NL2019817B1 - Low bend loss optical fiber with a chlorine doped core and offset trench - Google Patents

Abstract

The invention relates to an optical fiber, wherein the optical fiber includes: (i) a chlorine doped silica based core having a core alpha (Coreu) Z 4, a radius r 1, and a maximum refractive index delta A 1max%; and (ii) a cladding surrounding the core. The cladding surrounding the core includes: a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta A2, a radius r2, and a minimum refractive index delta A2… such that A2… < Al…”; b) a second inner cladding adjacent to and in contact with the first inner cladding having a refractive index A3, a radius r3, and a minimum refractive index delta A3… such that A3… < A2; and c) an outer cladding region surrounding the second inner cladding region and having a refractive index A5, a radius r…… and a minimum refractive index delta A3… such that A3… < A2. The optical fiber has a mode field diameter MFD at 1310 of Z 9 microns, a cable cutoff of S 1260 nm, a zero dispersion wavelength of 1300 nm £ zero dispersion wavelength S 1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB/turn.

Description

Patent center

Θ 2019817

Application number: 2019817

Application submitted: October 27, 2017

Int. CL:

G02B 6/036 (2018.01)

0 Priority: 0 Patent holder (s): August 8, 2017 US 62 / 542,518 Coming Incorporated in Coming, New York, United States of America, US. 0 Application registered: February 21, 2019 0 Inventor (s): Dana Craig Bookbinder in Coming, 0 Request published: New York (US). - Ming-Jun Li in Coming, New York (US). Snigdharaj Kumar Mishra in Coming, 0 Patent granted: New York (US). February 21, 2019 Pushkar Tandon in Coming, New York (US). 0 Patent issued: May 17, 2019 0 Authorized representative: ir. P.J. Hylarides et al. In The Hague.

LOW BEND LOSS OPTICAL FIBER WITH A CHLORINE DOPED CORE AND OFFSET TRENCH © The invention relates to an optical fiber, including the optical fiber includes:

(i) a chlorine doped silica-based core having a core alpha (Core »)> 4, a radius n, and a maximum refractive index delta Aimax%; and (ii) a cladding surrounding the core.

The cladding surrounding the core includes:

a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta A _2m inSuch that A _2mi n <Ai _ma x;

b) a second inner cladding adjacent to and in contact with the first inner cladding having a refractive index Δ ₃ , a radius r ₃ , and a minimum refractive index delta A _3min such that A _3min <A ₂ ; and

c) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ ₅ , a radius r _max and a minimum refractive index delta A _3min such that A _3min <Δ ₂ .

The optical fiber has a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or> 1260 nm, a zero dispersion wavelength or 1300 nm> zero dispersion wavelength> 1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.75 dB / turn.

NL B1 2019817

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

LOW BEND LOSS OPTICAL FIBER WITH A CHLORINE DOPED CORE AND OFFSET TRENCH

The present disclosure generally relates to optical fibers, for example single mode optical fibers, having low bend losses, and in particular related to optical fibers having chlorine doped cores and more particularly to single fashion fibers with a chlorine doped core and a cladding having an offset trench region surrounding the core.

There is a need for low bend loss optical fibers, particularly for optical fibers utilized in so-called "access" and fiber to the premises (FTTx) optical networks. Optical fiber can be deployed in such networks in a manner which induces bend losses in optical signals transmitted through the optical fiber. Some applications that can impose physical demands, such as tight bend radii, compression of optical fiber, etc., that induce bend losses include the deployment of optical fiber in optical drop cable assemblies, distribution cables with Factory Installed Termination Systems (FITS) and slack loops, small bend radius multiports located in cabinets that connect feeder and distribution cables, and jumpers in network access points between distribution and drop cables. It has been difficult in some optical fiber designs to achieve low macrobending loss, low microbending loss, low cable cutoff wavelength, a zero dispersion wavelength between 1300 nm and 1324 nm, 1310 mode field diameter or 8.2 to 9.6 microns, and ITU G. 652 / G.657 standards compliance.

According to the present disclosure, an optical fiber is provided. The optical fiber includes:

(i) a chlorine doped silica-based core, preferably having a core alpha (Core _a )> 10, and having a radius r ,, and a maximum refractive index delta A _{! max} %; and (ii) a cladding surrounding the core.

The cladding surrounding the core is adjacent to and in contact with the core and has a refractive index delta A ₂ , a radius r ₂ , and a minimum refractive index delta A _2min such that A _2min <Aj niax ·

The optical fiber preferably comprises a second inner cladding adjacent to and in contact with the first inner cladding and having a refractive index A ₃ , a radius r ₃

The second inner cladding preferably has a minimum refractive index delta A _3min such that A _3min <Δ ₂ .

The optical fiber can have an outer cladding region surrounding the second inner cladding region, which outer cladding region preferably has a refractive index A ₅ and a radius r _max , such that Δ _3πώ) <A ₂ .

The optical fiber can have a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or <1260 nm, a zero dispersion wavelength ranging from 1300 nm <λ ₀ <1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.75 dB / turn.

An example of the optical fiber includes:

(i) a chlorine doped silica-based core having a core alpha (Core ,,)> 4, a radius r _i; and a maximum refractive index delta A _{) max} %; and (ii) a cladding surrounding the core.

The cladding surrounding the core can include:

a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta A _2million such that Δ _2ηώ , <Δ _{1ηκ (Χ} ;

b) a second inner cladding adjacent to and in contact with the first inner cladding and having a refractive index Δ ₂ "a radius r ₂ " and a maximum refractive index delta Ajniax such that Δ ₂₁₁ ^ _η <A-.niax 'and

c) an outer cladding region surrounding the inner cladding region and having a refractive index Δ ₅ and a radius r _max , such that Δ ₅ <A _3max .

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 that description or recognized by practicing the expired as described, including the detailed description which follows, the clauses , as well as the appended drawings.

It is understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework for understanding the nature and character of the clauses. The accompanying drawings are included to provide a further understanding, and are incorporated in a part of this specification. The drawings illustrate one or more expat, and together with the description serve to explain principles and operation of the various various.

FIG. 1 is a side perspective view of an optical fiber according to the present disclosure;

FIG. 2 is a cross-sectional view of the optical fiber tasks through line II-Π or FIG. 1 according to the present disclosure;

FIG. 3A is a plot of the relative refractive index profile Δ versus the radius of the optical fiber or FIG. 2;

FIG. 3B is a plot of the relative refractive index profile Δ versus the radius of the optical fiber according to examples of the present disclosure;

FIG. 4 is a plot of the relative refractive index profile Δ versus the radius of the optical fiber according to examples of the present disclosure; and

FIGS. 5-14 are profile schematic plots of the relative refractive index profile Δ versus the radius for various optical fibers according to examples of the present disclosure.

Additional features and advantages will be set forth in the detailed description which follows and will be apparent to those skilled in the art from the description or recognized by practicing as described in the following description together with the clauses and appended drawings.

Low attenuation is a critical property in optical fibers. Optical fibers disclosed are valuable for use as low attenuation optical fibers such as in optical fiber cables for submarine and terrestrial long haul systems.

The "refractive index profile" is the relationship between refractive index or relative refractive index (also referred to as refractive index delta read) and waveguide fiber radius. The radius for each segment or the refractive index profile is given by the abbreviations r _1? r ₂ , r ₃ , r ₄ , etc. and lower and upper case are used interchangeably such (eg, π is equivalent to R |).

Unless stated otherwise, the "relative refractive index percent" is defined as A% = 100 x (n ² -nc ² ) / ² nf, and as used used nc is the average refractive index of undoped silica glass. As used, the relative refractive index is represented by A and its values are given in units or “%”, unless otherwise specified. The terms: relative refractive index percent, relative refractive index, refractive index delta, refractive index, relative refractive index delta, delta. A, A%,% A, delta%,% delta and percent delta may be used interchangeably. In cases where the refractive index or region is less than the average refractive index or undoped silica, the relative index percentage is negative and is referred to as having a depressed region or depressed index. In cases where the refractive index of a region is greater than the average refractive index of the cladding region, the relative index percent is positive. An "updopant" is considered to be a dopant which has a propensity to raise the refractive index relative to pure undoped SiO ₂ . A "downdopant" is considered to be a dopant which has a propensity to lower the refractive index relative to pure undoped SiO ₂ . Examples of updopants include GeO ₂ (germania), A1 ₂ O ₃ , P ₂ O ₅ , TiO ₂ , Cl, and / or Br. Examples of downdopants include fluorine and B ₂ O ₃ . As described, while the relative refractive index or the optical profiles are calculated where index or n _t . is undoped silica, the entire index profile of the optical fiber can be linearly shifted up (or down) in order to obtain equivalent optical fiber properties.

