JP4066804B2 - Optical fiber module, chromatic dispersion adjusting method for optical fiber module, and optical transmission system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber module having a dispersion compensating optical fiber, a chromatic dispersion adjusting method for an optical fiber module, and an optical transmission system.
[0002]
[Prior art]
As a conventional optical fiber module, one in which a dispersion compensating optical fiber is wound around a coil body to compensate for chromatic dispersion of an optical fiber transmission line is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-31120 [0004]
[Problems to be solved by the invention]
By the way, when the dispersion compensating optical fiber module is actually used, it may be necessary to adjust the amount of chromatic dispersion. However, in the above prior art, since one dispersion compensation optical fiber is wound around one coil body with respect to one optical fiber module, the total chromatic dispersion amount of the module is constant (fixed). Therefore, the amount of chromatic dispersion cannot be adjusted as necessary. In order to adjust the amount of chromatic dispersion, a plurality of optical fiber modules are required, which is expensive.
[0005]
An object of the present invention is to provide an optical fiber module, a chromatic dispersion adjusting method for an optical fiber module, and an optical transmission system capable of adjusting a chromatic dispersion amount.
[0010]
[Means for Solving the Problems]
An optical fiber module according to the present invention is formed by winding a dispersion compensating optical fiber in a coil shape, and includes a plurality of optical fiber coil portions arranged in one module housing, and the module housing or the outside of the module housing. Are provided with a plurality of optical connectors connected to both ends of the dispersion compensating optical fiber of each optical fiber coil portion, and by connecting / disconnecting a connection cord to / from the optical connector, The dispersion compensating optical fiber of any one of the optical fiber coil sections is configured to be switchable and connectable with the dispersion compensating optical fiber of any other optical fiber coil section.
In this way, by providing a plurality of optical fiber coil portions and making the dispersion compensating optical fiber of any optical fiber coil portion switchably connectable to the dispersion compensating optical fiber of any other optical fiber coil portion, The total chromatic dispersion amount of the optical fiber module can be adjusted without preparing a plurality of optical fiber modules.
Further, by connecting arbitrary optical connectors with a connection cord, only a necessary optical fiber coil portion is selected from a plurality of optical fiber coil portions and used. Thereby, the total chromatic dispersion amount of the required optical fiber module can be obtained. Further, since it is only necessary to insert / remove the connection cord to / from the optical connector, the amount of chromatic dispersion can be easily adjusted.
[0012]
Preferably, one end of a single-mode optical fiber having a structure different from that of the dispersion-compensating optical fiber is connected to both ends of the dispersion-compensating optical fiber of each optical fiber coil section, and the other end of each single-mode optical fiber is connected to each end. Is connected to the optical connector. In this case, since a normal single mode optical fiber that is easier to handle than the dispersion compensating optical fiber is used as a connection cord for connecting the optical connectors to each other, it becomes easy to adjust the chromatic dispersion amount.
[0013]
Further preferably, the plurality of optical fiber coil portions are formed by winding dispersion compensating optical fibers around a plurality of bobbins. Thereby, a some optical fiber coil part can be manufactured easily.
[0015]
Further, the wavelength dispersion adjusting method for an optical fiber module according to the present invention includes a module housing, a plurality of optical fiber coil portions that are disposed in the housing and are formed by winding a dispersion compensating optical fiber in a coil shape, and a module housing. Prepare an optical fiber module with multiple optical connectors connected to both ends of the dispersion compensating optical fiber of each optical fiber coil section, and connect any connectors with a connection cord By doing so, the chromatic dispersion amount of the optical fiber module is adjusted. Also in this case, the required total chromatic dispersion amount of the optical fiber module can be obtained by selecting and using only the required optical fiber coil portion from the plurality of optical fiber coil portions.
[0016]
An optical transmission system according to the present invention includes the above-described optical fiber module. By providing the optical fiber module as described above, the total chromatic dispersion amount of the optical fiber module can be adjusted as described above.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an optical fiber module, an optical fiber module wavelength dispersion adjusting method, and an optical transmission system according to the invention will be described with reference to the drawings.
[0018]
FIG. 1 is a configuration diagram showing a first embodiment of an optical fiber module according to the present invention. In the figure, an optical fiber module 1 of the present embodiment has a module housing 2, and a plurality (here, five) of optical fiber coil portions 3 (hereinafter referred to as optical fiber coil portions) are included in the module housing 2. 3A to 3E).
[0019]
Each of the optical fiber coil portions 3A to 3E is formed by winding a dispersion compensating optical fiber 5 (hereinafter sometimes referred to as dispersion compensating optical fibers 5A to 5E) around the body portions of a plurality of bobbins 4 arranged in parallel. It is. The dispersion compensating optical fiber 5 has negative chromatic dispersion and a negative dispersion slope. The chromatic dispersion values of the optical fiber coil portions 3A to 3E may all be the same value or may be different values.
