JP2011069721A - Splitter module, detection method for remaining optical connector using the same, detection method of number of output ports, and optical transmission loss measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a splitter module for producing time difference in light signal transmission in a plurality of optical fiber transmission lines. <P>SOLUTION: The splitter module 7 includes: a light splitter 23 for branching a light signal input to an input terminal 29, and outputting the light signal to output terminals 31<SB>1</SB>to 31<SB>8</SB>; output ports 25<SB>1</SB>to 25<SB>8</SB>each in which an insertion opening is formed at one end, an optical connector 33 being to be inserted into the insertion opening; and optical fiber transmission lines 27<SB>1</SB>to 27<SB>8</SB>for optically connecting the respective output terminals 31<SB>1</SB>to 31<SB>8</SB>and the respective output ports 25<SB>1</SB>to 25<SB>8</SB>. The optical fiber transmission lines 27<SB>1</SB>to 27<SB>8</SB>are different in optical path length. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a splitter module, a method for detecting a remaining optical connector using the splitter module, a method for detecting the number of output ports, and an optical transmission loss measurement system.

  2. Description of the Related Art Conventionally, a splitter module that is used in an optical subscriber network construction method, for example, a PON (Passive Optical Network) or the like and distributes an optical signal is known (see Patent Document 1 below). The splitter module is provided between an OLT (Optical Line Terminal) as a base station and ONUs (Optical Network Units) of a plurality of user stations so that a plurality of ONUs can receive optical signals transmitted from the OLT. The optical signal is used to branch an optical signal into a plurality of optical signals using an optical splitter and a plurality of optical fiber transmission lines optically connected to the optical splitter.

NTT Technical Journal, December 2006, “R & D that contributes to the economic and responsiveness of optical services” (5) Aerial optical closure

  However, in the splitter module described in Patent Document 1, since there is no difference in optical path length between the plurality of optical fiber transmission lines, it is impossible to cause a time difference in optical signal transmission between the plurality of optical fiber transmission lines. . Therefore, various applications using the time difference in the transmission are also impossible.

  The present invention has been made to solve the above-described problems, and provides a splitter module capable of causing a time difference in optical signal transmission in a plurality of optical fiber transmission lines in the splitter module. Objective.

  The splitter module according to the present invention includes an optical splitter that branches an optical signal input to an input terminal and outputs the branched optical signal to a first output terminal and a second output terminal, and an insertion port into which an optical connector is inserted at one end. A first optical path that optically connects the first output port and the second output port, a first output terminal and the first output port, and a second optical path that optically connects the second output terminal and the second output port; The optical path lengths of the first optical path and the second optical path are different from each other.

  In the splitter module according to the present invention, since the optical path lengths of the first optical path and the second optical path are different from each other, the distances from the output terminal of the optical splitter to the first output port and the second output port are different from each other. Thereby, it is possible to cause a difference in the time from when an optical signal, for example, pulse test light is input to the input terminal of the optical splitter until it reaches each of the first and second output ports. Similarly, it is possible to cause a difference in the time until the pulse test light that has reached the first and second output ports is reflected by the first and second output ports and reaches the optical splitter.

  Further, a method for detecting a residual optical connector according to the present invention is a method for detecting a residual optical connector using the above-described splitter module, wherein the pulse test light is propagated to the splitter module and backscattering that occurs during the propagation is performed. Data on temporal change of light intensity is obtained, and based on the position and intensity of reflection of the pulse test light by the first output port and the second output port in the temporal change data of the intensity of backscattered light, the first It is detected whether or not the optical connector is left at the insertion port of each of the output port and the second output port.

  According to the detection method of the remaining optical connector according to the present invention, the pulses generated by the first output port and the second output port in the temporal change data of the intensity of the backscattered light due to the optical path length difference between the first optical path and the second optical path. It is possible to distinguish the reflection of the test light. Further, when the optical connector is inserted into the insertion port of the first and second output ports, the height of the reflected signal is small. On the other hand, when the optical connector is not inserted, the height of the reflected signal increases due to Fresnel reflection. Therefore, it is possible to detect whether or not an optical connector is connected to each output port based on the position and magnitude of reflection in the temporal change data of the intensity of backscattered light. As a result, unnecessary optical connectors are left behind. It can be detected whether or not. Here, the backscattered light means light that is reflected or scattered by the pulse test light propagated to the splitter module and returns in the direction opposite to the propagation direction.