"Chromatic dispersion", referred to as "dispersion" unless otherwise noted, or a waveguide fiber is the sum of the material dispersion, the waveguide dispersion, and the intermodal dispersion. In the case of single-mode waved fibers, the inter-modal dispersion is zero. Zero dispersion wavelength is a wavelength at which the dispersion has a value of zero. Dispersion slope is the rate of change or dispersion with respect to wavelength.

"Effective area" is defined in equation 1 as:

A _ef f = 2π (Jf ² r drjVcff ⁴ r dr) Eq. 1 where the integration limits are 0 to oo, and f is the transverse component of the electric field associated with light propagated in the waveguide. As used, "effective area" or "A _eff " refers to optical effective area at a wavelength or 1550 nm unless otherwise noted.

The term “α-core profile, refers to a relative refractive index profile of the core, expressed in terms of A (r) which is in units or where r is radius, which follows the equation (Eq. 2),

A (r) - A (r _o) (1 - [| rr ₀ | / (r _r r ₀₎ J ^ucore) Eq. 2 where r _o is the point at which A (r) is maximum and is the initial point of the α-core profile, Γ] is the outer radius of the core and conformed to the final point of the core's α-profile, it is defined as where a tangent line is drawn through maximum slope of the refractive index or core crosses the zero delta line (ie, the point at which A (r)% is zero), and r is in the range η <r <r _t , where Δ is defined above, r _o corresponds to the initial point of the core's α-profile, η agreed to the final point of the α-profile, Core _a , and a _core (also referred to as “core alpha”) is an exponent which is a real number. In some, the core alpha is 1 <ac _Ore <100. In other, the core alpha is 4 <a _core <30. In the discussion below, example values of a _wre are provided for at least some of the described described like.

The term "α-profile of the inner cladding", also referred to as the alpha _pedestal or Oped, refers to a relative refractive index profile of the inner cladding region, expressed in terms of Δ (γ) which is in units of "% ”, Where r is radius, which follows the equation (Eq. 3),

Δ (γ) - Δ (γ ₂ ) + (Δ ( _Γ1 ) - Δ (γ ₂ )) (1 - [Ir-rj | / (r ₂ -r ₁ )] ^oped ) Eq. 3 where r ₍ is defined as above, and is typically the point at which Δ (γ) or hte inner cladding region is maximum, r ₂ is the outer radius or inner cladding and agreed to a point at which a (vertical) line drawn through refractive index profile or inner cladding associated with its minimum refractive index crosses the zero delta line (ie, the point at which Δ (γ)% is zero), and r is in the range r, <r <r _f , where Δ is defined above, η is the initial point of the α-profile of the inner cladding region, r _t is the final point of the α-profile of the inner cladding region, and a _ped is an exponent which is a real number ( In some cases, the pedestal alpha is 1 <a _ped <100. In some cases, the pedestal alpha is 5 <ctj, _ed <20.

The term "α-profile of the trench", also referred to as the alpha _uench or a _T , refers to a relative refractive index profile of the inner cladding region, expressed in terms of Δ (γ) which is in units of "% ", Where r is radius, which follows the equation (Eq. 4),

Δ (γ) = Δ (γ ₃ ) + (Δ (γ ₂ ) - Δ (γ ₃ )) (1 - [| rr ₂ | / (r ₃ -r ₂ )] ^aT ) Eq. 4 where r, is defined as above, and is typically the point at which Δ (γ) or the trench region is maximum, r ₃ is the outer radius of the inner cladding and agreed to a point at which a (vertical) line drawn through refractive index profile or trench associated with its minimum refractive index crosses the zero delta line (ie, the point at which Δ (γ)% is zero), and r is in the range η <r <r <_ where Δ is defined above, r _; is the initial point of the α-profile of the trench region, r _f is the final point of the α-profile of the trench region, and a _T is an exponent which is a real number (also referred to as a trench alpha, ). In some, the trench alpha is 1 <a _T <100. In some, the pedestal alpha is 5 <a _T <20.

The term "trench" as used refers to a cladding region that has a variable refractive index with a minimum refractive index at A _3max that is lower than that or the adjacent cladding regions that are in contact therewith. The trench volume V _T is defined in equation 5 axis:

V _mnch = 2 | Δ ₅ _ ₃ (γ) ζϊ / γ Eq. 5? 2 where Δ ₅ . ₃ (γ) is Δ ₅ - Δ ₃ (γ) for a given radial position r situated between the radial positions of r ₂ and r ₃ , and r ₂ is the radial position where the refractive index in the trench cladding region, moving radially outward from centerline, is first equal to the refractive index or the outer cladding region. Trench volumes are reported in absolute value in units or% delta microns ² . In some embodiments, the trench volumes are 0.4% delta'microns ² <Vtrench <15% delta * ² microns. In other variables, the trench volumes are 0.3% delta »microns ² <Vtrench <5% delta * microns ² .

The term “pedestal” as used refers to a cladding region that has a refractive index Δ ₂ that is higher than that of the refractive index Δ ₅ cladding region that is in contact therewith. The ring volume V _pede5 is defined in equation 6 axis:

^r 2

V _pai es _ial -2jA ₅ _ ₂ (r) rt / r Eq. 6 '1 in Δ ₅ . ₂ (γ) is Δ ₅ - Δ ₂ (γ) for a given radial position r situated between the radial positions of Γ | and r ₂ , and with r ₂ is the radial position where the refractive index in the pedestal cladding region, moving radially outward from centerline, is first equal to the refractive index or the outer cladding region. Pedestal volumes are reported in absolute value in units or% delta »microns ² . In some variables, the pedestal volumes are 1% delta «microns ² <Vpedestaj <15% delta» microns ² . In other variables, the pedestal volumes are 2% delta * microns ² <Vpedestai <6% delta * microns ² .

The mode field diameter (MFD) is measured using the Peterman II method, 2w = MFD, and w ² = (2Jf ² rd / J [df / dr] ² rd), the integral limits being 0 to ».

The term "ring" as used refers to a cladding region that has a variable refractive index with a maximum refractive index at A _3max that is higher than that of the adjacent cladding regions that are in contact therewith.

The term "ring entry α-profile", also referred to as the alphari _ug . _e ntiy ^or «ïing-ent» refers to a relative refractive index profile of the inner cladding region, expressed in terms of Δ (γ) which is in units of “%”, where r is radius, which follows the equation (Eq. 7)

A (r) = Afe) + (Δ (γ,) - Δ (γ ₂ )) (1 - [| rr _t | / (r ₂ -r,)] ⁰ ™ *) Eq. 7 where ïq is defined as above, and is typically the point at which Δ (γ) or inner cladding region is maximum, r ₂ is the outer radius or inner cladding and agreed to a point at which a (vertical) line drawn through refractive index profile or inner cladding associated with its minimum refractive index crosses the zero delta line (ie, the point at which Δ (γ)% is zero), and r is in the range r ₍ <r <r _f , where Δ is defined above, η is the initial point of the α-profile of the inner cladding region, r _t is the final point of the α-profile or hte inner cladding region, and a _{rail. ent} is an exponent-which is a real number (In some cases, the ring entry alpha is 1 <a _r i _{! lg} . _ent <100. In some, the ring entry alpha is 5 <a _ring . _and t < 30. In the other variant, (eg, Figure 4 and Table 2), the ring alpha can also be referred to as a _3a .