[0020]
A general single mode optical fiber 6 is fused and connected to both ends of the dispersion compensating optical fibers 5A to 5E of the optical fiber coil portions 3A to 3E so that the dispersion compensating optical fibers 5A to 5E are connected in series. Yes. That is, one end of the dispersion compensating optical fiber 5 of the optical fiber coil unit 3 and one end of the dispersion compensating optical fiber 5 of the adjacent optical fiber coil unit 3 are connected via the single mode optical fiber 6. Further, one end of the dispersion compensating optical fibers 5A and 5E of the optical fiber coil portions 3A and 3E located on the outermost side is connected to an external device (not shown) via the single mode optical fiber 6.
[0021]
The single mode optical fiber 6 has a chromatic dispersion value of zero at a wavelength of 1.3 μm, a positive chromatic dispersion, and a positive dispersion slope.
[0022]
The single mode optical fiber 6 has a larger core diameter than the dispersion compensating optical fiber 5. For this reason, when the single mode optical fiber 6 and the dispersion compensating optical fiber 5 are fusion-spliced, by expanding the core at the end of the dispersion compensating optical fiber 5 using the thermal diffusion expansion core (TEC) technology, The core diameter of the single mode optical fiber 6 and the core diameter of the dispersion compensating optical fiber 5 are made substantially equal. Thereby, the connection loss between the single mode optical fiber 6 and the dispersion compensating optical fiber 5 can be reduced.
[0023]
The fused portion 7 between the single mode optical fiber 6 and the dispersion compensating optical fiber 5 is disposed in the module housing 2. The single mode optical fiber 6 is drawn out from the front surface of the module housing 2 to the outside of the module housing 2.
[0024]
The total chromatic dispersion amount of the optical fiber module 1 configured in this way is the total value of the chromatic dispersion values of the optical fiber coil portions 3A to 3E. For example, when the chromatic dispersion values of the optical fiber coil portions 3A to 3E are -10 ps / nm, -20 ps / nm, -30 ps / nm, -40 ps / nm, -50 ps / nm, the total chromatic dispersion amount is- 150ps / nm.
[0025]
In such an optical fiber module 1, the total chromatic dispersion amount of the optical fiber module 1 can be adjusted. For example, when changing the total chromatic dispersion amount to -130 ps / nm, the following is performed.
[0026]
That is, first, outside the module housing 2, the single mode optical fiber 6 (referred to as 6a) connecting the dispersion compensating optical fibers 5A and 5B of the optical fiber coil portions 3A and 3B and the dispersion compensation of the optical fiber coil portions 3B and 3C. The single mode optical fiber 6 (6b) connecting the optical fibers 5B and 5C is cut. Next, as shown in FIG. 2, the cut single-mode optical fibers 6 a and 6 b are fusion-connected to each other, and a new fusion part 8 is formed in the single-mode optical fiber 6. In this case, the optical fiber coil portion 3B is not used, and the dispersion compensating optical fiber portions 5A and 5C to 5E of the optical fiber coil portions 3A and 3C to 3E are formed to be connected in series. As a result, the total chromatic dispersion amount of the optical fiber module 1 is −130 ps / nm.
[0027]
When the total chromatic dispersion amount of the optical fiber module 1 is adjusted in this way, any number of single mode optical fibers 6 drawn to the outside of the module housing 2 are cut, and the cut single mode optical fibers 6 are cut. Only the required optical fiber coil unit 3 is selected from the plurality of optical fiber coil units 3 by fusion-bonding them. Thereby, the total chromatic dispersion amount of the required optical fiber module 1 is obtained. At this time, when the chromatic dispersion values of the optical fiber coil portions 3A to 3E are all the same value, fine dispersion adjustment can be performed, and the chromatic dispersion values of the optical fiber coil portions 3A to 3E are different values. Can be adjusted over a wide range.
[0028]
Further, since the single mode optical fiber 6 to be cut and fusion-bonded has a larger core diameter than the dispersion compensating optical fiber 5, the fusion work can be performed relatively easily using a general fusion machine. The single mode optical fiber 6 is more resistant to bending loss and easier to handle than the dispersion compensating optical fiber 5. Therefore, even the user who actually uses the optical fiber module 1 can adjust the total chromatic dispersion amount of the optical fiber module 1.
[0029]
Furthermore, since the dispersion adjustment of the optical fiber module 1 is performed by cutting and fusion-connecting the single mode optical fiber 6, the parts used for the optical fiber module 1 can be minimized, and the structure can be simplified. .
