JP2013002811A - Light path testing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accomplish a light path testing system which reduces manufacturing costs and maintenance and management costs.SOLUTION: A light path testing system 1 comprises (n) pieces of light path side ports connected directly or indirectly to a light path group, (m) pieces of slave fiber selectors (1≤i≤m, (m) and (n) are arbitrary natural numbers) each having a tester side port connectable to any one of the (n) pieces of light path side ports, (n) pieces of light path side ports ((n) is an arbitrary natural number) connected to the light path group, (m) pieces of light path side ports connected to the tester side ports included in the (m) pieces of slave fiber selectors, one master fiber selector including a single tester side port connectable to any one of these (n+m) pieces of light path side ports, and a light path testing device connected to the single tester side port of the master fiber selector.

Description

  The present invention relates to an optical line test system used for testing an optical line.

  As the number of subscribers to the optical network has increased, it has become important to efficiently maintain the optical lines (optical fibers) constituting the access network. Non-Patent Document 1 describes an access network that can efficiently maintain an optical line by providing an optical line test device (OTM: Optical Test Module) in the accommodation station.

  The configuration of the access network described in Non-Patent Document 1 is shown in FIG. The access network 50 shown in FIG. 1 roughly includes an ONU (Optical Network Unit) 51 disposed in each home and an OLT (Optical Line Terminal) 52 disposed in the accommodation station through an optical fiber 53. It is an optical network realized by connecting. A plurality of ONUs 51 (not shown except for one) are connected to one OLT 52 via an optical splitter 59.

  As shown in FIG. 9 (a), a plurality of IDM racks including an IDM (Integrated Distribution Module) rack 54 and an IDM rack 54 'are arranged in the accommodation station (one base). It is drawn into one of the IDM racks. A demultiplexing coupler 55 is inserted into the optical fiber 53, and upstream (toward the OLT 52 from the ONU 51) and downstream (from the OLT 52 to the ONU 51) signal light are extracted from the two output ports of the demultiplexing coupler 55.

  There are IDM racks that contain the optical line test apparatus 10 '(IDM rack 54) and those that do not contain the optical line test apparatus 10' (IDM rack 54 '). The signal light extracted from the optical fiber 53 drawn into the IDM rack 54 that houses the optical line testing apparatus 10 ′ is passed through the fiber selector group 20 ′ housed in the IDM rack 54, and the optical line testing apparatus 10 ′. Is input. On the other hand, the signal light taken out from the optical fiber 53 drawn into the IDM rack 54 ′ that does not accommodate the optical line testing apparatus 10 ′ passes through the fiber selector group 20 ′ accommodated in the IDM rack 54 ′. This is input to the optical line testing apparatus 10 ′ accommodated in the IDM rack 54 described above.

  FIG. 9B shows a configuration example of the fiber selector group 20 ′ housed in the IDM rack 54 and the IDM rack 54 ′. As shown in FIG. 9B, in the IDM rack 54 (IDM rack 54 '), for example, one parent fiber selector 20'a and three child fiber selectors 20'b are accommodated. The parent fiber selector 20′a and the child fiber selector 20′b have about 2000 optical line side ports, and 1000 pairs (2000 lines) drawn from about 1000 optical fibers 53 to these optical line side ports. ) About a transmission optical fiber can be connected. In addition, the master fiber selector 20'a has three extension ports, and three slave fiber selectors 20'b can be connected to these extension ports. That is, when the fiber selector group 20 'is configured as shown in FIG. 9B, a maximum of about 4000 optical fibers 53 can be drawn into one IDM rack 54 (IDM rack 54').

  The optical line testing apparatus 10 'has an optical pulse test (OTDR: Optical Time Domain Reflectometer) function and an optical power measurement (OPM: Optical Power Meter) function. Here, the optical pulse test function refers to a function of generating pulsed light input to the optical fiber 53 and detecting the waveform of backscattered light of the pulsed light extracted from the optical fiber 53. The optical power measurement function refers to a function for detecting the power of an optical signal taken out from the optical fiber 53. The optical line test apparatus 10 ′ detects a physical failure in the optical fiber 53 based on the detected waveform of backscattered light and the power of the signal light. In order to prevent the test light (wavelength 1650 nm) emitted from the optical line test apparatus 10 ′ from entering the ONU 51 and the OLT 52, filters 57 to 58 for selectively blocking the test light are usually provided at both ends of the optical fiber 53. Inserted.

  In the access network described in Non-Patent Document 1, by using such an optical line test apparatus 10 ′, optical power measurement for a large number of optical fibers drawn into the IDM rack 54 and the IDM rack 54 ′ and The optical pulse test is realized.

  As a document disclosing the configuration of an optical line test apparatus having an optical pulse test function and an optical power measurement function, for example, Patent Document 1 is cited.

JP 2008-124573 A (published May 29, 2008)

"Economicization AURORA makes track maintenance more efficient! Development of optical test module (OTM)", [Online], [Search September 30, 2010], Internet <URL: http://times.ansl.ntt. co.jp/gijyutu/2003_06/Topic_02/index.html>

  As described above, a plurality of parent fiber selectors housed in each IDM rack are connected to the optical line testing apparatus described in Non-Patent Document 1. For this reason, the optical line testing apparatus described in Non-Patent Document 1 needs to include a measuring instrument termination selection device as a means for switching the parent fiber selector connected to the optical measuring instrument. Thereby, the problem that the manufacturing cost and maintenance cost of an optical-line testing apparatus will raise has arisen.

