JP2003065893A - Signal intensity changing device for pair identification and using method of signal intensity changing device for pair identification - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically perform pair identification for executing individual discrimination of an optical coated fiber in order to avoid erroneous cut or erroneous connection of the optical coated fiber in construction or maintenance of an optical fiber communication network. SOLUTION: The optical fiber communication network is a PDS network having a distribution from wherein one upper side optical coated fiber 1 is branched into plural lower side optical coated fibers 4, 5 through an optical splitter 3. In the network, the differential between the intensity of contrast light detected by a light-receiving device 9 by using this signal intensity changing device 10 for pair identification for giving bending having a radius of curvature of 6 mm-7 mm on an optical fiber part on the upper side of the optical splitter 7 and the lower part side of the light-receiving device 9, and the intensity of contrast light detected by the light-receiving device 9 without using the signal intensity changing device 10 for pair identification, is calculated. Thus, when the intensity difference exists, the pair identification is performed by determining as the same optical fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core wire control for individually identifying the optical fiber core wires in order to avoid erroneous disconnection and connection of the optical fiber core wires when constructing or maintaining an optical fiber communication network. The invention relates to an apparatus used in a system and an invention related to a method of using the apparatus.

[0002]

2. Description of the Related Art In constructing or maintaining an optical fiber communication network, in order to prevent accidental disconnection or connection of the optical fiber core wire, at the work site, in the optical fiber cable or at the customer's home. It is necessary to perform individual identification (hereinafter referred to as “optical fiber”). This work is called core wire control, and is usually performed by the method shown in FIG. That is, from the optical signal light source device (hereinafter, referred to as a “light source device”) 7 for optical fiber control installed on the upper side (left side in FIG. 4) of the optical fiber 1 ′ requiring optical fiber contrast, the optical signal for optical fiber control. A core line reference optical signal (hereinafter referred to as “contrast light”) is incident on the optical fiber 1 ′ via an incident device (hereinafter referred to as “incident device”) 8. On the lower side (right side in FIG. 4) of the optical fiber 1 ′, the optical fiber 1 ′ is curved by using an optical signal receiving device (hereinafter, referred to as “light receiving device”) 9 for optical fiber comparison to provide the reference light. The reference light is detected by being emitted to the outside of the optical fiber 1.

Here, the light source device 7 is a laser diode (LD) or a light emitting diode (LED) having a longer wavelength than a communication optical signal (hereinafter referred to as "communication light") for providing information and the like to a customer's house. ) Is added to the light such as 270 Hz frequency-modulated in the audible range to emit light. For example, when the wavelength of the communication light is 1.31 μm, the wavelength of the reference light is 1.55 μm, and when the wavelength of the communication light is 1.55 μm, the wavelength of the reference light is 1.65 μm.

An optical fiber coupler, a waveguide type directional coupler, or the like is used as the incident device 8, or the reference light is directly incident from the upper end face of the optical fiber 1 '.

Further, the light receiving device 9 is provided with a bending mechanism for efficiently emitting only the reference light to the outside of the optical fiber 1'without affecting the communication light, and the emitting mechanism emits the reference light. A light receiving element such as a Ge photodiode or an InGaAs photodiode for receiving the reference light is provided, and the intensity of the reference light can be measured. With such a configuration, even when the normal light is being transmitted, the worker on the lower side detects the reference light incident from the upper side of the optical fiber 1 ′ by using the light receiving device 9, so that the optical fiber can be checked. Carried out.

Incidentally, as a typical example of the core wire comparison system including a light source device, an incident device, and a light receiving device which have been conventionally used, it is shown in the following document, for example.

Enomoto et al .: "Design of Small Optical Fiber ID Tester Using Hybrid Optical Module", 1996
Proceedings of IEICE Communications Society Conference (Volume 2: Communication 2), Lecture No. B-976, P. 461 On the other hand, a fiber that connects optical fibers to ordinary households.
A passive double star network (hereinafter referred to as "PDS network") in which an optical splitter (wavelength-independent optical branching device) is installed in the middle of an optical line is one of the network forms for economically realizing the two-to-home (FTTH). ") Is being introduced.
A description of this PDS network is given in the following document, for example.

