CN101523258A - Low bend loss optical fiber with deep depressed ring - Google Patents

Abstract

Optical waveguide fiber that is bend resistant and single moded at 1260 nm and at higher wavelengths. The optical fiber includes a core and cladding, the cladding having an annular inner region, an annular ring region, and an annular outer region. The annular ring region has a low relative refractive index. The fiber has a zero dispersion falling between 1300 and 1324 nm, a mode field diameter at 1310 nm of between 8.20 and 9.50 mu m, and a 10 nm diameter mandrel bend loss of less than 1.0 dB/turn.

Description

Low bend loss optical fiber with dark inhibition ring

The cross reference of relevant application

The application requires the right of priority of the U.S. Provisional Patent Application 60/841,458 submitted on August 31st, 2006, and its content is relevant with this paper and all quote at this as a reference.

Technical field

The present invention relates generally to optical fiber, relate in particular to bend resistant single moded fibers.

Background technology

Employed optical fiber may stand various crooked environment in so-called " access " optical-fiber network and Fiber to the home (FTTx) optical-fiber network.May in light signal, introduce bending loss when in this network, using optical fiber by this Optical Fiber Transmission.Some application may be forced some the physics requirements that can introduce bending loss, and such as bending radius, optical fiber compression etc. closely, these application comprise fiber deployment in following environment: the optical branching cable assembly; Distribution cable with installing terminal system of factory (FITS) and slack loop (slack loop); Be arranged in the small-bend radius multiport of the rack that connects feed line and distribution cable; And the bonding line in the Network Access Point between distribution cable and branch-off cables.

Summary of the invention

This paper has disclosed a kind of optical waveguide fiber, and it is resistant to bending and is single mode at the wavelength place of 1260nm and Geng Gao.This optical fiber has very big useful area, and for example, this is particularly useful for the signal non-linear when suppressing high bit rate.Preferably, this optical fiber has the attenuation loss that attenuation loss that very low macrobending causes and very low microbend cause.

Optical fiber disclosed herein comprises glass core and glass-clad, and covering contacts round core and with core, and core is provided with round center line, and radially extends from center line.Covering comprises: the interior zone of annular, this interior zone be regional and contact with it round core; The ring zone of annular, this ring zone is round the interior zone of annular and contact with it; And the perimeter of annular, this perimeter also extends to the outermost of glass radius round the ring zone and the contact with it of annular.The perimeter of annular is the glass part of the outermost of optical fiber.In preferred implementation, the perimeter of annular is covered by one or more coatings, such as urethane acrylate material.The ring zone of annular has lower relative index of refraction.In some embodiments, optical fiber disclosed herein has covering, and this covering has the ring zone of annular, and this ring zone has the narrower and dark relative index of refraction that suppresses of band.

The maximum relative refractive index of glass core is less than 0.45%.The minimum relative refractive index in ring zone of annular is less than-0.63%, less than-0.65% preferable, be less than or equal to-0.7% better.The size of the relative index of refraction of the interior zone of annular is very low, less than 0.05%.The relative index of refraction of most of radial width of the interior zone of annular can be positive, negative and/or zero.The maximum relative refractive index of core is the maximum relative refractive index of whole optical fiber.The maximum relative refractive index of the interior zone of annular is more than or equal to the minimum relative refractive index of the interior zone of annular.The minimum relative refractive index of the interior zone of annular is more than or equal to the minimum relative refractive index in the ring zone of annular.

The index distribution of optical fiber disclosed herein provides: the mode field diameter at the 1310nm place between 8.20～9.50 μ m, and 8.40～9.20 μ m are preferable; The zero-dispersion wavelength of 1300～1324nm; 2 meters fiber cut off wavelength less than 1260nm; And at the superior flexing resistance of macrobending and microbend.Preferably, optical fiber disclosed herein presents the 20mm bending loss (i.e. the attenuation incrementation that causes because of macrobending) less than the 0.05dB/ circle when optical fiber twines around 20mm diameter plug at the 1550nm place, and is better less than the 0.03dB/ circle.Preferably, optical fiber disclosed herein presents the 10mm bending loss (i.e. the attenuation incrementation that causes because of macrobending) less than the 1.0dB/ circle when optical fiber twines around 10mm diameter plug at the 1550nm place, and is better less than the 0.75dB/ circle.Preferably, optical fiber disclosed herein presents the pin array bend loss that is not more than 15dB, and is better less than 10dB, good especially less than 5dB.In some embodiments, lateral load wire mesh loss is less than 0.5dB, preferably less than 0.25dB.

In one group of embodiment, the ring zone of annular comprises silica glass, and adulterant wherein is selected from the group that germanium, aluminium, phosphorus, titanium, boron and fluorine constitute.