  A method for detecting the number of output ports according to the present invention is a method for detecting the number of output ports using the splitter module described above, wherein the pulse test light is propagated to the splitter module, and backscattering that occurs during the propagation is performed. Data of temporal change in light intensity is monitored, and the number of output ports of the splitter module including the first output port and the second output port is detected based on the monitoring result.

  According to the method for detecting the number of output ports according to the present invention, the output port of the splitter module to be detected can be monitored by monitoring the temporal change data of the intensity of the backscattered light without confirming the installation status in the field. , That is, the number of light branches by the splitter module can be easily detected.

  An optical transmission loss measurement system according to the present invention is laid between a base station and a user station, and includes an optical transmission unit including the splitter module according to claim 1, and an optical transmission from the base station toward the user station. A pulse test light to be propagated to the transmission unit, receiving back scattered light generated in the light transmission unit, and obtaining data of temporal change in the intensity of the back scattered light, and The optical transmission loss of the optical transmission unit is measured based on the reflection intensity of the pulse test light from the first output port and the second output port in the data of the temporal change in the intensity of the backscattered light.

  In the optical transmission loss measurement system according to the present invention, the optical path lengths of the first and second optical paths are different from each other, and therefore, according to the first output port and the second output port in the data of temporal change in the intensity of the backscattered light, respectively. Using a splitter module in which the influence of the pulse test light can be distinguished, the optical transmission loss of the optical transmission unit is measured in more detail by monitoring the intensity of the reflection of the pulse test light by the first output port and the second output port. be able to.

  ADVANTAGE OF THE INVENTION According to this invention, the splitter module which can produce the time difference in transmission of the optical signal in a some optical fiber transmission line can be provided.

It is the schematic which shows the structure of the optical transmission loss measuring system which concerns on this embodiment. The data of the time change of the intensity | strength of the backscattered light acquired in the measuring apparatus of FIG. 1 are shown. It is a figure which shows the optical transmission loss measuring system using the conventional splitter module. The data of the time change of the intensity | strength of the backscattered light acquired by the measuring apparatus of FIG. 3 are shown. It is a figure for demonstrating the detection operation of the remaining optical connector by this optical transmission loss measuring system. It is a figure for demonstrating the detection operation of the remaining optical connector by this optical transmission loss measuring system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic diagram illustrating a configuration of an optical transmission loss measurement system 1 according to the present embodiment. As shown in FIG. 1, in the optical transmission loss measurement system 1 according to the present embodiment, between a base station (center station) 3 and user stations (subscriber stations) 5 _{1 to} 5 ₈ which are a plurality of terminal stations. The optical transmission unit 9 including the splitter module 7 transmits and receives signal light. The optical transmission loss measurement system 1 includes an optical transmission unit 9, reflection means 11 and 13, an optical multiplexer / demultiplexer 15, and a measurement device 17.

The optical transmission unit 9 optically connects the splitter module 7, the optical fiber transmission path 19 that optically connects the base station 3 and the splitter module 7, and the splitter module 7 and the user stations 5 _{1 to} 5 _8. having an optical fiber transmission path ₂₁ 1 to 21 _8.

The splitter module 7 includes an optical splitter 23, output ports 25 _{1 to} 25 ₈ and optical fiber transmission lines 27 _{1 to} 27 ₈ . Optical splitter 23, an optical signal input to the input terminal 29 by an optical fiber transmission line 19, for example 8 branched and is output to the output terminal ₃₁ 1 to 31 _8. Each output port 25 ₁ to 25 _8, the insertion opening is formed in one end, the optical fiber transmission line 21 ₁ to 21 ₈ optical connector 33 provided on each end is inserted into each insertion opening . Output terminals ₃₁ 1 to 31 ₈ and the output port ₂₅ 1 to 25 ₈ of the optical splitter 23 is an optical path length is optically connected by different optical fiber transmission line ₂₇ 1-27 ₈ together.