  This problem will be described more specifically with reference to FIGS. FIG. 10 is a block diagram showing the configuration of the optical line testing apparatus 10 ′ described in Non-Patent Document 1. As shown in the figure, the optical line test apparatus 10 ′ includes an optical measuring unit (OTU: Optical Test Unit) 100 ′ and a measuring instrument termination frame selector (FTES: Frame and Test Equipment Selector) 200 ′. The IDM rack 54 is housed together with the fiber selector group 20 '. The IDM rack 54 in which the optical line test apparatus 10 ′ is housed constitutes the optical line test system 1 ′ together with another IDM rack 54 ′ in which the optical line test apparatus 10 ′ is not housed.

  As shown in FIG. 10, a plurality of parent fiber selectors 20a 'housed in each IDM rack (IDM rack 54 and IDM rack 54') are connected to the optical line testing apparatus 10 '. The optical line testing apparatus 10 ′ selects which optical fiber drawn into which IDM rack is the test target, and for the optical fiber selected as the test target (hereinafter also referred to as “target optical fiber”), (1) Optical pulse test using pulsed light having a wavelength of 1650 nm (also referred to as “1650 nm optical pulse test”), (2) Optical pulse test using pulsed light having a wavelength of 1310 nm (also referred to as “1310 nm optical pulse test”) (3) Optical power measurement test for upstream signal light with a wavelength of 1310 nm (also referred to as “1310 nm optical power measurement test”), and (4) Optical power measurement test for downstream signal light with a wavelength of 1550 nm (“ Any test of “1550 nm optical power measurement test” is also performed.

  The optical measuring device 100 ′ includes an optical pulse tester 120 ′ and an optical power measuring device 130 ′ in order to perform these four types of test functions. The optical pulse tester 120 ′ is for performing an optical pulse test of 1650 nm and an optical pulse test of 1310 nm, and includes a branch coupler 122 ′, a light source 123 ′, a WDM coupler 124 ′, an avalanche photodiode (APD: Avalanche Photodiode) 125 ′, branch coupler 126 ′, and light source 127 ′. On the other hand, the optical power measuring device 130 ′ is for performing a 1310 nm optical power measurement test and a 1550 nm optical power measurement test, and may be configured by a photodiode (PD) 133 ′.

  Corresponding to a plurality of types of test functions, the optical measuring device 100 ′ includes a plurality of optical connectors (shown as white rectangles in FIG. 10). In the example shown in FIG. 10, three optical connectors C1 'to C3' correspond to this. Here, the optical connector C1 ′ is an optical connector for an optical pulse test of 1650 nm, the optical connector C2 ′ is an optical connector for an optical pulse test of 1310 nm, and the optical connector C3 ′ is an optical connector of 1310 nm and 1550 nm. This is an optical connector for a power measurement test.

  As described above, a plurality of parent fiber selectors 20a 'housed in each IDM rack are connected to the optical line testing apparatus 10'. Therefore, in the optical line test apparatus 10 ′, which IDM rack the optical fiber drawn into is selected as the test object, that is, the parent fiber selector 20a ′ accommodated in which IDM rack is set as the optical measuring device 100 ′. It is necessary to switch the connection. Furthermore, the optical measuring device 100 ′ has the four types of test functions described above. Therefore, in the optical line test apparatus 10 ′, which test function is to be used is selected, that is, the parent fiber selector 20a ′ is connected to which optical connector among the optical connectors C1 ′ to C3 ′ of the optical measuring device 100 ′. It is necessary to switch the connection. The measuring instrument termination rack selection device 200 ′ included in the optical line testing device 10 ′ has a configuration for this purpose.

  In the example illustrated in FIG. 10, the measuring instrument termination rack selection device 200 ′ includes a plurality of optical line side ports (PA1 to PA20) and a plurality of tester side ports (PB1 to PB6). As shown in FIG. 10, when the optical line test system 1 ′ includes five IDM racks (IDM rack 54 and IDM rack 54 ′), the sixth of the optical line side ports PA1 to PA20. Subsequent optical line side ports PA6 to PA20 can be omitted. As shown in FIG. 10, when the optical measuring device 100 ′ includes three optical connectors C1 ′ to C3 ′, the fourth and subsequent tester side ports among the tester side ports PB1 to PB6. PB4 to PB6 can be omitted.

  In each of the optical line side ports PA1 to PA20 included in the measuring instrument termination rack selection device 200 ′, a parent fiber selector 20′a housed in the same IDM rack 54 as the measuring instrument termination rack selection apparatus 200 ′, and others Any of the parent fiber selectors 20′a housed in the IDM rack 54 ′ can be connected. In the example shown in FIG. 10, the five master fiber selectors 20′a housed in the IDM rack 54 and the IDM rack 54 ′ are connected to the optical line side ports PA1 to PA5 of the measuring instrument termination rack selection device 200 ′. Yes.

