JP2003063744A - Winding method of optical fiber on reel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding method of an optical fiber on a reel capable of winding the optical fiber easily affected by a bending and a side pressure on the reel such that an increase in a transmitting loss and a winding collapse are not generated. SOLUTION: In the optical fiber, an effective core cross section Aeff is higher than 50 μm<2> ; a zero dispersion wavelength is out of a wavelength range of 1,530 to 1,565 mm; an absolute value of a dispersion value at a whole area of a wavelength range of 1,530 to 1,565 nm is within a range of 2 to 14 ps/nm/ km and a bending loss at a diameter of 20 mm at a wavelength of 1,550 nm is within a range of 1 to 100 dB/m. In the winding method of an optical fiber for winding the optical fiber on a reel having a body diameter of 100 mm to 200 mm, when the covering outer diameter of the optical fiber is defined as d (mm); a body diameter of the reel is defined as D (mm); a winding tension is defined as T (N); and a winding pitch is defined as p (mm); a relationship of d<p<2d and 0.004<=(2T/D)<=0.007 is satisfied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of winding an optical fiber on a reel used for storage and transportation of the optical fiber, and more particularly to a method effective for a non-zero dispersion shifted optical fiber.

[0002]

2. Description of the Related Art Conventionally, techniques for increasing transmission capacity in optical transmission using an optical fiber have been actively studied. In order to increase the transmission capacity in optical transmission, it is necessary that the optical fiber for optical transmission is capable of single mode transmission at the wavelength used. The reason is,
If multiple modes propagate in an optical fiber,
This is because mode dispersion inevitably occurs due to the difference in group velocity for each propagation mode, which causes deterioration of the signal waveform. Therefore, single mode optical fibers (SMF) having a zero dispersion wavelength near the wavelength of 1300 nm have begun to be used.
Since this optical fiber has a zero-dispersion wavelength near the wavelength of 1300 nm, the transmission distance near this wavelength is 10
Optical transmission of more than 0 km and a transmission capacity of several 100 Mbps has become possible. This SMF has, for example, as shown in FIG. 6, a refractive index distribution structure composed of a central region 61 serving as a core and a cladding 62.

On the other hand, the transmission loss of an optical fiber has a wavelength of 155
Since it becomes the smallest in the vicinity of 0 nm, it is desired to perform optical transmission using this wavelength band, and a dispersion-shifted optical fiber (DSF) having a stepwise refractive index distribution structure having a zero dispersion wavelength in the vicinity of 1550 nm has been developed. It was This optical fiber enables optical transmission with a transmission capacity of several Gbps near a wavelength of 1550 nm.

Further, in recent years, as a technique for further increasing the transmission capacity, research and development on wavelength division multiplexing (WDM) optical transmission have been extremely actively conducted. Many studies have also been conducted on optical fibers that are preferably used for WDM optical transmission. When using an optical fiber for WDM optical transmission, it is required that there is no zero-dispersion wavelength in the used wavelength band from the viewpoint of preventing four-wave mixing, so a non-zero dispersion that does not have a zero-dispersion wavelength in the used wavelength band. Shifted optical fiber (NZDSF) was developed. In this NZDSF, since four-wave mixing hardly occurs,
At present, it is considered to be most suitable for WDM optical transmission, and its introduction is proceeding at a rapid pace.

Further, in the NZDSF, in consideration of wide band WDM optical transmission, the effective core area (A _eff ) is increased to reduce the nonlinearity, and the dispersion is reduced to reduce the dispersion difference between wavelengths. There are things with a smaller slope.

Specifically, the characteristics of the conventional DSF are, for example, A _eff of 50 μm ² and dispersion slope of 0.07 ps /.
nm ² / km. Compared with this, as an example of the characteristics of NZDSF in which A _eff is increased, A _{ef f} is 72 μ.
m ² and dispersion slope of 0.11 ps / nm ² / km. This example focuses on the expansion of A _eff . Further, as an example of the characteristics of the NZDSF having a reduced dispersion slope, there are A _eff of 55 μm ² and a dispersion slope of 0.045 ps / nm ² / km. This example is an example in which the dispersion slope is reduced while making A _eff equal to or higher than that of the conventional DSF. Also, some NZDSFs have other characteristics. In order to obtain these characteristics, the refractive index distribution structure of NZDSF has a conventional DSF.
Tends to be complex compared to.

