiber used for transmitting information as light pulses from one end to another. The optical fiber 100 is a thin strand of glass or plastic capable of transmitting optical signals. In addition, the optical fiber 100 allows transmission of information in the form of optical signals over long distances. In addition, the optical fiber 100 allows the transmission of information at high bandwidth. In general, a bandwidth is a measure of data-carrying capacity of the optical fiber 100.

[0029] In an embodiment of the present disclosure, the optical fiber 100 is utilized for broadband communication applications. In another embodiment of the present disclosure, the optical fiber 100 may be utilized for other applications. Moreover, the optical fiber 100 complies with specific telecommunication standards. The telecommunication standards are defined by International Telecommunication Union-Telecommunication (hereinafter “ITU-T”). In an embodiment of the present disclosure, the optical fiber 100 is compliant with G.657 recommendation standard set by the ITU-T. Further more, the ITU-T G.657 recommendation describes a geometrical, mechanical and transmission attributes of a single mode optical fiber (the optical fiber 100).

[0030] In an embodiment of the present disclosure, the optical fiber 100 is a bend insensitive optical fiber. In general, the bend insensitive optical fiber is defined as an optical fiber which shows low sensitivity to bending. Further, the ITU-T G.657 standard defines a plurality of characteristics associated with the optical fiber 100. The plurality of characteristics include a mode field diameter, a cladding diameter, cable cut-off wavelength, macro bending loss, dispersion and refractive index. In addition, the plurality of characteristics includes core concentricity error, cladding non-circularity, attenuation coefficient and the like.

[0031] In general, the cladding non-circularity is defined as a percentage value obtained when the difference between minimum cladding radius and the maximum cladding radius associated with the optical fiber 100is divided by an average cladding radius of the optical fiber100. In an embodiment of the present disclosure, the cladding non-circularity parameter associated with the optical fiber 100is less than equal to 1 %. In general, the core concentricity error is defined as a distance between the center of a core and the center of a cladding. In an embodiment of the present disclosure, the core concentricity error associated with the optical fiber 100is less than equal to 0.5 µm. Furthermore, the telecommunication standards are defined by International Electrotechnical Commission (hereinafter “IEC”). In an embodiment of the present disclosure, the optical fiber100is compliant with IEC 60794-2 standard.

[0032] Going further, the optical fiber 100 is manufactured by adopting a plurality of manufacturing techniques. In general, the manufacturing of optical fibers has two major stages. The first stage involves the manufacturing of optical fiber preforms and the second stage involves drawing the optical fibers from the optical fiber preforms. In general, the quality of optical fibers is determined during the manufacturing of the optical fiber preforms. So, a lot of attention is paid towards the manufacturing the optical fiber preforms. These optical fiber preforms include an inner glass core surrounded by a glass cladding having a lower index of refraction. Also, these preforms are manufactured as per the requirements related to a specific refractive index profile, a core diameter, a cladding diameter and the like. The plurality of manufacturing techniques adopted for manufacturing the optical fiber 100 includes but may not be limited to modified chemical vapor deposition, outside vapor deposition, vapor axial deposition and the like.

[0033] Going further, the optical fiber 100 includes a core region 102 a cladding region 104, a first coating layer 106 and a second coating layer 108. The core region 102 is an inner part of the optical fiber 100. Moreover, the core region 102and the cladding region 104are formed during the manufacturing stage of the optical fiber 100. The core region 102 is defined by a region around a central longitudinal axis110 of the optical fiber100. In general, the core region 102 is defined as the region around the central longitudinal axis 110 of the optical fiber 100 through which light transmits. Furthermore, the central longitudinal axis 110 is associated with the optical fiber 100. In general, the central longitudinal axis 110 of the optical fiber 100 passes through a geometrical center of the optical fiber 100 and is parallel to a length of the optical fiber 100 (as shown in FIG. 1B). In addition, the central longitudinal axis 110is mutually perpendicular to a cross-section of the optical fiber 100. Moreover, the core region 102 is made of a plurality of materials. The plurality of materials includes germanium dioxide, silicon dioxide or silica, fluorine or combination thereof and the like.

[0034] Further, the cladding region 104of the optical fiber 100 surrounds the core region 102 of the optical fiber 100. In general, the cladding region 104 is defined as a region around the core region 102 which confines a light ray to travel within the core region 102 of the optical fiber 100. In addition, the cladding region 104confines the light ray in the core region 102 based on total internal reflection at a core-cladding interface. In general, total internal reflection in optical fiber 100 is a phenomena of complete reflection of the light ray reaching the core-cladding interface. Furthermore, the core region 102 has a refractive index which is greater than a refractive index of the cladding region 104. In an embodiment of the present disclosure, the core region 102 has a higher refractive index than the cladding region 104. In an embodiment of the present disclosure, the cladding region 104 of the optical fiber 100 has a diameter (A) in a range of 124µm – 126µm.