  On the other hand, the tester side ports PB1 to PB3 included in the measuring instrument termination rack selecting device 200 'are connected to optical connectors C1' to C3 'included in the optical measuring instrument 100', respectively. A band pass filter 201 'that selectively transmits light having a wavelength of 1650 nm (pulse light and its backscattered light) is inserted into the optical fiber FB1 connected to the tester side port PB1. The optical fiber FB3 connected to the tester side port PB3 is branched into two optical fibers FB3a to FB3b by the WDM coupler 204 '. The optical fiber FB3a has a filter 202 ′ that selectively transmits light (signal light) having a wavelength of 1310 nm, and the optical fiber FB3b has a filter that selectively transmits light (signal light) having a wavelength of 1550 nm. 203 'are respectively inserted.

The measuring instrument termination rack selecting device 200 ′ is a test selected from among seven optical fibers (hereinafter referred to as “tester side optical fibers”) groups FB1 to FB6 connected to the tester side ports PB1 to PB6. The end of the tester side optical fiber corresponding to the function and 20 optical fibers connected to the optical line side ports PA1 to PA20 (hereinafter referred to as “optical line side optical fiber”) groups FA1 to FA20 were selected ( The optical fiber side optical fiber end corresponding to the optical fiber is connected. For example, when an optical pulse test of 1310 nm is performed on an optical fiber (for communication) connected to the optical line side port PA3 via the parent fiber selector 20a ′, the measuring instrument termination selection device 200 ′ The end of the tester side optical fiber FB2 connected to PB2 and the end of the optical line side optical fiber FA3 connected to the optical line side port PA3 are connected.
In this way, the measuring instrument termination rack selection device 200 ′ is used to connect any of the plurality of parent fiber selectors 20a ′ to any of the plurality of optical connectors C1 ′ to C3 ′ included in the optical measuring device 100 ′. It is necessary to have a fiber moving mechanism for moving the tester side optical fiber groups FB1 to FB6 and a fiber fixing mechanism for fixing the moved tester side optical fiber groups FB1 to FB6. .

  FIG. 11A shows a configuration example of the measuring instrument termination rack selection device 200 ′. In the measuring instrument termination rack selection device 200 ′ shown in FIG. 11 (a), a tester-side optical fiber corresponding to the selected test function and an optical line-side optical fiber corresponding to the selected (for communication) optical fiber; After the fiber moving mechanism (not shown) moves the tester-side optical fiber groups FB1 to FB6 so that they are placed on the common V-shaped groove, the pressing tool 205 ′ functioning as the fiber fixing mechanism is lowered to perform the test. The structure which press-fixes the apparatus side optical fiber group FB1-FB6 is employ | adopted.

  In general, such a fiber moving mechanism and a fiber fixing mechanism become more complex as the number of measuring instrument side optical fibers and optical line side optical fibers is increased, and high working accuracy is required. For example, in the configuration example shown in FIG. 11A, the tester side optical fiber corresponding to the selected test function and the optical line side optical fiber corresponding to the selected (for communication) optical fiber are common V-shaped. A fiber moving mechanism that moves the tester side optical fiber groups FB1 to FB6 with high accuracy so as to be placed on the groove is required. The pressing tool 205 ′ functioning as a fiber fixing mechanism is required to uniformly press all the tester side optical fibers FB 1 to FB 6. In the fiber selector 20a having one tester-side optical fiber PFB, such a requirement is not imposed on the pressing tool 205 that functions as a fiber fixing mechanism (see FIG. 11B). ).

  Thus, when the number of measuring instrument side optical fibers and optical line side optical fibers increases, the manufacturing cost of the measuring instrument termination rack selecting device increases. In addition, as the number of measuring instrument side optical fibers and optical line side optical fibers increases, the failure rate in the measuring instrument termination selection device increases and the reliability decreases. A rise is inevitable.

  The present invention has been made in view of the above problems, and the object thereof is to realize an optical line test system that does not require a measuring instrument termination selection device, and thus, the manufacturing cost of the optical line test system, and It is to reduce maintenance costs.

In order to solve the above problems, an optical fiber line testing system according to the present invention, n _i pieces of light roadside port that is directly or indirectly connected to the optical line group, and the n _i-number of beam roadside port M optical fiber selectors having a tester side port connectable to any one of (1 ≦ i ≦ m, m and _ni are arbitrary natural numbers), and n optical line side ports connected to the optical line group (N is an arbitrary natural number), can be connected to any one of the m optical line side ports connected to the tester side port of each of the m child fiber selectors, and any of these n + m optical line side ports One master fiber selector having a single tester side port and an optical line test apparatus connected to the single tester side port of the parent fiber selector, each connected to each of the child fiber selectors Optical line group, and It is characterized in that comprises an optical line testing apparatus for testing a selected target light path from the optical line group connected to Kioya fiber selector, a.

  According to the above configuration, the m child fiber selectors and the one parent fiber selector select a target optical line from the optical line group, and the selected target optical line is the one parent fiber selector. Is connected to the optical line testing apparatus via a single tester side port. That is, according to said structure, the test with respect to the object optical line selected from the optical line group can be performed, without using a measuring device termination stand selection apparatus.

  In this way, by performing a test on the target optical line selected from the optical line group without using the measuring instrument termination selection device, the optical transmission line can be compared with the conventional configuration having the measuring instrument termination selection device. The manufacturing cost and maintenance cost of the test system can be reduced.