  The measuring device 17 outputs pulse test light to be propagated to the optical fiber transmission line 19 and receives backscattered light of the test light that has arrived from the optical fiber transmission line 19, and temporally measures the intensity of the backscattered light. Get change data. The optical multiplexer / demultiplexer 15 is provided on the optical fiber transmission line 19, couples the pulse test light output from the measuring device 17 to the optical fiber transmission line 19, and reaches the back scattered light that has reached the optical fiber transmission line 19. Is coupled to the measuring device 17.

The reflecting means 11 is provided immediately before the input terminal 29 of the splitter module 7, and transmits the test light from the measuring device 17 and the signal light from the base station 3 that reach the optical fiber transmission path 19 to the splitter module 7. . Further, the reflecting means 11 transmits the backscattered light of the test light that has reached by the splitter module 7 to the optical fiber transmission line 19. Reflecting means 13 is disposed directly in front of each user station 5 ₁ to 5 ₈ receives the signal light and test light arriving been transmitted by the optical fiber transmission line 21 ₁ to 21 _8, of which the signal light Is transmitted to the user stations 5 _{1 to} 5 ₈ and the test light is reflected.

The optical transmission loss measurement system 1 operates as follows. The test light output from the measuring device 17 reaches the reflecting means 11 through the optical multiplexer / demultiplexer 15, and a part of the reached test light is reflected. The backscattered light due to this reflection is transmitted in the reverse direction through the optical fiber transmission line 19 and reaches the measuring device 17. Test light transmitted through the reflecting means 11, 8 is branched by the optical splitter 23, the branch pulse test light is transmitted by the optical fiber transmission line 27 _{1-27 8} in which the optical path lengths are different from each other output port of the splitter module 7 25 _{1 to} 25 ₈ are reached. Some of reaching the output port ₂₅ 1 to 25 ₈ test light is reflected by the connection between the optical connectors 33 are inserted into the respective output ports ₂₅ 1 to 25 _8. The backscattered light due to this reflection is transmitted in the reverse direction by the splitter module 7 and the optical fiber transmission path 19 and reaches the measuring device 17.

Test light transmitted through the output port ₂₅ 1 to 25 ₈ reaches the reflecting means 13 provided in each of the immediately preceding user station ₅ 1 to 5 ₈ by an optical fiber transmission path ₂₁ 1 to 21 _8, the reflection Reflected by means 13. The backscattered light due to this reflection is transmitted in the reverse direction by the optical fiber transmission lines 21 _{1 to} 21 ₈ , the splitter module 7 and the optical fiber transmission line 19, and reaches the measuring device 17. Further, backscattered light due to Rayleigh scattering of the test light at each point on the light transmission unit 9 is also transmitted in the reverse direction and reaches the measuring device 17. The measurement device 17 receives backscattered light that has been reflected or scattered and receives data of temporal change in the intensity of the backscattered light.

FIG. 2 shows data of temporal changes in the intensity of backscattered light acquired by the measuring device 17. In FIG. 2, the horizontal axis indicates the position on the optical transmission unit 9 (that is, the elapsed time from the time when the test light is output from the measuring device 17), and the vertical axis indicates the power of the backscattered light of the test light. Show. As shown in FIG. 2, the peak A of the reflected light generated by reflecting the test light in the optical multiplexer / demultiplexer 15, the peak B of the reflected light generated by reflecting the test light in the reflecting means 11, The measurement device 17 observes the peak C of the reflected light generated by the test light reflected at the output ports 25 _{1 to} 25 ₈ and the peak D of the reflected light generated by the test light reflected at each reflecting means 13. The The optical transmission loss measurement system 1 includes an optical transmission unit 9 between the base station 3 and the user poles 5 _{1 to} 5 ₈ based on the magnitudes of the peaks A to D in the temporal change data of the intensity of the backscattered light. The optical transmission loss of each optical path in is measured.

