JP6755825B2 - Optical pulse test device and optical pulse test method - Google Patents

Description

The present disclosure relates to an optical pulse test apparatus and an optical pulse test method.

Due to the expansion of communication demand in recent years, coaxial cables have been replaced by optical fiber cables as the leading medium for communication. Optical fiber cables are used from trunk lines to access systems and are laid everywhere.

Recently, optical fiber cables have become the mainstream of media used for communication wiring in data centers and wiring between communication devices for mobile access and antennas. In order to improve the laying efficiency and realize large-capacity communication, these optical fiber cables are laid with multi-core optical fiber cables instead of single-core ones. At the time of construction, it is necessary to measure the laying state of all optical fiber cables with an optical pulse test device, so improvement in measurement efficiency is required.

A connector for measuring each optical fiber provided in an optical fiber cable at once has been proposed (see, for example, Patent Document 1). The connector of Patent Document 1 connects the optical fibers provided in the optical fiber cable to one. This makes it possible to measure a multi-core optical fiber cable as a single optical fiber with an optical pulse test device.

Japanese Unexamined Patent Publication No. 2013-238592

When the optical fibers are connected to each other, there is a problem that it is difficult to understand the correspondence between the distance from the optical pulse test device and the measurement waveform of each optical fiber. Therefore, in the present disclosure, even when each optical fiber provided in a multi-core optical fiber cable is connected and an optical pulse test is performed as one optical fiber, the distance from the optical pulse test apparatus and each optical fiber are disclosed. The purpose is to make it easier to understand the correspondence with the measured waveform of.

Specifically, the optical pulse test apparatus (10) of the present disclosure is
A plurality of optical fibers (31, 32, 33, 34) are laid side by side with a near end and a far end, respectively, and each optical fiber other than the near end of the first optical fiber of the plurality of optical fibers In one optical fiber in which the near ends or the far ends of the fiber are connected to each other, the near end of the first optical fiber is used as an incident end of an optical pulse, and the rear side of the optical fiber to be measured is used. A measuring unit (11) for measuring scattered light and
A reflection detection unit (23) that detects a light loss point from the measurement waveform measured by the measurement unit, and
From the sections between the light loss points, the first section and the second section having the same distance are detected, and each distance of each section located in order from the first section toward the second section side and the first section. When the distances of the sections located in order from the two sections toward the first section side are equal to each other, it is determined that the intermediate point between the first section and the second section is a turning point of the plurality of optical fibers. Folding point detection unit (25)
To be equipped.

In the optical pulse test apparatus of the present disclosure, among the measurement waveforms measured by the measurement unit, the far end of the measurement waveform of the even-numbered optical fiber starting from the odd-numbered turnaround point detected by the turnaround point detection unit. A waveform inversion unit (21) that inverts the start point located at and the end point located at the near end to each other to generate a first inverted waveform, and a display unit (13) that displays the waveform generated by the waveform inversion unit. ) And may be further provided.
In the waveform inversion portion, the light intensity at the far end of the even-order optical fiber matches the light intensity at the near end of the even-order optical fiber, and the light intensity at the near end of the even-th optical fiber. The first inverted waveform may be further inverted to generate a second inverted waveform so that the optical intensity of the optical fiber matches the optical intensity at the far end of the even-order optical fiber.
Further, a waveform moving unit (22) that translates at least a part of the waveform displayed on the display unit on the light intensity axis may be further provided.

In the optical pulse test apparatus of the present disclosure, the far end and the near end of the even-th optical fiber starting from the odd-th turning point detected by the turning point detection unit are specified, and the even-th optical fiber of the even-th optical fiber is identified. An icon inversion unit (24) that inverts the arrangement of light loss points from the far end to the near end to the arrangement of light loss points from the near end to the far end of the even-order optical fiber, and the plurality. With the light loss point at the near end of the optical fiber on one side and the light loss point at the far end of the plurality of optical fibers on the other side, from the near end to the far end of the plurality of optical fibers. A display unit (13) for displaying an icon in which the light loss points are arranged may be further provided.