Reference name: "2001 Information and Communication New Word Dictionary", P.P. 192, P.I. 204, and P. 523, 20
Published by Nikkei BP on October 16, 2000 The basic configuration of this PDS network is shown in FIG. This PDS network includes one optical fiber 1 on the upper side connected to one optical transmission device 2 on the station (instep) side and a plurality of optical fibers on the lower side (branch optical fiber 4A1, etc.) via an optical splitter 3. , Drop optical fiber 5A1 etc.) and is connected to a plurality of subscribers' (Otsu A1, Otsu A2, ... Otsu An; Otsu B1, Otsu B2, ... Otsu Bn) homes in a wiring form of an optical fiber communication network. . That is, one upper optical fiber 1 connected to the optical transmission device 2 has a plurality of branch optical fiber cores (hereinafter referred to as “branch optical fibers”) (4A) via the optical splitter 3.
1, 4A2, ... 4An; 4B1, 4B2, ..., 4Bn)
Furthermore, these branch fibers are connected to the single-fiber connection points (5A1, 5A2, ... 5An; 5B1, 5B2,
, 5Bn) via drop optical fibers for subscriber wiring (hereinafter referred to as "drop optical fibers") (6A1, 6A2, ... 6An; 6B1, 6B2).
, 6Bn).

For the sake of convenience of description, hereinafter, the generic name of the plurality of subscribers is “subscriber (Otsu)”, the generic name of the plurality of branch optical fibers is “branch fiber 4”, and the plurality of single-fiber connection points. Will be collectively referred to as "single-fiber connection point 5", and the generic name of the plurality of drop optical fibers will be referred to as "drop optical fiber 6".

The branched optical fibers 4 are bundled in a spiral shape to form a plurality of branched optical fibers. In FIG. 5, for convenience of explanation, a plurality of branch optical fibers (4A1, 4A4
Branch optical fiber group 4 composed of A2, ... 4An)
A and a plurality of branch optical fibers (4B1, 4B2, ..., 4
Bn) shows a branched optical fiber group 4B.

By using this PDS network, it is possible to distribute communication light from the optical transmission device 2 on the station (A) side to a plurality of subscriber's homes, and at the same time, from the plurality of subscriber's homes to the station (A) side. The communication light can be transmitted to. Further, the communication lights transmitted from a plurality of subscribers' houses are adjusted in transmission timing of optical signals so as not to act or interfere with each other in the optical fiber 1 above the optical splitter 3. By adopting such a wiring form by the PDS network, one optical fiber 1 on the upper side can be shared by a plurality of subscribers, so that communication equipment can be economically constructed.

In the case of performing the core line comparison in this PDS network, as shown in FIG. 6, the light source device 7, the incident device 8 and the receiving device 9 are installed. That is, the reference light is incident on the upper optical fiber 1 from the light source device 7 installed on the upper side of the optical splitter 3 via the incident device 8. On the lower side of the optical splitter 3, the drop light fiber 6Bn near the subscriber's house (here, the subscriber (B Bn)) is curved by using the light receiving device 9 so that the reference light is dropped. This control light is detected by emitting it to the outside.

By the way, since the reference light is distributed from the optical splitter 3 to the respective branch optical fibers 4 on the downstream side substantially evenly, when the conventional optical fiber comparison method is applied to optical fiber comparison of a PDS network, the optical splitter 3 It is not possible to individually distinguish the optical fibers (branch optical fiber 4, drop optical fiber 6) on the downstream side of the optical fiber and perform the core line comparison.

Further, different identification numbers are printed on the surface of the branched optical fiber 4 in order to distinguish the optical fibers, but only different identification numbers are printed in the same branched optical fiber group. Thus, in another branch optical fiber group, there is a branch optical fiber in which the same identification number is printed. For example, there is no branch optical fiber group 4A in which the same identification number as that of the branch optical fiber 4A1 is printed, but there is no branch optical fiber group 4B in the branch optical fiber group 4B.
A1 There is a branched optical fiber 4B1 printed with the same identification number. Therefore, even if the identification number is printed on the branched optical fiber 4, the operator cannot actually perform the core wire comparison.

On the other hand, an invention for solving the above problem is disclosed in Japanese Patent Application Laid-Open No. 9-127362. Therefore, with reference to FIG. 7 and FIG.
The contents of the invention disclosed in Japanese Patent No. 127362 will be briefly described.