  This is because the fiber selector normally includes a plurality of spare fibers, and therefore, with respect to the parent fiber selector, the m units are maintained while maintaining the number n of optical line side ports directly connected to the optical line group. It is easy to add m optical line side ports connected to each of the optical fiber selectors. The cost reduction due to the omission of the measuring instrument termination selection device is larger than the increase in manufacturing cost associated with the addition of these m optical line side ports, so that the manufacturing cost can be reduced as a whole. it can. In addition, even if an optical line side port is added to the master fiber selector, the failure rate hardly increases, so that maintenance costs can be reduced compared to the conventional configuration using the measuring instrument termination selection device. it can.

  Compared with the optical line test system described in Non-Patent Document 1, the optical line test system of the present invention has the following merits.

  In the optical line test system described in Non-Patent Document 1, the number of fiber selectors that can be directly connected to the optical line test apparatus is the number of light beams provided in the measuring instrument termination selection device built in the optical line test apparatus. It matches the number of roadside ports. Therefore, if you want to increase the number of fiber selectors connected to the optical line testing device, increase the number of optical line side ports provided in the measuring instrument termination selection device and increase the number of fiber selectors that can be directly connected to the optical line testing device. Need to increase.

  However, it is difficult to increase the number of fiber selectors that can be directly connected to the optical line testing device by increasing the number of optical line side ports provided in the measuring instrument termination selection device. This is because, since the measuring instrument termination selection device is built in the optical line testing device, the size cannot be increased in order to increase the number of optical line side ports.

  On the other hand, in the above configuration, the number of optical fiber selectors that can be directly connected to the optical line testing device matches the number of optical line side ports provided in the parent fiber selector that can be housed in the optical wiring module rack together with the optical line testing device. To do. Therefore, it is easy to increase the number of optical fiber selectors that can be connected to the optical line testing apparatus by increasing the number of optical line side ports provided in the optical fiber selector. Further, the size of the optical line testing apparatus can be reduced as compared with the optical line testing system described in Non-Patent Document 1.

  In addition, an optical line group and an optical line side port being indirectly connected means that an optical line side port is connected to an optical line group via optical components, such as an optical switch and a fiber selector, for example. Further, the direct connection between the optical line group and the optical line side port means that the optical line side port is connected to the optical line group using only an optical fiber without using such an optical component.

  Further, the optical line test system includes m−k + 2 optical wiring module racks that can accommodate k fiber selectors (k is a natural number smaller than m), and k−1 of the m child fiber selectors. For each of the m−k + 1 optical fiber selectors excluding the optical fiber selector, a plurality of optical line side ports connected to the optical line group, and a tester side port connected to the optical line side port of the optical fiber selector K-1 grandchild fiber selectors, and of the m child fiber selectors, the k-1 child fiber selectors are mounted on one optical wiring module rack together with the optical line testing device. Each of the m−k + 1 sub-fiber selectors, together with the k−1 grandchild fiber selectors, includes m−k + 1 optical wiring module racks. Are housed people, it is preferred.

  According to the above configuration, k−1 grandchild fiber selectors having a plurality of optical line side ports connected to the optical line group are connected to the optical line side ports of the m−k + 1 sub fiber selectors. Therefore, it is possible to perform a test on a target optical line selected from an optical line group including a larger number of optical lines without increasing the number of sub-fiber selectors.

  In addition, according to the above configuration, each of the parent fiber selectors housed in the m−k + 1 optical wiring module racks and one optical line testing device housed in the one optical wiring module rack. Therefore, the complexity of routing the optical fiber between the optical wiring module frames can be kept to a minimum.

  The optical line testing system includes L optical wiring module racks that can accommodate k fiber selectors (k is a natural number smaller than m, and L is a minimum natural number larger than (m + 1) / k). ), Of the m sub-fiber selectors, k-1 sub-fiber selectors are housed in one optical wiring module frame together with the optical line testing device, and of the m sub-fiber selectors Preferably, the m−k + 1 sub-fiber selectors excluding the k−1 sub-fiber selectors are housed in L−1 optical wiring module racks.

  According to the above configuration, the parent fiber selector and the child fiber selector can be efficiently distributed to the L optical wiring module racks.

  Compared to the optical line test system described in Non-Patent Document 1, the above configuration has the following merits.

  In the optical line test system described in Non-Patent Document 1, a configuration is adopted in which a fiber selector directly connected to the measuring instrument termination selection device is used as a parent fiber selector, and a plurality of child fiber selectors are connected to each parent fiber selector. In this case, since a three-level hierarchical structure including a measuring instrument termination selection device, a parent fiber selector, and a child fiber selector is configured, an increase in insertion loss is inevitable.

  On the other hand, in the above configuration, a two-level hierarchical structure including a parent fiber selector and a child fiber selector is generated, but compared with the above-described three-level hierarchical structure in the optical line test system described in Non-Patent Document 1. Therefore, insertion loss is small.

