CN102841401A - Single-mode fiber with insensitive curve for optimizing broadband dispersion - Google Patents

Abstract

The invention discloses a single-mode fiber with an insensitive curve for optimizing broadband dispersion. The single-mode fiber comprises a fiber core center round sub-layer, a first annular sub-layer coated on the filter core center round sub-layer, a second annular sub-layer coated on the first annular sub-layer, and a cladding layer coated on the second annular sub-layer; an refractive index of the first annular sub-layer is lower than that of an uniform cladding layer; a higher mode cutoff wavelength of an optical fiber is smaller than 1300nm under a conventional manufacturing tolerance; a zero-dispersion wavelength is between 1300nm and 1324nm; an effective area is not smaller than 70.0 mum<2> under the condition that a wavelength is 1550nm; the maximal dispersion value is smaller than 18.0ps/(nm.km) under the condition that the wavelength is 1700nm; bending loss is smaller than 0.5dB/100 circles under the condition that the wavelength is 1550nm when a diameter of a mode field is not smaller than 9.30 mu m and bending radius is 5mm, and the minimal dispersion value is smaller than 18.0ps/(nm.km) under the condition that the wavelength is 1700nm.

Description

The wide band dispersion of bend-insensitive is optimized single-mode fiber

Invention field

The present invention relates to single-mode fiber, relate in particular to, wide band dispersion is optimized single-mode fiber and bend-insensitive single-mode optical fiber.

Background technology

Following elder generation provides definition to the term that the present invention relates to, and wherein general term meets this area convention; The proprietary term of this instructions is through the common terminology explanation.

The radius of each layering of optical fiber is in the μ m of unit, and by the refractive index definition, each particular hierarchical has the first refractive index point and last refractive index point.Radius from shaft axis of optic fibre to the first refractive index point position is the inside radius of this layering; From shaft axis of optic fibre to the end the radius of refractive index point position be the external radius of this layering.Referring to refractive index profile figure, the external radius of radius from the shaft axis of optic fibre amount to this layering of fibre core central, circular layering; The width of the first annular layering is from the external radius of the annular layering of inside radius amount to the first of the first annular layering; The width of the second annular layering is from the external radius of the annular layering of inside radius amount to the second of the second annular layering.

The refractive index contrast Δ of the layering of fibre core central, circular, the first annular layering and the second annular layering ₀, Δ ₁And Δ ₂In the % of unit, be defined as respectively

Δ ₀＝(n ₀ ²-n _c1 ²)/2n ₀ ²

Δ ₁＝(n ₁ ²-n _c1 ²)/2n ₀ ²

Δ ₂＝(n ₂ ²-n _c1 ²)/2n ₀ ²

Wherein, n ₀And n ₂The largest refractive index of representing the layering of fibre core central, circular and the second annular layering respectively; n ₁The minimum refractive index of representing the first annular layering; n _C1The homogeneous refractive index of expression surrounding layer.

n ₁Less than n _C1Optical fiber be called depressed cladding fiber, depressed clad fiber, wherein relatively cup depth is defined as Δ ₁And Δ ₀The ratio.

Refractive index profile is defined as the relation between refractive index contrast or refractive index and the radius.

Fibre core central, circular layering α refractive index profile is defined as

Δ _co(r)＝Δ ₀[1-(r/a) ^α]，0≤r≤a

Wherein, r is the present position radius; A is the radius of said fibre core central, circular layering; α gets arbitrary value, and α can regard the step change type refractive index profile as greater than 10.The α refractive index profile comprises other refractive index profiles similar with its optical transmission performance.

Chromatic dispersion coefficient is in the ps/ of unit (nmkm), and this instructions abbreviates chromatic dispersion as.

The chromatic dispersion slope coefficient is with the ps/ (nm of unit ²Km) meter, this instructions abbreviates chromatic dispersion gradient as.

Useful area is with the μ m of unit ²Meter is defined as

A _eff＝2π(∫E ²(r)r?dr) ²/(∫E ⁴(r)r?dr)

Wherein, integration is limited to 0 to ∞; E (r) is that light is propagated the electric field of being followed, and r is the present position radius.

