CN104345383A - Bending-insensitive broadband dispersion flat single-mode optical fiber - Google Patents

Abstract

The invention discloses a bending-insensitive broadband dispersion flat single-mode optical fiber which includes a fiber core center round layer, a first annular layer which wraps the fiber core center round layer, a second annular layer which wraps the first annular layer, and a uniform outer cladding layer which wraps the second annular layer, wherein the refractivity of the first annular layer is lower than the refractivity of the uniform outer cladding layer. The optical fiber spreads in an improved total internal reflection method. The high-order mode cutoff wavelength is smaller than 1400nm. The dispersion minimum value under a wavelength of 1400nm is larger than 2.0 ps/(nm*km). The effective area under a wavelength of 1550nm is not smaller than 70.0 mum<2>. When the mode field diameter is not smaller than 9.30 mum and the bending radius is 5mm, the bending loss is from being smaller than 0.2dB/100rings to being smaller than 0.004dB/100rings. Under a wavelength of 1700nm, the dispersion maximum value is from being smaller than 10.7 ps/(nm*km) to being smaller than 10.1 ps/(nm*km).

Description

The smooth single-mode fiber of wide band dispersion of bend-insensitive

Invention field

The present invention relates to single-mode fiber, particularly relate to, the smooth single-mode fiber of wide band dispersion and bend-insensitive single-mode optical fiber.

Background technology

First provide definition to the term that the present invention relates to below, wherein general term meets this area convention; The proprietary term of this instructions is illustrated by common terminology.

The radius of each layering of optical fiber is in unit μm, and by refractive index definition, each particular hierarchical has first refractive rate point and last refractive index point.Radius from shaft axis of optic fibre to first refractive rate point position is the inside radius of this layering; Radius from shaft axis of optic fibre to last refractive index point position is the external radius of this layering.See refractive index profile figure, the radius of core center circular sublaminate is from shaft axis of optic fibre amount to the external radius of this layering; The external radius of width from the inside radius amount of the first annular segment to the first annular segment of the first annular segment; The external radius of width from the inside radius amount of the second annular segment to the second annular segment of the second annular segment.

The refractive index contrast Δ of core center circular sublaminate, the first annular segment and the second annular segment ₀, Δ ₁and Δ ₂in 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 ₂represent the largest refractive index of core center circular sublaminate and the second annular segment respectively; n ₁represent the minimum refractive index of the first annular segment; n _c1represent the homogeneous refractive index of surrounding layer.

N ₁be less than n _c1optical fiber be called depressed cladding fiber, depressed clad fiber, wherein the opposing recesses degree of depth is defined as Δ ₁and Δ ₀ratio.

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

Core center circular sublaminate α refractive index profile is defined as

Δ _co(r)＝Δ ₀[1-(r/a) ^α]，0≤r≤a，

Wherein, r is present position radius; A is the radius of described core center circular sublaminate; α gets arbitrary value, and α is greater than 10 can regard Stepped-index section as.α refractive index profile comprises other refractive index profiles similar to its optical transmission performance.

Chromatic dispersion coefficient is in unit ps/ (nmkm), and this instructions is referred to as dispersion.

Chromatic dispersion slope coefficient is with unit ps/ (nm ²km) count, this instructions is referred to as chromatic dispersion gradient.

Useful area is with unit μm ²meter, is defined as

A _eff＝2π(∫E ²(r)rdr) ²/(∫E ⁴(r)rdr)，

Wherein, integration is limited to 0 to ∞; E (r) is that light propagates adjoint electric field, and r is present position radius.

