JP2009025211A - Coated-fiber identification system and coated-fiber identification method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform individual coated-fiber identification on branch lines in a branch-type optical line such as a PON. <P>SOLUTION: This coated-fiber identification system and this coated-fiber identification method are characterized in that, in performing coated-fiber identification as to a branch-type optical line such as a PON, a required bend 12-1 is formed on one branch line 6-1 out of branch lines 6-1 to 6-4 after an optical line 4 is branched off to input signal light 11-1 for coated-fiber identification into the bent branch line 6-1 from a side face thereof, and the signal light 11-1 is caused to penetrate through a bend part 21 for light detection in the middle of the branch line 6-1 and received by a signal light detection part 13'. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical core contrast technique used for construction or maintenance of a branching optical line network commercialized for economically constructing an optical access network.

  In order to construct an economical optical access network, an optical communication system called a branched optical line network (hereinafter referred to as PON: Passive Optical Network) has been put into practical use (for example, see Patent Document 1). FIG. 4 is a line configuration example of the PON. A signal transmitted through one optical line 4 is divided by an optical splitter 5 into n branch lines 6-1 to 6-n. In such a communication system, since a plurality of external devices 7-1 to 7-n are controlled by a single in-house device 1, the equipment cost of the in-house device 1 is reduced, and at the same time, the optical line equipment is also part of the line. Since it is shared within the ward (optical line 4), the cost of the entire communication facility is greatly reduced.

  By the way, in the construction and maintenance of the optical fiber communication network, there is a need to individually identify the optical fiber core wires in the off-site equipment connected by the branch lines 6-1 to 6-n or the work site such as the user's house. Arise. This operation is called core contrast, and signal light 11 ′ for contrast control is normally incident on the optical line 4 via the optical coupler 3 from the light source 10 ′ for core contrast provided in the station 8. At the work site, a bend is applied to the optical fiber, and the signal light 11 ′ for controlling the core wire is radiated out of the optical fiber. Here, as the light source 10 ′ for contrasting the core wire, a signal obtained by applying intensity modulation of about 270 Hz to light of LD or LED having a wavelength longer than that of the communication light source is used. Further, in the bending means of the optical fiber, a bending radius is selected such that the influence of the communication light is minimized and only the signal light 11 ′ for controlling the core wire is efficiently radiated (for example, see Patent Document 2). ). In this way, the contrast control is performed by detecting the signal light 11 'for contrast control sent from the upper side of the optical line 4 by the operator on the lower side. This work is indispensable even in the PON in order to perform smooth construction or maintenance and to maintain the quality of the communication network.

However, as apparent from FIG. 4, when the conventional core line contrast method is applied to the PON, the signal light 11 ′ for core line contrast is almost evenly distributed from the optical splitter 5 to each of the branch lines 6-1 to 6-n. Therefore, the signal light 11 'for contrasting the cores cannot be used as a unique signal of the branch lines 6-1 to 6-n, and therefore cannot be individually contrasted. Further, the signal light for contrasting the core wire is inputted from the remote side (external devices 7-1 to 7-n) of the branch lines 6-1 to 6-n, and the test light input port 9 of the optical coupler 3 is used. Even if light is received, it does not hold as a means for contrasting the cores. Therefore, there is a problem that the conventional method cannot be applied to the branch lines 6-1 to 6-n after the optical splitter at the work site.
JP-A-8-102710 Japanese Patent No. 3407812

  As described above, in the PON, there is a problem in that the branch line after the optical splitter cannot be individually specified in the conventional contrast control. It is an object of the present invention to individually contrast the branch lines in a branched optical line such as PON.

  In order to solve the above-mentioned object, the core line contrast system and the core line contrast method according to the present invention are required for one branch line after branching in the core line contrast of the branch optical line such as PON. Then, the signal light for core wire comparison is input from the side of the bent branch line, and the signal light is leaked from the terminal part of the branch line or from the light detection bent part in the middle of the branch line. And receiving.

  As a result, similarly to the single star network, it becomes possible to make the signal light for contrasting the core line incident on only one target branch line, and the input and output of the signal light for contrasting the core line is 1: 1. Because of this relationship, the branch lines can be individually contrasted in the branch type optical line such as PON.

  Specifically, the optical fiber contrast system according to the present invention includes a branched optical line that communicates by dividing one optical line into a plurality of branched lines by an optical splitter, and a predetermined curvature in one of the branched lines. Forming a bent portion bent at a radius, detecting an optical side surface incident portion from which the signal light for core line contrast is incident from the bent portion, and detecting the signal light incident on the optical side surface incident portion; A signal light detection unit that identifies the one of the above.

  By providing the bent portion and the light side incident portion, the signal light can be incident on one of the plurality of branch lines of the branch type optical line. By including the signal light detection unit, it is possible to identify one branch line into which the signal light is incident from each of the plurality of branch lines of the branch optical line.