This instructions of macrobending loss is called bending loss again, utilizes following formula to calculate:

${\mathrm{\&alpha;}}_{\mathrm{macro}}=\frac{10}{\ln 10}\left(\frac{{\mathrm{\&pi;V}}^8}{16r_0{R}_b{W}^3}\right)\exp \left(\frac{-4R_b\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="3"\; label="W"\; filenames="HSA00000520488100021.png"\; state="\{\{state\}\}">W</figure-callout>}}^3}{3r_0{V}^2}\right)\frac{{\left[{\&Integral;}_0^{\&infin;}(1-g){\mathrm{<figure-callout\; id="0"\; label="F"\; filenames="HSA00000520488100021.png"\; state="\{\{state\}\}">F</figure-callout>}}_0\mathrm{rdr}\right]}^2}{{\&Integral;}_0^{\&infin;}{\mathrm{<figure-callout\; id="0"\; label="F"\; filenames="HSA00000520488100021.png"\; state="\{\{state\}\}">F</figure-callout>}}_0^2{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HSA00000520488100011.png,HSA00000520488100021.png"\; state="\{\{state\}\}">r</figure-callout>}}^2\mathrm{rdr}}$

$g=\frac{{n\left(r\right)}^2-n_{\min }^2}{n_{\max }^2-n_{\mathrm{<figure-callout\; id="2"\; label="min"\; filenames="HSA00000520488100011.png,HSA00000520488100021.png"\; state="\{\{state\}\}">min</figure-callout>}}^2},V={\mathrm{kr}}_0\sqrt{n_{\max }^2-n_{\mathrm{<figure-callout\; id="2"\; label="min"\; filenames="HSA00000520488100011.png,HSA00000520488100021.png"\; state="\{\{state\}\}">min</figure-callout>}}^2}$

$W=r_0\sqrt{{\mathrm{\&beta;}}^2-{\left({\mathrm{kn}}_{\min }\right)}^2},\mathrm{\&Delta;}=\frac{n_{\max }^2-n_{\mathrm{<figure-callout\; id="2"\; label="min"\; filenames="HSA00000520488100011.png,HSA00000520488100021.png"\; state="\{\{state\}\}">min</figure-callout>}}^2}{{2n}_{\max }^2}$

The invention of optical fiber has changed the world, needs fully to excavate the potentiality of optical fiber now.Dispersion Flattened Fiber always can't commercial application since three more than ten years.Dispersion shifted optical fiber leans on the zero-dispersion wavelength of dispersion characteristics to move about, and bandwidth is restricted.The optical transmission performance of conventional single-mode fiber and photonic crystal fiber and microstructured optical fibers form strong contrast.The main supporting use of the non-displacement optical fiber of chromatic dispersion with the 1300nm window of Fiber to the home special-purpose bend-insensitive optical fiber, the welding loss needs cancellation, and macrobending loss needs to reduce, and bandwidth needs increase.

According to well-known principle, the inventor carries out infinitesimal analysis again to optical fiber property and calculates, and has proposed rake to method for designing, in the 1300-1800nm wavelength coverage, fully excavates the optical fiber potentiality, has invented the wide band dispersion of bend-insensitive and has optimized single-mode fiber.The optical fiber advantage of inventing following: dispersion characteristics are near microstructured optical fibers; Free area and minimum dispersion are enough to reduce nonlinear distortion such as four-wave mixing; Have concurrently simultaneously near desirable transport property and excellent bend-insensitive characteristic; Simple in structure, easy to use, with low cost; Meet the recent tendency that hypervelocity is downloaded.

Summary of the invention

The wide band dispersion of the bend-insensitive of inventing is optimized single-mode fiber, and the higher mode cutoff wavelength is less than 1300nm under conventional tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 19.0ps/ (nmkm) under wavelength 1800nm.

Other useful area under wavelength 1550nm are not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss is from enclosing less than 5 * 10 less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm ^-5The dB/100 circle; Under wavelength 1800nm the chromatic dispersion maximal value from less than 19.0ps/ (nmkm) to less than 14.5ps/ (nmkm).

Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 18.0ps/ (nmkm) under wavelength 1700nm.

Other useful area under wavelength 1550nm are not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses from enclosing less than 0.004dB/100 less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; Under wavelength 1700nm the chromatic dispersion maximal value from less than 18.0ps/ (nmkm) to less than 15.5ps/ (nmkm).

Description of drawings

With reference to the following drawings, those skilled in the art that, from detailed description of the present invention, above-mentioned and other purposes, feature and advantage will be apparent of the present invention.

Fig. 1 be the synoptic diagram of the desirable α refractive index profile of the optical fiber of inventing.The α variation range is very big, and it is wherein a kind of only to draw.Do not draw central concave, the actual refractive index of not drawing section and the little difference of said desirable refractive index profile near the shaft axis of optic fibre.

