JPH05297243A - Optical start coupler - Google Patents

Abstract

PURPOSE:To provide an optical star coupler, with which a stellate optical data link system can be laid along any existing communications system which requiring simple wirings and a narrow space. CONSTITUTION:A wire harness 24 of an existing communications system is inserted through a through-hole provided in the center of a coupler fixture 21, which is thus mounted in the communications system. A mixing part 15, input fiber terminations 12a-12d, and output fiber terminations 14a-14d are fixed to the coupler fixture 21 while they are bent at least in one place. Thus a plurality of termination couples are produced consisting of input terminations and output terminations stretching arbitrarily in the same direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an n.times.n channel fiber-welded optical star coupler which is used when an optical fiber is further laid along an existing communication system to add a star type optical data link system. ..

[0002]

2. Description of the Related Art In the past, when a star type optical data link system was added to an existing communication system, both were installed independently. That is, for example, in the automobile industry, it was laid separately from the wire harness already laid in the final stage (vehicle assembly process).

However, the elements (optical fiber and optical star coupler) that make up the star type optical data link system.
Due to its relatively low mechanical strength, it has been proposed to lay a star-type optical data link system along a part of an existing communication system, for example a wire harness.

Here, the star type optical data link system shown in FIG. 14, for example, will be described as an example. In this star type optical data link system, as shown in the figure, for example, four terminals A to D are interconnected by an optical star coupler SC of 4 × 4 channels. That is, the optical star coupler SC is provided with four input channels, and the transmitters TXA to TX of the terminals A to D are provided.
Connected to D respectively. Also, four output channels are provided and connected to the reception units RXA to RXD of the terminals A to D, respectively.

Therefore, when an optical signal S is transmitted from a certain terminal, for example, the terminal A, not only the optical signal S is received by each of the terminals B to D, but the optical signal S is also received by the terminal A.
Can be received.

An example of the optical star coupler SC having the above function is disclosed in Japanese Patent Laid-Open No. 63-214709 (FIG. 15). This optical star coupler S
In C, a plurality of optical fibers 1a are connected to one end of the optical mixing waveguide 2 made of a high refractive index material, and a plurality of optical fibers 1b are also connected to the other end. Also,
The connecting portion and the optical mixing waveguide 2 are covered with a cladding portion 3 made of a low refractive index material. For this reason,
When an optical signal related to predetermined information is input to one of the optical fibers 1a, the optical signal related to the information is distributed by the optical mixing waveguide 2 and branched and output from each optical fiber 1b. That is, this optical star coupler SC
Then, the optical fiber 1a functions as an input channel, and the optical fiber 1b functions as an output channel.

[0007]

By the way, in the optical star coupler SC of FIG. 15, the optical fiber 1a functioning as an input channel is always connected to one side of the optical star coupler SC (left-hand side in the figure). The optical fiber 1b functioning as an output channel is always connected to the other side (right hand side in the figure) of the optical star coupler SC. Therefore, each of the terminals A to D has an optical fiber 1 for input and output.
In order to connect a and 1b, it is necessary to largely bend near the optical star coupler SC. As a result, the wiring of the optical fibers 1a and 1b near the optical star coupler SC becomes complicated, and a large arrangement space is required. further,
There is also a problem that the number of points where the optical fibers 1a and 1b intersect increases and optical loss occurs at that point.

Further, in order to lay the star type optical data link system along the existing wire harness as described above, it is necessary to attach the optical star coupler SC to the wire harness, but this optical star coupler SC is attached. It is designed without considering the space. Therefore, when the optical star coupler SC is attached along the wire harness to construct a star type optical data link system, a large space is required at the attaching position of the optical star coupler SC.

The present invention has been made to solve the above-mentioned problems, and requires a simple wiring and a small space,
An object of the present invention is to provide an optical star coupler capable of laying a star type optical data link system along with an existing communication system.