In another group embodiment, the ring zone of annular comprises the silica glass with a plurality of holes, and these holes are empty (vacuum) or be filled with gas, and wherein these holes provide internal light reflection, provide waveguide for the light that advances along core thus.These holes also can provide the effective refractive index lower than pure silicon dioxide.

Now, in detail with reference to better embodiment of the present invention, its example shown in the drawings.

Description of drawings

The relative index of refraction that Fig. 1 shows the embodiment of optical waveguide fiber described herein distributes.

The relative index of refraction that records that Fig. 2 shows the embodiment of optical waveguide fiber described herein distributes.

Fig. 3 is the schematic cross section of the embodiment of optical waveguide fiber described herein.

Fig. 4 has schematically shown the optical fiber telecommunications system of use optical fiber described herein.

Fig. 5 schematically shows another embodiment of optical fiber telecommunications system described herein.

Embodiment

Other features and advantages of the present invention will be illustrated in the following detailed description, and those skilled in the art will be easy to see from instructions and draw or by implementing the present invention like that and recognize these feature and advantage by detailed description, claims and accompanying drawing being described.

" index distribution " is the relation between refractive index or relative index of refraction and the waveguide fiber radius.

Relative index of refraction number percent is defined as Δ %=100x (n _i ²-n _c ²)/2n _i ², n wherein _iBe the largest refractive index among the regional i, except as otherwise noted, n _cIt is the mean refractive index of the annular outer region of covering.In this article, relative index of refraction is represented that by Δ its value is that unit provides with " % ", except as otherwise noted.When the refractive index in a zone during less than the mean refractive index of annular outer region, relative index of refraction number percent is the refractive index of bearing and be called as the regional or inhibition with inhibition, and minimum relative refractive index is to calculate for that place of minimum negative value in refractive index, except as otherwise noted.When the refractive index in a zone during greater than the mean refractive index of cladding regions, relative index of refraction number percent is positive and this zone can be said to be and raise or have positive refracting power." go up adulterant " herein is regarded as a kind of refractive index that can make with respect to pure undoped silicon dioxide and the adulterant that promotes to some extent." following adulterant " herein is regarded as a kind of adulterant that refractive index is descended with respect to pure undoped silicon dioxide and to some extent.When with one or more not being other adulterant of upward adulterant, last adulterant may reside in the fiber area with negative relative refractive index.Equally, one or more are not that other adulterant of going up adulterant also may reside in the fiber area with positive relative index of refraction.When with one or more not being other adulterant of adulterant down, following adulterant may reside in the fiber area with positive relative index of refraction.Equally, one or more are not to play other adulterant of adulterant to may reside in the fiber area with negative relative refractive index yet.

In this article, except as otherwise noted, otherwise " chromatic dispersion " that be called " chromatic dispersion " of waveguide fiber here is meant the summation of material dispersion, waveguide dispersion and intermode dispersion.For single mode waveguide optical fiber, intermode dispersion is zero.Chromatic dispersion gradient is that chromatic dispersion is with respect to the wavelength change rate.

" useful area " is defined as:

A _eff＝2π(∫f ² r dr) ²/(∫f ⁴ r dr)，

Wherein the limit of integration is 0 to ∞, and f is the cross stream component of the electric field relevant with the light propagated in the waveguide.In this article, except as otherwise noted, otherwise " useful area " or " A _Eff" be meant optics useful area at wavelength 1550nm place.

Term " α-distribution " or " Alpha's distribution " are meant that relative index of refraction distributes, and are to express with Δ (r) that unit is " % ", and wherein r is a radius, establish an equation under meeting,

Δ(r)＝Δ(r _o)(1-[|r-r _o|/(r ₁-r _o)] ^α)，

R wherein _oBe the point of Δ (r) when reaching maximum, r ₁Be the point of Δ (r) when % equals zero, r is between r _i≤ r≤r _fIn the scope, wherein Δ is above defined such, r _iBe the initial point of α-distribution, r _fBe the last point of α-distribution, and α is this index as real number.

Mode field diameter (MFD) is to measure with Peterman II method, 2w=MFD wherein, w ²=(2 ∫ f ²R dr/ ∫ [df/dr] ²R dr), the limit of integration is 0 to ∞.

By under the test condition of regulation, introducing decay, just can measure the flexing resistance of waveguide fiber.

A kind of crooked test is the test of lateral load microbend.In this so-called " lateral load " test, the waveguide fiber of specified length is placed between two flat boards.The #70 silk screen is attached to one of these two plates.The waveguide fiber of known length is sandwiched between these two plates, and when the power with 30 newton is pressed onto these two plates together, the witness mark decay.Then, apply 70 newton's power, and to measure with dB/m be the attenuation incrementation of unit to these two plates.This attenuation incrementation is exactly the lateral load attenuation of this waveguide.