[0030]
FIG. 3 is a configuration diagram illustrating an example of an optical transmission system including the optical fiber module 1 described above. In the figure, an optical transmission system 10 includes an optical transmitter 11 and an optical receiver 12 connected to an optical fiber module 1 via a single mode optical fiber 6. The optical transmitter 11 multiplexes and outputs multi-wavelength signal light. The optical receiver 12 receives multi-wavelength signal light transmitted through an optical transmission line composed of the single mode optical fiber 6 and the dispersion compensating optical fiber 5.
[0031]
In such an optical transmission system 10, since the optical fiber module 1 having the dispersion compensating optical fiber 5 is provided, when the multi-wavelength signal light transmitted from the optical transmitter 11 is received by the optical receiver 12, The chromatic dispersion between the signal lights is compensated.
[0032]
In the above-described embodiment, the dispersion compensating optical fibers 5 of the adjacent optical fiber coil units 3 are connected to each other by the single mode optical fiber 6. However, the adjacent optical fiber coil units 3 are adjacent to each other without using the single mode optical fiber 6. The dispersion compensation optical fibers 5 of the optical fiber coil unit 3 may be directly connected to each other. For example, one dispersion compensating optical fiber 5 may be continuously wound around a plurality of bobbins 4, and the dispersion compensating optical fiber 5 in the middle between the bobbins 4 may be drawn out of the module housing 2.
[0033]
FIG. 4 is a block diagram showing a second embodiment of the optical fiber module according to the present invention. In the figure, the same or equivalent members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0034]
In the same figure, the optical fiber module 20 of this embodiment has the module housing | casing 2 mentioned above and the some optical fiber coil part 3. FIG. Optical fiber pigtails 21 are respectively connected to both ends of the dispersion compensating optical fiber 5 of each optical fiber coil section 3. The optical fiber pigtail 21 is provided with an optical connector adapter 23 at one end of a single mode optical fiber 22, and the other end of the single mode optical fiber 22 is fused to the dispersion compensating optical fiber 5.
[0035]
The fused portion 24 between the single mode optical fiber 22 and the dispersion compensating optical fiber 5 of the optical fiber pigtail 21 is disposed in the module housing 2. The optical connector adapter 23 of the optical fiber pigtail 21 is fixed to the front surface of the module housing 2 while being pulled out of the module housing 2. The optical connector adapter 23 may not be fixed to the module housing 2 but pulled out of the module housing 2.
[0036]
Of the plurality of optical fiber coil portions 3, the optical connector adapter 23 connected to one end of the dispersion compensating optical fibers 5A and 5E of the optical fiber coil portions 3A and 3E located on the outermost side has a connection cord 25 with a connector, respectively. It is connected. This connection cord 25 with a connector is provided with an optical connector plug 27 that can be inserted into and removed from an optical connector adapter 23 at at least one end of a single mode optical fiber 26. The other end of the single mode optical fiber 26 is connected to an external device (not shown).
[0037]
The optical connector adapter 23 connected to one end of the dispersion compensating optical fiber 5 of the optical fiber coil unit 3 and the optical connector adapter 23 connected to one end of the dispersion compensating optical fiber 5 of the adjacent optical fiber coil unit 3 are The connection cord 28 with a connector is connected. This connection cord 28 with a connector is provided with optical connector plugs 30 that can be inserted into and removed from the optical connector adapter 23 at both ends of a single mode optical fiber 29.
[0038]
Thus, in the initial state of the optical fiber module 20, the connection cord with connector 28 is connected so that the dispersion compensating optical fibers 5A to 5E of all the optical fiber coil portions 3A to 3E are connected in series.
[0039]
The single mode optical fiber 22 of the optical fiber pigtail 21 and the single mode optical fibers 26 and 29 of the connection cords 25 and 28 with connectors have the same structure as the single mode optical fiber 6 in the first embodiment.
[0040]
The dispersion compensating optical fiber 5 of the optical fiber coil section 3 is directly connected to the optical connector adapter 23 without providing the optical fiber pigtail 21, and a general optical fiber for the connecting cords 25 and 28 with connectors is used. A dispersion compensating optical fiber may be used instead of the single mode optical fibers 26 and 29.