The term "ring exit α-profile", also referred to as the alpha _ring _ _exit or a _ring . _ex , refers to a relative refractive index profile of the inner cladding region, expressed in terms of Δ (γ) which is in units or “%”, where r is radius, which follows the equation (Eq. 8),

Δ (Γ) = Δ (γ ₂ ) + (Δ (γ ₂ ) - Δ (γ ₃ )) (1 - [| rr ₂ | / (rr ₃ ) .r ^ig ' ^ex ) Eq. 8 where r ₂ is defined as above, and is typically the point at which Δ (γ) or the ring region is maximum, r ₃ is the outer radius or the ring and requires a point at which a (vertical) line drawn through refractive index profile or ring associated with its minimum refractive index crosses the zero delta line (ie, the point at which Δ (γ)% is zero), and r is in the range r _; <r <r _f , where Δ is defined above, r, is the initial point of the α-profile of the ring region, r _f is the final point of the aprofile of the ring region, and a _nng , _ex is tin exponent which is a real number (also referred to as an alpha read exit ring). In some, the ring exit alpha is 1 <a _r j _ng -exit <100. In some, the ring exit alpha is 5 <a _lina . _exil <30. In the following, (eg, Figure 4 and Table 2), the ring exit alpha can also be referred to as a _3b .

The terms "pm" and "microns" can be used interchangeably read.

The bend resistance of a waveguide fiber can be gauged by induced attenuation under prescribed test conditions, for example by deploying or wrapping the fiber around a mandrel of a prescribed diameter, eg, by wrapping 1 turn around either a 6 mm, 10 mm, or 20 mm or similar diameter mandrel (eg "1x10 mm diameter macro bend loss" or the "1x20 mm diameter macro bend loss") and measuring the increase in attenuation per turn.

One type of bend test is the lateral load microbend test. In this so-called "lateral load" test (LEWM), a prescribed length or waveguide fiber is placed between two flat plates. A # 70 wire mesh is attached to one of the plates. A known length of waveguide fiber is sandwiched between the plates and a reference attenuation is measured while the plates are pressed together with a force of 30 Newton. A 70 Newton force is then applied to the plates and the increase in attenuation is measured in dB / m. The increase in attenuation is the lateral load attenuation of the waveguide in dB / m at a specified wavelength (typically within the range of 1200 nm - 1700 nm, e.g., 1310 nm or 1550 nm or 1625 nm).

Another type of bend test is the wire mesh covered microbend loss lest (WMCD). In this test, a 400 mm diameter aluminum drum is wrapped with wire mesh. The mesh is wrapped tightly without stretching, and should have no holes, dips, or damage. Wire mesh material specification: McMaster-Carr Supply Company (Cleveland, OH), part number 85385T106, corrosion-resistant type 304 stainless steel woven wire cloth, mesh per linear inch: 165x165, wire diameter: 0.0483 mm (0.0019), width opening: 0.1041 mm (0.0041), open area%: 44.0. A prescribed length (750 meters) or waveguide fiber is wound at 1 m / s on the wire mesh drum at 0.050 cm take-up pitch while applying 80 (+/- 1) gram tension. The ends of the prescribed length of fiber are taped to maintain tension and there are no fiber crossovers. The attenuation of the optical fiber is measured at a specified wavelength (typically within the range of 1200-1700 nm, e.g., 1310 nm or 1550 nm or 1625 nm); a reference attenuation is measured on the optical fiber wound on a smooth drum. The increase in attenuation is the wire mesh covered drum attenuation or the waveguide in dB / km at a specified wavelength (typically within the range of 1200-1700 nm, e.g., 1310 nm or 1550 nm or 1625 nm).

The "pin array" bend test is used to compare relative resistance or waveguide fiber to bending. To perform this test, attenuation loss is measured for a waveguide fiber with essentially no induced bending loss. The waveguide fiber is then woven about the pin array and attenuation measured again. The loss induced by bending is the difference between the two measured attenuations. The pin array is a set of ten cylindrical pins arranged in a single row and held in a fixed vertical position on a flat surface. The pin spacing is 5 mm, center to center. The pin diameter is 0.67 mm. During testing, sufficient tension is applied to make the waveguide fiber conform to a portion of the pin surface. The increase in attenuation is the pin array attenuation in dB or the waveguide at a specified wavelength (typically within the range of 1200-1700 nm, e.g., 1310 nm or 1550 nm or 1625 nm).

The theoretical fiber cutoff wavelength, or "theoretical fiber cutoff", or "theoretical cutoff", for a given mode, is the wavelength above which guided light cannot propagate in that mode. A mathematical definition can be found in Single Mode Fiber Optics, Jeunhomme, pp. 3944, Marcel Dekker, New York, 1990 in which the theoretical fiber cutoff is described as the wavelength at which the mode propagation constantly becomes equal to the plane wave propagation constant in the outer cladding. This theoretical wavelength is appropriate for an infinitely long, perfectly straight fiber that has no diameter variations.

Fiber cutoff is measured by the standard 2m fiber cutoff test, FOTP-80 (ΕΙΑ-ΊΊΑ-45580), to yield the “fiber cutoff wavelength”, also known as the “2m fiber cutoff” or “measured cutoff”. The FOTP-80 standard test is performed to either strip out the higher order modes using a controlled amount of bending, or to normalize the spectral response of the fiber to that or a multimode fiber.

By cabled cutoff wavelength, or “cabled cutoff” as used, we mean the 22 m cabled cutoff test described in the EIA-445 Fiber Optic Test Procedures, which are part of the EIATIA Fiber Optics Standards, that is, the Electronics Industry Alliance - Telecommunications Industry Association Fiber Optics Standards.

The ratio of MFD at 1310 nm to Cable Cutoff wavelength (MFD at 1310 nm / Cable Cutoff wavelength in microns) is defined as MACC.

Unless otherwise noted, optical properties (such as dispersion, dispersion slope, etc.) are reported for the LP01 mode.

Referring now to FIG. 1, a side view or a single mode optical fiber 10 is provided. The optical fiber 10 has a centerline AC and a radial coordinate r. The optical fiber 10 has a chlorine doped silica central core 14 or radius r _; surrounded by a cladding 18 having a maximum radius r ₄ . In some, the optical fiber 10 includes an undoped silica layer 22 that surrounds the cladding 18, and having a maximum radius of _riax .

The core 14 has a core alpha profile (Core _a ) where 1 <Core _a <100 and a maximum relative refractive index delta A _{) max} , where some are in the following ranges: 0.10% <A _max <0.45%, 0.13% <A _lmax <0.39%, 0.14% <A _lfflax <0.37%, 0.10% <A _lmax <0.40%, or 0.13% <Ajmax <0.36%. In some, the core 14 has a radius r, in the range 3.5 microns <rj <5.5 microns, 3.6 microns <r, <4.5 microns, or 3.7 <is <4.3.

The core 14 can be made from silica doped with chlorine (Cl) at a Cl concentration, [Cl],> 1.5 wt%. The Cl concentration in the core may be> 2.0 wt%, may be> 2.5 wt%; may be> 3.0 wt%; may be> 3.5 wt%,> 4.0 wt%,> 4.5 wt%, or> 5.5 wt%; may be 1.5 wt% <[Cl] <8.5 wt%; may be 1.5 wt% <[Cl] <5.5 wt%; may be 2.0 wt% <[Cl] 5.5 wt%. The single mode optical fiber 10 can include the chlorine doped silica central core 14 region where the core alpha profile (CoreJ is 1 <Core _a <100, 1 <Core _a <10, 4 <Core _a <30, or 10 <Core _a <30. The core alpha profile (Core _ff ) may be>10,>15,> 20, or> 25.

The optical fiber 10 may have a mode field diameter (MFD) at 1310 nm or> 9 microns and can be in the range of 9 microns <MFD <9.5 microns. The optical fiber 10 can exhibit a mode field diameter at 1310 nm or 8.2 microns <MDF _{) 310nm} <9.6 microns or 9.0 <MDF _i3101uu <9.6.

The optical fiber 10 may have a 22 m cable cutoff less than or equal to 1260 nm, a macrobending loss at 1550 nm or <0.75 dB / turn on a 20 mm diameter mandrel, may exhibit a

MACC number between 6.6 and 8.3, and a zero dispersion wavelength, λ ₀ ranging from 1300 nm <λ ₀ <1324 nm. The optical fiber 10 may have a 22 m cable cutoff less than or equal to 1260 nm, a macrobending loss at 1550 nm or <0.70 dB / turn on a 20 mm diameter mandrel, may exhibit a MACC number between 7.1 and 8.1, a zero dispersion wavelength, λ ₀ ranging from 1300 nm <λ ₀ <1324 nm, and may exhibit a mode field diameter at 1310 nm or 8.2 microns <MDF | ₃ 10, _un <9.6 microns.