  Specifically, in the method of contrasting cores according to the present invention, a plurality of branch lines are individually identified from a branch type optical line that communicates by dividing one optical line into a plurality of branch lines by an optical splitter. In the optical fiber contrast method, a bent portion bent at a predetermined radius of curvature is formed in one of the branch lines, and an optical side surface incident portion procedure for injecting optical signal for optical fiber contrast from the bent portion; and A signal light detection procedure for detecting signal light incident in the light side incidence procedure and specifying the one of the branch lines.

  By having the bending procedure and the light side incident portion procedure, the signal light can be incident on one of the plurality of branch lines. By having the signal light detection procedure, it is possible to identify one branch line that has received signal light from a plurality of branch lines.

  In the cord contrast method according to the present invention, in the signal light detection procedure, the signal light is received at a terminal portion of each of the branch lines, or the plurality of branch lines are bent and the signal light is bent. It is preferable to receive the leaked light. By receiving the signal light at the terminal part of the branch line, the signal light can be detected with a large signal intensity. Further, by bending a plurality of branch lines and receiving the leaked light of the signal light, the signal light can be detected even in the branch line transmitting and receiving the communication signal.

  According to the present invention, in a branched optical line such as PON, the branch lines can be individually contrasted. For this reason, the construction or maintenance work of the PON becomes easy, which contributes to the reduction of the operation of the optical communication system architecture and the improvement of the work reliability.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment. FIG. 1 is a configuration diagram of a cord control system according to the present embodiment. In FIG. 1, 1 is an in-house device, 2 and 2 'are test light blocking filters, 3 is an optical coupler, 4 is an optical line, 5 is an optical splitter, 6-1, 6-2, 6-3 and 6-4. Is a branch line, 7-1, 7-2, 7-3, 7-4 are external devices, 8 is an in-house, 9 is a test light input / output port, 10-1, 10-4, and 10 'are cord contrasts 11-1, 11-4, and 11 ′ are signal lights for contrasting the core wire, 12-1 and 12-4 are optical side surface incident portions, 13 and 13 ′ are signal light detection portions, and 16-1 and 16 -4 is an optical fiber for light incidence, and 21 is a bent portion for light detection. Hereinafter, a case where the branch line 6-1 and the branch line 6-4 are specified will be described.

  The optical fiber reference system includes a branched optical line that communicates by dividing one optical line 4 into a plurality of branched lines 6-1, 6-2, 6-1, and 6-4 by an optical splitter 5. The number of the plurality may be any number, but in the present embodiment, description will be made assuming that the number is four.

  When specifying the branch line 6-1, the optical side light incident part 12-1 and the signal light detection part 13 ′ for contrasting the core wires are installed on the branch line 6-1. The optical side surface incident part 12-1 forms a bent part 12-1 bent at a predetermined curvature radius on one of the plurality of branch lines 6-1 and a signal for contrasting the core wire from the bent part 12-1. Light 11-1 is incident. The signal light detection unit 13 ′ detects the signal light 11-1 incident on the light side surface incident unit 12-1, and one branch line 6-1 among the plurality of branch lines 6-1 to 6-4. Is identified.

  When the branch line 6-4 is specified, the optical side surface incident part 12-4 and the signal light detection part 13 for contrasting the core wires are installed on the branch line 6-4. The optical side surface incident portion 12-4 forms a bent portion 12-4 bent at a predetermined radius of curvature on one of the plurality of branch lines 6-4, and a signal for contrasting the core wire from the bent portion 12-4. Light 11-4 is incident. The signal light detection unit 13 detects the signal light 11-4 incident on the light side surface incident unit 12-4, and identifies one branch line 6-4 among the plurality of branch lines. The signal light 11-4 for contrasting the core wire enters from the light side surface incident part 12-4, and the signal light detection part 13 receives the signal light 11-4. When the signal light detector 13 receives the signal light 11-4, the target branch line 6-4 is specified.

  A plurality of branch lines 6-1 to 6-4 are individually identified from a branched optical line that communicates by dividing one optical line 4 into a plurality of branch lines 6-1 to 6-4 by an optical splitter 5. A method of contrasting the cores will be described. The core wire contrast method according to the present embodiment includes a light side incident part procedure and a signal light detection procedure. Hereinafter, a case where the branch line 6-1 is specified will be described.

  In the optical side incident part procedure, the optical side incident part 12-1 is installed on one branch line 6-1 of the branch lines 6-1 to 6-4 to be specified. The light side surface incident part 12-1 forms a bent part bent at a predetermined curvature radius on one branch line 6-1 of a plurality of branch lines. Next, the signal light 11-1 is incident on the branch line 6-1 from the bent portion formed by the optical side surface incident portion 12-1. The signal light 11-1 is sent out by the light source 10-1 for controlling the core wire.