The peak C of the light reflected by the output port ₂₅ 1 to 25 ₈ corresponds to the reflection caused by the output port ₂₅ 1 to 25 ₈ are constituted by eight peaks _C 1 -C ₈ which are distinguished from each other. This optical transmission loss measuring system 1, the number of branches of the peak _C n (n = 1,2,3 ...) splitter module 7 the number of which constitutes the peak C, that the output terminal ₂₅ n (n = 1,2,3 ...) can be calculated. The optical path length difference of the optical fiber transmission line ₂₇ 1-27 ₈ is longer than the resolution of the measuring device 17.

FIG. 3 is a schematic diagram showing a configuration of an optical transmission loss measurement system 1A using a conventional splitter module 7A. The optical transmission loss measurement system 1 </ b> A is the same as the optical transmission loss measurement system 1 except for the splitter module 7. Splitter module 7A, all of the optical path length of the optical fiber transmission line 27 _{1-27 8} differs from the splitter module 7 at the point which is the same length. FIG. 4 shows data of temporal change in the intensity of the backscattered light acquired by the measuring device 17 of the optical transmission loss measuring system 1A of FIG. In FIG. 4, the horizontal axis indicates the position on the optical transmission unit 9, and the vertical axis indicates the power of the backscattered light of the test light.

As shown in FIG. 4, in the measuring device 17 of the optical transmission loss measurement system 1A, the optical demultiplexer 15, reflecting means 11, the output port 25 ₁ to 25 ₈ and the test light at each of the reflecting means 13 The peak A, peak B, peak C, and peak D of the reflected light generated by the reflection are observed. However, the peak C due to the output ports 25 _{1 to} 25 ₈ is composed of one peak, and reflections occurring at the respective output ports in the data of temporal change in the intensity of the backscattered light are overlapped, and the influence of each reflection is distinguished. Can not.

Next, the detection operation of the remaining optical connector by the present optical transmission loss measurement system 1 provided with the splitter module 7 will be described with reference to FIGS. Figure 5 is a diagram illustrating a case where the optical connector 33 to the output port 25 ₂ and 25 ₄ in the optical transmission loss measuring system 1 of Figure 1 is not inserted. FIG. 6 shows data of temporal changes in the intensity of backscattered light acquired by the measuring device 17 of the optical transmission loss measuring system 1 in FIG. As shown in FIG. 6, each of the peaks A to D similar to those in FIG. 2 is obtained by the measuring device 17 in FIG. 5, and the peak C corresponds to each of the output ports 25 _{1 to} 25 _{8 of the} splitter module 7. it can be seen that consists peak _C 1 -C ₈ to.

However, since the optical connectors 33 are inserted into all of the output ports 25 _{1 to} 25 ₈ , the optical connectors 33 are inserted in FIG. 6 unlike FIG. 2 where the peaks C _{1 to} C ₈ have the same height. Differences occur in the heights of the peaks C _{1 to} C ₈ depending on whether or not they are set. Specifically, the output ports 25 ₂ and 25 ₄ into which the optical connector 33 is not inserted have peaks C ₂ and C ₄ having a large height due to Fresnel reflection. On the other hand, the peak due to the other output terminal into which the optical connector 33 is inserted has a smaller peak height due to reflection when the optical connector 33 is inserted into the insertion port of the output port. As described above, the optical transmission loss measurement system 1 detects whether or not the optical connector 33 is connected based on the difference in the reflection height of the test light from the output ports 25 _{1 to} 25 ₈ , and an unnecessary optical connector is left behind. Detect whether or not.

In splitter module 7 according to the present embodiment, since the optical path length of the optical fiber transmission line ₂₇ 1-27 ₈ are different from each other, the distance from the output terminal ₃₁ 1 to 31 ₈ of the optical splitter 23 to the output port ₂₅ 1 to 25 ₈ Different from each other. Accordingly, it is possible to cause a difference in the time from when the pulse test light is input to the input terminal 29 of the optical splitter 23 until it reaches each of the output ports 25 _{1 to} 25 ₈ .