The optical pulse test method of the present disclosure is
The measuring unit (11) is laid side by side with a plurality of optical fibers (31, 32, 33, 34) having a near end and a far end, respectively, and is the first optical fiber of the plurality of optical fibers. The near end of the first optical fiber in one optical fiber to be measured in which the near ends or the far ends of each optical fiber other than the near end are connected to each other is used as an incident end of an optical pulse. A measurement procedure for measuring backscattered light in the optical fiber to be measured, and
A reflection detection procedure in which the reflection detection unit (23) detects a light loss point from the measurement waveform measured by the measurement unit, and
The turning point detection unit (25) detects the first section and the second section having the same distance from the sections between the light loss points, and is located in order from the first section toward the second section side. When each distance of each section and each distance of each section located in order from the second section toward the first section side are equal to each other, the intermediate point between the first section and the second section is set as the plurality of points. The turning point detection procedure that determines that it is the turning point of the optical fiber,
To execute.

The above disclosures can be combined as much as possible.

According to the present disclosure, in order to determine the turning point of a plurality of optical fibers, even when each optical fiber provided in a multi-core optical fiber cable is connected and an optical pulse test is performed as one optical fiber. , The correspondence between the distance from the optical pulse test device and the measurement waveform of each optical fiber can be easily understood.

An application example of the optical pulse test method according to the present disclosure is shown. A first example of an optical fiber cable is shown. This is a configuration example of the optical pulse test apparatus according to the first embodiment. This is the first example of the measurement waveform. This is an example of the first inverted waveform. This is an example of the second inverted waveform. This is a configuration example of the optical pulse test apparatus according to the second embodiment. This is an example of moving the second inverted waveform. This is a configuration example of the optical pulse test apparatus according to the third embodiment. This is the first detection example of the light loss point. This is an example of optical fiber separation in adjusting the arrangement of light loss points. This is an example of inversion of an optical fiber in adjusting the arrangement of light loss points. A second example of an optical fiber cable is shown. A third example of an optical fiber cable is shown. This is a configuration example of the optical pulse test apparatus according to the fourth embodiment. This is the second example of the measurement waveform. This is a third example of the measurement waveform.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the embodiments shown below. Examples of these implementations are merely examples, and the present disclosure can be implemented in a form in which various modifications and improvements have been made based on the knowledge of those skilled in the art. In the present specification and the drawings, the components having the same reference numerals shall indicate the same components.

The present disclosure has been made in order to efficiently measure an optical fiber cable including a plurality of optical fibers. In this embodiment, the case where the optical fiber cable is provided with two optical fibers will be described. The optical pulse test device is a device that measures the characteristics of an optical fiber cable by measuring an OTDR (Optical Time Domain Reflectometer) waveform. The OTDR waveform is obtained by incident an optical pulse from the incident end of the optical fiber and measuring the light intensity of the backscattered light scattered in the optical fiber at the incident end.

(Embodiment 1)
FIG. 1 shows an application example of the optical pulse test method according to the present disclosure. There is an antenna 41 on the steel tower 42, and an optical fiber cable 3 which is a multi-core optical fiber cable is laid up to the antenna 41. In this case, there are many cases where two of the plurality are used for transmission and reception. In the optical pulse test method of the present disclosure, the optical fiber cable 3 in which two optical fibers are connected by a patch cord at the end 36 is used as the optical fiber to be measured, and the end of one optical fiber provided in the optical fiber cable 3 is used. The optical pulse test device 10 is connected to 35 to perform an optical pulse test of the optical fiber cable 3.