" pin array " crooked test is used to the relative tolerance of comparison waveguide fiber to bending.In order to carry out this test, under the situation of not introducing bending loss basically, waveguide fiber is measured attenuation loss.Then, weave this waveguide fiber, and measure decay once more around the pin array.Because of the crooked loss of introducing the poor of the decay that records for this twice.Above-mentioned pin array is one group of 10 columniform pin, and they are arranged in the single row and keep fixing in the plane upright position.Pin spacing is 5mm, i.e. the spacing of center to center.The pin diameter is 0.67mm.At test period, apply enough big tension force so that waveguide fiber meets the part of wire surface.

For given pattern, theoretic fiber cut off wavelength (or " theoretic fiber cutoff " or " theoretic ending ") is such wavelength, can't propagate by this pattern at this light that is guided more than wavelength.At " Single Mode Fiber Optics " (Jeunhomme, pp.39-44, Marcel Dekker, New York, 1990) can find mathematical definition in the book, wherein theoretic fiber cut off wavelength is described as such wavelength, and becoming at this wavelength place mode propagation constant equals plane wave propagation constant in the surrounding layer.For limited length, straight and do not have for the optical fiber of vary in diameter, this theoretic wavelength is suitable.

Can be by the test of standard 2m fiber cut off wavelength, FOTP-80 (EIA-TIA-455-80) measures actual fiber cut off wavelength, to produce " fiber cut off wavelength ", is also referred to as " 2m fiber cut off wavelength " or " cutoff wavelength that records ".Carry out the FOTP-80 standard testing, remove the more pattern of high-order to utilize controlled amount of bow, thereby perhaps make of the spectral response normalization of the spectral response of this optical fiber divided by multimode optical fiber.

Because of highly bending and mechanical pressure are arranged in the cable environment, so cable cutoff wavelength (or " cable by ") even be lower than the fiber cut off wavelength that records.Cable cutoff wavelength test described in the EIA-445 test optical fiber program can be near actual cable condition, these test procedures are parts of EIA-TIA (being ElectronicsIndustry Alliance-Telecommunications Industry Association) optical fiber optical device standard, are referred to as FOTP usually.Measure the cable cutoff wavelength (Cable Cutoff Wavelength of Single-mode Fiber byTransmitted Power) of single-mode fiber by emitted power at EIA-455-170, promptly in " FOTP-170 ", the cable cutoff wavelength test has been described.Cable cutoff wavelength used herein is meant the value of utilizing approximate test and obtaining.

Except as otherwise noted, otherwise optical property (such as chromatic dispersion, chromatic dispersion gradient etc.) all report at the LP01 pattern.Except as otherwise noted, otherwise the wavelength of 1550nm is exactly a reference wavelength.Here employed optical transmission line comprises one section optical fiber or a plurality of series welding optical fiber together, and they extend between a plurality of optical device, for example, is extending between two image intensifers or between multiplexing devices and image intensifer.This optical transmission line can comprise Transmission Fibers and dispersion compensating fiber, wherein can in module (DC module), dispose dispersion compensating fiber or longitudinally laying, or both all can, be selected to the system performance or the parameter that realize a kind of expectation, such as the residual dispersion of optical transmission line end.

Optical fiber 10 disclosed herein comprises core 100 and covering (or coating) 200, covering 200 round core 100 and with its direct neighbor.Covering 200 has the index distribution Δ _CLAD(r).In some embodiments, covering 200 comprises pure silicon dioxide.

It is as follows to define various wave bands or operating wavelength range or wavelength window: " 1310nm wave band " is 1260-1360nm; " E-wave band " is 1360-1460nm; " S-wave band " is 1460-1530nm; " C-wave band " is 1530-1565nm; " L-wave band " is 1565-1625nm; And " U-wave band " is 1625-1675nm.

In some embodiments, core comprises the silicon dioxide that is mixed with germanium.Form, except germanium alone or in combination adulterant can be applied in the core, particularly near the centerline of optical fiber disclosed herein or its, to obtain the refractive index and the density of expectation.

In some embodiments, from the center line of annular section to inside radius R ₂, the index distribution of optical fiber disclosed herein is non-negative.In some embodiments, optical fiber does not comprise the adulterant of refractive index-reduce in core.