The optical fiber 10 may have a macrobending loss at 1550 nm or <0.5 dB / turn on a 20 nun diameter mandrel. In other variants, the optical fiber 10 has a macro bending loss at 1550 nm or <0.05 dB / turn on a 30 mm diameter mandrel. The optical fiber 10 may have a macrobending loss at 1550 nm or <0.005 dB / turn on a 30 mm diameter mandrel.

The optical fiber 10 may have an outer radius for cladding 18 or about r _max =

62.5 microns. The optical fiber 10 may have an outer radius for cladding 18 or r _ItHX = 62.5 microns.

The optical fibers shown see meet ITU G.652 and G.657A optical performance properties, and can demonstrate or yield very low macrobend and microbending losses in addition to a very low attenuation at 1310 and 1550 nm.

The optical fiber 10 may have a number or additional features as set forth below.

Pedestal and Trench Examples

Referring now to FIG. 2, a schematic cross-sectional diagram of the optical fiber 10 is shown according to the present disclosure. The optical fiber 10 may include:

(i) the chlorine doped silica-based core 14 including the core alpha (Core _a )> 4, the radius r, and the maximum refractive index delta A _lmax %; and (ii) the cladding 18 surrounding the core 14.

The cladding 18 surrounding the core 14 may include:

a) a pedestal layer 26 adjacent to and in contact with the core 14 and having a refractive index delta A ₂ , a radius r ₂ , and a minimum refractive index delta A _2min such that A _2min <A, _max ;

b) an inner cladding layer 30 or trench layer 30a adjacent to and in contact with the first inner cladding 26 having a refractive index Δ ₃ , a radius r ₃ , and a minimum refractive index delta A _3min such that Δ _3πώ) <A ₂ ; and

c) an outer cladding 34 adjacent to and in contact with the first inner cladding 30 having a refractive index A ₅ and a radius r ₄ (which in this case is r _max ), such that A _3m j _n <A ₂ .

The optical fiber 10 may have a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or <1260 nm, a zero dispersion wavelength ranging from 1300 nm <λ ₀ <1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.5 dB / tum.

Still referring now to FIG. 2, another aspect of the schematic cross-sectional diagram of the single-mode optical fiber 10 is shown. The single mode optical fiber 10 may include:

(i) the chlorine doped silica central core region 14 having a core alpha (Core ')> 4, a radius r ₁ and a maximum refractive index delta A _lmax %; and (ii) the cladding 18 surrounding the core 14, the cladding 18 including:

a) the pedestal layer 26 adjacent to and in contact with the core 14 and having a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta ^ 2min such that A _2min <A _lmax ;

b) the inner cladding 30 or trench layer 30a adjacent to and in contact with the pedestal layer 26 having a refractive index Δ ₃ , a radius r ₃ , and a maximum refractive index delta Δ _3ιϊβχ such that Δ _2ιη , _η <A _3max ; and

c) an outer cladding region 34 surrounding the inner cladding region 30 or trench layer 30a and having a refractive index Δ ₅ and a radius r ₄ (which in this case is r _max ), such that Δ ₅ <A _3max ; if the optical fiber has a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or <1260 nm, a zero dispersion wavelength ranging from 1300 nm <λ ₀ <1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.75 dB / turn.

Referring now to FIG. 3 A, a plot of the relative refractive index profile Δ versus radius r for the optical fiber 10 represented in FIG. 2. The cladding 18 of the pedestal and trench of optical fiber 10 may include two regions that progress outwardly from the core 14 in the following order: the pedestal layer 26 surrounding the core 14 having the radius r ₂ and the refractive index Δ ₂ ; the inner cladding layer 30 or trench layer 30a having the radius r ₃ and the refractive index D ₃ ; and the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _max ) and having the refractive index Δ ₅ . The respective refractive indexes of the core 14 and cladding 18 are Δ | _ΠΚΧ > Δ ₅ > Δ ₂ > A _3min .

Referring now to FIG. 3B, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal or optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _b refractive index Δ], and the refractive index A _{) max} in the following order: the pedestal layer 26 surrounding the core 14 having the radius r ₂ , the refractive index Δ ₂ , and the alpha pedestal and the outer cladding layer 34 having a radius r ₄ (and in this case which is equal to r _max ) and having a refractive index Δ ₅ . The respective refractive indexes of the core 14 and cladding 18 are A _lmax > Δ ₂ > Δ ₅ .

Referring now to FIG. 4, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 or the pedestal or optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _1? refractive index Δ], and the refractive index A _{] max} in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ and the refractive index Δ ₂ ;

- the inner cladding layer 30 or ring layer 30b having the radius r ₃ , a ring entry alpha a _3a , a ring exit alpha a _3b , and the refractive index A _3jnax ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _max ) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 tire A _iJnax > Δ _3ηΗΧ > Δ ₅ > Δ ₂ .

The pedestal layer 26 can be made from silica doped with chlorine (Cl) at a Cl concentration, [Cl],> 0.2 wt%. The Cl concentration in the pedestal may be> 0.4 wt%; may be> 0.5 wt%; may be> 0.7 wt%; may be> 1.0 wt%; may be 0.2 wt% <[Cl] <1.5 wt%; may be 0.5 wt% <[Cl] <1.5 wt%; The pedestal layer 26 can be made from silica doped with fluorine (F) at a F concentration, [F],> 0.2 wt%. The F concentration in the pedestal may be> 0.5 wt%,> 0.7 wt%, or> 1 wt%.

Adjacent cladding regions can be coupled with one another while the pedestal layer 26 is in contact and coupled with the core 14. Inner cladding or trench layer 30a can be positioned outside and in contact with the pedestal layer 26. The outer cladding layer 34 can be positioned outside and in contact with inner cladding or trench layer 30a. Outer cladding layer 34 can be adjacent to and in contact with the outermost layer 22 or undoped silica.

The inner cladding or trench layer 30a can be made from undoped silica or silica doped with chlorine (Cl) at a Cl concentration, [Cl],> 0.1 wt%. The Cl concentration in the inner cladding or trench layer 30a may be> 0.4 wt%; may be 0 wt% <[Cl] <1.5 wt%. The inner cladding or trench layer 30a can be made from silica doped with fluorine (F) at a F concentration, [F],> 0.2 wt%. The F concentration in the pedestal may be> 0.5 wt%,> 0.7 wt%, or> 1 wt%. The F concentration in the inner cladding or trench layer 30a may be 0 wt% <[F] <1.5 wt%.

The outer cladding layer 34 can be made from undoped silica or silica doped with chlorine (Cl) at a chlorine concentration, [Cl],> 0.1 wt%. The Cl concentration in the outer cladding layer 34 may be> 0.4 wt%; may be 0 wt% <[Cl] <1.5 wt%. The outer cladding layer 34 can be made from silica doped with fluorine (F) at a F concentration, [Fj,> 0.2 wt%. The F concentration in the pedestal may be> 0.5 wt%,> 0.7 wt%, or> 1 wt%. The F concentration in the outer cladding layer 34 may be 0 wt% <[F] 1.5 wt%.

The chlorine concentration in the core 14 in wt%, [Cl] _core , to the fluorine concentration in the pedestal wt%, [F] _pedestal , can be greater than or equal to 1, ie, ([ClJ _core / [F] _{ped (stable.)>} 1, for example ([CLJ _core / [Fj _pedestal)> 2, whereby ([Crj _core / [F] _{pedest; il)} can be> 10.

The chlorine concentration in the core 14 wt%, [Cl] _TOr , to the fluorine concentration in the trench in wt%, [F] _ffench , can be greater than or equal to 1, ie, ([Clkore / LFJtrench)> 1, for example ([ClJcore / fF] ^ *)> 2, For ([Cl] _core / [FJ _trcnch ) can be> 10.

Table 1 below sets forth eight examples (Ex. 1.1 through Ex. 1.8) of the Pedestal and

Trench Examples used in the optical fiber 10 where the core dopant is chlorine and the pedestal dopant is at least one of chlorine or fluorine. In some examples the outer clad dopant (referred to in Table 1 as Δ ₅ ) is chlorine. The term "na" refers to "not applicable." The term "Attn" refers to attenuation.