FIG. 2 shows an example of the optical fiber cable 3. Of the two optical fibers 31 and 32, the optical pulse test device 10 is connected to the end 35 of the optical fiber 31, and the end 36 of the optical fiber 31 and the end 36 of the optical fiber 32 are connected by the optical fiber patch cord 5. To do. By performing the optical pulse test in this state, the optical pulse test of all the optical fibers provided in the optical fiber cable 3 can be continuously measured at once.

In the following the present embodiment, referred to the end 35 and proximal end, called the end 36 and the far-end, showing a case where optical fibers 31 and 32 are connected with two connection points C _A and C _B .. The length of the optical fiber patch cord 5 is arbitrary, but for example, a patch cord of about 1 m can be used.

FIG. 3 shows an example of the optical pulse test apparatus according to the present embodiment. The optical pulse test device 10 includes a measurement unit 11, a signal processing unit 12, and a display unit 13. The signal processing unit 12 includes a waveform inversion unit 21.

In the optical pulse test method according to the present embodiment, the optical pulse test apparatus 10 executes a measurement procedure, a waveform inversion procedure, and a display procedure in order. In the measurement procedure, the measuring unit 11 measures the OTDR waveform of the optical fiber cable 3. In the waveform inversion procedure, the waveform inversion unit 21 adjusts the OTDR waveforms of the optical fibers 31 and 32 so as to match the actual distance from the optical pulse test device 10.

FIG. 4 shows an example of the OTDR waveform obtained by the measurement procedure. Distances P1 to P4 indicate the measurement result of the optical fiber 31, and distances P4 to P7 indicate the measurement result of the optical fiber 32. Here, since the optical fiber patch cord is as short as 1 m, it is assumed that the reflection can be seen only at one place at the distance P4. In the OTDR waveform, the reflection at the near end of the optical fiber 32 is located at the distance P7, and the reflection at the far end of the optical fiber 31 is located at the distance P4. Therefore, in this OTDR waveform, the near end of the optical fiber 32 is displayed on the display unit 13 so as to be farther than the far end of the optical fiber 31.

In the waveform inversion procedure, the waveform inversion unit 21 generates a first inversion waveform in which the near end and the far end are mirror-inverted with each other on the distance axis of the OTDR waveform of the optical fiber 32. The starting point of the optical fiber 32 is a distance P4 located at the far end of the optical fiber 32. The end point of the optical fiber 32 is a distance P7 located at the near end of the optical fiber 32. Therefore, the waveform inversion unit 21 inverts each other at the start point and the end point of the portion corresponding to the optical fiber 32 in the OTDR waveform measured by the measurement unit 11, that is, the far end and the near end of the optical fiber 32. FIG. 5 shows an example of the first inverted waveform. In the first inverted waveform, the reflection position at the distance P7 among the distances P4 to P7 coincides with the distance P1, and the reflection position at the distance P4 among the distances P4 to P7 is folded back as a turning point. .. As described above, the OTDR waveform of the optical fiber 32 in the first inverted waveform coincides with the actual position of the optical fiber 32.

Here, the positions of the near end and the far end of the optical fiber 32, that is, the optical fiber patch cord 5, are specified by using the method of the fourth embodiment described later.

Since the light intensity of the first inverted waveform decreases by ΔL from the distance P4 to P1, the direction of decrease in the light intensity is different from that of the OTDR waveform when the optical pulse is incident from the near end of the optical fiber 32. Therefore, in the waveform inversion procedure, the waveform inversion unit 21 may further generate a second inversion waveform in which the first inversion waveform is mirror-inverted on the light intensity axis. FIG. 6 shows an example of the second inverted waveform.

In the second inverted waveform, the light intensity at the far end of the optical fiber 32 matches the light intensity at the near end of the optical fiber 32, and the light intensity at the near end of the optical fiber 32 is at the far end of the optical fiber 32. Matches the light intensity of. That is, the light intensity L1 at the turning point between the optical fibers 31 and 32 in the first inverted waveform is defined as the light intensity L2, and the light intensity L2 at the distance P1 in the first inverted waveform is defined as the light intensity L1. As a result, the second inverted waveform becomes an OTDR waveform similar to that in which an optical pulse is incident from the near end of the optical fiber 32, in which the light intensity decreases by ΔL from the distances P1 to P4.