[0035] Going further, the optical fiber 100includes the first coating layer 106 and the second coating layer 108. The first coating layer 106 surrounds the cladding region 104of the optical fiber 100. In an embodiment of the present disclosure, the first coating layer 106 is an inner coating layer. In an embodiment of the present disclosure, the first coating layer 106 is in direct contact with the cladding region 104. In another embodiment of the present disclosure, one or more adhesive layers are present between the first coating layer 106 and the cladding region 104.

[0036] The first coating layer 106serves as a cushion and protects the core region 102 during bending, cabling and spooling of the optical fiber 100. In addition, the first coating layer 106 protects the core region 102 and preserves the ability of the optical fiber 100 to transmit signals. In an embodiment of the present disclosure, the first coating layer 106 is present between the cladding region 104 and the second coating layer 108. Moreover, the first coating layer 106 has a first diameter (B). The first diameter (B) lies in the range of 200 µm – 300 µm.

[0037] Further, the first coating layer 106 is formed of a material having low Young’s modulus. The first coating layer 106 is formed from a material selected from a group of a crylates and polyimides. In an embodiment of the present disclosure, the acrylate material used for manufacturing the first coating layer 106 is UV cured acrylate material. UV cured acrylate material are soft and have low Young’s modulus. Furthermore, the second coating layer 108 surrounds the first coating layer 106. In an embodiment of the present disclosure, the second coating layer 108 is an outer coating layer. In an embodiment of the present disclosure, the second coating layer108 is in direct contact with the first coating layer 106. In another embodiment of the present disclosure, the one or more adhesive layers are present between the second coating layer 108 and the first coating layer 106. The second coating layer 108 protects the optical fiber 100 from environmental exposure, mechanical damages, chemical attacks and the like. In addition, the second coating layer 108 enables an easy deployment of optical fiber 100.

[0038] The second coating layer 108 is formed of a material having high Young’s modulus. In an embodiment of the present disclosure, the Young’s modulus of the second coating layer 108is higher than the Young’s modulus of the first coating layer 106. The second coating layer 108 is formed of polyimide material. In general, the polyimide material is thermally stable in nature. In addition, the polyimide materials have high chemical resistance and provide mechanical strength to the optical fiber 100. Furthermore, the second coating material has a second diameter (C). The second diameter (C) lies in the range of 300 µm – 400 µm.

[0039] The combination of the first coating layer 106 and the second coating layer 108 maintains the optical performance of the optical fiber 100. In addition, the combination of the first diameter (B) and the material of the first coating layer106 and the second diameter (C) and the material of the second coating layer108 provides strength greater than or equal to5 Giga-Pascal (hereinafter “GPa”). Different material combinations of the first coating layer 106 and the second coating layer 108 may be formed to maintain the optical performance and strength of the optical fiber 100. In an embodiment of the present disclosure, the first coating layer 106 is formed of UV cured acrylate material and the second coating layer 108 is formed of polyimide material. In another embodiment of the present disclosure, the first coating layer 106 and the second coating layer 108 each is formed of polyimide material. The polyimide material utilized for the first coating layer 106has relatively low Young’s modulus than the polyimide material utilized for the second coating layer 108. Furthermore, the optical fiber 100 is compact in size.

[0040] Furthermore, different diameter combinations associated with the first coating layer 106 and the second coating layer 108 may be used to maintain the strength of the optical fiber 100 no less than 5 GPa. In an embodiment of the present disclosure, the strength of the optical fiber 100 is no less than 5 GPa when the first coating layer 106 has a diameter of 200 µm and the second coating layer 108 has the diameter of 300 µm. In another embodiment of the present disclosure, the strength of the optical fiber 100 is no less than 5 GPa when the first coating layer 106 has the diameter of 300 µm and the second coating layer 108 has the diameter of 400 µm. In yet another embodiment of the present disclosure, the strength of the optical fiber 100 is no less than 5 GPa when the first coating layer 106 has the diameter of 250 µm and the second coating layer 108 has the dosimeter of 350 µm.

[0041] Going further, the present disclosure provides numerous advantages over the prior art. The present disclosure provides the optical fiber of strength greater than equal to5GPa. The present disclosure provides the optical fiber of reduced size. The optical fiber can be directly deployed for indoor applications without any need of cabling, buffering over the optical fiber and hence reduces cost of manufacturing. Moreover, the optical fiber 100 has crush resistant properties suitable for an indoor staple installation and can withstand harsh environment.

[0042] The foregoing descriptions of specific embodiments of the present technology have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present technology to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present technology and its practical application, to thereby enable others skilled in the art to best utilize the present technology and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present technology.

[0043] While several possible embodiments of the disclosure have been described above and illustrated in some cases, it should be interpreted and understood as to have been presented only by way of illustration and example, but not by limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments.