Claims:Claims

What is claimed is:

1. An optical fiber (100) comprising:

a core region (102), wherein the core region (102) has a radius R1, wherein the core region (102) is defined along a central longitudinal axis (110) of the optical fiber (100); and

a cladding region (104) having a radius R3, wherein the cladding region (104) is defined along the central longitudinal axis (110) of the optical fiber (100),

wherein the optical fiber (100) has a Mode Field Diameter in a range of 8.5 +/- 0.3 microns at a wavelength of 1310 nanometers, a micro-bending loss of less than equal to 0.5 dB/Km at a wavelength of 1550 nanometers and a macro-bending loss of less than 1 dB/Km at a wavelength 1550 nanometers.

2. The optical fiber (100) as claimed in claim 1, wherein the cladding region (104) further comprising:
an inner clad region (106) defined by an inner clad refractive index profile; and
an outer clad region (108) surrounding the inner clad region (106), wherein the outer clad region (108) is defined by an outer clad refractive index profile, wherein the inner clad refractive index profile is different from the outer clad refractive index profile.

3. The optical fiber (100) as claimed in claim 2, wherein the inner clad region (106) is down-doped silica region adjacent to the core region (102) such that there is no buffer region between the core region (102) and the inner clad region (106).

4. The optical fiber (100) as claimed in claim 2, wherein the inner clad region (106) is a trench region defined by one or more of trench delta in a range of -0.05 to -0.2, a trench radius R2 between 14 microns to 16.5 microns and trench alpha between 6 and 9.

5. The optical fiber (100) as claimed in claim 4, wherein the core region (102) is defined by a core alpha, wherein the core alpha of the core region (102) is less than the trench alpha of the trench region.

6. The optical fiber (100) as claimed in claim 2, wherein the outer clad region (108) is un-doped silica region.

7. The optical fiber (100) as claimed in claim 1, wherein the core region (102) is up-doped silica region.

8. The optical fiber (100) as claimed in claim 1, wherein the optical fiber (100) is defined by a refractive index dip, wherein the refractive index dip is a difference between maximum refractive index and minimum refractive index, and wherein an absolute value of the difference between the maximum refractive index and the minimum refractive index is between 0.005 to 0.009.

9. The optical fiber (100) as claimed in claim 1, wherein the optical fiber (100) is defined by a delta ratio, wherein the delta ratio is a ratio of absolute values of a trench delta of a trench region to absolute values of a core delta of the core region (102), and wherein the delta ratio is between 0.12 to 0.67.

10. The optical fiber (100) as claimed in claim 1, wherein the optical fiber (100) has a diameter of less than 210 microns.

11. The optical fiber (100) as claimed in claim 1, wherein the optical fiber (100) is used in a cable (300) such that a cable filling coefficient is in a range of 25-40% when the optical fiber (100) has a diameter in a range of 250+-15 microns, the cable filling coefficient is in a range of 35-55% when the optical fiber (100) has a diameter in a range of 200+-15 microns and the cable filling coefficient is greater than 50% when the optical fiber (100) has a diameter of less than 185 microns, wherein the cable filling coefficient is defined as total cross sectional area of fiber divided by an inner cross section area of the cable (300), wherein the inner cross section area of the cable is defined by an outermost sheath of the cable (300).
, Description:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)


TITLE OF THE INVENTION

“SINGLE MODE OPTICAL FIBER SUITABLE FOR RIBBON APPLICATIONS”

APPLICANTS:

Name: Sterlite Technologies Limited

Nationality: Indian

Address: 3rd Floor, Plot No. 3, IFFCO Tower, Sector29
Gurugram, Haryana - 122002

The following specification describes the invention and the manner in which it is to be performed:-

TECHNICAL FIELD

[0001] The present disclosure relates to the field of optical fibers and, more particularly relates to a single mode optical fiber for use in Intermittently Bonded Ribbon cables.

BACKGROUND

[0002] With the advancement of science and technology, classic optical fiber cable technology has been replaced with new technologies. Optical fibers can be bonded intermittently along a longitudinal length to form an intermittent bonded ribbon unlike a conventional optical fiber ribbon. The intermittently bonded ribbon (IBR) consists of fibers bonded using matrix material at intermittent or irregular intervals. The intermittently bonded ribbons are being used in optical fiber cables known as an intermittently bonded ribbon cable. The intermittently bonded ribbon cables require stringent micro bend performance of the optical fibre due to its complex design. One of the key characteristics required to be maintained or controlled is a Mode Field Diameter. It is essential for the Mode Field Diameter of the optical fiber to be low in combination with an immediate trench around the core. This makes it possible for the optical fiber and the optical fiber cable to give expected performance. The optical fiber with this combination helps in making the complex Intermittently Bonded Ribbon like cables with good performance.

[0003] However, the optical fibers used in the conventional intermittently bonded ribbon cables do not have desired values of micro-bending loss, macro-bending loss and Mode Field Diameter. There are a few patent applications that provide an enhanced intermittently bonded ribbon. In an example, the patent application AU2001292225A1 provides an optical fiber with macro-bending losses at 1550 nanometers that are less than about 0.5 dB/m and micro-bending losses at 1550 nanometers that are less than 15 about 15 (dB/km)/(g/mm). However, the optical fiber of the above prior art is a dispersion shifted fibre and no values of macro-bending loss are shown at 15mm diameter. In another example, the patent application CA2382957A1 provides a single mode optical fiber exhibiting micro-bending loss of less than 0.7 dB/m and a macro-bending loss of less than 11 dB/m at 1700 nanometers. However, the optical fiber of the above prior art provides macro-bending loss value without mentioning mandrel diameter. In yet another example, the patent application NL2019817B1 provides an optical fiber having wire mesh covered drum with micro-bending loss of less than 0.1 dB/km and a Mode Field Diameter greater or equal to 9 microns at 1310 nanometers. However, the optical fiber of the above prior art has a different refractive index profile. In yet another example, the patent application IN-MUM-200500929A provides an optical fiber with a Mode Field Diameter of about 8.3+0.6 um with macro-bending loss of less than 0.05 dB at 1550 nanometers and micro-bending loss of less than 0.5 dB at 1550 nanometers. However, the optical fiber of the above prior art is a dispersion shifted fibre and has a different refractive index profile.

[0004] Thus, in light of the above stated discussion there is a need for an optical fiber with modified design and optimized characteristics for intermittently bonded ribbon cables with desired performance characteristics.

OBJECT OF THE DISCLOSURE

[0005] A primary objective of the present disclosure is to provide an optical fiber with a modified design.

[0006] Another objective of the present disclosure is to provide the optical fiber with a different refractive index profile.

[0007] Yet another objective of the present disclosure is to provide the optical fiber with optimized values of characteristics such as macro-bending loss, micro-bending loss and Mode Field Diameter which is required for specific cable types.

SUMMARY

[0008] The present disclosure provides an optical fiber. The optical fiber includes a core region and a cladding region. The core has a radius R1. The core region is defined along a central longitudinal axis of the optical fiber. The cladding region has a radius R3. The cladding region is defined along the central longitudinal axis of the optical fiber. The optical fiber has a Mode Field Diameter in a range of 8.5 +/- 0.3 microns at a wavelength of 1310 nanometers. In addition, the optical fiber has a micro-bending loss of less than equal to 0.5 dB/Km at a wavelength of 1550 nanometers. Moreover, the optical fiber has a macro-bending loss of less than 1 dB/Km at a wavelength 1550 nanometers.

STATEMENT OF THE DISCLOSURE

[0009] The present disclosure provides an optical fiber. The optical fiber includes a core region and a cladding region. The core has a radius R1. The core region is defined along a central longitudinal axis of the optical fiber. The cladding region has a radius R3. The cladding region is defined along the central longitudinal axis of the optical fiber. The optical fiber has a Mode Field Diameter in a range of 8.5 +/- 0.3 microns at a wavelength of 1310 nanometers. In addition, the optical fiber has a micro-bending loss of less than equal to 0.5 dB/Km at a wavelength of 1550 nanometers. Moreover, the optical fiber has a macro-bending loss of less than 1 dB/Km at a wavelength 1550 nanometers.

BRIEF DESCRIPTION OF FIGURES

[0010] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0011] FIG. 1 illustrates a cross sectional view of an optical fiber, in accordance with various aspects of the present disclosure;

[0012] FIG. 2 illustrates a refractive index profile of the optical fiber of FIG. 1, in accordance with an aspect of the present disclosure; and

[0013] FIG. 3 illustrates a cross sectional view of a cable having the optical fiber of FIG. 1, in accordance with an aspect of the present disclosure.

[0014] It should be noted that the accompanying figures are intended to present illustrations of exemplary aspects 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

[0015] 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 may 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.

[0016] Reference in this specification to “one aspect” or “an aspect” means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect of the present technology. The appearance of the phrase “in one aspect” in various places in the specification are not necessarily all referring to the same aspect, nor are separate or alternative aspects mutually exclusive of other aspects. Moreover, various features are described which may be exhibited by some aspects and not by others. Similarly, various requirements are described which may be requirements for some aspects but not other aspects.

[0017] 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. Although the following description provides an optical fiber cable, the shown cable construction method can be applied to any cable with loose tube and sheath.

[0018] It should be noted that the terms "first", "second", and the like, herein do not denote any order, ranking, quantity, or importance, but rather are used to distinguish one element from another. Further, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0019] FIG. 1 illustrates a cross sectional view of an optical fiber 100, in accordance with various aspects of the present disclosure. FIG. 2 illustrates a refractive index profile 200 of the optical fiber 100 of FIG. 1, in accordance with an aspect of the present disclosure. The optical fiber 100 includes a core region 102 and a cladding region 104. . The optical fiber 100 is defined by a central longitudinal axis 110 passing through a center of the optical fiber 100 (as shown in FIG. 1).

[0020] The optical fiber 100 maybe used in ribbon cables. The intermittently bonded ribbon cables include intermittently bonded ribbons inside a core of the intermittently bonded ribbon cables. The intermittently bonded ribbon corresponds to an optical fiber ribbon with a plurality of optical fibers (such as the optical fiber 100) joined at intermittent locations along a longitudinal length of the intermittently bonded ribbon. The intermittent bonding enables the optical fiber ribbon to be flexible and rollable. Also, the intermittent bonding enables high density of optical fibers inside the intermittent bonded ribbon cable.

[0021] The optical fiber 100 is manufactured using one of a plurality of manufacturing methods. The plurality of manufacturing methods includes Outside Vapor Phase Oxidation (OVPO), Modified Chemical Vapor Deposition (MCVD), and Vapor-phase Axial Deposition (VAD). However, the plurality of manufacturing methods may not be limited to the above mentioned methods.

[0022] In general, the optical fiber 100 is a fiber used for transmitting information as light pulses from one end to another. In addition, the optical fiber 100 is a thin strand of glass or plastic capable of transmitting optical signals. The optical fiber 100 is configured to transmit large amounts of information over long distances with relatively low attenuation. In general, the intensity of the light beam reduces (or signal) with respect to distance travelled through a transmission medium. The optical fiber 100 is utilized for data transmission. Further, the optical fiber 100 is a single mode optical fiber. The single mode optical fiber 100 is a fiber which is configured for transmission of single mode of light.

[0023] The core region 102 of the optical fiber 100 has a radius R1. The core region 102 is defined from a center of the optical fiber 100 to an outer periphery of the core region 102 of the optical fiber 100. The light travels through the core region 102. In an aspect of the present disclosure, the core region 102 is up-doped silica region. In general, a core of an optical fiber is made of silica glass in which a dopant such as germanium, phosphorus and the like is introduced for raising refractive index of the core.

[0024] In an aspect of the present disclosure, the radius R1 of the core region 102 is about 5.1 microns. In another aspect of the present disclosure, the radius R1 of the core region 102 is in a range of 4.5 microns to 5.6 microns. In yet another aspect of the present disclosure, the radius R1 of the core region 102 may vary. The core region 102 is defined by a refractive index value. In general, the refractive index is the speed of light in a vacuum divided by the speed of light in a material. The refractive index measures how much a material refracts light.

[0025] In addition, the core region 102 has a refractive index ?_core. In addition, the core region 102 has percentage change in refractive index factor denominated as ?_core (%). In an aspect of the present disclosure, a minimum working value of ?_core (%) maybe 0.3 and a maximum working value of ?_core (%) maybe 0.4. In another aspect of the present disclosure, the value of ?_core (%) maybe 0.31. Further, the core region 102 is defined by a curve parameter core alpha. In an aspect of the present disclosure, the curve parameter core alpha is in a range of about 2.5 to 5.0. In another aspect of the present disclosure, the curve parameter core alpha is about 5.0. In yet another aspect of the present disclosure, the value of the curve parameter core alpha may vary.

[0026] The optical fiber 100 includes the cladding region 104. The cladding region 104 has a radius R3. In an aspect of the present disclosure, the cladding region 104 further includes an inner clad region 106 and an outer clad region 108. The outer clad region 108 surrounds the inner clad region 106. The inner clad region 106 is defined by an inner clad refractive index profile. The outer clad region 108 is defined by an outer clad refractive index profile. In an aspect of the present disclosure, the inner clad refractive index profile is different from the outer clad refractive index profile. In an aspect, the cladding region 104 has a total radius of R2 + R3 when the inner clad region 106 is present.

[0027] In an aspect of the present disclosure, the inner clad region 106 is down-doped silica region. The inner clad region 106 is adjacent to the core region 102 such that there is no buffer region between the core region 102 and the inner clad region 106. In an aspect of the present disclosure, the inner clad region 106 is a trench region. The trench region or the inner clad region 106 is formed by down doping the cladding region 104 up to the radius R2. In an aspect of the present disclosure, the inner clad region 106 is defined by one or more of the trench delta in a range of -0.05 to -0.2, a trench radius R2 (or the radius R2) between 14 microns to 16.5 microns and the trench alpha between 6 and 9 (as explained above in the detailed description).

[0028] In an aspect of the present disclosure, the outer clad region 108 is un-doped silica region. The outer clad region 108 is made of pure silica without any doping. So, the outer clad region 108 has a percentage change in refractive index value of zero.

[0029] The inner clad region 106 concentrically surrounds the core region 102. The inner clad region 106 is defined by the radius R2 from the center of the optical fiber 100 to an outer periphery of the inner clad region 106 of the optical fiber 100. In an aspect of the present disclosure, the radius R2 of the inner clad region 106 is about 14 microns to 16.5 microns. In another aspect of the present disclosure, the radius R2 of the inner clad region 106 is 16.2 microns. In yet another aspect of the present disclosure, the radius R2 of the inner clad region 106 may vary.

[0030] The inner clad region 106 has a percentage change in refractive index factor denominated as ?_trench (%). In an aspect of the present disclosure, a minimum working value of ?_trench (%) maybe -0.05. In an aspect of the present disclosure, a maximum working value of ?_trench (%) maybe -0.2. In another aspect of the present disclosure, the value of ?_trench (%) of the inner clad region 106 is -0.08. In yet another aspect of the present disclosure, the value of ?_trench (%) of the inner clad region 106 may vary.

[0031] Further, the inner clad region 106 is defined by a curve parameter trench alpha. In an aspect of the present disclosure, the trench alpha of the inner clad region 106 is in a range of about 6.0 to 9.0. In another aspect of the present disclosure, the trench alpha of the inner clad region 106 is about 9.0. In yet another aspect of the present disclosure, the value of the trench alpha of the inner clad region 106 may vary. In an aspect of the present disclosure, the core alpha of the core region 102 is less than the trench alpha of the inner clad region 106 or the trench region. The core alpha of the core region 102 is less because fluorine doping of glass reduces zero dispersion wavelength towards a lower value. Hence, a low value of the core alpha of the core region 102 ensures that the zero dispersion wavelength is in a desired range. In addition, the low value of the core alpha of the core region 102 helps to get good confinement of light.

[0032] The trench alpha of the inner clad region 106 is driven by low temperature doping of fluorine which always gives a high alpha trench region. In an aspect of the present disclosure, if the value of the trench delta of the inner clad region 106 is decreased or the value of the core delta of the core region 102 is increased, the Mode Field Diameter reduces. The inner clad region 106 which is immediate to the core region 102 helps in getting good confinement of the light signal inside the core region 102 of the optical fibre 100. This helps in achieving the required or expected Micro-bend performance relatively as compared to an optical fibre with a buffer layer in between and with similar doping levels of a trench region.

[0033] The optical fiber 100 includes the outer clad region 108. In an aspect of the present disclosure, the outer clad region 108 concentrically surrounds the inner clad region 106. The outer clad region 108 is made of pure silica. In an aspect of the present disclosure, the outer clad region 108 maybe doped with a down dopant such as fluorine for lowering the refractive index of the outer clad region 108.

[0034] The outer cladding region 108 is defined by a radius R3 from the center of the optical fiber 100 to an outer periphery of the outer clad region 108 of the optical fiber 100. In an aspect of the present disclosure, the radius R3 of the outer clad region 108 is in a range of 62 microns to 63 microns. In another aspect of the present disclosure, the radius R3 of the outer clad region 108 is about 62.5 microns. In general, cladding maybe defined as one or more layers of materials of lower refractive index, in contact with a core material of higher refractive index. The outer clad region 108 causes light to be confined to the core region 102 of the optical fiber 100 by total internal reflection at a boundary between the two regions.

[0035] FIG. 2 illustrates the refractive index profile 200 of the optical fiber 100, in accordance with an aspect of the present disclosure. The refractive index profile 200 is a graph showing a change in refractive index from the central longitudinal axis 110 to an outermost periphery of the optical fiber 100. Specifically, the refractive index profile 200 shows the change in refractive index from the core region 102 to the cladding region 104. The graph of the refractive index profile 200 is plotted between a radius of the optical fiber 100 and the refractive index of the optical fiber 100.

[0036] In an aspect of the present disclosure, the refractive index delta of the core region 102 initially increases and then decreases sharply from the center of the optical fiber 100 towards the outer periphery of the core region 102 to come down to absolute zero. In an aspect of the present disclosure, the refractive index delta of the inner clad region 106 having the radius R2 is negative. Hence, the value of the refractive index delta of the inner clad region 106 is negative. In an aspect, the inner clad region 106 is the trench region formed by down doping the cladding region 104 till the radius R2. In an aspect of the present disclosure, the value of the refractive index delta for the outer clad region 108 is zero throughout, as it is formed by pure silica.

[0037] In an aspect of the present disclosure, the optical fiber 100 maybe used to form intermittently bonded ribbon or IBR. The value of parameters such as Mode Field Diameter or MFD, Micro-bending loss and Macro-bending loss of the optical fiber 100 is optimized. The values of the above mentioned characteristics are altered during the manufacturing stage. The Mode Field Diameter in an optical fiber maybe defined as a measure of the width of an irradiance distribution, that is, the optical power per unit area, across an end of a single-mode fiber.

[0038] The mode field diameter (MFD) of the optical fiber 100 is a section of fiber where most of the light energy travels. The Mode Field Diameter represents an effective diameter of the light mode propagating through the optical fiber. The Mode Field Diameter is analogous to a measurement of a beam diameter for a beam propagating in free space. Further, a value of the Mode Field Diameter is twice a value of a mode field radius.

[0039] The optical fiber 100 has the Mode Field Diameter in a range of 8.5 +/- 0.3 microns at a wavelength of 1310 nanometers. In an aspect of the present disclosure, the Mode Field Diameter of the optical fiber 100 may vary. The Mode Field Diameter for the optical fiber 100 is low as compared to Mode Field Diameter of other fibers. The low Mode Field Diameter in combination with the inner clad region 106 makes it possible for the intermittently bonded ribbon cable to provide expected performance.

[0040] The optical fiber 100 suffers attenuation or loss of optical power as light travels through the core. In one of the cases, the attenuation is due to bending. The optical fiber 100 has stringent micro-bending properties, which enables the optical fiber 100 to be used in the intermittently bonded ribbon cables. In general, the micro-bending loss relates to the light signal loss associated with lateral stresses along the length of the optical fiber. The micro-bending loss is due to the coupling from the fiber’s guided fundamental mode to lossy, higher-order radiation modes. Mode coupling occurs when fibers suffer small random bends along a fiber axes. This random bending is usually caused by external mechanical stresses against the cable material that compress the optical fiber. The result is random, high-frequency perturbations to the optical fiber.

[0041] The optical fiber 100 has the micro-bending loss of less than equal to 0.5 dB/Km at a wavelength of 1550 nanometers. The inner clad region 106 which is immediate to the core region 102 helps in getting good confinement of the light signal in the core region 102 of the optical fiber 100. This helps in achieving the desired micro-bend performance. In general, the complex intermittently bonded ribbon cables require stringent micro-bend performance of the optical fiber to be used. The aforementioned values help in achieving the stringent micro-bend performance of the optical fiber 100. In an aspect of the present disclosure, the micro-bending loss measurement is done at 250 grams winding tension in drum method. The above measurements are made using a proprietary measurement method using an apparatus. The apparatus consists of a fixed diameter drum. In order to avoid macro-bending effects, the drum of 200 mm diameter is used. The surface of the drum is coated with a material of fixed roughness (sandpaper –grade 40). The optical fiber 100 having a length of 400 meters is wounded on the drum with 250 grams winding tension for measuring change in attenuation.

[0042] In an aspect of the present disclosure, the optical fiber 100 has stringent macro-bending properties which enable the optical fiber 100 to be used in intermittently bonded ribbon cables. The optical fiber 100 experiences the macro-bending loss. In general, the macro-bending loss or attenuation of light signals due to macro-bending occurs when the optical fiber is bent into a visible curvature. A relatively large-radius bend in an optical fiber may be found in a splice organizer tray or a fiber-optic cable that has been bent. Macro-bends may be caused by incorrect installation and are commonly found at fiber organizers and patch cables. Environmental changes may cause lead to the macro-bending loss.

[0043] The optical fiber 100 has the macro-bending loss of less than 1 dB/Km at a wavelength 1550 nanometers. In general, the complex intermittently bonded ribbon cables require stringent macro-bend performance of the optical fiber to be used. The aforementioned values help in achieving the stringent macro-bend performance of the optical fiber 100.

[0044] In an aspect of the present disclosure, the macro-bending loss measurement is done at 15 millimeters mandrel diameter. The above measurements are made using a proprietary measurement method. The measuring apparatus consists of an optical fiber wrapped around the mandrel having 15 millimeters diameter to measure the macro-bending loss. In general, the macro-bending loss occurs when the optical fiber cable is subjected to a significant amount of bending above a critical value of curvature. The macro-bending losses are also called as large radius losses. Optical fibers suffer radiation losses at bends or curves on their paths.

[0045] In an aspect of the present disclosure, the optical fiber 100 is defined by a delta ratio. The delta ratio is a ratio of absolute values of the trench delta of the inner clad region 106 to absolute values of the core delta of the core region 102. The delta ratio is between 0.12 to 0.67.

[0046] In an aspect of the present disclosure, the optical fiber 100 is defined by a refractive index dip. The refractive index dip is a difference between maximum refractive index and minimum refractive index. In addition, an absolute value of the difference between the maximum refractive index and the minimum refractive index is between 0.005 to 0.009. In an aspect of the present disclosure, the optical fiber 100 has a diameter of less than 210 microns. In another aspect of the present disclosure, the optical fiber 100 may have a diameter of about 250 microns with coating.

[0047] In an aspect of the present disclosure, the optical fiber 100 is used in a cable 300 (as shown in FIG. 3). In an aspect of the present disclosure, the cable 300 includes a plurality of optical fiber bundles 302 and a sheath 304. The cable 300 is defined by a cable filling coefficient. The cable filling coefficient is defined as total cross sectional area of fiber divided by an inner cross section area of the cable 300. An outermost sheath (the sheath 304) of the cable 300 defines the inner cross section area of the cable 300. In an aspect of the present disclosure, the cable filling coefficient is in a range of 25-40% when the optical fiber 100 has a diameter in a range of 250+-15 microns. In another aspect of the present disclosure, the cable filling coefficient is in a range of 35-55% when the optical fiber 100 has a diameter in a range of 200+-15 microns. In yet another aspect of the present disclosure, the cable filling coefficient is greater than 50% when the optical fiber 100 has a diameter of less than 185 microns.

[0048] Each of the plurality of optical fiber bundles 302 includes a plurality of optical fibers. Each of the plurality of optical fibers corresponds to the optical fiber 100. In an aspect of the present disclosure, a number of the plurality of optical fibers in each of the plurality of optical fiber bundles 302 shown in FIG. 3 is 12. In another aspect of the present disclosure, there may be any number of optical fibers in each of the plurality of optical fiber bundles 302. In an aspect of the present disclosure, a number of the plurality of optical fiber bundles 302 in the cable 300 shown in FIG. 3 is 3. In another aspect of the present disclosure, there may be any number of the plurality of optical fiber bundles 302 in the cable 300. In an aspect of the present disclosure, the cable 300 may have more layers or elements such as water blocking yarns, buffer tubes and the like. These layers may surrounds the plurality of optical fiber bundles 302.

[0049] The foregoing descriptions of specific aspects 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 aspects 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 aspects with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance 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.

[0050] While several possible aspects of the invention 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 aspect should not be limited by any of the above-described exemplary aspects.