  Further, in the optical line test system, the optical line test apparatus includes an optical coupler in which a common port is directly or indirectly connected to a single tester side port of the parent fiber selector, and a first of the optical coupler. An optical pulse tester connected to one branching port for generating pulsed light to be input to the target optical line and detecting a waveform of the backscattered light of the pulsed light extracted from the target optical line A pulse tester; and an optical power measurement device connected to the second branch port of the optical coupler, the optical power measurement device measuring the power of the signal light extracted from the target optical line. It is preferable.

  According to the above configuration, it is possible to realize an optical line test apparatus in which the common port of the optical coupler is a single input / output port and both the optical pulse test and the optical power measurement can be performed. As described above, by adopting a configuration in which the common port of the optical coupler and the single tester side port of the parent fiber selector are connected, the measuring device termination selection device is not required, and the target Optical pulse tests and optical power measurements on optical lines can be performed. Therefore, compared with the optical line testing apparatus described in Non-Patent Document 1, it is possible to perform an optical pulse test and optical power measurement related to the target optical line with a configuration with low manufacturing cost and maintenance management cost.

  Moreover, according to said structure, the optical line test system of the nonpatent literature 1 which performed the switching of an optical pulse test and an optical power test by operating the fiber moving mechanism with which a measuring device termination stand selection apparatus is operated. In comparison, the time required for switching between the optical pulse test and the optical power test can be shortened.

  In addition, according to the above configuration, since the optical pulse test and the optical power measurement can be performed simultaneously, the time required for the optical line test can be further shortened.

  Note that the common port of the optical coupler and the tester side port of the parent fiber selector are indirectly connected, for example, these ports are optical parts such as optical switches (however, the measuring instrument termination selection device is installed). It is connected through (except). In addition, the common port of the optical coupler and the tester side port of the parent fiber selector are directly connected to each other by using only optical fibers without using such optical components. Point to.

  In the optical line test system, the optical line test apparatus includes an optical line side port connected to a single tester side port of the parent fiber selector, and one of the optical line side test devices is connected to the optical line side port. The optical pulse tester further includes an optical switch having a first tester side port and a second tester side port, and a common port is connected to the first branch port of the optical switch through the optical coupler. A first branch coupler, a first light source connected to a first branch port of the first branch coupler, the first light source generating pulse light having a first wavelength, and a common port of the optical switch A second branch coupler connected to the second tester side port, and a second light source connected to the first branch port of the second branch coupler, wherein the second wavelength is different from the first wavelength. Pal with A second light source for generating light, a multiplexing coupler in which a first branch port is connected to a second branch port of the first branch coupler, and a second branch port is connected to a second branch port of the second branch coupler And a photodetector connected to the common port of the multiplexing coupler, wherein the backscattered light of the pulsed light having the first wavelength and the backscattered light of the pulsed light having the second wavelength are electrically And a photodetector for converting into a signal.

  According to the above configuration, the optical line testing device includes an optical line side port connected to a single tester side port of the parent fiber selector, and a first one of which one is connected to the optical line side port. An optical switch having a tester side port and a second tester side port is provided. The parent fiber selector includes a plurality of optical line side ports.

  Therefore, a configuration in which any one of the n + m optical line side ports provided in the parent fiber selector is connected to any one of the two tester side ports provided in the optical switch by the parent fiber selector and the optical switch. Realized.

  In the above configuration, the first light source is connected to the first tester side port of the optical switch via the first branch coupler and the optical coupler, and the second light source is connected to the second light source. Are connected to the second tester side port of the optical switch via the branch coupler. The optical detector is connected to the first tester side port of the optical switch via the multiplexing coupler, the first branching coupler, and the optical coupler. It is also connected to the second tester side port of the optical switch via two branch couplers.

  Therefore, according to said structure, it is an optical line test apparatus which can perform the optical pulse test regarding two wavelengths, Comprising: The optical line test apparatus which does not require a measuring device termination | terminus terminal selection apparatus is realizable.

In order to solve the above problems, an optical fiber line testing system according to the present invention, n _i pieces of light roadside port that is directly or indirectly connected to the optical line group, and the n _i-number of beam roadside port M optical fiber selectors having a tester side port connectable to any one of (1 ≦ i ≦ m, m and _ni are arbitrary natural numbers), and n optical line side ports connected to the optical line group (N is an arbitrary natural number), can be connected to any one of the m optical line side ports connected to the tester side port of each of the m child fiber selectors, and any of these n + m optical line side ports One parent fiber selector having x tester side ports (x is an arbitrary natural number) and x optical line side ports connected to each of the x tester side ports of the parent fiber selector Optical line test with built-in optical measuring instrument An optical line group connected to each of the child fiber selectors, and an optical line testing apparatus for testing a target optical line selected from the optical line group connected to the parent fiber selector. It is characterized by having.

  According to the above configuration, since the number of measuring device side ports of the parent fiber sector and the number of optical line side ports of the optical measuring device are the same number (both are x), the parent fiber selector and the optical measuring device are measured. They can be connected to each other without using a device terminal selection device or an optical switch.

  Since it is not necessary to use a measuring instrument termination selection device, the manufacturing cost and the maintenance cost can be kept lower than those of the conventional optical line test system. Moreover, since it is not necessary to use a measuring instrument termination stand selection device, and it is not necessary to use an optical switch, the size of the optical line testing device can be kept small.