[0010]

According to a first aspect of the present invention, there is provided an optical branching portion formed by welding the intermediate portions of a plurality of optical fibers,
An optical mixing section for distributing the input optical signal into n (n ≧ 2) optical signals, and n input fiber end sections functioning as input channels for inputting the optical signal to the optical mixing section, An optical star coupler of n × n channels, which can be attached to an existing communication system, comprising: n output fiber ends that function as output channels for extracting an optical signal from the optical mixing unit. In order to achieve the, substantially finished in a donut shape having a through hole in the center thereof, further comprising a fixing member that can be attached to the communication system by inserting the signal line of the communication system into the through hole, At least one of the optical mixing section, the input fiber end section and the output fiber end section is curved while bending the optical mixing section, A force fiber ends and said output fiber end is fixed to the fixing member, optionally, moreover the input and fiber ends pairs of output fiber ends extending in the same direction, are respectively n sets.

According to a second aspect of the present invention, there is provided an optical branching part formed by welding the intermediate parts of a plurality of optical fibers, and the input optical signal is distributed to n (n ≧ 2) optical signals. Section, and n input fiber ends that function as input channels for inputting an optical signal to the optical mixing section,
An optical star coupler of n × n channels, which can be attached to an existing communication system, comprising: n output fiber ends that function as output channels for extracting an optical signal from the optical mixing unit. In order to achieve the above, a flexible sheet that is flexible, is deformable according to the outer shape of the signal line of the communication system, and is attachable to the communication system is further provided, and the optical mixing unit and the input fiber are provided. The optical mixing part, the input fiber end part and the output fiber end part are fixed to the flexible sheet while bending at least one or more of the end part and the output fiber end part, and in the same direction. N fiber end pairs each consisting of the input and output fiber ends extending to

[0012]

According to the first aspect of the present invention, the signal line of the existing communication system is inserted into the through hole provided in the central portion of the fixing member, and the fixing member is attached to the communication system. The optical mixing section, the input fiber end section, and the output fiber end section are fixed to the fixing member while the optical mixing section, the input fiber end section, and the output fiber end section are curved at least at one or more locations. ,
Optionally, a plurality of fiber end pairs consisting of the input and output fiber ends extending in the same direction are formed.

According to the second aspect of the present invention, a flexible sheet having flexibility and being deformable according to the outer shape of the signal line of the existing communication system is attached to the communication system. And
At least one of the optical mixing section, the input fiber end section and the output fiber end section is curved while the optical mixing section, the input fiber end section and the output fiber end section are fixed to the flexible sheet, In addition, a plurality of fiber end-pairs are formed, which are composed of the input and output fiber ends extending in the same direction.

[0014]

1 is a schematic diagram showing an embodiment of an optical star coupler according to the present invention. This optical star coupler 20
Has a coupler fixing tool 23 that is formed into a substantially donut shape and includes two covers 21 and 22 that can be integrated. The figure (a) shows a state where one cover 22 is removed, and the figure (b) shows a state where the cover 22 is attached. In the coupler fixture 23 (covers 21 and 22),
As shown in the figure, a through hole is provided in the center thereof. Then, a signal wire of an existing communication system, for example, a wire harness 24 is inserted into the through hole, and the coupler fixture 23 is attached to the communication system (FIG. 2). The manner of attaching the coupler fixture 23 to the wire harness 24 is not limited to that shown in FIG.
As shown in FIGS. 3 and 4, the coupler fixture 23 may be attached so as to be inclined with respect to the longitudinal direction (Y direction) of the wire harness 24. In this case, the fiber ends 12 a to 12 d extending from the coupler fixture 23. , 14a to 14d can be increased in curvature radius, and light loss in the curved portion can be further suppressed as compared with the case of FIG.

Further, the optical star coupler 20 is provided with an optical mixing section 15 having four optical branching sections (described later). Then, as shown in FIG. 1 (a), two input fiber ends 12b and 12d functioning as input channels and two output fiber end parts functioning as output channels from the optical mixing section 15 in one direction X. 14
b and 14d extend, while two input fiber ends 12 function as input channels in the other direction (-X).
a and 12c and two output fiber ends 14a and 14c, which function as output channels, extend. The fiber ends 12a to 12d, 14a to 14d and the optical mixing unit 15 are fixed by integrating the two covers 21 and 22 while being curved as described later.

Next, the details of the structure of the optical star coupler 20 will be clarified by explaining the manufacturing procedure thereof.

