JP2018169232A - Optical pulse testing device and method for testing optical pulse - Google Patents

Abstract

To make the correspondence easier to understand of the distance from the optical pulse testing device and the measured waveform of each optical fiber when an optical pulse testing is conducted by connecting the optical fibers of a multicore optical fiber cable to one another and making one optical fiber by the connected optical fibers.SOLUTION: The optical pulse testing device includes: a measurement unit for measuring back-scattered light in a measurement target optical fiber, the measurement target optical fiber having lined first optical fibers (31-1, 31-2, 31-3) and second optical fibers (32-1, 32-2, 32-3), each having a near end and a far end, the far ends of the first optical fibers being connected to the far ends of the second optical fibers; and a waveform reversion unit for reversing, in turn, the start point and the end point showing the far end and the near end of each of the second optical fibers ((32-1, 32-2, 32-3), respectively, of the waveforms measured by the measurement unit and generating a first reversion waveform.SELECTED DRAWING: Figure 5

Description

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

  With the recent increase in communication demand, media that support communication has been replaced by optical fiber cables instead of coaxial cables. Optical fiber cables are used from the trunk line system to the access system, and are laid everywhere.

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

  A connector for measuring each optical fiber provided in an optical fiber cable at a time has been proposed (for example, see Patent Document 1). The connector of patent document 1 connects the optical fibers with which an optical fiber cable is equipped to one. As a result, a multi-fiber optical fiber cable can be measured as a single optical fiber by an optical pulse test apparatus.

JP 2013-238292 A

  When 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 apparatus and the measurement waveform of each optical fiber. Therefore, the present disclosure provides the distance from the optical pulse test apparatus and each optical fiber even when the optical pulse test is performed as one optical fiber by connecting the optical fibers provided in the multi-fiber optical fiber cable. The purpose is to make it easy to understand the correspondence with the measured waveform.

Specifically, the optical pulse test apparatus (10) of the present disclosure includes:
Both the first optical fiber (31) and the second optical fiber (32) are laid side by side with a near end and a far end, and the far end of the first optical fiber is the second light. A measuring unit (11) that measures the backscattered light in the measured optical fiber by using the near end of the first optical fiber in the measured optical fiber connected to the far end of the fiber as an incident end of an optical pulse. )When,
Of the measurement waveforms measured by the measurement unit, the measurement waveform of the second optical fiber is inverted between the start point and the end point indicating the far end and the near end of the second optical fiber, respectively. A waveform inversion unit (21) for generating a first inversion waveform;
Is provided.

  In the optical pulse testing device of the present disclosure, the waveform inversion unit has a light intensity at the far end of the second optical fiber that matches a light intensity at the near end of the second optical fiber, The first inversion waveform is further inverted so that the light intensity at the near end of the second optical fiber matches the light intensity at the far end of the second optical fiber, and the second inversion waveform is It may be generated.

  The optical pulse test apparatus according to the present disclosure may further include a display unit (13) that displays the waveform generated by the waveform inversion unit.

  The optical pulse test apparatus of the present disclosure may further include a waveform moving unit (22) that translates at least a part of the waveform displayed on the display unit in the light intensity axis.

Specifically, the optical pulse test method of the present disclosure includes:
The measurement unit (11) is constructed such that the first optical fiber (31) and the second optical fiber (32) are laid side by side with a near end and a far end, and the far end of the first optical fiber is arranged. Using the near end of the first optical fiber in the optical fiber to be measured having an end connected to the far end of the second optical fiber as an incident end of an optical pulse, backscattered light in the optical fiber to be measured Measuring procedure to measure
A waveform reversing unit (21), wherein the measurement waveform of the second optical fiber of the measurement waveforms measured by the measurement unit is a starting point indicating the far end and the near end of the second optical fiber, respectively; A waveform inversion procedure for inverting the end points with each other and generating a first inversion waveform;
Execute.

  In the optical pulse test method of the present disclosure, in the waveform inversion procedure, the light intensity at the far end of the second optical fiber matches the light intensity at the near end of the second optical fiber. The first inversion waveform is further inverted so that the light intensity at the near end of the second optical fiber matches the light intensity at the far end of the second optical fiber, and the second inversion waveform is It may be generated.