Fig. 2 be the synoptic diagram of the desirable step change type refractive index profile of the optical fiber of inventing.Δ only draws ₂=Δ ₀A kind of situation.The layering of fibre core central, circular can be adopted pure SiO ₂Material avoids near shaft axis of optic fibre, occurring central concave.The actual refractive index of not drawing section and the little difference of said desirable refractive index profile.

Said α refractive index profile, when in fact α can regard the step change type refractive index profile as greater than 10 the time, the transition between above-mentioned two kinds of refractive index profiles is continuous.

Embodiment

In Fig. 1,1,2,3 and 4 represent the layering of fibre core central, circular, the first annular layering, the second annular layering and the surrounding layer of said optical fiber respectively, and 5,6 and 7 represent said fibre core central, circular layering radius a, the said first annular layering width H respectively ₁With the said second annular layering width H ₂n ₀Be the maximum refractive index of said fibre core central, circular layering α refractive index profile, n ₁And n ₂The homogeneous refractive index of representing the said first annular layering and the said second annular layering respectively, n _C1The homogeneous refractive index of representing said surrounding layer.

In Fig. 2,1,2,3 and 4 represent the layering of fibre core central, circular, the first annular layering, the second annular layering and the surrounding layer of said optical fiber respectively, and 5,6 and 7 represent said fibre core central, circular layering radius a, the said first annular layering width H respectively ₁With the said second annular layering width H ₂, n ₀, n ₁And n ₂The homogeneous refractive index of representing the layering of said fibre core central, circular, the said first annular layering and the said second annular layering respectively, n _C1The homogeneous refractive index of representing said surrounding layer.

Table 1 has provided the one group of example structure parameter that realizes the wide band dispersion optimization single-mode fiber of the bend-insensitive of inventing by the said embodiment of Fig. 1.

Table 1

Structural parameters	Index
		Fibre core central, circular layering refractive index profile parameter	α≥5
Fibre core central, circular layering refractive index contrast	Δ 0=0.26 to 0.60%
		Fibre core central, circular layering radius	A=3.10 is to 5.80 μ m
The first annular layering refractive index contrast	Δ 1=-0.30 to-1.10 Δs 0
		The first annular layering width	H 1=0.40 to 1.75a
The second annular layering refractive index contrast	Δ 2=0.4 to 1.0 Δ 0
		The second annular layering width	H 2=0.15 to 0.95a

One group of structural parameters can be realized following characteristic shown in the table 1: the higher mode cutoff wavelength is less than 1300nm under conventional tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 19.0ps/ (nmkm) under wavelength 1800nm.

Other useful area under wavelength 1550nm are not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss is from enclosing less than 5 * 10 less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm ^-5The dB/100 circle; Under wavelength 1800nm the chromatic dispersion maximal value from less than 19.0ps/ (nmkm) to less than 14.5ps/ (nmkm).

Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 18.0ps/ (nmkm) under wavelength 1700nm.

Other useful area under wavelength 1550nm are not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses from enclosing less than 0.004dB/100 less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; Under wavelength 1700nm the chromatic dispersion maximal value from less than 18.0ps/ (nmkm) to less than 15.5ps/ (nmkm).

Table 2 has provided by the said embodiment of Fig. 2 and has realized above-mentioned one group of example structure parameter of inventing the wide band dispersion optimization single-mode fiber of bend-insensitive.

Table 2

Structural parameters	Index
		Fibre core central, circular layering refractive index profile parameter	α≥10
Fibre core central, circular layering refractive index contrast	Δ 0=0.26 to 0.46%
		Fibre core central, circular layering radius	A=3.30 is to 4.40 μ m
The first annular layering refractive index contrast	Δ 1=-0.30 to-0.42 Δ 0
		The first annular layering width	H 1=1.30 to 1.60a
The second annular layering refractive index contrast	Δ 2=0.4 to 1.0 Δ 0
		The second annular layering width	H 2=0.17 to 0.34a

One group of structural parameters can be realized following characteristic shown in the table 2: the higher mode cutoff wavelength is less than 1300nm under conventional manufacturing tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 19.0ps/ (nmkm) under wavelength 1800nm.

Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 18.0ps/ (nmkm) under wavelength 1700nm.

Table 3 has provided by the said embodiment of Fig. 2 and has realized above-mentioned one group of example structure parameter of inventing the wide band dispersion optimization single-mode fiber of bend-insensitive.