  In the optical line testing system according to the present invention, when x is 2, (1) the parent fiber selector cuts off communication light incident on one of the two optical line side ports of the optical measuring device. It is preferable that the device has a function, or (2) further includes a blocking unit that blocks communication light incident on one of the two optical line side ports of the optical measuring device.

  According to said structure, the problem that the communication light which propagates another optical path affects the test regarding a certain optical path can be avoided.

  As described above, according to the present invention, the manufacturing cost and the maintenance cost of the optical line test system can be reduced.

It is a block diagram which shows the example of 1 structure of the optical line test system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the other structural example of the optical line test system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the optical measuring device with which the optical line test system which concerns on the 1st Embodiment of this invention is provided. It is a figure for demonstrating the optical pulse test by the optical line test apparatus with which the optical line test system which concerns on the 1st Embodiment of this invention is provided. (A) is a waveform example of pulsed light generated by a light source provided in the optical line testing apparatus, and a waveform example of backscattered light generated by the pulsed light when there is no physical obstacle such as a scratch in the target optical fiber; The example of the waveform of the electric signal output from the avalanche photodiode which received the said backscattered light is shown, (b) is the example of the waveform of the pulsed light which the light source with which an optical-path test apparatus is equipped, and object light Examples of waveforms of backscattered light generated by the pulsed light when there are physical obstacles such as scratches in the fiber and examples of waveforms of electrical signals output from the avalanche photodiode that received the backscattered light are shown. Yes. It is a block diagram which shows the structure of the optical measuring device with which the optical line test system which concerns on the 1st modification of the 1st Embodiment of this invention is provided. It is a block diagram which shows the structure of the optical measuring device with which the optical line test system which concerns on the 2nd modification of the 1st Embodiment of this invention is provided. It is a block diagram which shows one structural example of the optical line test system which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the other structural example of the optical line test system which concerns on the 2nd Embodiment of this invention. (A) is a block diagram which shows the structure of the access network containing the conventional optical line testing apparatus. (B) is a block diagram which shows the structural example of the fiber selector group used together with the conventional optical line testing apparatus. It is a block diagram which shows the structure of the conventional optical line test apparatus and an optical line test system. (A) is a figure which shows the structural example of a measuring device termination stand selection apparatus, (b) is a figure which shows the structural example of a fiber selector, (c) is another structural example of a fiber selector. FIG.

  An embodiment of an optical line testing system according to the present invention will be described below with reference to the drawings. The optical line test system according to the present embodiment selects a target optical fiber to be tested from optical fibers (optical lines) constituting an access network, and the selected target optical fiber is physically disconnected, increased loss, etc. It is used to detect the presence / absence of a fault and the location where the physical fault has occurred.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration of an optical line test system 1 according to the first embodiment. As shown in FIG. 1, an optical line test system 1 includes a parent fiber selector (FS) 20a, m child fiber selectors 20b1 to 20bm (m is the total number of child fiber selectors), and an optical line test apparatus. (OTM: Optical Test Module) 10 is provided.

  The parent fiber selector 20a and the child fiber selectors 20b1 to 20bm are used to select one target optical fiber connected to the optical line testing apparatus 10 from an optical fiber group including a plurality of communication optical fibers.

  When one master fiber selector 20a and m child fiber selectors 20b1 to 20bm are stored in a plurality of IDM racks that can store k fiber selectors, m−k + 2 IDM racks may be used. Further, the optical line test system 1 is connected to the optical fiber group for each of the m−k + 1 child fiber selectors except the k−1 child fiber selectors among the m child fiber selectors 20b1 to 20bm. It can be set as the structure provided with the k-1 grandchild fiber selector which has a plurality of optical line side ports and the tester side port connected to the optical line side port of a child fiber selector.

  As shown in FIG. 1, when the number of fiber selectors that can be stored in each IDM rack is four, of the m child fiber selectors 20b1 to 20bm, the three child fiber selectors 20b1 to 20b3 are the parent fiber selectors. 20a is housed in one IDM rack 54, and each of the m-3 child fiber selectors 20b4 to 20bm is housed in each of the m-3 IDM racks 54 'together with three grandchild fiber selectors. .

  By adopting such a configuration, the optical line test system 1 selects one target optical fiber to be tested from an optical fiber group including a larger number of communication optical fibers, and the selected target optical fiber. Can be tested. Further, since each IDM frame 54 'and the IDM frame 54 may be connected by a single optical fiber, the complexity of routing the optical fiber between the IDM frames can be minimized. In addition, since it can be controlled by the same control direction as a conventional optical line test system in which one master fiber selector and three child fiber selectors are housed in an IDM frame, it is compatible with the conventional optical line test system. There is also an advantage of high nature.