In the display procedure, either the first inverted waveform or the second inverted waveform is displayed on the display unit 13 as a result of the optical pulse test. As a result, the optical pulse test device 10 measures the first inverted waveform divided at the half position (the position of the optical fiber patch cord 5) as if the optical fiber 31 and the optical fiber 32 were measured once. Display as a result. The OTDR waveform of the optical fiber 32 in the first inverted waveform coincides with the actual position of the optical fiber 32. Therefore, the optical pulse test device 10 can halve the measurement time and obtain a desired measurement result.

Further, the second inverted waveform is a waveform similar to that obtained by individually performing the OTDR measurement of the optical fiber 31 and the optical fiber 32. Therefore, it becomes easy to compare the OTDR waveforms of the optical fiber 31 and the optical fiber 32. The optical pulse test device 10 may be able to display the OTDR waveform before processing shown in FIG. 4 on the display unit 13.

When the display unit 13 displays the OTDR waveform, the first inverted waveform, or the second inverted waveform on the display unit 13, the optical fibers 31-1, 31-2, 31-3, 32-1, respectively. The loss at 32-2 and 32-3 may be displayed.

(Embodiment 2)
FIG. 7 shows an example of the optical pulse test apparatus according to the present embodiment. In the optical pulse test device 10 according to the present embodiment, the signal processing unit 12 further includes a waveform moving unit 22. Further, the optical pulse test method according to the present embodiment further includes a waveform moving procedure after the waveform inversion procedure.

In the waveform movement procedure, the waveform movement unit 22 translates at least a part of the waveform displayed on the display unit 13. The waveform displayed on the display unit 13 is, for example, a first or second inverted waveform. At least a part of the waveform is, for example, an OTDR waveform of an optical fiber 31 or 32, or a part thereof. The parallel movement may be in the distance axis direction, in the light intensity axis direction, or in both of these. The moving method is arbitrary, but for example, the OTDR waveform of the optical fiber 32 displayed on the display unit 13 is selected and slid.

For example, as shown in FIG. 8, the second inverted waveform is translated on the light intensity axis. As a result, by superimposing the OTDR waveform of the optical fiber 31 and the OTDR waveform of the optical fiber 32 and comparing the inclinations, it is easy to compare the state of optical loss in the optical fiber 31 and the state of optical loss in the optical fiber 32. Can be

As described in the above-described embodiment, the optical pulse test device 10 and the optical pulse test method according to the present disclosure connect the optical fibers 31 and 32 constituting the multi-core optical fiber cable 3 to one optical fiber. Even when the optical pulse test is performed as a fiber, it can be displayed so that the correspondence between the distance from the optical pulse test device 10 and the OTDR waveforms of the optical fibers 31 and 32 match.

Even in the case of three or more fibers, the ends 35 and 36 of the respective optical fibers are connected by the optical fiber patch cord 5 to form one fiber, the measurement is performed once, and the morphological information is an optical pulse. By inputting to the test device 10, the measurement result is separated from the result of each optical fiber cable 3, and by storing and reporting, efficient construction can be carried out.

Further, in the above embodiment, it has been described that the multi-core optical fiber cable 3 including the optical fibers 31 and 32 is laid, but the present disclosure is not limited to this, and the present disclosure is each independent optical fiber. Needless to say, it is applicable even when two wires are laid side by side.

(Embodiment 3)
FIG. 9 shows an example of the optical pulse test apparatus according to the present embodiment. The optical pulse test device 10 includes a measurement unit 11, a signal processing unit 12, and a display unit 13. The signal processing unit 12 includes a reflection detection unit 23 and an icon inversion unit 24.