Table 3

Structural parameters	Index
		Fibre core central, circular layering refractive index profile parameter	α≥10
Fibre core central, circular layering refractive index contrast	Δ 0=0.26 to 0.46%
		Fibre core central, circular layering radius	A=3.30 is to 4.50 μ m
The first annular layering refractive index contrast	Δ 1=-0.42 to-0.55 Δ 0
		The first annular layering width	H 1=0.95 to 1.40a
The second annular layering refractive index contrast	Δ 2=0.4 to 1.0 Δ 0
		The second annular layering width	H 2=0.17 to 0.40a

One group of structural parameters can be realized following characteristic shown in the table 3: the higher mode cutoff wavelength is less than 1300nm under conventional manufacturing tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.01dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 18.0ps/ (nmkm) under wavelength 1800nm.

Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.13dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 17.5ps/ (nmkm) under wavelength 1700nm.

Table 4 has provided by the said embodiment of Fig. 2 and has realized above-mentioned one group of example structure parameter of inventing the wide band dispersion optimization single-mode fiber of bend-insensitive.

Table 4

Structural parameters	Index
		Fibre core central, circular layering refractive index profile parameter	α≥10
Fibre core central, circular layering refractive index contrast	Δ 0=0.26 to 0.46%
		Fibre core central, circular layering radius	A=3.40 is to 4.50 μ m
The first annular layering refractive index contrast	Δ 1=-0.55 to-0.75 Δ 0
		The first annular layering width	H 1=0.85 to 1.20a
The second annular layering refractive index contrast	Δ 2=0.4 to 1.0 Δ 0
		The second annular layering width	H 2=0.20 to 0.40a

One group of structural parameters can be realized following characteristic shown in the table 4: the higher mode cutoff wavelength is less than 1300nm under conventional manufacturing tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.004dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 15.0ps/ (nmkm) under wavelength 1800nm.

Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.06dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 15.5ps/ (nmkm) under wavelength 1700nm.

Table 5 has provided by the said embodiment of Fig. 2 and has realized above-mentioned one group of example structure parameter of inventing the wide band dispersion optimization single-mode fiber of bend-insensitive.

Table 5

Structural parameters	Index
		Fibre core central, circular layering refractive index profile parameter	α≥10
Fibre core central, circular layering refractive index contrast	Δ 0=0.26 to 0.46%
		Fibre core central, circular layering radius	A=3.45 is to 4.75 μ m
The first annular layering refractive index contrast	Δ 1=-0.75 to-1.10 Δs 0
		The first annular layering width	H 1=0.65 to 0.90a
The second annular layering refractive index contrast	Δ 2=0.4 to 1.0 Δ 0
		The second annular layering width	H 2=0.20 to 0.45a

One group of structural parameters can be realized following characteristic shown in the table 5: the higher mode cutoff wavelength is less than 1300nm under conventional manufacturing tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

Wherein a kind of under wavelength 1550nm useful area be not less than 60.0 μ m ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss is less than 5 * 10 when wavelength 1550nm and bending radius 5mm ^-5The dB/100 circle; The chromatic dispersion maximal value is less than 14.5ps/ (nmkm) under wavelength 1800nm.Wherein a kind of under wavelength 1550nm useful area be not less than 70.0 μ m ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.004dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 15.5ps/ (nmkm) under wavelength 1700nm.

Table 1 to table 5 column data corresponding to following condition: the layering of said fibre core central, circular is the α refractive index profile basically, and no central concave comprises other refractive index profiles that the optical transmission performance close with this section is similar.The said first annular layering, the said second annular layering and said surrounding layer base material are uniformly basically, comprise optical transmission performance similar approach other refractive index profiles uniformly.When actual conditions and said condition were variant slightly, corresponding data and tabular were slightly different.

Different with existing various optical fiber, the wide band dispersion of the bend-insensitive of being invented is optimized single-mode fiber and had following feature and advantage: dispersion characteristics are very smooth, equal to microstructured optical fibers; Free area and minimum dispersion are enough to reduce nonlinear distortion such as four-wave mixing; Wide band dispersion is optimized optical fiber and had the bend-insensitive characteristic concurrently, and is simple in structure, easy to use, with low cost; Bending loss can drop to extremely low, meets the recent tendency that hypervelocity is downloaded.