As shown in FIG. 1, the optical fiber selector 20bk (k is an arbitrary integer satisfying 1 ≦ k ≦ m) is a plurality of optical line side ports DPAk_1 to DPAk_n _k (n _k is an optical fiber selector) connected to the optical fiber group. 20bk) and a tester side port DPBk that is selectively connected to any of the plurality of optical line side ports. Further, the optical line side ports DPAq_1 to DPAq_3 (q is an arbitrary integer satisfying 4 ≦ q ≦ m) are connected to the optical fiber group via the grandchild fiber selector, and the optical line side ports DPAq_4 to DPAq_n _q are It is directly connected to the optical fiber group. Note that the total number n _k of the ray path side port provided in the child fiber selector 20bk, for example, about 2000. Therefore, for example, about 1000 pairs (2000) of transmission optical fibers drawn from about 1000 communication optical fibers can be connected to the optical line side ports provided in each of the optical fiber selectors 20b1 to 20b3. . The total number of optical line side ports provided in the grandchild fiber selector is, for example, about 2000. Therefore, about 1000 pairs (2000) of transmission optical fibers drawn from about 1000 communication optical fibers can be directly connected to the optical line side port provided in the optical fiber selector 20bq, and about 3000. About 3000 pairs (6000) of transmission optical fibers drawn from the communication optical fiber can be connected via a grandchild fiber selector. However, the present embodiment is not limited by the specific total number of optical line side ports included in the child fiber selector 20bk and the grandchild fiber selector. The configuration of the optical line test system 1 is not limited to the example shown in FIG. 1, and at least one of the optical line side ports included in each of the child fiber selectors 20b1 to 20b3 is connected via the grandchild fiber selector. It is good also as a structure connected to an optical fiber group.

  On the other hand, as shown in FIG. 1, the master fiber selector 20a is a single tester selectively connected to m + n optical line side ports PPA1 to PPAm + n and any one of these m + n optical line side ports. A side port PPB is provided. Of these m + n optical line-side ports, m optical line-side ports PPA1 to PPAm are connected to tester-side ports DPB1 to DPBm included in the child fiber selectors 20b1 to 20bm via transmission optical fibers, respectively. Among these m + n optical line side ports, n optical line side ports PPAm + 1 to PPAm + n are connected to an optical fiber group including a plurality of communication optical fibers. Further, the tester-side port PPB provided in the parent fiber selector 20a is connected to a single optical connector C (shown as a white rectangle in FIG. 1) provided in the optical line testing apparatus 10 via a transmission optical fiber. The

  In addition, the value of m is about 20, for example, and the value of n is about 2000, for example. Accordingly, the optical fiber side port of the parent fiber selector 20a has 1000 transmission optical fibers respectively connected to about 20 tester side ports of the child fiber selector and about 1000 communication optical fibers. A pair (2000) of optical fibers for transmission can be connected. However, the present embodiment is not limited to a specific value of n.

As described above, the parent fiber selector 20a and the child fiber selectors 20b1 to 20bm select one target optical fiber to be tested from a total of n + n ₁ + n ₂ +... + N _m optical fibers. The selected target optical fiber is connected to the optical line testing apparatus 10.

  The configuration of the optical line test system 1 is not limited to the example shown in FIG. For example, the optical line test system 1 is configured not to include the above-mentioned grandchild fiber selector, and a plurality of master fiber selectors 20a and m child fiber selectors 20b1 to 20bm can accommodate a plurality of k fiber selectors. It is good also as a structure accommodated in IDM rack. In this case, L IDM racks may be used, where L is the smallest natural number of (m + 1) / k or more. More specifically, as shown in FIG. 2, when the number of fiber selectors that can be stored in each IDM rack is 4, the smallest one of the natural numbers of (m + 1) / 4 or more is L, and L units An IDM rack may be used. More specifically, as shown in FIG. 1, among the m child fiber selectors 20b1 to 20bm, three child fiber selectors 20b1 to 20b3 are housed in the IDM frame 54 together with the parent fiber selector 20a, and the remaining m It is only necessary to store four of the three sub-fiber selectors 20b4 to 20bm in the other L-1 IDM racks 54 ′.

  In such a configuration, since the target optical fiber can be selected by the parent fiber selector and the child fiber selector without using the grandchild fiber selector, the insertion loss is reduced compared to the configuration using the grandchild fiber selector. Can be made.

  The optical line testing apparatus 10 determines whether or not there is a physical failure such as disconnection or increased loss and the physical failure of one target optical fiber selected by the parent fiber selector 20a and the child fiber selectors 20b1 to 20bm. For example, as shown in FIG. 1, the device includes an optical switch 11 and an optical measuring unit (OTU: Optical Test Unit) 100. The optical line testing apparatus 10 includes a control unit (not shown), and each unit included in the optical line testing apparatus 10 and the parent fiber selector 20a and the child fiber selectors 20b1 to 20bm are controlled by the control unit.

  The optical switch 11 is a target optical fiber selected by the parent fiber selector 20 and the child fiber selectors 20b1 to 20bm, and the optical line side port 11c included in the optical switch 11 is provided through the single optical connector C provided in the optical line test apparatus 10. The target optical fiber connected to is selectively connected to any one of the tester-side ports 11a and 11b included in the target optical fiber according to the test item to be performed on the target optical fiber. Further, as shown in FIG. 1, the tester-side ports 11a and 11b are connected to single optical connectors C1 and C2 included in the optical measuring device 100 by transmission optical fibers, respectively.

  The optical measuring device 100 has the presence or absence of a physical failure such as disconnection or increased loss in the target optical fiber connected to any of the optical connectors C1 and C2 included in the optical measuring device 100, and the place where the physical failure has occurred. It is the structure for detecting. FIG. 3 is a block diagram illustrating a configuration example of the optical measurement device 100. As shown in FIG. 3, the optical measurement device 100 includes a WDM coupler 110, an optical pulse tester (OTDR: Optical Time Domain Reflectometer) 120, and an optical power measurement device (OPM: Optical Power Meter) 130.