In the optical pulse test method according to the present embodiment, the optical pulse test device 10 sequentially executes a measurement procedure, a reflection detection procedure, an icon inversion procedure, and a display procedure. In the measurement procedure, the measuring unit 11 measures the OTDR waveform of the optical fiber cable 3. FIG. 4 shows an example of the OTDR waveform obtained by the measurement procedure. Based on this, it is assumed that the following processing is performed.

In the reflection detection procedure, the reflection detection unit 23 detects the event occurrence point, which is the light loss point, from the OTDR waveform measured by the measurement unit 11. FIG. 10 shows an example in which each detected event is indicated by an icon as the entire array before conversion. The display becomes farther toward the right, and No. The icons 1 and 7 represent the "end" of the optical fiber, and No. The 2 to 6 icons represent "Fresnel reflections" such as connector connection points. The reflection at the near end of the optical fiber 32 is No. It is located at No. 7, and the reflection at the far end of the optical fiber 31 is No. Located at 4. Therefore, the display unit 13 is displayed so that the near end of the optical fiber 32 is located farther than the far end of the optical fiber 31.

In the icon inversion procedure, the icon inversion unit 24 adjusts the arrangement of the optical loss points of the optical fibers 31 and 32 so as to match the actual distance from the optical pulse test device 10. For example, the detected No. 1-No. No. 7 located at the far end of the optical fiber 32 from the light loss points of No. 7. No. 4 and No. located at the near end. 7 is identified and these are separated as shown in FIG. Then, as shown in FIG. 12, No. No. 5 to No. The array of events up to 7 is No. No. 7 to No. Invert to the sequence of 5. As a result, the arrangement of the icons of the event occurrence points of the optical fiber 32 can be matched with the actual position of the optical fiber 32.

Here, the positions of the near end and the far end of the optical fiber 32, that is, the optical fiber patch cord 5, are specified by using the method of the fourth embodiment described later.

In the display procedure, as shown in FIG. 12, the display unit 13 indicates the event occurrence point of the optical fiber 31. 1 to No. No. 4 icon and No. 1 indicating the event occurrence point of the optical fiber 32. No. 7 to No. The icon of 5 and is displayed as a separated array after conversion. The display unit 13 displays as a measurement result the event occurrence points divided at half positions (positions of the optical fiber patch cord 5) as if the optical fiber 31 and the optical fiber 32 were measured once. .. No. No. 7 to No. The array of 5 icons matches the actual distance. Therefore, the optical pulse test device 10 can halve the measurement time and obtain a desired measurement result. Here, when the optical fiber 31 is for transmission and the optical fiber 32 is for reception, the display unit 13 is No. 1 to No. The icon of 4 is the transmitting side (Tx), and No. No. 7 to No. It is preferable that the icon of 5 indicates that it is the receiving side (Rx).

Further, in FIG. 12, No. The icon of 4 may be changed to an icon representing the "end" of the optical fiber and displayed. This makes it easier for the operator to imagine that each optical fiber is separated. Further, the entire array before conversion shown in FIG. 10 and the separated array after conversion shown in FIG. 12 may be displayed together.

The display unit 13 is No. 1-No. The loss at each optical fiber 31-1, 31-2, 31-3, 32-1, 32-2, 32-3 may be displayed between the event occurrence points of 7.

Further, in the above-described embodiment, the number of optical fibers constituting the optical fiber cable 3 is arbitrary. For example, as shown in FIG. 13, when four optical fibers 31, 32, 33, and 34 are laid side by side with a near end and a far end, the optical fiber 31 functions as a first optical fiber. Then, the far ends of the optical fibers 31 and 32 are connected by the optical fiber patch cord 5-1 and the near ends of the optical fibers 32 and 33 are connected by the optical fiber patch cord 5-2, and the far ends of the optical fibers 33 and 34 are connected. May be connected with an optical fiber patch cord 5-3. In this case, in the waveform inversion procedure in the first and second embodiments, the waveform inversion unit 21 does not invert the OTDR waveforms of the optical fibers 31 and 33 which are connected to the optical pulse test device 10 in odd numbers, and is in even numbers. The OTDR waveforms of the optical fibers 32 and 34 connected to the are inverted. In the inversion procedure in the third embodiment, the icon inversion unit 24 does not invert the arrangement of the icons of the optical fibers 31 and 33 connected to the optical pulse test device 10 in odd numbers, and the optical fibers are connected in even numbers. The arrangement of the icons of 32 and 34 is reversed.