With reference to Fig. 1, the optical waveguide fibers 100 that this paper discloses comprises: core 20 extends radially outwardly into the external radius R of core from center line ₁, and have relative index of refraction distribution Δ with percentage calculation ₁(r), has maximum relative index of refraction percent delta _1MAXAnd covering 200, this covering 200 round core 20 and with core 20 direct neighbors, promptly directly the contact.Covering 200 comprises: the interior zone 30 of annular, this zone 30 round core 20 and with its direct neighbor, this zone 30 extends radially outwardly into the external radius R of interior zone of annular ₂, have the mid point of being arranged at R _2MIDThe width W at place ₂, this zone 30 has the relative index of refraction distribution Δ with percentage calculation ₂(r), has maximum relative index of refraction percent delta _2MAX%, minimum relative index of refraction percent delta _2MIN%, and maximum value relative index of refraction number percent | Δ ₂(r) _MAX|; The ring zone 50 of annular, this zone 50 is round zone 30 and directly be adjacent, from R ₂Ring zone radius R to annular ₃Outward radial extends, and this zone 50 has the mid point of being arranged at R _3MIDThe width W at place ₃, and have relative index of refraction distribution Δ with percentage calculation ₃(r), has the minimum relative refractive index percent delta _3MIN%, wherein Δ _1MAX0〉Δ _3MINAnd the perimeter 60 of annular, this zone 60 round zone 50 and with its direct neighbor, and have relative index of refraction percent delta with percentage calculation _CLAD(r) %.R ₁Be defined by appearing at Δ 1 (r) at first to reach+0.05% radius.That is, at radius R ₁The place, relative index of refraction at first reaches+0.05% (radially outward), and this also is that core 20 finishes and the ring zone 30 of annular begins parts, and zone 30 is defined by at radius R ₂The place finishes, the relative index of refraction Δ ₂(r) at radius R ₂The place reaches-0.05% (radially outward) first.For this group embodiment, the ring zone 50 of annular starts from R ₂And end at R ₃R ₃Be defined by appearing at Δ ₃(r) relative index of refraction Δ after descending at least-0.1% ₃(r) reach-0.05% (radially outward) part first.The width W of annular section ₃Be R ₃-R ₂, its mid point R _3MIDBe (R ₂+ R ₃)/2.In some embodiments, the radial width of core have positive relative index of refraction more than 90%, in some embodiments, for 0 to R ₁All radiuses, Δ ₁(r) be positive.In some embodiments, for more than 50% of radial width of the interior zone 30 of annular, | Δ ₂(r) |＜0.025%, and in other embodiments, for more than 50% of radial width of the interior zone 30 of annular, | Δ ₂(r) |＜0.01%.For from R ₂To R ₃All radiuses, Δ ₃(r) bear.Preferably, for for all radiuses of 30 μ m, Δ _CLAD(r)=0%.At radius R _COREThe place, core is through with and covering has begun.Covering 200 extends to radius R ₄, radius R ₄It also is the outermost of the glass part of optical fiber.In addition, Δ _1MAXΔ _2MAXΔ _3MIN, and Δ _MAXΔ _2MINΔ _3MIN

Core has volume of distribution V ₁, be defined as follows:

$2\underset{0}{\overset{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="A200780036323E00191.png,A200780036323E00192.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}{\&Integral;}}{\mathrm{\&Delta;}}_1\left(r\right)\mathrm{dr}.$

The ring zone of annular has volume of distribution V ₃, be defined as follows:

$2\underset{R_2}{\overset{{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="A200780036323E00191.png"\; state="\{\{state\}\}">R</figure-callout>}}_3}{\&Integral;}}{\mathrm{\&Delta;}}_3\left(r\right)\mathrm{dr}.$

Preferably, Δ _1MAX＜0.45%, Δ _2MIN〉-0.05%, Δ _2MAX＜0.05%, Δ _3MIN＜-0.63%, 0.2＜R ₁/ R ₂＜0.6, and the absolute value of the volume of distribution in the ring zone of annular | V ₃| greater than 20%-μ m ²More preferably, Δ _3MIN＜-0.65% ,≤-0.7% better.In some embodiments, 0.35＜R ₁/ R ₂＜0.5.For example, when we said Δ＜-0.63%, we meaned that Δ is more severely more negative than-0.63%.

Preferably, W ₂2/3R ₁, in some embodiments, W ₂2 μ m.

In some embodiments, 20%-μ m ²＜| V ₃|＜80%-μ m ²In other embodiments, 30%-μ m ²＜| V ₃|＜70%-μ m ²In other embodiments, 40%-μ m ²＜| V ₃|＜60%-μ m ²

Preferably, 0.28%＜Δ _1MAX＜0.45%, more preferably, 0.30%＜Δ _1MAX＜0.40%, in some embodiments, 0.31%≤Δ _1MAX≤ 0.38%.

Preferably, R ₁＜5.0 μ m, 3.0 μ m＜R ₁＜5.0 μ m are then better, in some embodiments, and 4.0 μ m＜R ₁＜5.0 μ m.

Preferably, R ₂8.0 μ m, in some embodiments, 8.0 μ m＜R ₂＜15.0 μ m.

Preferably, R ₃10.0 μ m, in some embodiments, 10.0 μ m＜R ₃＜20.0 μ m.

In some embodiments, W ₃1.0 μ m, in other embodiments, 1.0＜W ₃＜6.0 μ m, in other embodiments, 1.0＜W ₃＜5.0 μ m.