5 to 10 are schematic views showing the manufacturing procedure of the optical star coupler 20 of FIG. First, the 2 × 2 channel optical elements 10a and 10b are formed as follows. That is, two optical fibers F, F are prepared, and these optical fibers F, F are arranged in parallel as shown in FIG. 5 (a). It should be noted that this processing may be performed manually by an operator or by an appropriate mechanical device.

Then, the intermediate portions (regions surrounded by dotted lines) of the optical fibers F, F are welded to each other over a predetermined length L. In this way, as shown in FIG.
And fiber ends 12a and 12b extending from one end of the optical branching portion 11a in the longitudinal direction X of the optical fiber F, and fiber ends 13a and 13b extending from the other end in the direction X. As a welding method, a conventionally well-known heat welding method or an application previously filed by the applicant (Japanese Patent Application No. 2-17554)
No.), there is an ultrasonic welding method, and any method may be used. Further, since the optical element 10b is manufactured in the same manner, the same or corresponding parts are designated by the corresponding reference numerals and the description thereof is omitted.

Next, the optical element 10 thus manufactured
a and 10b are arranged in parallel (FIG. 6). Then, the intermediate portions of the fiber end portions 13b and 13c of the optical elements 10a and 10b are welded to each other by a thermal welding method or an ultrasonic welding method (FIG. 7). As a result, the optical branching portion 11c is formed and the fiber end portions 14a and 14b extending from the optical branching portion 11c in the longitudinal direction X of the optical fiber are formed. Similarly, the intermediate portions of the fiber end portions 13a and 13d of the optical elements 10a and 10b are welded to each other (FIG. 8), and the optical branch portion 11d and the fiber end portion 14 are welded.
c, 14d are formed. Thus, the four light branching parts 11
a to 11d, which divides the input optical signal into four optical signals, an optical mixing section 15, four fiber ends 12a to 12d that function as input channels, and four fibers that function as output channels. End 14a-
A 4 × 4 channel optical star coupler with 14d is formed.

Subsequently, the optical mixing section 15 is further provided.
Is curved by 180 °, that is, the optical branching portions 11a and 11b in the first row and the optical branching portions 11c and 11d in the second row in FIG.
The optical fiber portion located between the
Curve d) 180 degrees in a plane including the plane of FIG.
In this way, the optical star coupler of FIG. 9 is formed.

Further, the fiber ends 12b, 12d, 1
By bending each of 4b and 14d by 180 degrees, as shown in FIG.
Fiber end pairs and fiber ends 12c, 1
The fiber end pair consisting of 4c should be extended in the (-X) direction, while the fiber end pair consisting of the fiber ends 12b and 14b and the fiber end pair consisting of the fiber ends 12d and 14d should be extended in the X direction. You can And the fiber ends 12b, 12c, 14a, 1
4d to the fiber ends 14b, 14c, 12a,
The fiber end portions 12a to 12d, 14a to 14d and the optical mixing portion 1 are curved while being curved so as to be paired with 12d.
5 is inserted into the cover 21, and then the cover 22 is replaced with the cover 21.
Attach to and integrate. In this way, the optical star coupler 20 of FIG. 1 is formed.

Next, the operation of the optical star coupler 20 manufactured as described above will be described. For convenience of description, the description will be made with reference to FIG. 8, but the basic operation is the same when the fiber end or the like is bent (FIG. 1) or not (FIG. 8).

First, when the optical signal S1 is input from one of the input fiber ends 12a to 12d functioning as an input channel, for example, the input fiber end 12a, the optical signal S1 is guided to the optical branching part 11a. , Optical signals S2, S
Branched to 3.

The one optical signal S2 is sent to the optical branching unit 11
The light is guided to the optical fiber c, branched into optical signals S4 and S5, and output to the output fiber ends 14a and 14b, respectively. Further, the optical signal S3 is guided to the optical branching section 11d, and the optical signals S6 and S7 are sent.
And output to the output fiber ends 14c and 14d, respectively.

The optical signals S2 to S7 have different intensities according to the branching characteristics (distribution ratio) of the optical branching sections 11a to 11d, but the information content is the same as the information of the optical signal S1. is there. Therefore, the optical star coupler 20
In the above, by appropriately setting the branching characteristics of the optical branching portions 11a to 11d, the fiber end portions 14a to 14d
The intensity of the optical signal output from d can be adjusted to an arbitrary ratio, that is, the distribution ratio of the optical star coupler 20 can be controlled.