FIG. 7 is a diagram showing the overall configuration of a conventional core wire checking system. The conventional system shown in FIG. 7 is an optical bandpass filter (100A1, 100A2, ..., 100An;) that transmits reference lights of different wavelengths through the drop optical fiber 6 of the PDS network shown in FIG.
100B1, 100B2, ... 100Bn) are provided. For convenience of explanation, the optical bandpass filters 1 are collectively referred to as “optical bandpass filter 1” below.
00 ”.

Further, in the conventional optical fiber comparison system, instead of the existing light source device 7, a dedicated light source device 101 for emitting the reference light of the wavelength that is transmitted through each optical bandpass filter 100 is provided. . This light source device 10
1, a wide wavelength spectrum width light source 1 as shown in FIG.
02, a wavelength tunable optical filter control device 103, and a bandpass type wavelength tunable optical filter 104 are provided. Of these, the wide wavelength spectrum width light source 102 is an LD or an LED having a wide wavelength spectrum, and generates light which is a source of the reference light. In addition, the bandpass tunable optical filter 1
Reference numeral 04 is a well-known bandpass type wavelength tunable optical filter,
By the operation control of the wavelength tunable optical filter control device 103,
Each of the optical bandpass filters 10 is selected from the wavelength spectrum components of the light emitted from the wide wavelength spectrum width light source 102.
Only the light of the wavelength spectrum component that transmits 0 is transmitted,
It is to be sent to the incident device 8 as the reference light. If this conventional system is adopted, the optical fibers on the downstream side of the optical splitter 3 (branching optical fiber 4 and drop optical fiber 6) can be individually discriminated to perform core line comparison.

[0018]

However, according to the conventional optical fiber comparison system, the optical bandpass filter 100 is provided in each drop optical fiber 6, and
It is necessary to replace the light source device 7 with the dedicated light source device 101. Therefore, even if the PDS network that is economical in constructing the communication equipment is adopted, the economical efficiency is deteriorated in the maintenance and inspection, and there is a possibility that the entire system becomes uneconomical.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and an object thereof is to economically perform core wire comparison.

[0020]

In order to achieve the above object, the invention according to claim 1 is intended to avoid erroneous disconnection or connection of an optical fiber core wire in construction or maintenance of an optical fiber communication network. At the upper side of the optical fiber core wire, a core wire contrasting optical signal is made incident on the optical fiber core wire from a core wire contrasting optical signal light source device through a core wire contrasting optical signal injection device, and the optical fiber core wire The optical fiber core wire is curved at the lower side of the optical fiber by using the optical fiber light receiving device for core wire contrast, so that the incident optical fiber for core wire comparison is radiated to the outside of the optical fiber core wire and the core A device for use in a system for performing core line comparison by detecting a line contrast optical signal, wherein the optical fiber is transmitted from the core line contrast optical signal light source device through the core line contrast optical signal incident device. Optical signal for optical fiber reference incident on the optical fiber A change in signal strength for core line comparison, comprising change means capable of changing the intensity to change the intensity of the optical signal for core line detection detected by the optical signal receiving device for core line comparison. It is a device.

In the invention according to claim 2, the changing means is
2. The core wire according to claim 1, further comprising a bending unit capable of changing the intensity of the optical signal for core wire comparison by giving the optical fiber core wire a curvature having a predetermined radius of curvature. This is a control signal intensity changing device.

In the invention according to claim 3, the bending means is
In order to sandwich the optical fiber core wire and give a curve according to a predetermined radius of curvature, a gripping convex part formed with a convex part having a predetermined radius of curvature, and the optical fiber core wire can be pressed together with the convex part. 3. The signal intensity changing device for core wire comparison according to claim 2, wherein the signal intensity changing device comprises a sandwiching recess in which a recess is formed.

The invention according to claim 4 is the signal intensity changing apparatus for core wire comparison according to claim 3, wherein the predetermined radius of curvature of the convex portion is 3 mm to 10 mm.

The invention according to claim 5 is the signal intensity changing apparatus for core wire comparison according to claim 3, wherein the predetermined radius of curvature of the convex portion is 6 mm to 7 mm.