As another embodiment, for example, when three optical fibers 31, 32, 33 are laid side by side with a near end and a far end, as shown in FIG. 14, the optical fiber 31 is the first. It functions as an optical fiber, and the far ends of the optical fibers 31 and 32 may be connected by an optical fiber patch cord 5-1 and the near ends of the optical fibers 32 and 33 may be connected by an optical fiber patch cord 5-2. In this case, in the waveform inversion procedure in the first and second embodiments, the waveform inversion unit 21 does not invert the OTDR waveforms of the optical fibers 31 and 33 which are connected to the optical pulse test device 10 in odd numbers, and is in even numbers. The OTDR waveform of the optical fiber 32 connected to is inverted. In the inversion procedure in the third embodiment, the icon inversion unit 24 does not invert the arrangement of the icons of the optical fibers 31 and 33 connected to the optical pulse test device 10 in odd numbers, and the optical fibers are connected in even numbers. The arrangement of the 32 icons is reversed.

(Embodiment 4)
FIG. 15 shows an example of the optical pulse test apparatus according to the present embodiment. In the optical pulse test device 10 according to the present embodiment, the signal processing unit 12 described in the first embodiment further includes a reflection detection unit 23 and a turnaround point detection unit 25. Further, the optical pulse test method according to the present embodiment further includes a reflection detection procedure and a turning point detection procedure between the measurement procedure and the waveform inversion procedure of the first and second embodiments.

First, as shown in FIG. 13, an even number of optical fibers are laid side by side with a near end and a far end, and the near end or the far end of each optical fiber is connected to each other to an optical fiber to be measured. An application example of is described. FIG. 16 shows an example of an OTDR waveform measured as an optical fiber to be measured as an example of the optical fiber cable shown in FIG.

In the reflection detection procedure, the reflection detection unit 23 detects the event occurrence point, which is the light loss point, from the OTDR waveform measured by the measurement unit 11. As a result, the distances P1 to P13, which are the event occurrence points, are detected. Then, in the turn-around point detection procedure, the turn-around point detection unit 25 detects the turn-around point connected by the optical fiber patch cord using the sections D1 to D12 between the event occurrence points P1 to P13.

The turnaround point detection unit 25 detects the first section and the second section having the same distance from the sections D1 to D12. For example, it is determined whether or not the section D1 and the section D2 are equal, with the section D1 at the incident end as the first section. When the section D1 and the section D2 are different, it is determined whether or not the section D1 and the section D3 are equal. In this way, it is determined in order whether or not the distance between the section at the incident end and the event occurrence point is equal until the event occurrence points having the same interval are detected.

When a section D6 having the same distance as the section D1 is detected, the section D2 immediately after the section D1 and the section D5 immediately before the section D6 are equal, and the section D3 and the section D5 immediately after the section D2 It is determined whether or not the previous section D4 is equal. In the configuration shown in FIG. 16, the section D2 and the section D5 are equal, and the section D3 and the section D4 are equal. As a result, the turning point detection unit 25 sets the distance of each section (D2, D3) sequentially located from the section D1 to the section D6 side and the distance of each section (D5, D4) sequentially located from the section D6 to the section D1 side. Determine if they are equal to each other.

When the distance of each section (D2, D3) and the distance of each section (D5, D4) are equal to each other, the distance P4 which is the intermediate point between the section D1 and the section D6, that is, the event occurrence point between the distance P2 and the distance P6. Is determined as a turning point.