  In the optical pulse test method of the present disclosure, the display unit (13) may further include a display procedure for displaying the waveform generated by the waveform inversion unit.

  In the optical pulse test method of the present disclosure, the waveform moving unit (22) may further execute a waveform moving procedure for translating at least a part of the waveform displayed on the display unit on the light intensity axis.

  According to the present disclosure, even when each optical fiber included in a multi-core optical fiber cable is connected and the optical pulse test is performed as one optical fiber, the distance from the optical pulse test apparatus and each optical fiber This makes it easy to understand the correspondence with the measured waveform.

An application example of the optical fiber test method according to the present disclosure will be described. The 1st example of an optical fiber cable is shown. 1 is a configuration example of an optical pulse test apparatus according to Embodiment 1. It is a 1st example of a measurement waveform. It is an example of a 1st inversion waveform. It is an example of a 2nd inversion waveform. It is a 2nd example of a measurement waveform. It is two examples of the 1st inversion waveform. It is two examples of the 2nd inversion waveform. The 2nd example of an optical fiber cable is shown. 3 is a configuration example of an optical pulse test apparatus according to a second embodiment. It is an example of a movement of the 2nd inversion waveform.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, this indication is not limited to embodiment shown below. These embodiments are merely examples, and the present disclosure can be implemented in various modifications and improvements based on the knowledge of those skilled in the art. In the present specification and drawings, the same reference numerals denote 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 the present embodiment, a case where two optical fibers are provided in an optical fiber cable will be described. An optical pulse test apparatus is an apparatus that measures the characteristics of an optical fiber cable by measuring an OTDR (Optical Time Domain Reflectometer) waveform. The OTDR waveform is obtained by making an optical pulse incident from the incident end of the optical fiber and measuring the light intensity of backscattered light scattered in the optical fiber at the incident end.

(Embodiment 1)
FIG. 1 shows an application example of an optical fiber test method according to the present disclosure. An antenna 41 is provided on the steel tower 42, and the optical fiber cable 3, which is a multi-core optical fiber cable, is laid 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 fiber testing method of the present disclosure, an optical fiber cable 3 in which two optical fibers are connected by a patch cord at the end 36 is an 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 apparatus 10 is connected to 35 and the optical pulse test of the optical fiber cable 3 is performed.

  FIG. 2 shows an example of the optical fiber cable 3. The optical pulse test apparatus 10 is connected to the end portion 35 of the optical fiber 31 of the two optical fibers 31 and 32, and the end portion 36 of the optical fiber 31 and the end portion 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 a time.

In the following embodiment, the end 35 is referred to as the near end, the end 36 is referred to as the far end, and the optical fibers 31 and 32 are connected at two connection points C _A and C _B. . Moreover, although the length of the optical fiber patch cord 5 is arbitrary, for example, a cord of about 10 m can be used.

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

  In the optical pulse test method according to the present embodiment, the optical pulse test apparatus 10 sequentially executes a measurement procedure, a waveform inversion procedure, and a display procedure. In the measurement procedure, the measurement 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 apparatus 10.

  FIG. 4 shows an example of the OTDR waveform obtained by the measurement procedure. The distances P1 to P4 indicate the measurement results of the optical fiber 31, and the distances P5 to P8 indicate the measurement results of the optical fiber 32. In the OTDR waveform, the reflection at the near end of the optical fiber 32 is located at the distance P8, and the reflection at the far end of the optical fiber 31 is located at the distance P4. Therefore, the OTDR waveform is displayed on the display unit 13 so that the near end of the optical fiber 32 exists 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 on the distance axis of the OTDR waveform of the optical fiber 32. The starting point of the optical fiber 32 is a distance P5 located at the far end of the optical fiber 32. The end point of the optical fiber 32 is a distance P8 located at the near end of the optical fiber 32. Therefore, the waveform inversion unit 21 inverts 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 second optical fiber 32. Let FIG. 5 shows an example of the first inverted waveform. In the first inverted waveform, the reflection position at the distance P8 among the distances P5 to P8 matches the distance P1, and the reflection position at the distance P5 among the distances P5 to P8 matches the distance P4. Thus, the OTDR waveform of the optical fiber 32 in the first inverted waveform matches the actual position of the optical fiber 32.