The invention according to claim 6 is a method of performing core wire comparison in order to avoid erroneous disconnection and connection of the optical fiber core wire in construction and maintenance of the optical fiber communication network,
An incident step of injecting an optical signal for optical fiber comparison on the optical fiber optical fiber through an optical signal injection device for optical fiber optical fiber optical fiber light source device for optical fiber optical fiber input on the upper side of the optical fiber optical fiber optical fiber input device By giving a curve to the optical fiber core wire by using the optical signal receiver for core wire contrast on the lower side of the fiber core wire, the incident optical signal for core wire contrast is radiated to the outside of the optical fiber core wire. A first detection step of detecting the intensity of the optical fiber for optical fiber comparison, and a portion of the optical fiber optical fiber that is lower than the optical signal injection device for optical fiber identification and is for optical fiber identification. An intensity change that changes the intensity of the optical fiber signal for optical fiber transmission sent to the optical signal receiving device for optical fiber identification by using the optical fiber signal intensity changing device for the optical fiber receiving device on the upper side of the optical signal receiving device. And, after the intensity changing step, By giving a curvature to the optical fiber core wire by using a line-contrast optical signal receiving device, the incident optical fiber core-corresponding optical signal is radiated to the outside of the optical fiber core wire, and the optical fiber for core wire comparison is emitted. Second to detect signal strength
And a difference calculation step of calculating a difference between the intensity detected by the first detection step and the intensity detected by the second detection step. This is a method of using the signal strength changing device for controlling the core wire.

The invention according to claim 7 is a PDS in which the optical fiber communication network is a wiring form in which one optical fiber core wire on the upper side is branched into a plurality of optical fiber core wires on the lower side through an optical splitter. In the network, the intensity changing step includes a portion of the optical fiber core wire that is on a lower side of the optical splitter and is on an upper side of the optical fiber receiving device for optical fiber comparison, which is used for optical fiber comparison. By applying a curve having the predetermined radius of curvature using a signal intensity changing device, the intensity of the optical signal for optical fiber comparison sent to the optical signal receiving device for optical fiber inspection is changed. 6 is a method of using the signal intensity changing device for controlling the core wire according to 6.

According to an eighth aspect of the present invention, the installation place of the optical signal receiving device for optical fiber comparison in the second detecting step is the installation of the optical signal receiving device for optical fiber comparison in the first detecting step. It is the same as a place, It is a usage method of the signal strength changing device for core wire comparisons of Claim 6 or 7 characterized by the above-mentioned.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A signal intensity changing device (hereinafter, referred to as a "changing device") 10 for use in a cord checking system will be described below with reference to the drawings.

FIG. 1 shows the entire structure of a changing device 10 according to the present embodiment, and is a view showing a state where the optical fiber 1 is not sandwiched (supported in a sandwiched state). Of these, Figure 1
1A is a side view of the changing device 10, and FIG. 1B is a top view of the changing device 10.

As shown in FIG. 1, in the changing device 10, the convex portion 11a having a predetermined radius of curvature is provided in order to sandwich the optical fiber (here, the optical fiber 4Bn) and to give a curve having a predetermined radius of curvature. The formed gripping protrusion 11 and this protrusion 1
1a, a holding concave portion 12 in which a concave portion 12a capable of press-contacting the optical fiber 4Bn is formed, a grip 13 held by a worker when the optical fiber 4Bn is held between the holding concave portion 11 and the holding convex portion 12, and a holding operation by a worker. It is composed of a grip trigger 14 for pulling to the front side (grip side) when doing.

Of these, the holding recess 11 is shown in FIG.
As shown in, a concave portion 11a for bending a part of the optical fiber 4Bn is formed. The radius of curvature of the concave portion 11a is within a range from the extent that the optical fiber 4Bn having a diameter of 0.25 mm is not broken even if it is sandwiched to the extent that the light receiving device 9 can calculate a difference in optical signal intensity described later, that is, 3 mm to 10
mm may be sufficient. More preferably, it may be in a range where a difference in strength, which will be described later, clearly appears, that is, 6 mm to 7 mm. In addition, as shown in FIG. 1A, the holding recess 11 has an optical fiber 4Bn when the optical fiber 4Bn is gripped.
In order to prevent scratching, the groove portion 11b having a substantially semicircular shape with a radius of curvature substantially the same as the radius of the optical fiber 4Bn is formed.