That is, the distance P4 is a turning point of the optical fiber forming the distance P1 to the distance P7. Subsequently, the turning point detection unit 25 determines whether or not the distances from the previous distances P4 to P7 are equal for the section D7 and thereafter. For example, the section D4 is set as a new first section.

In FIG. 16, section D4 and section D9 are equal. In this case, it is determined whether or not the section D5 and the section D8 are equal and the section D6 and the section D7 are equal. In the configuration shown in FIG. 16, the section D4 and the section D9 are equal, the section D5 and the section D8 are equal, and the section D6 and the section D7 are equal. As a result, the turning point detection unit 25 determines that the middle point between the section D4 and the section D9, that is, the distance P7, which is the event occurrence point between the distance P5 and the distance P9, is the turning point.

That is, the distance P7 is a turning point of the optical fiber forming the distance P4 to the distance P10. Subsequently, the turning point detection unit 25 determines whether or not the distances from the previous distances P7 to P10 are equal for the section D10 and thereafter.

For example, it is determined whether or not the section D7 and the section D12 are equal, the section D8 and the section D11 are equal, and the section D9 and the section D10 are equal. In the configuration shown in FIG. 16, the section D7 and the section D12 are equal, the section D8 and the section D11 are equal, and the section D9 and the section D10 are equal. As a result, the turning point detection unit 25 determines that the middle point between the section 7 and the section D12, that is, the distance P10, which is the event occurrence point between the distance P8 and the distance P12, is the turning point.

In this way, when the sections D1 and D6, the sections D4 and D9, the sections D7 and the section D12 having the same distance are detected, whether or not the distances between the sections D1 to D3 and the sections D4 to D6 are equal, the sections D4 to D4 to It is determined whether or not the turning point is based on whether or not the distances between D6 and the sections D7 to D9 are equal, and whether or not the distances between the sections D7 to D9 and the sections D10 to D12 are equal.

After determining the section D12, which is the last section, the turnaround point detection unit 25 identifies the even-numbered optical fiber using the specified turnaround point. For example, in FIG. 16, the distances P4, P7, and P10 are determined to be turning points. The distance P4 to the distance P7, that is, the sections D4 to D6 starting from the first turning point, which is an odd number, is determined to be the second optical fiber 32-3, 32-2, 32-1, and is an odd number. The distance P10 to the distance P13, that is, the sections D10 to D12 starting from the third turning point are determined to be the fourth optical fibers 34-3, 34-2, 34-1.

Next, as shown in FIG. 14, an odd number of optical fibers are laid side by side with a near end and a far end, and the near end or the far end of each optical fiber is connected to each other. An example of application to the above will be described. FIG. 17 shows an example of an OTDR waveform measured as an optical fiber to be measured as an example of the optical fiber cable shown in FIG. In this case as well, sections D1 and D6, sections D4 and D9 having the same distance are detected, and whether or not the distances between the sections D1 to D3 and the sections D4 to D6 are equal, the sections D4 to D6 and the sections D7 to D9 It is determined whether or not it is a turning point based on whether or not the distances of are equal.

In this case, the turning point detection unit 25 determines that the distances P4 and P7 are turning points. The distance P4 to the distance P7, that is, the sections D4 to D6 starting from the odd-numbered first turning point can be determined as the second optical fibers 32-3, 32-2, and 32-1.

The present embodiment shows an example in which the signal processing unit 12 according to the first embodiment includes a reflection detection unit 23 and a turnaround point detection unit 25, but the present disclosure is not limited to this. For example, the signal processing unit 12 described in the second embodiment may further include a reflection detection unit 23 and a turn-back point detection unit 25, and the signal processing unit 12 described in the third embodiment further includes a turn-back point detection unit 25. You may have.

It can be applied to the information and communication industry of the present disclosure.