Preferably, R ₄40 μ m.In some embodiments, R ₄50 μ m.In other embodiments, R ₄60 μ m.In some embodiments, 60 μ m＜R ₄＜70 μ m.

In some embodiments, the core of core can comprise a kind of relative index of refraction distribution that so-called center line reduces that has, and this may be that one or more optic fibre manufacturing technologies cause.For example, this core can have local index distribution minimum value in the radius less than 1 μ m, wherein higher relative index of refraction value (maximum relative refractive index that comprises core segment) occurs in the radius bigger than r=0 μ m.

Preferably, optical fiber disclosed herein provides: the mode field diameter at 1310nm place be 8.20 μ m to 9.50 μ m, 8.4 μ m are better to 9.20 μ m; Zero-dispersion wavelength between 1300 and 1324nm between; And cable cutoff wavelength is less than 1260nm.Because cable cutoff wavelength is not more than (approximating in some embodiments) 2 meters fiber cut off wavelength, so produced cable cutoff wavelength less than 1260nm less than 2 meters fiber cut off wavelength of 1260nm.

First group of embodiment

Form 1-2 has been listed the feature of illustrated examples of the example 1-7 of first group of embodiment.The index distribution of example 2-7 is similar in appearance to Fig. 1, but has following corresponding numerical value.

Form 1
									Example		1	2	3	4	5	6	7
Δ 1MAX	％	0.38	0.35	0.38	0.38	0.38	0.38	0.34
									R 1	μm	4.4	4.5	4.4	4.4	4.4	4.4	4.6
α 1		10	10	10	10	10	10	10
									V 1	％-μm 2	5.95	5.76	5.95	5.95	5.95	5.95	5.96
R 2	μm	10.3	10.4	9.7	11.6	9.5	12.7	12.1
									R 1/R 2		0.43	0.43	0.45	0.38	0.46	0.35	0.38
W 2	μm	5.9	5.9	5.3	7.2	5.1	8.3	7.5
									R 2MID	μm	7.4	7.5	7.1	8.0	7.0	8.6	8.4
Δ 3MIN	％	-0.80	-0.79	-0.77	-0.75	-0.72	-0.72	-0.72
									R 3＝R CORE	μm	14.0	13.3	12.7	13.8	12.1	15.0	13.9
W 3	μm	3.7	2.9	3.0	2.2	2.6	2.3	1.8

R 3MID	μm	12.2	11.9	11.2	12.7	10.8	13.9	13.0
									|V 3|	％-μm 2	62.8	44.7	44.0	34.0	32.2	36.3	26.1

Form 2
									Example		1	2	3	4	5	6	7
Se San @1310nm	ps/nm-km	0.24	0.45	0.49	-0.14	0.53	-0.30	0.30
									Xie Shuai @1310nm	ps/nm 2-km	0.089	0.090	0.090	0.088	0.090	0.087	0.088
λ 0	nm	1307	1305	1305	1312	1304	1313	1307
									MFD @1310nm	μm	8.68	8.98	8.66	8.71	8.65	8.72	9.21
MFD @1550nm	μm	9.74	10.08	9.68	9.84	9.67	9.88	10.40
									Aeff @1550nm	μm 2	72.9	78.0	72.2	74.0	72.1	74.5	82.8
Pin Zhen Lie @1550nm	dB		3	8	4	4	4	4										9
									Heng Xiangfuzai @1550nm	dB/m	0.14	0.32	0.16	0.19	0.18	0.20	0.46
The LP11 theoretical value	nm	1241	1220	1235	1252	1233	1259	1253
									The LP02 theoretical value	nm	779	767	776	784	776	787	784
Fiber cut off wavelength (2 meters)	nm	1232	1208	1223	1228	1211	1232	1216
									Decay @1310nm	dB/km	0.340	0.338	0.340	0.340	0.340	0.340	0.338
Decay @1380nm	dB/km	0.278	0.277	0.278	0.278	0.278	0.279	0.277
									Decay	dB/km	0.193	0.191	0.192	0.193	0.193	0.193	0.191

@1550nm
									Se San @1550nm	ps/nm-km	18.1	18.4	18.5	17.2	184	16.7	17.7
Xie Shuai @1550nm	ps/nm 2-km	0.064	0.064	0.064	0.062	0.064	0.061	0.062

In some embodiments (such as example 1-7), optical fiber presents the mode field diameter of 8.60 μ m-9.30 μ m at the 1310nm place; Zero-dispersion wavelength between 1300 and 1324nm between; 2 meters fiber cut off wavelength are less than 1260nm, and this causes cable cutoff wavelength less than 1260nm.In addition, 2 meters fiber cut off wavelength had better not be too low, prevents that thus bending loss is too high.For example, 2 of the embodiment of example 1-7 meters fiber cut off wavelength are greater than 1190nm and less than 1260nm.