Further, it is possible to produce a difference in time of the backscattered light due to reflection of the pulse test light at the output port ₂₅ 1 to 25 ₈ from the output port ₂₅ 1 to 25 ₈ to reach the optical splitter 23. Therefore, to obtain the data of the temporal change in the intensity of the backscattered light, by monitoring the position and height of the reflected test light by the output port 25 ₁ to 25 ₈ in the data, during production of the splitter module 7 And the type and management number of the splitter module 7 can be specified.

  Further, in the optical transmission loss measurement system 1 including the splitter module 7 having such an effect, the optical transmission loss of the optical transmission path is measured in more detail by analyzing the temporal change data of the intensity of the backscattered light. can do.

According to the optical transmission loss measuring system 1, the position and height of the reflection of the pulsed test light by the output port ₂₅ 1 to 25 ₈ can detect the presence or absence of the connection of the optical connector 33 at the output port ₂₅ 1 to 25 _8, the As a result, it is possible to detect whether or not an unnecessary optical connector 33 is left.

As described above, in the plurality of optical transmission loss measurement system 1A conventional splitter modules 7A without light path length difference is used between the optical path, the peak corresponding to reflection of the pulse test light by the output port 25 ₁ to 25 ₈ Due to the position and height of the optical connector, it is not possible to confirm the remaining of the optical connector. For example, it is necessary to confirm whether the optical connector remains in the field at the start or end of use of the PON service. However, in the optical transmission loss measurement system 1 in which the splitter module 7 of the present embodiment is used, for example, by analyzing the temporal change data of the intensity of the backscattered light on the base station side without checking on the spot. The presence of the remaining optical connector can be easily grasped without affecting the service to other user stations.

  Further, according to the optical transmission loss measurement system 1, data of temporal change in the intensity of backscattered light is monitored, and the output port can be easily determined by the number of peaks corresponding to the reflection of the pulse test light at the position of the output port. The number can be detected.

The present invention is not limited to the above embodiment, and various modifications are possible. For example, the splitter module 7 of the present embodiment has eight output ports 25 _{1 to} 25 ₈ and can branch an optical signal into eight, but can split an optical signal into seven or less or nine or more. Also good.

1 ... optical transmission loss measuring system, 7 ... splitter module, ₂₅ to 253 8 _... output port, ₂₇ 1-27 8 _... optical fiber transmission line, 29 ... input terminal, ₃₁ 1-31 8 _... output terminal, 23 ... light Splitter, 33, optical connector.

Claims (4)

An optical splitter for branching an optical signal input to the input terminal and outputting the branched optical signal to the first output terminal and the second output terminal;
A first output port and a second output port formed with an insertion port into which an optical connector is inserted at one end;
A first optical path for optically connecting the first output terminal and the first output port;
A second optical path for optically connecting the second output terminal and the second output port;
With
Splitter modules in which the optical path lengths of the first optical path and the second optical path are different from each other. A method for detecting a remaining optical connector using the splitter module according to claim 1,
Pulse test light is propagated to the splitter module to obtain temporal change data of the backscattered light intensity generated during the propagation, and the first output in the temporal change data of the backscattered light intensity. Whether the optical connector is left in the insertion port of each of the first output port and the second output port is detected based on the position and intensity of reflection of the pulse test light by the port and the second output port To detect the remaining optical connector. A method for detecting the number of output ports using the splitter module according to claim 1,
Pulse test light is propagated to the splitter module, data of temporal change in intensity of backscattered light generated during the propagation is monitored, and the first output port and the second output port are based on the monitoring result. A method for detecting the number of output ports that detects the number of output ports of the splitter module. An optical transmission unit that is laid between the base station and the user station and includes the splitter module according to claim 1,
Outputs pulse test light to be propagated from the base station to the user station to the optical transmission unit, receives backscattered light generated in the optical transmission unit, and measures the time of the intensity of the backscattered light. A measurement unit that obtains data on the change
With
Optical transmission for measuring optical transmission loss of the optical transmission unit based on the intensity of reflection of the pulse test light by the first output port and the second output port in the temporal change data of the intensity of the backscattered light Loss measurement system.

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