Further, when an optical signal is input to the fiber end portions 12b to 12d for the input channel other than the fiber end portion 12a, the input optical signal is input from the fiber end portion for the output channel in the same manner as described above. The optical signals having the same information are distributed and output.

Next, the characteristics of the optical star coupler 20 made of uncrosslinked polymethylmethacrylate plastic fiber in which the optical branch portion is formed by the ultrasonic welding method will be verified. The length of each of the optical branching portions 11a to 11d is 20 mm, and the distance between the optical branching portion 11a (11b) and the optical branching portion 11c (11d) is 55 mm. After making the coupler, the optical star coupler 20 of FIG. 1 was formed as described above.

Then, the characteristics of the optical star coupler 20 manufactured as described above were evaluated using an optical power measuring system.
Specifically, the wavelength emitted from the light source of the optical power measurement system.
Red light of 660 nm (light intensity P1 = 15.4 μW) is input to the input fiber end 12a of the optical star coupler 20. On the other hand, the light emitted from each of the output fiber ends 14a to 14d was directly received, and the output values P5 to P8 from each of the fiber ends 14a to 14d were measured. As a result, the output values P5 to P8 are 2.8 μW, 2.5 μW and 4.1 μW, respectively.
W, 2.7 μW, and the distribution ratio was 1.1: 1.0: 1.6: 1.1. The excess loss LS in this case is 1.0d.
It was B.

As described above, in the optical star coupler 20 according to this embodiment, as shown in FIG.
The fiber end pairs consisting of 2a and 14a and the fiber end pairs consisting of the fiber ends 12c and 14c extend in the (-X) direction while the fiber ends 12b and 14b.
Fiber end pairs and fiber ends 12d, 1
The fiber end pair consisting of 4d extends in the X direction. Therefore, when constructing a star type optical data link system using the optical star coupler 20 of FIG. 1, for example, the fiber end pair of the input fiber end 12a and the output fiber end 14a is connected to the terminal A. When the remaining terminals B to D are connected in the same manner, the terminals A to D can be connected by simple wiring without crossing the optical fibers as shown in FIG. 11, and the optical loss is suppressed. be able to. Further, it is not necessary to bend the optical fiber in the vicinity of the optical star coupler 20, and the optical data link system can be constructed in a small space.

Moreover, in the optical star coupler 20, the wire harness 24 is inserted into the through hole of the coupler fixture 23 so as to be attached to the communication system. A data link system can be installed.

In the above embodiment, the fiber end 12
Although the a to 12d, 14a to 14d and the optical mixing section 15 are fixed by the coupler fixing tool 23, as shown in FIG. 12, instead of the coupler fixing tool 23, they are fixed by a flexible sheet 25 having flexibility. You can In the optical star coupler 20 'thus formed, the fiber end portions 12a to 12d, 14a to 14d and the optical mixing portion 15 are fixed to the flexible sheet 25,
It can be easily and freely transformed. Therefore, for example, as shown in FIG.
The optical star coupler 20 'can be attached to the wire harness 24 while deforming the optical star coupler 20', and the same effect as that of the above embodiment can be obtained.

Further, although the 4 × 4 channel optical star coupler 20 has been described in the above embodiment, the present invention is not limited to the above, and n (n ≧ 2) input fiber end portions functioning as input channels are provided. , An n × n channel optical star coupler having n output fiber ends that function as output channels.

Further, the curved portion and the angle are arbitrary. For example, when the optical star coupler shown in FIG. 9 is produced, the fiber end portions 12a to 12d and 14a to 14 are formed.
If the d and the light mixing portion 15 are fixed by a flexible sheet having flexibility, all the fiber end portions 12a to 12a
An optical star coupler in which 2d and 14a to 14d extend in a fixed direction (-X) is obtained.