This instructions of macrobending loss is also called bending loss, utilizes following formulae discovery:

${\mathrm{\&alpha;}}_{\mathrm{macro}}=\frac{10}{\ln 10}\left(\frac{\mathrm{\&pi;}{V}^8}{16a{R}_b{W}^3}\right)\exp \left(\frac{-4R_b\mathrm{\&Delta;}{W}^3}{3a{V}^2}\right)\frac{{\left[{\&Integral;}_0^{\&infin;}(1-g)F_0\mathrm{rdr}\right]}^2}{{\&Integral;}_0^{\&infin;}{F}_0^2{r}^2\mathrm{rdr}}$

$g=\frac{n{\left(r\right)}^2-n_{\min }^2}{n_{\max }^2-n_{\min }^2},V=\mathrm{ka}\sqrt{n_{\max }^2-n_{\min }^2}$

$W=a\sqrt{{\mathrm{\&beta;}}^2-{\left({\mathrm{kn}}_{\min }\right)}^2},\mathrm{\&Delta;}=\frac{n_{\max }^2-n_{\min }^2}{2n_{\max }^2}$

The invention of optical fiber changes the world, needs now the potentiality fully excavating optical fiber.Since three more than ten years, the smooth single-mode fiber of wide band dispersion never has business application.Dispersion shifted optical fiber moves about by the zero-dispersion wavelength of dispersion characteristics, and bandwidth is restricted.The optical transmission property of Standard single-mode fiber and photonic crystal fiber and microstructured optical fibers form powerful contrast.The special bend insensitive fiber of fiber to the home is main to be supported the use with the dispersion shifted optical fiber of 1300nm window, and welding loss needs to cancel, and macrobending loss needs to reduce, and bandwidth needs increase.

According to well-known principle, inventor carries out infinitesimal analysis calculating again to optical fiber property, proposes target design method, fully excavates the potentiality of optical fiber, invented the smooth single-mode fiber of wide band dispersion of bend-insensitive in 1400 to 1800nm wavelength coverage.Institute's invention optical fiber advantage is as follows: dispersion characteristics are very smooth, equal to microstructured optical fibers; Useful area and minimum dispersion are enough to reduce the nonlinear distortion such as four-wave mixing; Have concurrently close to desirable color dispersion plainness characteristic and excellent bend-insensitive characteristic simultaneously; Structure is simple, easy to use, with low cost; Meet the recent tendency that hypervelocity is downloaded.

Summary of the invention

The smooth single-mode fiber of wide band dispersion of institute's invention bend-insensitive, higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Wherein under wavelength 1550nm, useful area is not less than 60.0 μm ²optical fiber, under wavelength 1550nm, mode field diameter is not less than 8.60 μm; When wavelength 1550nm and bending radius 5mm, bending loss encloses be less than 5 × 10 from being less than 2.0dB/100 ^-7dB/100 encloses; Under wavelength 1800nm, dispersion maximal value is from being less than 12.7ps/ (nmkm) to being less than 10.0ps/ (nmkm).

Wherein under wavelength 1550nm, useful area is not less than 70.0 μm ²optical fiber, when under wavelength 1550nm, mode field diameter is not less than 9.30 μm and bending radius 5mm, bending loss encloses be less than 1 × 10 from being less than 5.0dB/100 ^-6dB/100 encloses; Under wavelength 1700nm, dispersion maximal value is from being less than 12.9ps/ (nmkm) to being less than 8.7ps/ (nmkm).

Accompanying drawing explanation

With reference to the following drawings, those skilled in the art, from detailed description of the present invention, by apparent above and other object of the present invention, feature and advantage.

Fig. 1 be a kind of situation of ideal refractive rate section of invention optical fiber.Do not draw the little central concave because technological reason occurs near shaft axis of optic fibre, do not draw actual refractive index section and the little difference of described ideal refractive rate section.

Fig. 2 be a kind of situation of ideal refractive rate section of invention optical fiber.Core center circular sublaminate adopts pure SiO ₂material, can avoid occurring central concave near shaft axis of optic fibre.Do not draw actual refractive index section and the little difference of described ideal refractive rate section.

Described α refractive index profile, can regard Stepped-index section as when α is greater than 10, and between above-mentioned two kinds of refractive index profiles is excessively continuous print.

Embodiment

In FIG, 1,2, the 3 and 4 core center circular sublaminate representing described optical fiber respectively, the first annular segment, the second annular segment and surrounding layer, 5,6 and 7 represent described core center circular sublaminate radius a, described first annular segment width H respectively ₁with described second annular segment width H ₂.N ₀the maximum refractive index of described core center circular sublaminate α refractive index profile, n ₁and n ₂represent the homogeneous refractive index of described first annular segment and described second annular segment respectively, n _c1represent the homogeneous refractive index of described surrounding layer.