On the other hand, as shown in FIG. 1B, the sandwiching convex portion 12 is formed with a convex portion 12a for sandwiching the optical fiber 4Bn together with the concave portion 11a and for bending a part of the optical fiber 4Bn. Has been done. The convex portion 12a is the concave portion 1
It is formed in a substantially semicircular shape having the same radius of curvature as the radius of curvature 1. Further, as shown in FIG. 1A, the sandwiching convex portion 12 has an optical fiber 4Bn1 when sandwiching the optical fiber 4Bn1.
In order not to damage n, a substantially semicircular groove 12b having the same radius of curvature as that of the groove 11b is formed.

FIG. 2 shows the entire structure of the bending device 10 according to the present embodiment, and is a view showing a state in which the optical fiber 4Bn is held. When the operator grips the grip 13 and pulls the grip trigger toward you (on the grip side), the gripping protrusion 12
Slides toward the grip concave portion 11 (on the grip side), and the groove portion 12b of the grip convex portion 12 and the groove portion 11b of the grip concave portion 11b.
Thus, the optical fiber 4Bn can be held. Further, when the optical fiber 4Bn is sandwiched, as shown in FIG. 2B, the convex portion 12a of the sandwiching convex portion 12 and the concave portion 11a of the sandwiching concave portion 11 can bend a part of the optical fiber 4Bn.

The sliding mechanism of the sandwiching convex portion 12 with respect to the sandwiching concave portion 11 is composed of a guide groove and a guide sliding mechanism (not shown), and one of the sandwiching concave portion 11 and the sandwiching convex portion 12 is provided with a guide groove. A guide is formed on the other side. In addition, without using the slide mechanism, the holding recess 1
A rotation mechanism in which 1 and the sandwiching convex portion 12 are locked by a fulcrum may be adopted.

FIG. 3 is a diagram showing the overall configuration of a PDS network using the changing apparatus 10 according to this embodiment. However,
Since the PDS network shown in FIG. 3 is the same type as the PDS network shown in FIG. 5 which has been conventionally used, the same components are designated by the same reference numerals and the description thereof will be omitted. Further, regarding the light source device 7, the incident device 8, and the light receiving device 9 shown in FIG.
Since each has the same configuration as the light source device 7, the incident device 8, and the light receiving device 9 shown in FIG. 6, the same reference numerals are given and the description thereof is omitted. That is, in the PDS network according to this embodiment, the changing device 10 shown in FIGS. 1 and 2 is used without using the dedicated light source device 101 and the optical bandpass filter 100 as shown in FIG.

Next, a method of using the changing device 10 according to this embodiment will be described with reference to FIGS. 1, 2 and 3.

First, as shown in FIG. 3, the worker enters the reference light from the light source device 7 into the optical fiber 4Bn, so that the operator enters the incident device 8 into any part of the optical fiber 1 on the upper side.
Set up. Also, the drop optical fiber 6 on the lower side
The light receiving device 9 is installed in an arbitrary part of (here, the drop optical fiber 6Bn). The installation location of this light receiving device 9 is
It is desirable to be closer to the subscriber's home.

Subsequently, the worker causes the reference light to enter the optical fiber 1 which is the upstream portion from the light source device 7 through the entrance device 8. Further, the operator uses the light receiving device 9 to bend the drop optical fiber 6Bn to emit the reference light to the outside of the drop optical fiber 6Bn and detect the reference light. At this time, another worker uses the receiver 9 to measure the intensity (I1) of the reference light.

Next, the worker uses an arbitrary portion of the branch optical fiber 4 (here, the branch optical fiber 4Bn) shown in FIG.
As shown in FIG. 1, the optical fiber 1 is inserted between the sandwiching concave portion 11 and the sandwiching convex portion 12. The insertion location is not limited to an arbitrary portion of the branch optical fiber 4 and may be an arbitrary portion of the drop optical fiber as long as it is located above the optical splitter 3 and below the receiving device 9.

Next, when the operator grips the grip 13 and pulls the grip trigger 14 to the front side (grip side), FIG.
The sandwiching convex portion 12 slides in the direction indicated by the arrow. As a result, as shown in FIG. 2, the groove 12b of the sandwiching protrusion 12 is formed.
The optical fiber 1 can be sandwiched by the groove portion 11b of the sandwiching concave portion, and a part of the branched optical fiber 4Bn can be curved. Further, another worker uses the light receiving device 9 to bend the drop optical fiber 6Bn to emit the reference light to the outside of the drop optical fiber 6Bn and detect the reference light. At this time, another worker uses the receiving device 9 to measure the intensity (I2) of the reference light. Then, the intensity of the reference light (I
The difference between (1, I2) (I2-I1) is calculated to perform the core line control. That is, in the present embodiment, the characteristic that a loss occurs in the optical signal when the optical fiber is curved is used.