Table 1

Parameter Ex. 1.1 Ex. 1.2 Ex. 1.3 Ex. 1.4 Ex. 1.5 Ex. 1.6 Ex. 1.7 Ex. 1.8 Core, _A1max , / q 0.15 0.15 0.36 0.37 0.375 0.373 0.38 0.362 Γ (, microns 4.20 4.00 4.25 4.50 4.46 4.65 4.55 4.0 Core alpha 20 100 10 6.7 6.0 4.5 10 100 Core dopant Cl Cl Cl Cl Cl Cl Cl Cl δ ₂ % -0.18 -0.13 0.087 0.087 0.10 0.087 0.10 0.10 r ₂ , microns 10.0 6.5 5.85 5.79 5.73 5.85 6.20 5.70 Pedestal alpha 20 20 20 20 20 20 20 20 Pedestal dopant F F Cl Cl Cl Cl Cl Cl Pedestal volume,% delta microns ² 2.5 1.8 1.4 1.2 1.3 1.1 1.2 1.6 -0.23 -0.23 0.00 0.00 0.00 0.00 0.00 0.00 r ₃ , microns 20 15 after after after after 15 after Trench alpha 20 20 after after after after 20 after Trench volume,% delta »microns ² 6.0 5.5 after after after after 5.6 after δ ₅ % -0.21 -0.20 0.00 0.00 0.00 0.00 0.03 0.00 Δ ₅ dopant F F after after after after Cl after r _mM , microns 62.5 62.5 62.5 62.5 62.5 62.5 62.5 62.5 Dispersion at 1310 nm (ps / nm / km) 0.37 0.20 -0.12 0.14 0.03 -0.13 0.32 0.31 Dispersion Slope at 1310 nm, (ps / nm ² / km) 0.085 0.089 0.088 0.088 0.088 0.088 0.089 0.088

Dispersion at 1550 nm, (ps / nm / km) 16.7 17.5 17.0 17.2 17.2 17.1 17.6 17.4 Dispersion at Slope 1550 nm, (ps / nm ² / km) 0.059 0.060 0.059 0.059 0.060 0.060 0.060 0.059 MFD at 1310 nm, microns 9.09 9.18 9.18 9.16 9.14 9.20 9.18 9.19 MFD at 1550 nm, microns 10.4 10.4 10.4 10.4 10.4 10.5 10.3 10.4 LLWM @ 1550nm, dB / m 0.362 0.40 0.45 0.33 0.32 0.42 0.43 0.33 WMCD at 1550 nm, dB / km <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.06 Pin Array at 1550 nm, dB 3.1 6.9 6.4 4.5 4.3 5.7 7.9 4.2 Zero dispersion wavelength, λο, nm 1318 1315 1319 1316 1317 1319 1314 1314 22 m Cable Cutoff, nm 1191 1259 1225 1254 1255 1240 1254 1256 MACC (MFD at 1310 nm / Cable Cutoff) 7.63 7.29 7.5 7.3 7.3 7.4 7.3 7.3 Macro bend loss 1x20mm mandrel, dB / turn at 1550nm 0.27 0.15 0.25 0.19 0.18 0.23 0.18 0.18 Macro Bend Loss 1x30mm mandrel, dB / turn at 1550nm 0.002 0.003 0.00 0.003 0.003 0.003 0.003 0.0025 Attn at 1550 nm, dB / km <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 <0.17 Attn at 1310 nm, dB / km <0.31 <0.31 <0.31 <0.31 <0.31 <0.31 <0.31 <0.31

The results from the modeled optical fibers in Table 1 show optical fibers that measures

ITU G.652 and G.657A optical performance properties, have very low macrobend and microbending losses and very low attenuation at 1310 and 1550 nm. In these examples, in wt% ([Cl] _core ) / wt% [F] _pedestaJ , the ([Cl] _TOre / [F] _pedes t _{! D} )> 1. In these examples in wt% ([Cl] _core / wt% [FJ ^ h, the ([ClJeore / EFJ ^ h> 1.

Referring now to FIG. 5 or Example 1.1, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal example of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r ,, refractive index

A ,, and the refractive index A _lmax in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ , the alpha pedestal Opedestat and the refractive index Δ ₂ ;

- the inner cladding layer 30 or trench layer 30a having the radius r ₃ , an alpha trench Otrench, and the refractive index Δ ₃ ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r max) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 are A _imax > Δ ₂ > Δ ₅ > Δ ₃ .

Referring now to FIG. 6 or Example 1.2, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal example of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r ,, refractive index Δ], and the refractive index A _lmax in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ , the alpha pedestal Opedestat and the refractive index Δ ₂ ;

- the inner cladding layer 30 or trench layer 30a having the radius r ₃ , an alpha trench ÖB-ench, and the refractive index Δ ₃ ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _max ) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 are A _imax > Δ ₂ > Δ ₅ > Δ ₃ .

Referring now to FIGS. 7-10 or Examples 1.3-1.6, an index profile Δ versus radius r for some the optical fiber 10 is represented. The cladding 18 of the pedestal example of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _b refractive index A _t , and the refractive index Δ _11ιω χ in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ , the alpha pedestal Opedestat and the refractive index Δ ₂ ; and

- the inner cladding layer 30 or trench layer 30a having the radius r ₃ (and in this case which is equal to r _niax ) and the refractive index Δ ₃ .

The respective refractive indexes of the core 14 and cladding 18 are Δ _1ηκχ > Δ ₂ > Δ ₃ .

Referring now to FIG. 11 or Example 1.7, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 or the pedestal example of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _)? refractive index Δι, and the refractive index Δ _1πΕ1χ in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r _2, the alpha pedestal a _{pedestal still} and the refractive index Δ _2;

- the inner cladding layer 30 or trench layer 30a having the radius r ₃ , an alpha trench then, and the refractive index Δ ₃ ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _max ) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 are Δ _1ηκχ > Δ ₂ > Δ ₅ > Δ ₃ .

Referring now to FIG. 12 or Example 1.8, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal example of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _B refractive index Δ ₍ , and the refractive index A _lmax in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ , the alpha pedestal a _pe destai and the refractive index Δ ₂ ; and

- the inner cladding layer 30 or trench layer 30a having the radius r ₃ (and in this case which is equal to r _max ) and the refractive index Δ ₃ .

The respective refractive indexes of the core 14 and cladding 18 are Δ _1ΙΠί1χ > Δ ₂ > Δ ₃ .

Table 2 below sets forth two examples (Ex. 2.1 and Ex. 2.2) or Ring examples used in the optical fiber 10 where the core dopant is chlorine and the ring (Δ ₂ ), as well as Δ ₃ and Δ4 dopant is chlorine.

Table 2

Parameter Ex. 2.1 Ex. 2.2 Core, Δ iniax, / 0 0.352 0.38 Γ], microns 4.30 4.53 Core alpha, Δ _core 20 20 Core dopant Cl Cl Δ ₂ % 0.00 0.00 r ₂ , microns 5.33 5.48 Δ _3m ax,% 0.10 0.10 r ₃ , microns 6.28 6.55 Ring entry alpha, Δ _3a 20 20 Ring exit alpha, Δ _3b 20 20 Ring dopant Cl Cl δ ₅ % 0.00 0.03 Δ 5 dopant none Cl r _max , microns 62.5 62.5 Dispersion at 1310 nm (ps / nm / km) -0.55 -0.59

Dispersion Slope at 1310 nm, (ps / nm ² / km) 0.087 0.088 Dispersion at 1550 nm, (ps / nm / km) 16.5 16.7 Dispersion at Slope 1550 nm, (ps / nm ² / km) 0.06 0.06 MFD at 1310 nm, microns 9.20 9.20 MFD at 1550 nm, microns 10.5 10.5 LLWM at 1550 nm, dB / m 0.57 0.53 WMCD at 1550 nm, dB / km <0.05 <0.05 Pin Array at 1550 nm, dB 8.0 7.5 Zero dispersion wavelength, nm 1316 1317 22 m Cable Cutoff, X _c , nm 1200 1205 MACC (MFD at 1310 nm / Cable Cutoff) 7.67 7.63 Macro bend loss 1 x20mm mandrel, dB / turn at 1550nm 0.41 0.33 Macro Bend Loss 1x30mm mandrel, dB / turn at 1550nm 0.005 0.00 Attn at 1550 nm, dB / km <0.17 <0.17 Attn at 1310 nm, dB / km <0.31 <0.31

The results from the modeled optical fibers in Table 2 show optical fibers that measures

ITU G.652 and G.657A optical performance properties, have very low macrobend and microbending losses and very low attenuation at 1310 and 1550 nm.