  Here, the signal light 11-1 is preferably distinguishable from a communication signal transmitted and received between the in-house device 1 and the outside device 7-1. For example, the signal light 11-1 is signalized by applying intensity modulation of about 270 Hz to light such as FP-LD (Fabric Perot Laser Diode) or DFB-LD (Distributed Feedback Laser Diode) having a wavelength longer than that of communication light. Is preferred. Since long wavelength light is used at the same time as the wavelength different from the communication wavelength, the signal light 11 is reduced while relaxing the bending diameter formed by the light side incident portion 12-1 and minimizing bending loss with respect to the communication light. -1 can be efficiently incident. In addition, it is possible to contrast the cores in the in-service state together with the test light blocking filters 2 and 2 '.

  In the signal light detection procedure, the signal light detection unit 13 ′ detects the signal light 11-1 incident in the light side incidence procedure. Since the signal light 11-1 is not input to the branch lines 6-2, 6-3, and 6-4, one branch line 6-1 among the plurality of branch lines 6-1 to 6-4. Can be specified. For example, a bent portion 21 for light detection in which a core wire is bent is formed on the branch line 6-1, and the signal light detection portion 13 'detects it with a photodetector. Here, the bending part 21 for light detection produces a required bend to a core wire in the closure in the middle of the branch line 6-1, for example. In the bending portion 21 for light detection, signal light radiates from the side surface of the branch line 6-1 core wire. The signal light detector 13 'detects the emitted signal light. Since the signal light is detected by the leaked light from the light detection bending portion 21, the signal light can be detected even for the branch line that is transmitting and receiving the communication signal, and the cords can be compared.

  The core wire contrast method according to the present embodiment is not limited to the core wire contrast method of the branch line 6-1, and the core wire contrast method of the branch line 6-4 shown in FIG. 1 may be used. The method of contrasting the branch lines 6-4 is the same as the method of contrasting the core lines of the branch line 6-1, but the signal light detection procedure is different.

  In the core line contrast method for the branch line 6-4, the signal light 11-4 incident on the branch line 6-4 is detected by connecting the signal light detector 13 to the terminal of the branch line 6-4. Since the signal light is detected from the terminal of the branch line 6-4, even when the signal light becomes weak at the installation point of the signal light detection unit 13, the signal light can be detected and the cords can be compared. it can.

  By using the above-described core line contrast method according to the present embodiment, the branch lines 6-1 or 6-4 can be individually contrasted in a branched optical line such as PON. In addition, it cannot be overemphasized that the optical side surface incident part 12-1 or 12-4 can be installed in the optical line 4 before branching, and can be utilized as a core line contrast of the optical line 4. FIG.

  Furthermore, by using the core wire contrast method according to the present embodiment, the construction or maintenance work of the PON becomes easy, which contributes to the reduction of the operation of the optical communication system architecture and the improvement of the work reliability. In addition to the PON line configuration, the single star network line is also limited to the place where the optical fiber and the optical connector are installed where the signal light for contrasting the core is incident. This contributes to improved workability.

  FIG. 2 is an enlarged view of the light side incident portion. In FIG. 2, 6-1 is a branch line, 11-1 is a signal light for contrasting a core wire, 12-1 is a light side incident part, 14 is a refractive index matching agent, 15 is a ferrule guide, and 16-1 is a light incident. An optical fiber for use, 17 is a fiber guide, and 18 is a flat plate. The optical side surface incident part 12-1 is provided with a fiber guide 17 and a ferrule guide 15 on a flat plate 18. The strands of the branch line 6-1 are installed in the fiber guide 17, and the light incident optical fiber 16-1 is installed in the ferrule guide 15, so that the positions of the branch line 6-1 and the light incident optical fiber 16-1 are set. Relationships can be determined.

  First, the strands of the branch line 6-1 are set along the fiber guide 17 of the light side incident portion 12-1, and a bent portion is formed by bending the strands of the branch line 6-1 with a predetermined radius of curvature. In the bending portion, the signal light transmitted from the end face of the optical fiber 16 for light incidence includes the refractive index matching agent 14 and the outermost coating of the branch line 6-1, the outermost coating and cladding of the branch line 6-1, and the branch line. It is necessary that the radius of curvature is incident on the core of the branch line 6-1 without being totally reflected on any surface of the cladding and the core of 6-1. For example, when a core wire reference signal light having a wavelength of 1.65 μm is incident on the branch line 6-1, the radius of curvature is 10 mm. At this time, since the effective incident position of the contrast control signal light at the wavelength of 1.65 μm is at a direction change angle of about 20 ° from the position D where the bending starts, in the embodiment, the structural margin is increased. Considering this, the shape has a bending angle of about 30 °. Here, the direction change angle and the bending angle indicate the direction change angle with respect to the center of curvature having a predetermined radius of curvature of 10 mm.