In fig. 2,1,2, the 3 and 4 core center circular sublaminate representing described optical fiber respectively, the first annular segment, the second annular segment and surrounding layer, 5,6 and 7 represent described core center circular sublaminate radius a, described first annular segment width H respectively ₁with described second annular segment width H ₂, n ₀, n ₁and n ₂represent the homogeneous refractive index of described core center circular sublaminate, described first annular segment and described second annular segment respectively, n _c1represent the homogeneous refractive index of described surrounding layer.

Table 1 gives one group of exemplary construction parameter of the smooth single-mode fiber of wide band dispersion realizing institute's invention bend-insensitive by embodiment described in Fig. 1.

Table 1

Structural parameters	Index
		Core center circular sublaminate refractive index profile parameter	α≥10
Core center circular sublaminate refractive index contrast	Δ 0=0.25 to 0.45%
		Core center circular sublaminate radius	A=3.21 is to 4.69 μm
First annular segment refractive index contrast	Δ 1=-0.367 to-1.413 Δs 0
		First annular segment width	H 1=0.50 to 1.71a
Second annular segment refractive index contrast	Δ 2=0.40 to 1.0 Δs 0
		Second annular segment width	H 2=0.19 to 1.10a

Described structural parameters satisfy condition Δ ₁h ₁+ Δ ₂h ₂< 0; Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0, can realize following characteristic: higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Table 2 gives one group of exemplary construction parameter of the smooth single-mode fiber of wide band dispersion realizing institute's invention bend-insensitive by embodiment described in Fig. 2.

Table 2

Structural parameters	Index
		Core center circular sublaminate refractive index profile parameter	α≥10
Core center circular sublaminate refractive index contrast	Δ 0=0.25 to 0.45%
		Core center circular sublaminate radius	A=3.21 is to 4.17 μm
First annular segment refractive index contrast	Δ 1=-0.367 to-0.486 Δ 0
		First annular segment width	H 1=1.06 to 1.71a
Second annular segment refractive index contrast	Δ 2=0.40 to 1.0 Δs 0
		Second annular segment width	H 2=0.19 to 0.71a

One group of structural parameters shown in table 2 satisfy condition Δ ₁h ₁+ Δ ₂h ₂< 0 and Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0, can realize following characteristic: higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Wherein under wavelength 1550nm, useful area is not less than 60.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 8.60 μm and bending radius 5mm time, bending loss from be less than 2.0dB/100 enclose be less than 0.2dB/100 circle; Under wavelength 1800nm, dispersion maximal value is less than 12.7ps/ (nmkm).

Wherein under wavelength 1550nm, useful area is not less than 70.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss from be less than 5.0dB/100 enclose be less than 1.0dB/100 circle; Under wavelength 1700nm, dispersion maximal value is from being less than 12.9ps/ (nmkm) to being less than 11.9ps/ (nmkm).

Table 3 gives one group of exemplary construction parameter of the smooth single-mode fiber of wide band dispersion realizing institute's invention bend-insensitive by embodiment described in Fig. 2.

Table 3

Structural parameters	Index
		Core center circular sublaminate refractive index profile parameter	α≥10
Core center circular sublaminate refractive index contrast	Δ 0=0.25 to 0.45%
		Core center circular sublaminate radius	A=3.24 is to 4.28 μm
First annular segment refractive index contrast	Δ 1=-0.486 to-0.621 Δ 0
		First annular segment width	H 1=0.96 to 1.38a
Second annular segment refractive index contrast	Δ 2=0.40 to 1.0 Δs 0
		Second annular segment width	H 2=0.20 to 0.80a

One group of structural parameters shown in table 3 satisfy condition Δ ₁h ₁+ Δ ₂h ₂< 0 and Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0, can realize following characteristic: higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Wherein under wavelength 1550nm, useful area is not less than 60.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 8.60 μm and bending radius 5mm time, bending loss from be less than 0.2dB/100 enclose be less than 0.02dB/100 circle; Under wavelength 1800nm, dispersion maximal value is from being less than 12.5ps/ (nmkm) to being less than 10.6ps/ (nmkm).