Optical fiber disclosed herein presents the good flexing resistance to macrobending and microbend.The pin array bend loss at 1550nm place (attenuation incrementation that is associated with optical fiber tested in the pin array), i.e. the measurement result of a kind of macrobend loss, preferable less than 15dB less than 10dB, in some embodiments less than 5dB.In addition, the lateral load wire mesh loss at 1550nm place, promptly a kind of measurement result of microbend loss is preferable less than 0.3dB less than 0.5dB, in some embodiments less than 0.2dB.

We find that also LP11 cutoff wavelength theoretical value can be used as the upper limit of 2 meters fiber cut off wavelength of optical fiber disclosed herein usually.Shown in example 1-7, LP11 cutoff wavelength theoretical value is less than 1270nm, and is preferable less than 1265nm, better less than 1260nm.We also find, distribute for given core, increase the size of volume of distribution, promptly | and V ₃|, will not make cutoff wavelength increase to such point and do not add restriction, make optical fiber at the 1310nm place or even become multimode optical fiber at the 1550nm place.Correspondingly, in some embodiments, 20%-μ m ²＜| V ₃|＜80%-μ m ², in other embodiments, 30%-μ m ²＜| V ₃|＜70%-μ m ², in other embodiments, 40%-μ m ²＜| V ₃|＜60%-μ m ²

We find that also higher core volume not only can increase the size of mould field usually, also can increase the cutoff wavelength theoretical value of LP11, therefore, can increase 2 meters fiber cut off wavelength.In some embodiments, the volume of distribution V1 of core is greater than 0 and less than 6.5%-μ m ², in other embodiments then less than 6.2%-μ m ², and in some embodiments (such as example 1-7), V1 is between 5.50 and 6.00%-μ m ²Between.

Core 20 shown in Figure 1 has the index distribution of α shape, wherein α ₁Be about 10.Yet core 20 can have other α ₁Value, perhaps core can have the distribution shape except that α distributes, such as the core of multistage.

Example 8

Optical fiber is made by outside steam deposition.The relative index of refraction that records that Fig. 2 shows optical fiber distributes.The silica glass plug of mixing germanium has pure silicon dioxide covering, they are as the chemical vapor deposited erbium rod of glass soot layer, the glass soot layer is mixed with fluorine and is compacted, then, apply the outer of glass soot and with its compacting to form preform.This prefabricated rods is drawn as optical fiber, and this optical fiber has the core 20 of mixing germanium, and covering 200 is round this core 20 and contact with it, and covering 200 has the interior zone 30 of annular, ring zone 50 and the perimeter 60 of annular, the wherein Δ of annular _1MAX=0.43%, R ₁=4.6 μ m, R ₂=8.5 μ m, Δ _3MIN=-0.70%, R ₃=11.7 μ m, W ₂=3.9, W ₃=3.2, R ₁/ R ₂=0.54, V ₁=6.4, and V ₃=-28.3 (| V ₃|=28.3).At the 1550nm place, the 20mm diameter bend test results that records (making fiber optic loop around 20mm diameter plug) is: under the situation of 20mm diameter plug one circle, be the 0.028dB/ circle; Under the situation of plug 5 circles, be the 0.126dB/ circle.At the 1550nm place, the 10mm diameter bend test results that records (making fiber optic loop around 10mm diameter axle) is: under the situation of 10mm diameter axle one circle, be the 0.60dB/ circle.At 1310nm and 1550nm place, the MFD that records is respectively 8.27 μ m and 9.24 μ m.2 meters fiber cut off wavelength are 1251nm.

Fig. 3 is the synoptic diagram (not in scale) of optical waveguide fibers 100 disclosed herein, this optical fiber has core 20 and covering 200, covering 200 is round core 20 and direct neighbor with it, and covering 200 comprises the interior zone 30 of annular, the ring zone 50 of annular and the perimeter 60 of annular.Core 20 can have one or more core segments.

Covering 200 can comprise clad material, for example, this clad material is deposited in deposition process, and perhaps the form (such as the pipe in the excellent preform configuration in the pipe) with overcoat provides this clad material, and perhaps the array configuration with deposition materials and overcoat provides this clad material.At least one coating 210 is round covering 200, and in some embodiments, this coating comprises low modulus master coating and high mode time coating.

Preferably, optical fiber disclosed herein has core and the covering based on silicon dioxide.In better embodiment, the overall diameter 2*Rmax of covering is about 125 μ m.Preferably, the overall diameter of covering is constant along the length direction of optical fiber.In better embodiment, the refractive index of optical fiber has radial symmetry.Preferably, the overall diameter of core is constant along the length direction of optical fiber.Preferably, one or more coatings are round covering and contact with it.This coating is polymer coating preferably, such as acrylate.Preferably, the diameter of coating diametrically with all be constant on the fiber length.