[0041]
In the optical fiber module 20 as described above, when the same dispersion adjustment as that of the embodiment of FIG. 2 is performed, first, the optical connector adapter 23 and the optical fiber coil portion 3B connected to the dispersion compensating optical fiber 5A of the optical fiber coil portion 3A. The connector-attached connection cord 28 for connecting the optical connector adapter 23 connected to the dispersion compensating optical fiber 5B is pulled out. Also, a connector-attached connection cord 28 that connects the optical connector adapter 23 connected to the dispersion compensating optical fiber 5B of the optical fiber coil section 3B and the optical connector adapter 23 connected to the dispersion compensating optical fiber 5C of the optical fiber coil section 3C. Pull out. Then, as shown in FIG. 5, an optical connector adapter 23 connected to the dispersion compensating optical fiber 5A of the optical fiber coil portion 3A, and an optical connector adapter 23 connected to the dispersion compensating optical fiber 5C of the optical fiber coil portion 3C, Are connected by a connection cord 28 with a connector.
[0042]
Thus, when performing dispersion adjustment of the optical fiber module 20, only the necessary optical fiber coil unit 3 is selected from the plurality of optical fiber coil units 3 by replacing the connection cords 25 and 28 with connectors. The total amount of chromatic dispersion can be obtained. Further, in this case, since the optical fiber does not need to be cut and fused, dispersion adjustment can be easily performed in a short time, and workability is improved.
[0043]
The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the dispersion compensating optical fiber 5 is wound around the plurality of bobbins 4 to form the plurality of optical fiber coil portions 3, but in addition to this, the dispersion compensating optical fiber 5 is wound around one bobbin. A plurality of optical fiber coil portions having the same or different chromatic dispersion values may be formed.
[0044]
Further, instead of winding the dispersion compensating optical fiber 5 around the bobbin 4 to form a plurality of optical fiber coil portions 3, the dispersion compensating optical fiber is simply wound into a coil bundle to form a plurality of optical fiber coil portions, and silicone. It is good also as a structure which accommodated each optical fiber coil part in the module housing | casing filled with resin, such as.
[0045]
Furthermore, the present invention is a configuration in which the dispersion compensating optical fiber of any one of the plurality of optical fiber coil parts can be switched and connected to the dispersion compensating optical fiber of any other optical fiber coil part. The present invention can also be applied to an optical fiber module without a module housing.
[0046]
【The invention's effect】
According to the present invention, a plurality of optical fiber coil portions are provided, and the dispersion compensating optical fiber of any one of the plurality of optical fiber coil portions is a dispersion compensating optical fiber of any other optical fiber coil portion. Since the switching connection is made possible, the chromatic dispersion amount can be adjusted with one optical fiber module without preparing a plurality of optical fiber modules. Therefore, it is advantageous in terms of cost.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of an optical fiber module according to the present invention.
2 is a diagram showing a method for adjusting the amount of chromatic dispersion in the optical fiber module shown in FIG. 1. FIG.
3 is a configuration diagram illustrating an example of an optical transmission system including the optical fiber module illustrated in FIG. 1. FIG.
FIG. 4 is a configuration diagram showing a second embodiment of an optical fiber module according to the present invention.
5 is a diagram showing a method for adjusting the amount of chromatic dispersion in the optical fiber module shown in FIG. 4. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical fiber module, 2 ... Module housing, 3 (3A-3B) ... Optical fiber coil part, 4 ... Bobbin, 5 (5A-5B) ... Dispersion compensation optical fiber, 6 ... Single mode optical fiber, 10 ... Light Transmission system, 20 ... optical fiber module, 21 ... optical fiber pigtail, 22 ... single mode optical fiber, 23 ... optical connector adapter (optical connector), 25 ... connection cord, 28 ... connection cord.

Claims (5)

  A plurality of optical fiber coil portions are formed by winding a dispersion compensating optical fiber in a coil shape and disposed in one module housing, and each of the optical fibers is provided outside the module housing or the module housing. A plurality of optical connectors connected to both ends of the dispersion compensating optical fiber of the coil portion are provided. An optical fiber module, wherein the dispersion compensating optical fiber of the optical fiber coil unit is configured to be switchable and connectable to the dispersion compensating optical fiber of any other optical fiber coil unit. One end of a single mode optical fiber having a structure different from that of the dispersion compensating optical fiber is connected to both ends of the dispersion compensating optical fiber of each optical fiber coil section, and the other end of each single mode optical fiber is connected to the other end of each single mode optical fiber. optical fiber module according to claim 1, wherein said optical connector is connected. Said plurality of optical fiber coil unit, the optical fiber module according to claim 1 or 2, wherein said one in which the dispersion compensating optical fiber is formed by winding a plurality of bobbins. A method for adjusting chromatic dispersion of an optical fiber module, comprising: preparing an optical fiber module according to claim 1 ; and connecting an arbitrary connector with a connection cord to adjust an amount of chromatic dispersion of the optical fiber module. . An optical transmission system, characterized in that it comprises an optical fiber module of any one of claims 1 to 3.

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