Wherein under wavelength 1550nm, useful area is not less than 70.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss from be less than 1.0dB/100 enclose be less than 0.2dB/100 circle; Under wavelength 1700nm, dispersion maximal value is from being less than 11.9ps/ (nmkm) to being less than 10.7ps/ (nmkm).

Table 4 gives one group of exemplary construction parameter of the smooth single-mode fiber of wide band dispersion realizing institute's invention bend-insensitive by embodiment described in Fig. 2.

Table 4

Structural parameters	Index
		Core center circular sublaminate refractive index profile parameter	α≥10
Core center circular sublaminate refractive index contrast	Δ 0=0.25 to 0.45%
		Core center circular sublaminate radius	A=3.34 is to 4.46 μm
First annular segment refractive index contrast	Δ 1=-0.621 to-0.876 Δ 0
		First annular segment width	H 1=0.74 to 1.19a
Second annular segment refractive index contrast	Δ 2=0.40 to 1.0 Δs 0
		Second annular segment width	H 2=0.25 to 0.88a

One group of structural parameters shown in table 4 satisfy condition Δ ₁h ₁+ Δ ₂h ₂< 0 and Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0, can realize following characteristic: higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Wherein under wavelength 1550nm, useful area is not less than 60.0 μm ²optical fiber, when under wavelength 1550nm, mode field diameter is not less than 8.60 μm and bending radius 5mm, bending loss encloses be less than 2 × 10 from being less than 0.02dB/100 ^-4dB/100 encloses; Under wavelength 1800nm, dispersion maximal value is from being less than 10.6ps/ (nmkm) to being less than 10.0ps/ (nmkm).

Wherein under wavelength 1550nm, useful area is not less than 70.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss from be less than 0.2dB/100 enclose be less than 0.004dB/100 circle; Under wavelength 1700nm, dispersion maximal value is from being less than 10.7ps/ (nmkm) to being less than 10.1ps/ (nmkm).

Table 5 gives one group of exemplary construction parameter of the smooth single-mode fiber of wide band dispersion realizing institute's invention bend-insensitive by embodiment described in Fig. 2.

Table 5

Structural parameters	Index
		Core center circular sublaminate refractive index profile parameter	α≥10
Core center circular sublaminate refractive index contrast	Δ 0=0.26 to 0.45%
		Core center circular sublaminate radius	A=3.47 is to 4.69 μm
First annular segment refractive index contrast	Δ 1=-0.876 to-1.413 Δs 0
		First annular segment width	H 1=0.50 to 0.92a
Second annular segment refractive index contrast	Δ 2=0.40 to 1.0 Δs 0
		Second annular segment width	H 2=0.28 to 1.10a

One group of structural parameters shown in table 5 satisfy condition Δ ₁h ₁+ Δ ₂h ₂< 0 and Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0, can realize following characteristic: higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

Wherein under wavelength 1550nm, useful area is not less than 60.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 8.60 μm and bending radius 5mm time, bending loss is from being less than 2 × 10 ^-4dB/100 encloses and is less than 5 × 10 ^-7dB/100 encloses; Under wavelength 1800nm, dispersion maximal value is less than 10.0ps/ (nmkm).

Wherein under wavelength 1550nm, useful area is not less than 70.0 μm ²optical fiber, under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss is from being less than 4 × 10 ^-3dB/100 encloses and is less than 1 × 10 ^-6dB/100 encloses; Under wavelength 1700nm, dispersion maximal value is from being less than 10.1ps/ (nmkm) to being less than 8.7ps/ (nmkm).

Table 1 corresponds to following condition to table 5 column data: described core center circular sublaminate is the α refractive index profile of Stepped-index section or equivalence, and non-stop layer caves in, and comprises other refractive index profiles that the optical transmission performance close to this section is similar.Described first annular segment, described second annular segment and described surrounding layer base material are uniform substantially, comprise optical transmission performance similar close to other refractive index profiles uniform.When actual conditions and described condition slightly difference time, corresponding data and tabular slightly different.