[0007]

By the way, in general, an optical fiber is shipped in a state of being wound on a reel. However, if the winding tension when the optical fiber is wound on the reel is too large, it causes an increase in transmission loss, which is a problem. If the winding tension is too low,
Problems such as collapse of the roll due to vibration during transportation occur.

In particular, in the case of NZDSF, the refractive index distribution structure is complicated in order to expand A _eff and reduce the dispersion slope as compared with the conventional DSF, and therefore, compared with the conventional SMF and DSF. Therefore, it tends to be weak against bending and lateral pressure.

For example, a wavelength of 1 at a bending diameter of 20 mm
Comparing the bending loss at 550 nm, the loss increase in the conventional DSF is smaller than 1 dB / m, whereas in the optical fiber with the dispersion slope lowered, it is about 5 dB / m, and in the optical fiber with the increased A _eff , 20 dB / m. A loss increase of about m is produced.

Therefore, it is important to optimize the winding condition of the optical fiber on the reel. For example, a conventional method of winding a DSF around a bobbin is disclosed in Japanese Patent Application Laid-Open No. 9-100064. It states that the winding tension (0.1N to 1N) and the hardness of the barrel of the optical fiber bobbin should be optimized in order to reduce the transmission loss and the increase in polarization dispersion.

However, as described above, the NZDSF is weaker in bending and lateral pressure than the conventional SMF and DSF.
The technology disclosed in Japanese Patent Laid-Open No. 100064 is directly applied to NZ.
When applied to the DSF winding condition, it causes an increase in transmission loss.

Further, in order to suppress the increase of transmission loss due to the lateral pressure of the optical fiber, it is necessary to consider not only the tension but also the winding diameter, the winding pitch and the like.
The technique disclosed in Japanese Patent Publication No. 000064 is incomplete.

On the other hand, for DSFs including NZDSF,
US Pat. No. 5,852,701 discloses that it is possible to suppress an increase in bending loss by moving the cutoff wavelength to the long wavelength side in order to increase A _eff .

However, although the technique disclosed in US Pat. No. 5,852,701 is suitable for an optical fiber used near a wavelength of 1550 nm, it does not become a single mode near a wavelength of 1300 nm, and therefore is suitable for optical transmission near a wavelength of 1300 nm. There is a problem that is not suitable.

Therefore, at the present time, it is considered that an increase in bending loss is unavoidable in an optical fiber which is suitably used for WDM optical transmission and which operates in a single mode near a wavelength of 1300 nm. It is indispensable to wind a weak optical fiber around a reel so that transmission loss does not increase and winding collapse does not occur.

Therefore, in the present invention, the conventional SMF and DS
An object of the present invention is to propose a method of winding an optical fiber, which is weaker in bending and lateral pressure than F, on a reel so that transmission loss does not increase and winding collapse occurs.

[0017]

The present invention has been made to achieve the above object. According to the invention of claim 1, the effective core area A _eff is larger than 50 μm ² , and the zero dispersion wavelength is 1530 to. It is outside the wavelength range of 1565 nm, the absolute value of the dispersion value in the entire wavelength range of 1530 to 1565 nm is within the range of 2 to 14 ps / nm / km, and the bending loss at a wavelength of 1550 nm at a diameter of 20 mm is 1 to 100 dB /. an optical fiber within the range of m
A reel winding method for an optical fiber wound on a reel having a barrel diameter of 100 mm or more and 200 mm or less, wherein the outer diameter of the coating of the optical fiber is d (mm), the barrel diameter of the reel is D (mm), and the winding tension is T (N ), When the winding pitch is p (mm),
d <p <2d and 0.004 ≦ (2T / D) ≦ 0.00
It is characterized by being 7.

That is, according to the first aspect of the present invention, regarding the winding condition of the optical fiber which is weak against bending and lateral pressure, the influence of the reel barrel diameter and the winding pitch of the optical fiber is more affected than the hardness of the reel barrel. It was made based on the experimental knowledge that it will grow. According to the invention as set forth in claim 1, the optical fiber, which is weak against bending and lateral pressure, is suitable for storage and transportation while suppressing an increase in transmission loss, so that the optical fiber does not collapse due to vibration during transportation. Can be wound on a reel. As a result, it is possible to prevent the occurrence of disconnection when the optical fiber is paid out from the reel for making the cable. It is desirable that the reel around which the optical fiber is wound be as compact as possible and that the optical fiber be wound in a large amount, from the viewpoint of reducing storage costs and transportation costs. From this point, the barrel diameter D of the reel is preferably 200 mm or less. Further, since the optical fiber may be stored for a long period in a state wound on a reel, when the barrel diameter D of the reel is small, a large strain is applied to the optical fiber. Therefore, in consideration of reliability of long-term storage, it is desirable that the barrel diameter D of the reel is 100 mm or more.