10: Optical pulse test device 11: Measuring unit 12: Signal processing unit 13: Display unit 21: Waveform inversion unit 22: Waveform moving unit 23: Reflection detection unit 24: Icon inversion unit 25: Folding point detection unit 3: Optical fiber cable 31-1, 31-2, 31-3, 32-1, 32-2, 32-3, 33-1, 33-2, 33-3, 34-1, 34-2, 34-3: Optical fiber 35, 36: End 41: Antenna 42: Steel tower 5, 5-1, 5-2, 5-3: Optical fiber patch cord

Claims (6)

A plurality of optical fibers (31, 32, 33, 34) are laid side by side with a near end and a far end, respectively, and each optical fiber other than the near end of the first optical fiber of the plurality of optical fibers In one optical fiber in which the near ends or the far ends of the fiber are connected to each other, the near end of the first optical fiber is used as an incident end of an optical pulse, and the rear end of the optical fiber to be measured is used. A measuring unit (11) for measuring scattered light and
A reflection detection unit (23) that detects a light loss point from the measurement waveform measured by the measurement unit, and
From the sections between the light loss points, the first section and the second section having the same distance are detected, and each distance of each section located in order from the first section toward the second section side and the first section. When the distances of the sections located in order from the two sections toward the first section side are equal to each other, it is determined that the intermediate point between the first section and the second section is a turning point of the plurality of optical fibers. Folding point detection unit (25)
An optical pulse test device (10). Among the measurement waveforms measured by the measurement unit, the measurement waveforms of the even-numbered optical fibers starting from the odd-numbered turnaround point detected by the turnaround point detection unit are at the start point located at the far end and the near end. A waveform inversion unit (21) that inverts the positioned end points to each other to generate a first inverted waveform, and
A display unit (13) that displays the waveform generated by the waveform inversion unit, and
The optical pulse test apparatus according to claim 1. In the waveform inversion portion, the light intensity at the far end of the even-order optical fiber matches the light intensity at the near end of the even-order optical fiber, and the light intensity at the near end of the even-th optical fiber. The first inverted waveform is further inverted to generate a second inverted waveform so that the optical intensity of the optical fiber matches the optical intensity at the far end of the even-th optical fiber.
The optical pulse test apparatus according to claim 2. A waveform moving unit (22) for translating at least a part of the waveform displayed on the display unit on the light intensity axis is further provided.
The optical pulse test apparatus according to claim 3. The far end and the near end of the even-numbered optical fiber starting from the odd-numbered turning point detected by the turning point detection unit are specified, and the far end to the near end of the even-numbered optical fiber is specified. An icon inversion unit (24) that inverts the arrangement of light loss points to the arrangement of light loss points from the near end to the far end of the even-numbered optical fiber.
The light loss point at the near end of the plurality of optical fibers is on one side, and the light loss point at the far end of the plurality of optical fibers is on the other side, and the near end to the far end of the plurality of optical fibers. Display unit (13) that displays an icon in which the light loss points up to
The optical pulse test apparatus according to claim 1. The measuring unit (11) is laid side by side with a plurality of optical fibers (31, 32, 33, 34) having a near end and a far end, respectively, and is the first optical fiber of the plurality of optical fibers. The near end of the first optical fiber in one optical fiber to be measured in which the near ends or the far ends of each optical fiber other than the near end are connected to each other is used as an incident end of an optical pulse. A measurement procedure for measuring backscattered light in the optical fiber to be measured, and
A reflection detection procedure in which the reflection detection unit (23) detects a light loss point from the measurement waveform measured by the measurement unit, and
The turning point detection unit (25) detects the first section and the second section having the same distance from the sections between the light loss points, and is located in order from the first section toward the second section side. When each distance of each section and each distance of each section located in order from the second section toward the first section side are equal to each other, the intermediate point between the first section and the second section is set as the plurality of points. The turning point detection procedure that determines that it is the turning point of the optical fiber,
An optical pulse test method to perform.

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