Different from existing various optical fiber, the smooth single-mode fiber of wide band dispersion of the bend-insensitive invented has following feature and advantage: dispersion characteristics are very smooth, equal to microstructured optical fibers; Useful area and minimum dispersion are enough to reduce the nonlinear distortion such as four-wave mixing; Dispersion Flattened Fiber has bend-insensitive characteristic concurrently; Structure is simple, easy to use, with low cost; Meet the recent tendency that hypervelocity is downloaded.

Provide the description to preferred embodiment above, can use to make any technician in this area or utilize the present invention.Carry out various amendment to these embodiments, be evident for personnel skilled in the art, total principle described here can be applied to other embodiments does not need creativeness.Thus, the embodiment shown in the present invention will be not limited to here, and should according to the most wide region meeting disclosed principle and new feature here.

Claims (10)

1. the smooth single-mode fiber of the wide band dispersion of bend-insensitive, comprises core center circular sublaminate, the first annular segment be coated on described core center circular sublaminate, the even surrounding layer that is coated on the second annular segment on described first annular segment and is coated on described second annular segment.The refractive index contrast of described core center circular sublaminate is Δ ₀, radius is a; The refractive index contrast of described first annular segment is Δ ₁, width is H ₁; The refractive index contrast of described second annular segment is Δ ₂, width is H ₂; Described core center circular sublaminate is the α refractive index profile of Stepped-index section or equivalence, described first annular segment and described second annular segment are homogeneous refractive index substantially, the refractive index of described first annular segment is lower than the refractive index of described even surrounding layer, and the refractive index of described second annular segment is higher than the refractive index of described even surrounding layer.It is characterized in that: propagate in the total internal reflection mode improved, satisfy condition Δ simultaneously ₁h ₁+ Δ ₂h ₂< 0 and Δ ₀a+ Δ ₁h ₁+ Δ ₂h ₂> 0.

2. optical fiber according to claim 1, is characterized in that: α>=10; Δ ₀=0.25 to 0.45%; Δ ₁=-0.367 to-1.413 Δs ₀Δ ₂=0.40 to 1.0 Δs ₀; A=3.21 is to 4.69 μm; H ₁=0.50 to 1.71a; H ₂=0.19 to 1.10a; Higher mode cutoff wavelength is less than 1400nm; Under wavelength 1400nm, minimum dispersion value is greater than 2.0ps/ (nmkm); Under wavelength 1550nm, useful area is greater than 55.0 μm ².

3. optical fiber according to claim 2, is characterized in that: Δ ₀=0.29 to 0.45%; Δ ₁=-0.367 to-0.486 Δ ₀; A=3.21 is to 3.96 μm; H ₁=1.06 to 1.71a; H ₂=0.19 to 0.67a; Under wavelength 1550nm, useful area is not less than 60.0 μm ²; Under wavelength 1800nm, dispersion maximal value is from being less than 12.7ps/ (nmkm) to being less than 12.5ps/ (nmkm); Under wavelength 1550nm mode field diameter be not less than 8.60 μm and bending radius 5mm time, bending loss from be less than 2.0dB/100 enclose be less than 0.2dB/100 circle.

4. optical fiber according to claim 2, is characterized in that: Δ ₀=0.25 to 0.39%; Δ ₁=-0.367 to-0.486 Δ ₀; A=3.31 is to 4.17 μm; H ₁=1.12 to 1.70a; H ₂=0.21 to 0.71a; Under wavelength 1550nm, useful area is not less than 70.0 μm ²; Under wavelength 1700nm, dispersion maximal value is from being less than 12.9ps/ (nmkm) to being less than 11.9ps/ (nmkm); Under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss from be less than 5.0dB/100 enclose be less than 1.0dB/100 circle.