According to the second aspect of the invention, the effective core area A _eff is larger than 50 μm ² , the zero dispersion wavelength is outside the wavelength range of 1530 to 1565 nm, and the wavelength of 1
The absolute value of the dispersion value in the entire wavelength range of 530 to 1565 nm is in the range of 2 to 14 ps / nm / km, and the bending loss at a wavelength of 1550 nm and a diameter of 20 mm is 1.
A method of winding an optical fiber having a cut-off wavelength after cable formation of 1260 nm or less in a range of 100 dB / m on a reel having a barrel diameter of 100 mm or more and 200 mm or less, Where d is the outer diameter of the coating, d is the reel barrel diameter is D, the winding tension is T N, and the winding pitch is p mm.
<P <2d and 0.004 ≦ (2T / D) ≦ 0.007
It is characterized by being.

According to the second aspect of the present invention, an optical fiber having a cut-off wavelength of 1260 nm or less after being made into a cable is preferably used for WDM optical transmission and has a wavelength of 1300.
It can be wound on a reel to allow single mode operation near nm.

Furthermore, the invention according to claim 3 has two or more annular regions between the central region and the cladding, and the minimum refractive index of at least one annular region is negative, and the effective core area is A _eff is larger than 50 μm ² , the zero dispersion wavelength is outside the wavelength range of 1530 to 1565 nm,
An optical fiber in which the absolute value of the dispersion value in the entire wavelength range of wavelengths 1530 to 1565 nm is in the range of 2 to 14 ps / nm / km, and the bending loss at a diameter of 20 mm in the wavelength of 1550 nm is in the range of 1 to 100 dB / m. To
A reel winding method for an optical fiber wound on a reel having a barrel diameter of 100 mm or more and 200 mm or less, wherein the outer diameter of the coating of the optical fiber is d (mm), the barrel diameter of the reel is D (mm), and the winding tension is T (N ), When the winding pitch is p (mm),
d <p <2d and 0.004 ≦ (2T / D) ≦ 0.00
It is characterized by being 7.

According to the third aspect of the present invention, there is provided a complex refractive index distribution structure having two or more annular regions between the central region and the cladding, and at least one annular region having a negative minimum refractive index. It is possible to wind an optical fiber that is weak against bending and lateral pressure around a reel so that transmission loss does not increase and winding collapse does not occur.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a reel for explaining an embodiment of an optical fiber reel winding method of the present invention. In FIG. 1, 1 is a reel and 2 is an optical fiber. Note that FIG. 1 shows a state in which the optical fiber 2 is wound halfway in the first layer.

The reel 1 has a barrel diameter D of 100 mm or more and 200 mm or less, and the reel 1 is provided with an optical fiber 2 having a coated outer shape of d (mm), tension T (N) and winding pitch p ( mm). The winding pitch p is the distance between the centers of adjacent optical fibers 2 in the same layer, as shown in FIG.

The optical fiber 2 is NZDSF.
And the effective core area A_eff Is 50 μm ² Bigger, ze
B Dispersion wavelength is outside the wavelength range of 1530 to 1565 nm
In the entire wavelength range of 1530 to 1565 nm
The absolute value of the dispersion value is within the range of 2-14 ps / nm / km
The curve with a diameter of 20 mm at a wavelength of 1550 nm
Loss is in the range of 1 to 100 dB / m.

When winding the optical fiber 2 on the reel 1,
The reel 1 has a body diameter of D (mm) and a winding tension of T.
(N), the outer diameter of the optical fiber 2 after coating is d (m
m) and the winding pitch is p (mm), d <p <2
d and 0.004 ≦ (2T / D) ≦ 0.007 are satisfied. Then, even the optical fiber 2 having the above characteristics and weak against bending and lateral pressure can be wound around the reel 1 so as to suppress an increase in transmission loss and prevent winding collapse.

Examples will be described below. Table 1 shows the characteristics of the two types of NZDSF optical fibers α and β used in the examples. The optical fibers α and β have an outer diameter of 125 μ.
The outer periphery of the m-clad is coated with two layers of an ultraviolet-curable urethane acrylate resin, and the outer diameter of the coating is 250 μm. In Table 1, the unit of dispersion is ps / nm / km and the unit of dispersion slope is ps / nm.
^{The unit of 2} / km, transmission loss and bending loss at a bending diameter of 20 mm is dB / m.