Referring now to FIG. 13 or Example 2.1, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal examples of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _1; refractive index Δ ₍ , and the refractive index Δ _{! ιη £ ιχ} in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ and the refractive index Δ ₂ ;

- the inner cladding layer 30 or ring layer 30b having the radius r ₃ , the ring entry alpha α ^ _α , the ring exit alpha a _3b , and the refractive index A _3max ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _{11! ax} ) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 are A _{! Max} > Δ _311ΒΧ and Δ ₅ = Δ ₂ .

Referring now to FIG. 14 or Example 2.2, an index profile Δ versus radius r for the optical fiber 10 is represented. The cladding 18 of the pedestal examples of optical fiber 10 may include two regions that progress outwardly from the core 14 having the radius r _{1 (} refractive index Δ ₍ , and the refractive index Δ _{! Ιη £ ιχ} in the following order:

- the pedestal layer 26 surrounding the core 14 having the radius r ₂ and the refractive index Δ ₂ ;

- the inner cladding layer 30 or ring layer 30b having the radius r ₃ , the ring entry alpha a _3a , the ring exit alpha a _3b , and the refractive index A _3max ; and

- the outer cladding layer 34 having the radius r ₄ (and in this case which is equal to r _{11! ax} ) and having the refractive index Δ ₅ .

The respective refractive indexes of the core 14 and cladding 18 are Δ _{! Πκχ} > Δ _311ιαχ > Δ ₅ > Δ ₂ .

The A _imax ranges can be from 0.10% <Δ _{1ηκ (Χ} <0.45%, 0.13% <A _imax <0.39%, 0.14% <A _{] max} <0.37%, 0.10% <A _lmax <0.40%, or 0.13% < A _iJnax <0.36% In other examples A _max can be 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38 %, or 0.39%.

The pedestal radius r ₂ ranges can be from 4.5 microns <r ₂ <20.5 microns, 4.5 microns <r ₂ <7.5 microns, 5.3 microns <r ₂ <17.5 microns, 5.3 microns <r ₂ <8.0 microns, 5.5 microns <r ₂ <20.5 microns, 7.5 microns <r ₂ <17.5 microns, 6.0 microns <r ₂ <17.5 microns, or 9.0 microns <r ₂ <16.0 microns. r ₂ can be about 6.0 microns, 6.3 microns, 6.5 microns, 6.8 microns, 7.0 microns, 7.3 microns, 10.0 microns, 12.5 microns, 15.0 microns, 17.5 microns, or 20.5 microns.

The refractive index Δ ₂ ranges can be from 0% <Δ ₂ <1.0% or 0% <Δ ₂ <0.5%, 0% <Δ ₂ <0.1%. Δ ₂ can be about 0.01%, 0.03%, 0.05%, 0.07%, or 0.09%.

Pedestal volumes are reported in absolute value in units or% delta * microns ² . The pedestal volumes can be 0.5% delta * microns ² <Vpedestal <15% delta »microns ² , preferably 0.5% delta» microns ² <VpedesIal <6% delta · microns ² . Trench volumes are reported in absolute value in units or% delta * microns ² . The trench volumes can be 1% delta microns ² <V _he , _K h <15% delta »microns ² preferably 2% delta microns ² <Vn-ench <6% delta» microns ² .

The inner cladding or trench radius r ₃ ranges can be from 15.0 microns <r ₃ <75.0 microns, 15.0 microns <r ₃ <65.0 microns, 15.0 microns <r ₃ <30.0 microns, or 50.0 microns <r ₃ <70.0 microns. In other variants, r ₃ can be about 15.0 microns, 20.0 microns, 25.0 microns, 30.0 microns, 35.0 microns, 40.0 microns, 45.0 microns, 50.0 microns, 55.0 microns, 60.0 microns, 65.0 microns, 7.3 microns, 10.0 microns, 12.5 microns , 15.0 microns, 17.5 microns, or 20.5 microns.

The Δ ₃ may include both a Δ _311ΜΧ and a A _3min . The refractive index Δ _3πκχ ranges can be from -1.5% <A _3max <1.5%, -0.5% <Δ _3ιηί1χ <0.5%, 0% <Δ _311ΗΧ <1.0%, 0% <Δ _3μιχ <0.5%, or 0% <Δ _3ιϊβχ <0.05%. Δ _311ΏΧ can be about 0%, 0.01%, 0.03%, 0.05%, 0.07%, 0.09%, -0.01%, -0.03%, 0.05%, -0.07%, or -0.09%. The refractive index Δ _3ηώ1 ranges can be from -1.5% <A _3min <1.5%, 0.5% <A _3min <0.5%, 0% <Δ _3πώ1 <1.0%, 0% <A _3min <0.5%, or 0% < A _3min <0.05%. A _3mill can be about 0%, 0.01%, 0.03%, 0.05%, 0.07%, 0.09%, -0.01%, -0.03%, -0.05%, -0.07%, or -0.09%.

The r _max can be about 62.5 microns. The refractive index Δ ₅ ranges can be from -1.5% <Δ ₅ <1.5%, -0.5% <Δ ₅ <0.5%, 0% <Δ ₅ <1.0%, 0% <Δ ₅ <0.5%, or 0% <Δ ₅ <0.05%. In other variants, Δ ₅ can be about 0%, 0.01%, 0.03%, 0.05%, 0.07%, 0.09%, 0.10%, 0.15%, 0.20%, 0.25%, -0.01%, -0.03%, -0.05% , -0.07%, -0.09%, -0.10%, -0.15%, -0.20, or -0.25%.

The optical fiber 10 can have a macrobending loss at 1550 nm or <0.75 dB / turn on a 20 mm diameter mandrel. The optical fiber 10 can have a macrobending loss at 1550 nm or 0.5 dB / turn on a 20 mm diameter mandrel. The optical fiber 10 can have a macrobending loss at 1550 nm or <0.05 dB / turn on a 30 mm diameter mandrel. The optical fiber 10 can have a macrobending loss for 1550 nm or <0.005 dB / turn on a 30 mm diameter mandrel.

The optical fiber 10 may exhibit the wire mesh covered drum microbend loss, WMCD, at 1550 nm is <0.1 dB / km. In other variants, the wire mesh covered microbend loss drum, WMCD, at 1550 nm is <0.05 dB / km.

The attenuation at 1550 nm can be <0.19 dB / km for the pedestal examples. The attenuation at 1550 nm can be <0.18 dB / km for the pedestal examples. The attenuation at 1550 nm can be <0.17 dB / km for the pedestal examples.

The attenuation at 1310 nm can be <0.33 dB / km, can be <0.32 dB / km, and can be <0.31 dB / km for the pedestal examples.

The attenuation at 1550 nm can be <0.19 dB / km; can be <0.18 dB / km, and can be <0.17 dB / km for the ring examples.

The attenuation at 1310 nm can be <0.33 dB / km, can be <0.32 dB / km, and can be <0.31 dB / km for the ring examples.

The optical fiber 10 can have a zero dispersion wavelength, λ ₀ , and 1300 nm <<

1324 nm.

The optical fiber 10 may exhibit a mode field diameter at 1310 nm (MDF _{J3] O} nm) or 8.2 <MDF | ₃₁ () _nm <9.6 microns. The optical fiber 10 may exhibit a mode field diameter at 1310 nm or 9.0 microns <MDFi _310nm <9.5 microns.

Referring now to FIG. 4, a plot or profile schematic of the relative refractive index profile ("index profile") Δ versus radius r for some aspects of the optical fiber 10 represented in FIG. 2. The optical fiber 10 represented by FIG. 4 include the chlorine doped core 14 with a gradual transition in refractive index between Δ ₃ and Δ ₅ . The respective refractive indexes of the core 14 and cladding 18 can be Δ, _Μ1Χ > Δ ₅ > Δ ₂ > Δ _31ιώ1 .