  Here, the near end and the far end of the optical fiber 32 may be specified using the lengths of the optical fibers 31 and 32, or may be specified using the length of the optical fiber patch cord 5. By acquiring the length of the optical fiber to be measured, the connection position of the optical fiber patch cord 5 can be specified. Also, by acquiring the length of the optical fiber patch cord 5, the position of the optical fiber patch cord 5 on the distance axis of the OTDR waveform can be specified.

  Since the light intensity of the first inverted waveform decreases by ΔL from the distance P4 to P1, the direction of decrease of the light intensity is different from the OTDR waveform when the light 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 obtained by mirror-inversion of the first inversion waveform 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. It matches the light intensity. That is, the light intensity L1 at the turning point between the optical fibers 31 and 32 in the first inversion waveform is the light intensity L2, and the light intensity L2 at the distance P1 in the first inversion waveform is the light intensity L1. As a result, the second inverted waveform is an OTDR waveform similar to that obtained when an optical pulse is incident from the near end of the optical fiber 32 in which the light intensity decreases by ΔL from the distance 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 apparatus 10 measures the first inverted waveform obtained by dividing the optical fiber 31 and the optical fiber 32 at half positions (positions of the optical fiber patch cord 5) as if they were measured once each. Display as a result. The OTDR waveform of the optical fiber 32 in the first inversion waveform matches the actual position of the optical fiber 32. For this reason, the optical pulse test apparatus 10 can halve the measurement time and obtain a desired measurement result.

  Further, the second inversion waveform is the same waveform as that obtained when the OTDR measurement of the optical fiber 31 and the optical fiber 32 is performed individually. For this reason, it becomes easy to compare the OTDR waveforms of the optical fiber 31 and the optical fiber 32. The optical pulse test apparatus 10 may be capable of displaying the OTDR waveform before processing shown in FIG.

  Although FIG. 4 shows an example in which the optical fiber patch cord 5 is long enough to identify the distances P4 and P5 at both ends of the optical fiber patch cord 5, the present disclosure is not limited to this. For example, as shown in FIG. 7, since the optical fiber patch cord 5 is short, the reflection at the distance P5 is buried in the reflection at the distance P4 and cannot be identified. In this case, the first inverted waveform is as shown in FIG. 8, and the second inverted waveform is as shown in FIG.

  Further, the folding position on the optical fiber patch cord 5 may be an intermediate distance from the distance P4 to the distance P5 (FIG. 5) or the distance P4 (FIG. 8).

  Further, when displaying the OTDR waveform, the first inverted waveform, or the second inverted waveform on the display unit 13, each of the optical fibers 31-1, 31-2, 31-3, 32-1, 32-2, 32. The loss at -3 may be displayed.

  Further, the number of optical fibers constituting the optical fiber cable 3 is arbitrary. For example, as shown in FIG. 10, when four optical fibers 31, 32, 33, 34 are provided, the far ends of the optical fibers 31 and 32 are connected by an optical fiber patch cord 5-1, and the optical fibers 32 and 33 are connected. The optical fiber patch cord 5-2 may be used to connect the near ends of the optical fibers 33 and the remote ends of the optical fibers 33 and 34 may be connected using the optical fiber patch cord 5-3. In this case, in the waveform inversion procedure, the waveform inversion unit 21 does not invert the OTDR waveforms of the optical fibers 31 and 33 that are connected oddly from the optical pulse test apparatus 10, and the optical fibers 32 that are connected evenly. And 34 OTDR waveforms are inverted.

(Embodiment 2)
FIG. 11 shows an example of an optical pulse test apparatus according to this embodiment. In the optical pulse test apparatus 10 according to the present embodiment, the signal processing unit 12 further includes a waveform moving unit 22. The optical pulse test method according to the present embodiment further includes a waveform moving procedure after the waveform inversion procedure.

  In the waveform moving procedure, the waveform moving 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, the first or second inverted waveform. At least a part of the waveform is, for example, an OTDR waveform of the optical fiber 31 or 32, or a part thereof. The translation may be in the distance axis direction, in the light intensity axis direction, or in both of these directions. Although the moving method is arbitrary, 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. 12, the second inverted waveform is translated on the light intensity axis. Thereby, by comparing 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 light loss in the optical fiber 31 and the state of light loss in the optical fiber 32. Can be.