The installation location of the bending device 10 and the light receiving device 9
We will keep in touch with each other by mobile phones etc.
If the work is advanced while coordinating the work timing, it can be surely recognized that the change from the measurement value of the intensity (I1) to the measurement value of the intensity (I2) is caused by the work performed by the changing device 10. , If this work is repeated multiple times, the accuracy will be further improved.

As described above, according to this embodiment, the change device 10 is used to give the drop optical fiber 6 a curve having a predetermined radius of curvature, thereby changing the intensity of the reference light. Difference in strength (I1-
I2) is calculated, and if there is a difference in strength, it can be determined that the optical fibers are the same, and the core wire can be compared. Therefore, since it is not necessary to install a plurality of optical bandpass filters 100 and a dedicated light source device 101 as in the conventional case, the core line comparison can be economically performed.

In the above embodiment, the case where the change device 10 is used in the PDS network has been described, but the present invention is not limited to this, and a single star type (a station and a subscriber's house are connected by one optical fiber). Alternatively, it may be used in an active double star type (branching from one optical fiber connected to a station to a plurality of metallic cables and connecting to each subscriber's house).

Further, in the above embodiment, the changing device 10 is used in an arbitrary portion of the branch optical fiber 4 which is the lower side, but it is on the lower side of the optical splitter 3 and the light receiving device 9 is used.
The branch optical fiber 4 or the drop optical fiber 6 may be provided on the upper side.

[0045]

As described above, according to the present invention,
The difference in intensity obtained by changing the intensities of the optical signals for optical fiber comparison is calculated by giving the optical fiber optical fiber a curve with a predetermined radius of curvature, and if there is an intensity difference, the same optical fiber is calculated. It is possible to perform the core line control by determining that Therefore, since it is not necessary to install a dedicated light source device or the like as in the conventional case, the core wire comparison can be economically performed.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a signal intensity changing device for core wire comparison (before gripping) of the present invention.

FIG. 2 is a diagram showing an overall configuration of a signal intensity changing device for core wire comparison (after gripping) of the present invention.

FIG. 3 is a diagram showing a case where a core line comparison is performed in the PDS network using the signal strength changing device for core line comparison of the present invention.

FIG. 4 is a diagram showing a case where a core wire control is performed.

FIG. 5 is a diagram showing a basic configuration of a PDS network.

FIG. 6 is a diagram showing a case where a core line is compared in a PDS network.

FIG. 7 is a diagram showing a case where a core line comparison is performed by a conventional method in a PDS network.

FIG. 8 is a diagram showing a configuration of a light source device 101 used when performing a core wire comparison by a conventional method in a PDS network.

[Explanation of symbols]

1 optical fiber core wire (upstream side optical fiber core wire) 1'optical fiber core wire 2 optical transmission device 3 optical splitter 4 (4A1, 4A2, ... 4An; 4B1, 4B2, ...,
4Bn) Branch optical fiber 4A, 4B Branch optical fiber group 5 (5A1, 5A2, ... 5An; 5B1, 5B2, ...
5Bn) Single-core connection point 6 (6A1, 6A2, ... 6An; 6B1, 6B2, ...,
6Bn) Drop optical fiber 7 Optical signal light source device for optical fiber comparison 8 Optical signal input device for optical fiber comparison 9 Optical signal light receiving device for optical fiber comparison 10 Optical signal intensity changing device for optical fiber comparison 11 Clamping recess (part of changing means) , Part of the bending means 11a concave part 11b groove part 12 clamping convex part (part of the changing means, part of the bending means) 12a convex part 12b groove part 13 grip 14 grip trigger 100 (100A1, 100A2, ..., 100An; 1)
00B1, 100B2, ..., 100Bn) Optical bandpass filter 101 Optical signal light source device 102 for core line comparison Wide wavelength spectrum width light source 103 Wavelength variable optical filter control device 104 Bandpass wavelength variable optical filter