[0028]

[Table 1]

The optical fiber α has the refractive index distribution structure shown in FIG. The refractive index distribution structure is such that the first annular region 22 is provided between the central region 21 serving as the core and the cladding 24.
And a second annular region 23. And the central region 21
And the refractive index of the second annular region 23 are higher than the refractive index of the cladding 24, and the refractive index of the first annular region 22 is lower than the refractive index of the cladding 24. Note that FIG.
In, the refractive index of the first annular region 22 is
However, the refractive index of the first annular region 22 may be substantially equal to the refractive index of the cladding 24.

The optical fiber β has the refractive index distribution structure shown in FIG. The refractive index distribution structure has a first annular region 32, a second annular region 33, and a third annular region 34 between the central region 31 and the cladding 35. The refractive index of the central region 31 and the refractive index of the second annular region 33 are higher than the refractive index of the cladding 35, and the refractive index of the first annular region 32 and the refractive index of the third annular region 34 are the refractive index of the cladding 35. It is lower than the rate. Although the refractive index of the first annular region 32 is lower than that of the cladding 35 in FIG. 3, the refractive index of the first annular region 32 is substantially equal to that of the cladding 35. Good.

The optical fibers α and β have a barrel diameter D of 100 to
About 25km wound on a 200mm reel, d <p
When <2d (in other words, 0.25 <p <0.50) and 0.104 ≦ (2T / D) ≦ 0.007 are satisfied, neither transmission loss increase nor winding collapse occurs, but d <
p <2d or 0.004 ≦ (2T / D) ≦ 0.007
It was found that when the above condition was not satisfied, transmission loss increased or winding collapse occurred.

More specifically, when p ≧ 2d, when the optical fibers α and β are wound, the optical fiber in the upper layer locally falls between the optical fiber pitches in the lower layer,
It may increase the possibility of increasing the transmission loss.
When T / D) <0.004, since the winding tension T is insufficient, the possibility of winding collapse increases,
When (2T / D)> 0.007, the winding tension T
Is too large, due to the effect of lateral pressure on the optical fiber 2,
Transmission loss increases. In particular, when (2T / D)> 0.7 and p ≧ 2d, the increase in transmission loss may exceed the transmission loss of the optical fiber itself.

Table 2 shows the results of winding the optical fibers α and β on the reel as described above. Here, regarding the transmission loss, if the increase is 0.03 dB / km or less,
Regarding the winding, the case where the winding was dropped from the position of 75 cm in the center axis direction of the reel, and the collapse of the winding that would affect the subsequent rewinding did not occur visually was evaluated as ◯.

[0034]

[Table 2]

As shown in Table 2, the light shown in FIGS. 2 and 3 (compared to the refractive index distribution structure of the SMF shown in FIG. 6) and having a complicated refractive index distribution structure and being weak against bending and lateral pressure. Even the fibers α and β can be wound on the reel by the method of the present invention so that the transmission loss does not increase and the winding collapse does not occur. In Table 2, the value of 2T / D is 0.0
When it is 075, it corresponds to the conventional SMF or DSF reel winding condition, and it is understood that it is unsuitable as the reel winding condition of the optical fibers α and β. That is, the winding condition of this embodiment has a smaller value of 2T / D than the conventional winding condition.

The measurement results shown in Table 2 are merely examples, and it goes without saying that the scope of the present invention is not limited to the points shown in Table 2.

The refractive index distribution structure of the optical fiber used in the optical fiber reel winding method of the present invention is shown in FIG.
Needless to say, it is not limited to those shown in FIG.

For example, the refractive index distribution structure shown in FIG. 4 may be used, and the first annular region 42 and the second annular region 43 are provided between the central region 41 and the cladding 44. The refractive index of the central region 41 and the refractive index of the second annular region 43 are lower than the refractive index of the cladding 44, and the refractive index of the first annular region 42 is higher than the refractive index of the cladding 44. In FIG. 4, the refractive index of the second annular region 43 is lower than that of the cladding 44, but it is not necessary. The maximum refractive index of the second annular region 43 is higher than that of the cladding 44. It may be higher.

Further, the refractive index distribution structure shown in FIG. 5 may be used, and it has a central region 51, an annular region 52 and a clad 53. The refractive index of the central region 51 is lower than that of the cladding 53, and the refractive index of the annular region 52 is higher than that of the cladding 53.