[0034]

According to the invention of claim 1, a signal line of an existing communication system is inserted through a through hole provided in a central portion of a fixing member, the fixing member is attached to the communication system, and an optical signal is transmitted. Fixing the optical mixing section, the input fiber end section and the output fiber end section to the fixing member while bending at least one or more of the mixing section, the input fiber end section and the output fiber end section,
Since a plurality of fiber end pairs consisting of the input and output fiber ends extending arbitrarily in the same direction are formed, a star type optical fiber can be used along with existing communication systems with simple wiring and in a narrow space. A data link system can be installed.

Further, according to the invention of claim 2, a flexible sheet having flexibility and being deformable according to the outer shape of the signal line of the existing communication system is attached to the communication system, and the optical mixing section, The optical mixing section, the input fiber end section and the output fiber end section are fixed to the flexible sheet while bending at least one or more of the input fiber end section and the output fiber end section, and optionally and the same. Since a plurality of fiber end pairs consisting of the input and output fiber end portions extending in the direction are formed, the same effect as the invention of claim 1 can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an optical star coupler according to the present invention.

FIG. 2 is a side view showing how the optical star coupler of FIG. 1 is attached to a wire harness.

FIG. 3 is a side view showing how the optical star coupler of FIG. 1 is attached to a wire harness.

FIG. 4 is a perspective view showing how the optical star coupler of FIG. 1 is attached to a wire harness.

FIG. 5 is a schematic view showing a manufacturing procedure of the optical star coupler of FIG.

FIG. 6 is a schematic view showing a manufacturing procedure of the optical star coupler of FIG.

FIG. 7 is a schematic view showing a manufacturing procedure of the optical star coupler of FIG.

FIG. 8 is a schematic view showing a manufacturing procedure of the optical star coupler of FIG.

FIG. 9 is a schematic view showing a manufacturing procedure of the optical star coupler of FIG.

10 is a schematic diagram showing a manufacturing procedure of the optical star coupler of FIG. 1. FIG.

11 is a diagram showing a star type optical data link system using the optical star coupler of FIG. 1. FIG.

FIG. 12 is a diagram showing an embodiment of an optical star coupler according to the present invention.

13 is a perspective view showing how the optical star coupler of FIG. 12 is attached to a wire harness.

FIG. 14 is a schematic diagram showing an example of a star type optical data link system as the background art of the present invention.

FIG. 15 is a perspective view showing a conventional optical star coupler.

[Explanation of symbols]

 11a-11d Optical branching part 12a-12d, 14a-14d Fiber end part 15 Optical mixing part 23 Coupler fixing tool 25 Flexible sheet

Claims (2)

[Claims] 1. An optical branching portion formed by welding the intermediate portions of a plurality of optical fibers, and n (n ≧ 2) input optical signals are provided.
Optical distribution section for distributing the optical signal to the optical mixing section, n input fiber end sections functioning as input channels for inputting the optical signal to the optical mixing section, and an output for extracting the optical signal from the optical mixing section. In an n × n channel optical star coupler that can be attached to an existing communication system, and has n output fiber ends that function as channels, it is finished into a substantially donut shape having a through hole in its center and While further comprising a fixing member that can be attached to the communication system by inserting the signal line of the communication system into the hole, at least one or more of the optical mixing unit, the input fiber end and the output fiber end are provided. While bending, the optical mixing section, the input fiber end section and the output fiber end section are fixed to the fixing member. 2. An optical star coupler, characterized in that n sets of fiber end pairs each consisting of the input and output fiber end portions extending in the same direction are defined. 2. An optical branching part formed by welding the intermediate parts of a plurality of optical fibers, and n (n ≧ 2) input optical signals are provided.
Optical distribution section for distributing the optical signal to the optical mixing section, n input fiber end sections functioning as input channels for inputting the optical signal to the optical mixing section, and an output for extracting the optical signal from the optical mixing section. An optical star coupler of n × n channels, which is equipped with n output fiber ends that function as channels and is attachable to an existing communication system, having flexibility and conforming to the outer shape of a signal line of the communication system. And a flexible sheet attachable to the communication system, the optical mixing section being curved while bending at least one or more of the optical mixing section, the input fiber end section and the output fiber end section. , Fixing the input fiber end and the output fiber end to the flexible sheet,
An optical star coupler, wherein n sets of fiber end pairs each consisting of the input and output fiber ends extending arbitrarily and in the same direction are provided.