  As described in the above-described embodiments, the optical pulse test apparatus 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 connect one optical fiber. Even when the optical pulse test is performed as a fiber, it is possible to display the correspondence between the distance from the optical pulse test apparatus 10 and the OTDR waveform of each of the optical fibers 31 and 32.

  Even in the case of three or more, the end portions 35 and 36 of the respective optical fibers are connected by the optical fiber patch cord 5 to form one fiber, and the measurement is performed once, and the configuration information is converted into the optical pulse. By inputting to the test apparatus 10, the measurement result is divided from the result of each optical fiber cable 3, and it becomes possible to perform efficient work by storing and reporting.

  Moreover, although the above embodiment has been described as laying one multi-fiber optical fiber cable 3 including the optical fibers 31 and 32, the present disclosure is not limited to this, and the present disclosure is independent of each other. Needless to say, the present invention is applicable even when two optical fibers are laid side by side.

  The present disclosure can be applied to the information communication industry.

10: Optical pulse test device 11: Measuring unit 12: Signal processing unit 13: Display unit 21: Waveform reversing unit 22: Waveform moving unit 3: Optical fiber cables 31-1, 31-2, 31-3, 32-1 32-2, 32-3, 33, 34: Optical fiber 35, 36: End 41: Antenna 42: Steel tower 5, 5-1, 5-2, 5-3: Optical fiber patch cord

Claims (8)

Both the first optical fiber (31) and the second optical fiber (32) are laid side by side with a near end and a far end, and the far end of the first optical fiber is the second light. A measuring unit (11) that measures the backscattered light in the measured optical fiber by using the near end of the first optical fiber in the measured optical fiber connected to the far end of the fiber as an incident end of an optical pulse. )When,
Of the measurement waveforms measured by the measurement unit, the measurement waveform of the second optical fiber is inverted between the start point and the end point indicating the far end and the near end of the second optical fiber, respectively. A waveform inversion unit (21) for generating a first inversion waveform;
An optical pulse test apparatus (10) comprising: The waveform inverting unit
The light intensity at the far end of the second optical fiber matches the light intensity at the near end of the second optical fiber, and the light intensity at the near end of the second optical fiber is equal to the first intensity. Further inverting the first inverted waveform to match the light intensity at the far end of the two optical fibers to generate a second inverted waveform;
The optical pulse test apparatus according to claim 1. A display unit (13) for displaying the waveform generated by the waveform inversion unit;
The optical pulse test apparatus according to claim 1 or 2. A waveform moving unit (22) for translating at least a part of the waveform displayed on the display unit in the light intensity axis;
The optical pulse test apparatus according to claim 3. The measurement unit (11) is constructed such that the first optical fiber (31) and the second optical fiber (32) are laid side by side with a near end and a far end, and the far end of the first optical fiber is arranged. Using the near end of the first optical fiber in the optical fiber to be measured having an end connected to the far end of the second optical fiber as an incident end of an optical pulse, backscattered light in the optical fiber to be measured Measuring procedure to measure
A waveform reversing unit (21), wherein the measurement waveform of the second optical fiber of the measurement waveforms measured by the measurement unit is a starting point indicating the far end and the near end of the second optical fiber, respectively; A waveform inversion procedure for inverting the end points with each other and generating a first inversion waveform;
Perform light pulse test method. In the waveform reversal procedure, the light intensity at the far end of the second optical fiber matches the light intensity at the near end of the second optical fiber, and at the near end of the second optical fiber. The first inversion waveform is further inverted so that the light intensity of the second optical fiber matches the light intensity at the far end of the second optical fiber, thereby generating a second inversion waveform.
The optical pulse test method according to claim 5. The display unit (13) further includes a display procedure for displaying the waveform generated by the waveform inversion unit.
The optical pulse test method according to claim 5 or 6. The waveform moving unit (22) further executes a waveform moving procedure for translating at least a part of the waveform displayed on the display unit in the light intensity axis.
The optical pulse test method according to claim 7.

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