The front provides the description to preferred embodiment, so that any technician in this area can use or utilize the present invention.Various modifications to these embodiment are conspicuous to those skilled in the art, can be applied to other embodiment to total principle described here and not use creativeness.Thereby, the embodiment shown in the present invention will be not limited to here, and the wide region of principle that should disclose and new feature according to meeting here.

Claims (10)

1. the wide band dispersion of a bend-insensitive is optimized single-mode fiber, comprises the layering of fibre core central, circular, is coated on the first annular layering in the layering of said fibre core central, circular, is coated on the second annular layering in the said first annular layering and is coated on the even surrounding layer in the said second annular layering.The refractive index contrast of said fibre core central, circular layering is a Δ ₀, radius is a; The refractive index contrast of the said first annular layering is a Δ ₁, width is H ₁The refractive index contrast of the said second annular layering is a Δ ₂, width is H ₂The layering of said fibre core central, circular is the α refractive index profile basically; The said first annular layering and the said second annular layering are homogeneous refractive index basically; The refractive index of the said first annular layering is lower than the refractive index of said even surrounding layer, and the refractive index of the said second annular layering is higher than the refractive index of said even surrounding layer.It is characterized in that: α>=5; Δ ₀=0.26 to 0.60%; Δ ₁=-0.30 to-1.10 Δs ₀Δ ₂=0.4 to 1.0 Δ ₀A=3.10 is to 5.80 μ m; H ₁=0.40 to 1.75a; H ₂=0.15 to 0.95a.

2. optical fiber according to claim 1 is characterized in that: the higher mode cutoff wavelength is less than 1300nm under conventional tolerance; Zero-dispersion wavelength is between 1300 to 1324nm; Useful area is greater than 55.0 μ m under wavelength 1550nm ²

3. optical fiber according to claim 2 is characterized in that: α>=10; Δ ₀=0.26 to 0.46%; Δ ₁=-0.30 to-0.42 Δ ₀A=3.30 is to 4.40 μ m; H ₁=1.30 to 1.60a; H ₂=0.17 to 0.34a.

4. optical fiber according to claim 3 is characterized in that: useful area is not less than 60.0 μ m under wavelength 1550nm ²Mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss encloses less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 19.0ps/ (nmkm) under wavelength 1800nm.

5. optical fiber according to claim 3 is characterized in that: useful area is not less than 70.0 μ m under wavelength 1550nm ²Mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; The chromatic dispersion maximal value is less than 18.0ps/ (nmkm) under wavelength 1700nm.

6. optical fiber according to claim 2 is characterized in that: α>=10; Δ ₀=0.26 to 0.46%; Δ ₁=-0.42 to-0.55 Δ ₀A=3.30 is to 4.50 μ m; H ₁=0.95 to 1.40a; H ₂=0.17 to 0.40a.

7. optical fiber according to claim 2 is characterized in that: α>=10; Δ ₀=0.26 to 0.46%; Δ ₁=-0.55 to-0.75 Δ ₀A=3.40 is to 4.50 μ m; H ₁=0.85 to 1.20a; H ₂=0.20 to 0.40a.

8. optical fiber according to claim 2 is characterized in that: α>=10; Δ ₀=0.26 to 0.46%; Δ ₁=-0.75 to-1.10 Δs ₀A=3.45 is to 4.75 μ m; H ₁=0.65 to 0.90a; H ₂=0.20 to 0.45a.

9. according to claim 6 or claim 7 or the described optical fiber of claim 8, it is characterized in that: useful area is not less than 60.0 μ m under wavelength 1550nm ²Optical fiber, mode field diameter is not less than 8.60 μ m under wavelength 1550nm; Bending loss is from enclosing less than 5 * 10 less than 0.1dB/100 when wavelength 1550nm and bending radius 5mm ^-5The dB/100 circle; Under wavelength 1800nm the chromatic dispersion maximal value from less than 19.0ps/ (nmkm) to less than 14.5ps/ (nmkm).

10. according to claim 6 or claim 7 or the described optical fiber of claim 8, it is characterized in that: useful area is not less than 70.0 μ m under wavelength 1550nm ²Optical fiber, mode field diameter is not less than 9.30 μ m under wavelength 1550nm; Bending loss encloses from enclosing less than 0.004dB/100 less than 0.5dB/100 when wavelength 1550nm and bending radius 5mm; Under wavelength 1700nm the chromatic dispersion maximal value from less than 18.0ps/ (nmkm) to less than 15.5ps/ (nmkm).

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