  Next, the refractive index matching agent 14 is applied to the bent portion of the branch line 6-1. The light incident optical fiber 16 held by the ferrule guide 15 is brought close to the refractive index matching agent 14 from the bent portion, and the signal light 11-1 is incident thereon. As shown in FIG. 2, the ferrule guide 15 has an efficient incident point at about 20 ° from the beginning of bending (as described above), and the normal direction of the position, about 68 °, is optimal. Have confirmed. At this time, the bent strands 6-1 and the light incident optical fiber 16 are close to each other on the same plane, that is, the axes of the cores of the branch line 6-1 and the light incident optical fiber 16 are aligned. The design is made in consideration of the depth of the V-groove and the amount of protrusion from the ferrule guide 15 so that there is no deviation. For example, the fiber guide 17 is a V-groove having a depth about half the outer diameter of the strand of the branch line 6-1, and if the outer diameter of the strand is 250 μm, the depth of the V-groove is, for example, 125 μm. is there. By setting the strands of the branch line 6-1 along the V-groove, it is possible to form a bent portion where the branch line 6-1 is bent with a predetermined radius of curvature. In this embodiment, the radius of curvature is 10 mm, but the bend radius and the incident angle differ depending on the type of optical fiber (difference in fiber parameters) of the branch line 6-1 and the wavelength of the core wire reference signal light. Needless to say. In order to prevent scattering of signal light on the surface of the branch line 6-1, the refractive index of the refractive index matching agent 14 is preferably substantially equal to the refractive index of the outermost coating of the branch line 6-1.

  FIG. 3 is an example of a reception result of signal light by the signal light detection unit. 19 is the signal light detected by the signal light detector 13 shown in FIG. 1, and 20 is the signal light detected by the signal light detector 13 'shown in FIG. In the embodiment shown in FIG. 1, the signal light 11 is incident on the light side incident unit 12 from the side surfaces of the branch line 6-1 and the branch line 6-4 on the lower side of the optical splitter 5. In the branch line 6-4, the signal light 11 is received by the signal light detection unit 13 from one end (terminal) of the branch line 6-4. In the branch line 6-1, the branch line 6-1 is bent (light detection bending part 21), and the signal light 11 from the side is received by the signal light detection part 13 ′. As shown in the figure, it can be seen that the signal light of 270 Hz (3.7 ms cycle) can be detected reliably. At this time, the branch lengths of the branch lines 6-1 and 6-4 were both 500 m, and the coupling loss in the light side incident parts 12-1 and 12-4 was both about 48 dB.

  It can be used for optical core control in the construction or maintenance of optical fiber cable networks.

It is a lineblock diagram of the core line contrast system concerning this embodiment. It is an enlarged view of a light side incident part. It is an example of the reception result of the signal light by a signal light detection part. It is a line configuration example of PON.

Explanation of symbols

1 In-house device 2, 2 ′ Test light blocking filter 3 Optical coupler 4 Optical line 5 Optical splitter 6-1, 6-2, 6-3, 6-4 Branch line 7-1, 7-2, 7-3, 7-4 Outside device 8 Inside 9 Test light input / output port 10-1, 10-4, 10 ′ Light source for contrast control 11-1, 11-4, 11 ′ Signal light for contrast control 12-1, 12-4 Light side incident part 13, 13 ′ Signal light detection part 14 Refractive index matching agent 15 Ferrule guide 16-1, 16-4 Light incident optical fiber 17 Fiber guide 18 Planar plate 19 Detected by signal light detection part 13 Signal light 20 Signal light detected by the signal light detection unit 13 ′ 21 Light detection bending part

Claims (3)

A branched optical line that communicates by dividing one optical line into a plurality of branched lines by an optical splitter;
Forming a bent portion bent at a predetermined radius of curvature in one of the branch lines, an optical side surface incident portion for injecting signal light for core wire comparison from the bent portion,
A signal light detection unit for detecting the signal light incident on the light side incident unit and identifying the one of the branch lines;
A core contrast system. From the branched optical line that communicates by dividing one optical line into a plurality of branch lines by an optical splitter, in the cord contrast method for individually specifying the plurality of branch lines,
Forming a bent portion bent at a predetermined radius of curvature in one of the branch lines, a light side incident portion procedure for injecting a signal light for contrast control from the bent portion,
A signal light detection procedure for detecting the signal light incident in the light side incidence procedure, and identifying the one of the branch lines;
A method of contrasting cardiac cords, comprising:   In the signal light detection procedure, the signal light is received at a terminal portion of each branch line, or the leakage light of the signal light is received by bending each of the plurality of branch lines. The cord control method according to claim 2.

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