5. optical fiber according to claim 2, is characterized in that: Δ ₀=0.29 to 0.45%; Δ ₁=-0.486 to-0.621 Δ ₀; A=3.24 is to 4.10 μm; H ₁=0.96 to 1.30a; H ₂=0.19 to 0.80a; Under wavelength 1550nm, useful area is not less than 60.0 μm ²; Under wavelength 1800nm, dispersion maximal value is from being less than 12.5ps/ (nmkm) to being less than 10.6ps/ (nmkm); Under wavelength 1550nm mode field diameter be not less than 8.60 μm and bending radius 5mm time, bending loss from be less than 0.2dB/100 enclose be less than 0.02dB/100 circle.

6. optical fiber according to claim 2, is characterized in that: Δ ₀=0.25 to 0.39%; Δ ₁=-0.486 to-0.621 Δ ₀; A=3.41 is to 4.28 μm; H ₁=0.96 to 1.38a; H ₂=0.22 to 0.77a; Under wavelength 1550nm, useful area is not less than 70.0 μm ²; Under wavelength 1700nm, dispersion maximal value is from being less than 11.9ps/ (nmkm) to being less than 10.7ps/ (nmkm); Under wavelength 1550nm mode field diameter be not less than 9.30 μm and bending radius 5mm time, bending loss from be less than 1.0dB/100 enclose be less than 0.2dB/100 circle.

7. optical fiber according to claim 2, is characterized in that: Δ ₀=0.29 to 0.45%; Δ ₁=-0.621 to-0.786 Δ ₀; A=3.34 is to 4.25 μm; H ₁=0.74 to 1.19a; H ₂=0.25 to 0.90a; Under wavelength 1550nm, useful area is not less than 60.0 μm ²; Under wavelength 1800nm, dispersion maximal value is from being less than 10.6ps/ (nmkm) to being less than 10.0ps/ (nmkm); When under wavelength 1550nm, mode field diameter is not less than 8.60 μm and bending radius 5mm, bending loss encloses be less than 2 × 10 from being less than 0.02dB/100 ^-4dB/100 encloses.

8. optical fiber according to claim 2, is characterized in that: Δ ₀=0.29 to 0.39%; Δ ₁=-0.621 to-0.876 Δ ₀; A=3.49 is to 4.46 μm; H ₁=0.75 to 1.18a; H ₂=0.25 to 0.88a; Under wavelength 1550nm, useful area is not less than 70.0 μm ²; Under wavelength 1700nm, dispersion maximal value is from being less than 10.7ps/ (nmkm) to being less than 10.1ps/ (nmkm); When under wavelength 1550nm, mode field diameter is not less than 9.30 μm and bending radius 5mm, bending loss encloses be less than 4 × 10 from being less than 0.2dB/100 ^-3dB/100 encloses.

9. optical fiber according to claim 2, is characterized in that: Δ ₀=0.29 to 0.45%; Δ ₁=-0.876 to-1.413 Δs ₀; A=3.47 is to 4.45 μm; H ₁=0.50 to 0.92a; H ₂=0.28 to 0.97a; Under wavelength 1550nm, useful area is not less than 60.0 μm ²; Under wavelength 1800nm, dispersion maximal value is from being less than 10.1ps/ (nmkm) to being less than 10.0ps/ (nmkm); When under wavelength 1550nm, mode field diameter is not less than 8.60 μm and bending radius 5mm, bending loss is from being less than 2 × 10 ^-4dB/100 encloses and is less than 5 × 10 ^-7dB/100 encloses.

10. optical fiber according to claim 2, is characterized in that: Δ ₀=0.26 to 0.40%; Δ ₁=-0.876 to-1.413 Δs ₀; A=3.64 is to 4.69 μm; H ₁=0.54 to 0.92a; H ₂=0.28 to 1.10a; Under wavelength 1550nm, useful area is not less than 70.0 μm ²; Under wavelength 1700nm, dispersion maximal value is from being less than 10.1ps/ (nmkm) to being less than 8.7ps/ (nmkm); When under wavelength 1550nm, mode field diameter is not less than 9.30 μm and bending radius 5mm, bending loss is from being less than 4 × 10 ^-3dB/100 encloses and is less than 1 × 10 ^-6dB/100 encloses.