In the example of the refractive index distribution structure of the optical fiber used in the optical fiber reel winding method of the present invention, it is desirable that the minimum refractive index of at least one annular region is negative, but the invention is not limited thereto. It is possible to freely select within the scope of the claims of the present invention.

Further, the optical fiber used in the method for winding an optical fiber according to the present invention preferably has a cutoff wavelength of 1260 nm or less after being made into a cable, which makes it suitable for WDM optical transmission. Wavelength 1
It becomes possible to perform single mode operation in the vicinity of 300 nm.

[0042]

As described above, according to the present invention, an optical fiber that is weak against bending and lateral pressure is suitable for storage and transportation while suppressing an increase in transmission loss, and is collapsed by vibration during transportation. It can be wound on a reel so as not to occur, and as a result, there is an excellent effect that it is possible to prevent the occurrence of disconnection when the optical fiber is paid out from the reel for forming a cable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reel for explaining an embodiment of an optical fiber reel winding method of the present invention.

FIG. 2 is a diagram showing a refractive index distribution structure of an optical fiber used in an example of an optical fiber winding method according to the present invention.

FIG. 3 is a view showing a refractive index distribution structure of another optical fiber used in the embodiment of the method for winding an optical fiber according to the present invention.

FIG. 4 is a view showing a refractive index distribution structure of another optical fiber used in the optical fiber reel winding method of the present invention.

FIG. 5 is a diagram showing a refractive index distribution structure of still another optical fiber used in the method for winding an optical fiber according to the present invention.

FIG. 6 is an explanatory diagram of a refractive index distribution structure of SMF.

[Explanation of symbols] 1 reel 2 optical fiber 21, 31, 41, 51 Central area 22, 32, 42 First annular region 23, 33, 43 Second annular region 24, 35, 44, 53 Clad 34 Third annular region 52 annular area

Claims (3)

[Claims] 1. The effective core area A _eff is larger than 50 μm ² , the zero dispersion wavelength is outside the wavelength range of 1530 to 1565 nm, and the absolute value of the dispersion value in the entire wavelength range of 1530 to 1565 nm is 2 to 14 ps. / Nm
Optical fiber having a bending loss of 1 to 100 dB / m at a diameter of 20 mm at a wavelength of 1550 nm and a barrel diameter of 100 mm or more and 200 mm.
A reel winding method of an optical fiber wound on a reel as described below, wherein the outer diameter of the optical fiber is d (mm), the barrel diameter is D (mm), the winding tension is T (N), and the winding pitch is p.
(Mm), d <p <2d and 0.004 ≦
(2T / D) ≦ 0.007, A method of winding an optical fiber reel. 2. The effective core area A _eff is larger than 50 μm ² , the zero dispersion wavelength is outside the wavelength range of 1530 to 1565 nm, and the absolute value of the dispersion value in the entire wavelength range of 1530 to 1565 nm is 2 to 14 ps. / Nm
/ Km, the bending loss at a diameter of 20 mm at a wavelength of 1550 nm is in the range of 1 to 100 dB / m, and the cut-off wavelength after cable formation is 1260 nm or less. , 200
A reel winding method of an optical fiber wound on a reel of mm or less, wherein the outer diameter of the coating of the optical fiber is d (mm), the barrel diameter of the reel is D (mm), the winding tension is T (N), and the winding pitch is p. (Mm), d <p <2d and 0.004 ≦
(2T / D) ≦ 0.007, A method of winding an optical fiber reel. 3. At least one annular region having a negative minimum refractive index and an effective core area A _eff of 50 μm ² having two or more annular regions between the central region and the cladding.
Larger, zero-dispersion wavelength 1530 to 1565n
m is out of the wavelength range, and the absolute value of the dispersion value is 2 to 14 ps / in the entire wavelength range of 1530 to 1565 nm.
An optical fiber having a bending loss of 1 to 100 dB / m at a wavelength of 20 mm at a wavelength of 1550 nm and a barrel diameter of 100 mm or more and 200
A reel winding method of an optical fiber wound on a reel of mm or less, wherein the outer diameter of the coating of the optical fiber is d (mm), the barrel diameter of the reel is D (mm), the winding tension is T (N), and the winding pitch is p. (Mm), d <p <2d and 0.004 ≦
(2T / D) ≦ 0.007, A method of winding an optical fiber reel.