As shown in Figure 4, can in optical fiber telecommunications system 330, realize optical fiber 100 disclosed herein.System 330 comprises transmitter 334 and receiver 336, and wherein optical fiber 100 allows light signal to transmit between transmitter 334 and receiver 336.System 330 preferably can carry out two-way communication, and transmitter 334 and receiver 336 are only used for illustrating.System 330 preferably includes a link, and this link has the part of optical fiber disclosed herein or one section.System 330 also can comprise one or more optical device, and they are connected to the one or more parts or the section of optical fiber disclosed herein optically, such as one or more regenerators, amplifier or dispersion compensation module.In at least one better embodiment, optical fiber telecommunications system of the present invention comprises the transmitter and receiver that couples together by optical fiber, does not have regenerator between the two.In another better embodiment, optical fiber telecommunications system of the present invention comprises the transmitter and receiver that couples together by optical fiber, does not have amplifier between the two.In another better embodiment, optical fiber telecommunications system of the present invention comprises the transmitter and receiver that couples together by optical fiber, does not have amplifier between the two, does not also have regenerator, does not also have repeater.

Preferably, optical fiber disclosed herein has lower liquid water content, and low-water-peak fiber preferably, and promptly the die-away curve that this optical fiber had presents relatively low water peak or do not have the water peak in particular wavelength region (especially E wave band).

In United States Patent (USP) 6477305, United States Patent (USP) 6904772 and PCT application publication WO01/47822, can find the method that is used for the production low-water-peak fiber.

All optical fiber disclosed herein can be applied in the light signal transmission system, and this system preferably includes transmitter, receiver and optical transmission line.Optical transmission line is coupled to transmitter and receiver optically.Optical transmission line preferably includes at least one fiber span, and this fiber span preferably includes at least one section optical fiber disclosed herein.Optical transmission line also can comprise one section second optical fiber, and this section second optical fiber has negative chromatic dispersion at the wavelength place of about 1550nm, for example, is used for realizing dispersion compensation at optical transmission line.

Fig. 5 schematically shows another embodiment of optical fiber telecommunications system 400 described herein.System 400 comprises transmitter 434 and receiver 436, and they connect optically by optical transmission line 440.Optical transmission line 440 comprises: first optical fiber 442, and it is a low attenuation large effective area optical fiber disclosed herein; And second optical fiber 444, it has negative chromatic dispersion at the 1550nm place.First optical fiber 442 can be connected by welding, optical conenctor etc. (as the symbol among Fig. 5 " X " is described) optically with second optical fiber 444.Optical transmission line 440 also can comprise one or more assemblies and/or other optical fiber (for example, one or more " optical fiber pigtails " 445 at the knot place between each optical fiber and/or assembly).In better embodiment, at least a portion of second optical fiber 444 is set randomly within dispersion compensation module 446.Optical transmission line 440 allows transmitting optical signal between transmitter 434 and receiver 436.This system preferably also comprises at least one amplifier, and such as raman amplifier, it is coupled to fiber section optically.This system preferably also comprises multiplexer, be used to make a plurality of channel interconnection, these channels can be with optical signal transmission to optical transmission line, and wherein at least one (at least 3 better, at least 10 the bests) light signal is propagated to a wavelength place between the 1625nm at about 1260nm.Preferably, at least one signal is propagated in one or more following wavelength region may: 1310nm wave band, E-wave band, S-wave band, C-wave band and L-wave band.

In some exemplary embodiment, this system can come work according to the Coarse Wavelength Division Multiplexing pattern, and wherein one or more signals are propagated at least in following at least one (two better) wavelength region may: 1310nm wave band, E-wave band, S-wave band, C-wave band, L-wave band.In a better embodiment, the one or more wavelength place work of this system between 1530～1565nm.

Should be appreciated that top description only is an example of the present invention, aim to provide a kind of general introduction so that understand essence of the present invention and feature by claims defined.Included accompanying drawing provides further understanding of the present invention, incorporates in the instructions and constitutes its part.These illustrate various feature of the present invention and various embodiment, are used from instructions one and explain principle of the present invention and operation.Under the situation of the spirit or scope of the present invention that does not deviate from appended claims and defined better embodiment of the present invention being made various modifications is conspicuous for those skilled in the art.