The core and cladding of the coated fibers may be produced in a single-step operation or multi-step operation by methods which are well known in the art. Suitable methods include:

- the double crucible method, rod-in-tube procedures; and

- doped deposited silica processes, also commonly referred to as chemical vapor deposition (“CVD”) or vapor phase oxidation.

A variety of CVD processes are known and are suitable for producing the core and cladding layer used in the coated optical fibers disclosed. They include external CVD processes, axial vapor deposition processes, modified CVD (MCVD), inside vapor deposition, and plasma enhanced CVD (PECVD).

The glass portion of the coated fibers may be drawn from a specially prepared, cylindrical preform which has been locally and symmetrically heated to a temperature sufficient to soften the glass, e.g., a temperature of about 2000 ° C for a silica glass. As the preform is heated, such as by feeding the preform into and through a furnace, a glass fiber is drawn from the molten material. See, for example, U.S. Patent Nos. 7,565,820; 5,410,567; 7,832,675; and 6,027,062; the disclosures of which are incorporated by reference, for further details about fiber making processes.

The optical fibers 10 described in the pedestal and trench chlorine examples may include one or more coatings positioned between the chlorine doped silica central core 14 region and the one or more layers of cladding 18. There can be a primary coating in contact with the outer radius of the chlorine doped silica central core 14 region and a secondary coating in contact with the outer radius of the primary coating.

The primary coating may be formed from a curable composition that includes an oligomer and a monomer. The oligomer may be a urethane acrylate or a urethane acrylate with acrylate substitutions. The urethane acrylate with acrylate substitutions may be a urethane methacrylate. The oligomer may include urethane groups. The oligomer may be a urethane acrylic that includes one or more urethane groups. The oligomer may be a urethane acrylate with acrylate substitutions that includes one or more urethane groups. Urethane groups may be formed as a reaction product or an isocyanate group and an alcohol group.

The primary coating may have an in situ modulus of elasticity or 10 bar (1 MPa) or less, 5 bar (0.50 MPa) or less, 2.5 bar (0.25 MPa) or less, 2 bar (0.20 MPa) or less, 1.9 bar (0.19 MPa) or less, 1.8 bar (0.18 MPa) or less, 1.7 bar (0.17 MPa) or less, 1.6 bar (0.16 MPa) or less, or

1.5 bar (0.15 MPa) or less. The glass transition temperature of the primary coating may be -15 ° C or less, -25 ° C or less, -30 ° C or less, or -40 ° C or less.

The secondary coating may be formed from a curable secondary composition that includes one or more monomers. The one or more monomers may include bisphenol-A diacrylate, or a bisphenol-A diacrylate, or an alkoxylated bisphenol-A diacrylate. The alkoxylated bisphenol-A diacrylate may be an ethoxylated bisphenol-A diacrylate. The curable secondary composition may further include an oligomer. The oligomer may be a urethane acrylate or a urethane acrylate with acrylate substitutions. The secondary composition may be free of urethane groups, urethane acrylate compounds, urethane oligomers or urethane acrylate oligomers.

The secondary coating may be a material with a higher modulus of elasticity and higher glass transition temperature than the primary coating. The in situ modulus of elasticity or the secondary coating may be 12,000 bar (1,200 MPa) or greater, 15,000 bar (1500 MPa) or greater, 18,000 bar (1800 MPa) or greater, 21,000 bar (2100 MPa) or greater, 24,000 bar (2,400 MPa) or greater, or 27,000 bar (2,700 MPa) or greater. The secondary coating may have an in situ modulus between about 15,000 bar (1,500 MPa) and 100,000 bar (10,000 MPa) or between 15,000 bar (1,500 MPa) and 50,000 bar (5,000 MPa). The in situ glass transition temperature of the secondary coating may be at least 50 ° C, at least 55 ° C, at least 60 ° C or between 55 ° C and 65 ° C.

The radius of the coated fibers coincides with the outer diameter or the secondary coating. The radius of the coated fiber may be 125 pm or less, 110 pm or less, 105 pm or less, or 100 pm or less. In some variants, the coated optical fiber diameter is 150 microns <coated optical fiber diameter <210 microns. Within the coated fiber, the glass radius (coinciding with the outer diameter of the cladding) may be at least 50 pm, at least 55 pm, at least 60 pm, or at least

62.5 pm. The chlorine doped silica central core 14 region may be surrounded by the primary coating. The outer radius of the primary coating may be 85 pm or less, 82.5 pm or less, 80 pm or less, 77.5 pm or less, or 75 pm or less. The balance of the coated fiber diameter is provided by the secondary coating.

EXAMPLES

Example A is a single mode optical fiber including:

(i) a chlorine doped silica-based core comprising a core alpha (CoreJ> 4, a radius η and a maximum refractive index delta A _lmax ; and (ii) a cladding surrounding the core, the cladding including:

a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta A _2min such that Δ _2πώ) <A _imax ; and

b) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ ₅ and a radius r _niax , such that Δ _2ηιίη > Δ ₅ .

The optical fiber has a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or <1260 nm, a zero dispersion wavelength ranging from 1300 nm <<1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB / turn.

The single mode optical fiber or example A including a second inner cladding adjacent to and in contact with the first inner cladding and having a refractive index Δ ₃ , a radius r ₃ , and a minimum refractive index delta Δ _3ιώη such that Δ _; , _Λ1ίη <Δ ₂ .

The single mode optical fiber or example A or example A with any of the intervening features the outer cladding region surrounding the second inner cladding region has a refractive index Δ ₅ and a radius r _max , such that Δ _3ηιίη <Δ ₅ .

The single mode optical fiber or example A or example A with any of the intervening features further including a chlorine concentration in the core or> 1.5 wt%.

The single mode optical fiber or example A or example A with any of the intervening features within the macrobending loss at 1550 nm is <0.5 dB / turn on a 20 mm diameter mandrel.

The single mode optical fiber or example A or example A with any of the intervening features provided with the maximum refractive index Δ _lmax ranges from 0.10% <Δ _1ηΏΧ <0.45%.

The single mode optical fiber or example A or example A with any of the intervening features with the minimum refractive index Δ _3ιηιη is -0.5% <A _3min <0.25%.

The single mode optical fiber or example A or example A with any of the intervening features with the minimum refractive index A _3min is _-0.25 % <Δ _311ώ1 <0.15%.

The single mode optical fiber or example A or example A with any of the intervening features from the outer radius r ₃ is 12.0 microns <r ₃ <25.0 microns.

The single mode optical fiber or example A or example A with any of the intervening features the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / turn on a 20 mm diameter mandrel and exhibits a MACC number between 7.1 and 8.1 .

Example B is a single mode optical fiber including:

(i) a chlorin doped silica-based core Comprising a core alpha (CoreJ> 4, r is a radius _b and a maximum refractive index delta _Δ 1πΕ1χ; and (ii) a cladding surrounding the core, the cladding Comprising:

a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta Δ _2η1 ί _η such that A _2min ^< A _lmax ;

b) a second inner cladding adjacent to and in contact with the first inner cladding and having a refractive index Δ ₃ , a radius r ₃ , and a maximum refractive index delta Δ _3πβχ such that A _2m i _n <A _3inax ; and

c) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ ₅ and a radius r _niax , such that Δ ₅ <Δ _3πΕ1χ .

The optical fiber has a mode field diameter MFD at 1310 or> 9 microns, a cable cutoff or <1260 nm, a zero dispersion wavelength ranging from 1300 nm <λ ₀ <1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.75 dB / turn.

The single mode optical fiber or example B further including a chlorine concentration in the core or> 1.5 wt%.

The single mode optical fiber or example B or example B with any of the intervening features The macrobending loss at 1550 nm is <0.5 dB / turn on a 20 mm diameter mandrel.

The single mode optical fiber or example B or example B with any of the intervening features in the macrobending loss at 1550 nm or <0.005 dB / turn on a 30 mm diameter mandrel.

The single mode optical fiber or example B or example B with any of the intervening features regarding the maximum refractive index _iJnax ranges from 0.10% <A _iJnax <0.45%.

The single mode optical fiber or example B or example B with any of the intervening features w'herein Core _a > 15.