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masao Tachizo             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation F-term (reference) 2G086 AA01

Claims (8)

[Claims] 1. When constructing or maintaining an optical fiber communication network, in order to avoid erroneous disconnection or connection of the optical fiber core wire, a core from an optical signal light source device for core wire comparison is provided above the optical fiber core wire. The optical fiber core optical signal is made incident on the optical fiber core wire through the optical fiber core light input device, and the optical fiber core is used on the lower side of the optical fiber core wire by using the optical fiber light receiver for optical fiber core contrast. Used in a system for performing core line comparison by giving a curve to a line to cause the incident core line comparison optical signal to be emitted outside the optical fiber core line and detect the core line comparison optical signal. A device for changing the intensity of the optical fiber signal for optical fiber contrast incident on the optical fiber optical fiber from the optical signal light source device for optical fiber optical fiber input device through the optical fiber input device for optical fiber optical fiber, Heart detected by the optical signal receiving device for the optical fiber comparison Core control signal strength changer, characterized by comprising a changing means capable of changing the intensity of the control light signal. 2. The changing means comprises a bending means capable of changing the intensity of the optical signal for optical fiber comparison by giving the optical fiber optical fiber a curvature having a predetermined radius of curvature. The signal strength changing device for core wire comparison according to claim 1. 3. The grasping convex portion having a convex portion with a predetermined radius of curvature, and the convex portion, wherein the bending means holds the optical fiber core wire and gives a curve having a predetermined radius of curvature. The signal intensity changing device for optical fiber comparison according to claim 2, wherein the optical fiber optical fiber is also constituted by a sandwiching recess formed with a recess capable of press-contacting the optical fiber optical fiber. 4. The signal intensity changing device for core wire comparison according to claim 3, wherein the predetermined radius of curvature of the convex portion is 3 mm to 10 mm. 5. The signal intensity changing device for core wire comparison according to claim 3, wherein the predetermined radius of curvature of the convex portion is 6 mm to 7 mm. 6. A method of performing core wire comparison in order to avoid erroneous disconnection and connection of the optical fiber core wire when constructing or maintaining an optical fiber communication network, the method comprising: An incident step of injecting an optical signal for optical fiber comparison from the optical signal light source device for optical fiber identification to the optical fiber optical fiber through an optical signal injection device for optical fiber identification, and an optical fiber at the lower side of the optical fiber optical fiber. By giving a curvature to the optical fiber core wire by using a reference optical signal receiving device, the incident optical fiber core reference optical signal is radiated to the outside of the optical fiber core wire, and the optical fiber reference optical signal is emitted. A first detection step of detecting the intensity of the optical fiber core, and, of the optical fiber cores, on the lower side of the optical fiber incident device for optical fiber comparison and on the upper side of the optical signal receiving device for optical fiber comparison. Use the signal intensity changing device for the core wire contrast in the part. Using an intensity changing step of changing the intensity of the optical fiber signal for optical fiber sent to the optical fiber receiving device for optical fiber contrast, and using the optical signal receiving device for optical fiber optical fiber after the intensity changing step. A second detection for bending the optical fiber core wire to radiate the incident optical fiber wire reference optical signal to the outside of the optical fiber core wire and detect the intensity of the optical fiber wire core signal. And a difference calculation step of calculating a difference between the intensity detected by the first detection step and the intensity detected by the second detection step. How to use the signal strength changing device for line comparison. 7. The PDS network in which the optical fiber communication network is a wiring form in which one upper optical fiber core is branched into a plurality of lower optical fiber cores through an optical splitter, In the intensity changing step, the optical fiber comparing signal intensity changing device is used in a portion of the optical fiber optical fibers which is lower than the optical splitter and higher than the optical fiber receiving optical signal receiving device. 7. The optical fiber according to claim 6, wherein the intensity of the optical fiber for optical fiber comparison sent to the optical fiber receiving device for optical fiber transmission is changed by giving a curvature having the predetermined radius of curvature. How to use the control signal strength changer. 8. The installation place of the optical signal receiving device for optical fiber comparison in the second detecting step is the same as the installation place of the optical signal receiving device for optical fiber comparison in the first detecting step. 8. The method of using the signal intensity changing device for core wire comparison according to claim 6 or 7.