Claims (20)

1. optical fiber comprises:

Extend to radius R from center line ₁Glass core;

Round core and contacted with it glass-clad, described covering comprises:

From R ₁Extend to radius R ₂The interior zone of annular, described interior zone comprises radial width W ₂=R ₂-R ₁,

From R ₂Extend to radius R ₃The ring zone of annular, described ring zone comprises radial width W ₃=R ₃-R ₂And

From R ₃Extend to outermost glass radius R ₄The perimeter of annular;

Its SMIS comprises the maximum relative refractive index Δ with respect to the perimeter _1MAX, and Δ _1MAX＜0.45%;

Wherein Huan Xing interior zone comprises radial width W ₂, with respect to the minimum relative refractive index Δ of perimeter _2MIN, and with respect to the maximum relative refractive index Δ of perimeter _2MAX, Δ wherein _2MIN〉-0.05%, Δ _2MAX＜0.05%, and W ₂2/3R ₁

Wherein Huan Xing ring zone comprises:

Minimum relative refractive index Δ with respect to the perimeter of annular _3MIN, Δ wherein _3MIN＜-0.63%;

Δ wherein _1MAXΔ _2MAXΔ _3MIN, and Δ _MAXΔ _2MINΔ _3MINWith

Its SMIS and covering provide fiber cut off wavelength less than 1260nm, between 1300 and 1324nm between zero chromatic dispersion, at the 1310nm place between 8.20 and 9.50 μ m mode field diameter and less than the 10mm diameter plug bending loss of 1.0dB/ circle.

2. optical fiber as claimed in claim 1 is characterized in that,

Core and covering provide the 20mm diameter plug bending loss less than the 0.05dB/ circle.

3. optical fiber as claimed in claim 1 is characterized in that,

Core and covering provide at the 1550nm place less than the pin array bend loss of 10dB.

4. optical fiber as claimed in claim 1 is characterized in that,

The ring zone of annular comprises volume of distribution V ₃, V ₃Equal:

$2\underset{R_2}{\overset{R_3}{\&Integral;}}\mathrm{\&Delta;}\left(r\right)\mathrm{dr};$

Wherein | V ₃| 20%-μ m ²

5. optical fiber as claimed in claim 1 is characterized in that,

0.2<R ₁/R ₂<0.6。

6. optical fiber comprises:

Extend to radius R from center line ₁Glass core;

Round core and contacted with it glass-clad, described covering comprises:

From R ₁Extend to radius R ₂The interior zone of annular, described interior zone comprises radial width W ₂=R ₂-R ₁,

From R ₂Extend to radius R ₃The ring zone of annular, described ring zone comprises radial width W ₃=R ₃-R ₂And

From R ₃Extend to outermost glass radius R ₄The perimeter of annular;

Its SMIS comprises the maximum relative refractive index Δ with respect to the perimeter _1MAX, and Δ _1MAX＜0.45%;

Wherein Huan Xing interior zone comprises radial width W ₂, with respect to the minimum relative refractive index Δ of perimeter _2MIN, and with respect to the maximum relative refractive index Δ of perimeter _2MAX, Δ wherein _2MIN〉-0.05%, Δ _2MAX＜0.05%, and W ₂2/3R ₁

Wherein Huan Xing ring zone comprises:

Minimum relative refractive index Δ with respect to the perimeter of annular _3MIN, Δ wherein _3MIN＜-0.63%; With

Volume of distribution V ₃, V ₃Equal:

$2\underset{R_2}{\overset{R_3}{\&Integral;}}\mathrm{\&Delta;}\left(r\right)\mathrm{dr};$

Wherein | V ₃| 20%-μ m ²

Δ wherein _1MAXΔ _2MAXΔ _3MIN, and Δ _MAXΔ _2MINΔ _3MINWith

0.2＜R wherein ₁/ R ₂＜0.6.

7. optical fiber as claimed in claim 6 is characterized in that,

0.4<R ₁/R ₂<0.6。

8. optical fiber as claimed in claim 6 is characterized in that,

20％-μm ²<|V ₃|<80％-μm ²。

9. optical fiber as claimed in claim 6 is characterized in that,

0.28％<Δ _1MAX<0.45％。

10. optical fiber as claimed in claim 6 is characterized in that,

R ₁<5.0μm。

11. optical fiber as claimed in claim 6 is characterized in that,

R ₂>8μm。

12. optical fiber as claimed in claim 6 is characterized in that,

R ₃>10μm。

13. optical fiber as claimed in claim 6 is characterized in that,

W ₃Between 2 and 5 μ m.

14. optical fiber as claimed in claim 1 is characterized in that,

Core comprises volume of distribution V ₁, V ₁Equal:

$2\underset{0}{\overset{R_1}{\&Integral;}}\mathrm{\&Delta;}\left(r\right)\mathrm{dr};$

V wherein ₁Greater than 0 and less than 6.2%-μ m ²

15. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide the fiber cut off wavelength less than 1260nm.

16. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide between 1300 and 1324nm between zero chromatic dispersion.

17. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide the mode field diameter between 8.20 and 9.50 μ m at the 1310nm place.

18. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide the 10mm diameter plug bending loss less than the 1.0dB/ circle.

19. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide the 20mm diameter plug bending loss less than the 0.05dB/ circle.

20. optical fiber as claimed in claim 6 is characterized in that,

Core and covering provide at the 1550nm place less than the pin array bend loss of 10dB.

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