The single mode optical fiber or example B or example B with any of the intervening features regarding the maximum refractive index A _3max is -0.5% <A _3jnin <0.25%.

The single mode optical fiber or example B or example B with any of the intervening features regarding the outer radius r ₃ is 15.0 microns <r ₃ <15.0 microns.

The single mode optical fiber or example B or example B with any of the intervening features with the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / turn on a 20 mm diameter mandrel and exhibits a MACC number between 7.1 and 8.1 .

The single mode optical fiber or example B or example B with any of the intervening features where the optical fiber has a wire mesh covered drum microbend loss, (WMCD) at 1550 nm or <0.1 dB / km.

Claims (22)

CLAUSES 1. An optical fiber including: i) a chlorine doped silica based core having a radius o and a maximum refractive index delta A _lmax , ii) a cladding surrounding the core, adjacent to and in contact with the core, having a refractive index delta A ₂ , a radius r ₂ , and a minimum refractive index delta A _2min such that A _2min <A] max · 2. The optical fiber according to clause 1, containing the chlorine doped silica based core comprises a core alpha (Core _a )> 4. 3. The optical fiber according to clause 1 or 2, having: - a mode field diameter MFD at 1310 or> 9 microns; - a cable cutoff or <1260 nm; - a zero dispersion wavelength ranging from 1300 nm <λ ₀ <1324 nm; and - a macrobending loss at 1550 nm for a 20 mm mandrel or less than 0.75 dB / turn. 4. The optical fiber or any of the clauses 1-3, further including a second inner cladding adjacent to and in contact with the first inner cladding surrounding the core, bearing the second inner cladding has a refractive index A ₃ , and a radius r ₃ . 5. The optical fiber according to clause 4, where the second inner cladding has a minimum refractive index delta A _3min such that A _3mi „<A ₂ 6. The optical fiber according to clause 4 or 5, the second inner cladding has a maximum refractive index delta A _3max such that A _2min <A _3111ax 7. The optical fiber according to any of the preceding clauses, further including an outer cladding region. 8. The optical fiber according to clause 7, the outer cladding region has a refractive index A ₅ and a radius r _max , such that A 2 _mm > A ₅ . 9. The optical fiber according to clause 6, further including an outer cladding region having a refractive index A ₅ and a radius r _max , with one or more of the following: - Flo Δ _21Ι1ίη > Δ ₅ ; - Flo Δ ₅ <Δ _3ηΐΜ ; and - Flo Δ _31Λ1ίη <Δ ₅ . 10. The optical fiber or any of the preceding clauses, further including a chlorine concentration in the core or> 1.5 wt%. 11. The optical fiber or any of the preceding clauses, including the macrobending loss 1550 nm is <0.5 dB / turn on a 20 mm diameter mandrel. 12. The optical fiber or any of the preceding clauses, with the maximum refractive index Δ _lmax ranges from 0.10% <Δ _{1π): ίχ} <0.45%. 13. The optical fiber or any of the preceding clauses 5-12, when dependent on clause 5, where the minimum refractive index A _3min is -0.5% <A _3min <0.25%, preferably with the minimum refractive index A _3min is -0.25 % <A _3min <0.15%. 14. The optical fiber or any of the clauses 4-13, when depended on clause 4, including the outer radius r ₃ is 12.0 microns <r ₃ <25.0 microns. 15. The optical fiber or any of the preceding clauses, the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / tum on a 20 mm diameter mandrel and exhibits a MACC number between 7.1 and 8.1. 16. The optical fiber according to any of the preceding clauses, being a single mode optical fiber. 17. The optical fiber or any of the preceding clauses, the macrobending loss at 1550 nm or <0.005 dB / turn on a 30 mm diameter mandrel. 18. The optical fiber according to any of the preceding clauses, the chlorine doped silica-based core comprises a core alpha (Core _a )> 15. 19. The optical fiber or any of the preceding clauses 6-18, when dependent on clause 6, where the maximum refractive index A _3max is -0.5% <A _3mi '<0.25%. 20. The optical fiber or any of the preceding clauses 4-19, when dependent on clause 4, including the outer radius r ₃ is 15.0 microns <r ₃ <15.0 microns. 21. The optical fiber according to any of the preceding clauses 3-20, when depend on 5 clause 3, the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / turn on a 20 mm diameter mandrel and exhibits a MACC number between 7.1 and 8.1. 22. The optical fiber according to any of the preceding clauses 3-21, when dependent on clause 3, where the optical fiber has a wire mesh covered drum microbend loss, (WMCD) at 10 1550 nm or <0.1 dB / km. CONCLUSIONS An optical fiber comprising: i) a chlorine-doped silicon-based core with a radius r ₁ and a maximum refractive index delta A 1 _max ; and ii) a cladding surrounding the core is contiguous and in contact with the core, and a refractive index delta Δ ₂ , a radius r ₂ , and a minimum refractive index delta A _{2min such} that Δ _21Λ1ίη <A has an _imax . The optical fiber of claim 1, wherein the chlorine-doped silicon-based core comprises a core alpha (Core _a )> 4. The optical fiber according to claim 1 or 2, comprising: - a field mode diameter MFD of 1310 at> 9 microns; - a cable cross-section of <1260 nm; - a zero dispersion wavelength in the range of 1300 nm <λο <1324 nm; and - a macro bending loss at 1550 nm for a 20 mm spindle of less than 0.75 dB / rotation. The optical fiber according to any of claims 1-3, further comprising a second inner liner abutting and in contact with the first inner liner surrounding the core, the second inner liner having a refractive index Δ ₃ and a radius r ₃ . The optical fiber according to claim 4, wherein the second inner liner has a minimum refractive index delta Δ _{3ηιίη such} that A has _3mm <Δ ₂ . The optical fiber according to claim 4 or 5, wherein the second inner liner has a maximum refractive index delta A _{3max such} that A _2min <Δ _3πμχ . The optical fiber according to any of the preceding claims, further comprising an outer coating area. The optical fiber according to claim 7, wherein the outer cladding region has a refractive index Δ ₅ and a radius r _Jnax , so that Δ _2η " _η > Δ ₅ . The optical fiber of claim 6, further comprising an outer cladding region that has a refractive index Δ ₅ and a radius r _lliax , with one or more of the following: - where A _2m in> Δ ₅ ; - where Δ ₅ <Δ _3ηΐί1χ ; and - where Δ _3πΛ1 <Δ ₅ . The optical fiber according to any of the preceding claims, further comprising a chlorine concentration in the core of> 1.5% by weight. The optical fiber according to any of the preceding claims, wherein the macrobending loss at 1550 nm is <0.5 dB / rotation on a 20 mm diameter spindle. The optical fiber according to any of the preceding claims, wherein the maximum refractive index Δ _{1ηκϋί is} in the range of 0.10% <A 1 _max <0.45%. The optical fiber according to any of the preceding claims 5-12, when dependent on claim 5, wherein the minimum refractive index A _{3min is} -0.5% <A _3min <0.25%, preferably wherein the minimum refractive index A _3min 0.25% <A _3min <0.15%. The optical fiber according to any of claims 4-13, when dependent on claim 4, where in the outer radius r _{3 is} 12.0 microns <r ₃ <25.0 microns. The optical fiber according to any of the preceding claims, wherein the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / rotation for a 20 mm diameter spindle and has a MACC number between 7.1 and 8.1. The optical fiber according to any of the preceding claims, is a single mode optical fiber. The optical fiber according to any of the preceding claims, wherein the macrobending loss at 1550 nm is <0.005 dB / rotation for a 30 mm diameter spindle. The optical fiber according to any of the preceding claims, wherein the chlorine-doped silicon-based core comprises a core alpha (Core J> 15). The optical fiber according to any of claims 6-18, when dependent on claim 6, where the maximum refractive index Δ _3πβχ -0.5% <Δ _{3ιη) η is} <0.25%. The optical fiber according to any of claims 4-19, when dependent on claim 4, wherein the outer radius r _{3 is} 15.0 microns <r ₃ <15.0 microns. The optical fiber according to any of claims 3 to 20 when dependent on exclusion 3, wherein the macrobending loss exhibited by the optical fiber at 1550 nm is <0.70 dB / rotation for a 20 mm diameter spindle and has a MACC number between 7.1 and 8.1. 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