  The WDM coupler 110 is an optical coupler using a wavelength division multiplexing system. (1) Light input from its own common port 110c is converted into demultiplexed light in a plurality of wavelength regions with low loss. And (2) the first branch port 110a and the first branch port included in the first branch port 110a and the second branch port 110b included in the first branch port 110a and the second branch port 110b. As a multiplexer that generates combined light by combining the light of each wavelength region input from each of the two branch ports 110b with low loss, and outputs the generated combined light from the common port 110c provided to itself It has both functions.

  In the present embodiment, the WDM coupler 110 demultiplexes the light input from the common port 110c, outputs the first demultiplexed light having high transparency in the wavelength region including 1650 nm from the first branch port 110a, and 1550 nm. And a second demultiplexed light having high transparency in the wavelength region including both 1310 nm and 1310 nm is output from the second branch port 110b. Further, the WDM coupler 110 outputs, from the common port 110c, pulsed light having a wavelength of 1650 nm supplied from the light source 123 via a branching coupler 122 and a band pass filter 121 described later.

  As shown in FIG. 3, in this embodiment, the common port 110c is connected to the optical connector C1 via a transmission optical fiber, and the first branch port 110a is connected to the transmission optical fiber. The second branch port 110b is connected to a band pass filter (BPF) 121 provided in the optical pulse tester 120, and the second branch port 110b is provided in the WDM provided in the optical power measuring device 130 via a transmission optical fiber and an optical connector. The common port 131c of the coupler 131 is connected.

  The optical pulse tester 120 performs an optical pulse test using pulsed light having a wavelength of 1650 nm (first wavelength) on a target optical fiber connected to the optical connector C1, and a target optical fiber connected to the optical connector C2. For example, as shown in FIG. 3, a band-pass filter 121, a branch coupler 122, a light source 123, and a WDM are configured to perform an optical pulse test using pulsed light having a wavelength of 1310 nm (second wavelength). A coupler 124, an avalanche photodiode (APD) 125, a branch coupler 126, and a light source 127 can be used. The band-pass filter 121, the branch coupler 122, and the light source 123 have a configuration for the former optical pulse test, and the branch coupler 126 and the light source 127 have a configuration for the latter optical pulse test. The WDM coupler 124 and the avalanche photodiode 125 are configured to be used in any optical pulse test.

  The optical pulse tester 120 supplies the above-described pulsed light to the target optical fiber connected to the optical connector C1 or C2, and the waveform of the backscattered light generated when the pulsed light propagates through the target optical fiber. Is detected.

  The band pass filter 121 selectively transmits light having a center wavelength of 1650 nm out of light input from the first branch port 110 a of the WDM coupler 110 via the transmission optical fiber, and between the ONU 51 and the OLT 52. The light of 1310 nm and 1550 nm, which is the communication band of the optical communication, is blocked. The band pass filter 121 supplies the light after transmission to the common port 122c of the branch coupler 122 via the optical fiber. The band-pass filter 121 transmits pulse light having a wavelength of 1650 nm supplied from the light source 123 via the branch coupler 122 and supplies the pulse light to the first branch port 110a of the WDM coupler 110 via the transmission optical fiber. .

  The branch coupler 122 (1) demultiplexes the light input from the common port 122c included in itself into two demultiplexed lights, and the first branch port 122a and the second branch port included in the demultiplexed light. 122b respectively functions as a demultiplexer and (2) multiplexes light input from the first branch port 122a and the second branch port 122b included in itself to generate combined light, It also has a function as a multiplexer that outputs the generated multiplexed light from its own common port 122c.

  In the present embodiment, the branch coupler 122 outputs light having a wavelength of 1650 nm supplied from the light source 123 via the transmission optical fiber to the first branch port 122a from the common port 122c. The branch coupler 122 outputs light having a wavelength of 1650 nm supplied from the bandpass filter 121 via the transmission optical fiber to the common port 122c from the second branch port 122b. The branching ratio of the branching coupler 122 is set, for example, to be 3 dB in the vicinity of the wavelength region of 1650 nm, and light having a wavelength of 1650 nm input from the common port 122c is demultiplexed at a ratio of 1: 1. Later, it is output from each branch port. However, any branch coupler having any known branch ratio can be used as the branch coupler 122.

  The light source 123 generates pulsed light having a wavelength of 1650 nm used for the optical pulse test, and supplies the generated pulsed light to the first branch port 122a of the branch coupler 122 via a transmission optical fiber. The pulse width of the pulsed light generated by the light source 123 can take a value from 20 ns (nano-seconds, nanoseconds) to 4 μs (micro-seconds, microseconds), for example.

  Further, the light source 123 generates a modulated optical signal having a modulation frequency of 270 Hz used for a light source test for the target optical fiber using light having a wavelength of 1650 nm, and the generated modulated optical signal is the first branch port 122a of the branch coupler 122. Can also be supplied. The light source test is a test performed by inputting a modulated optical signal to the target optical fiber and detecting the modulated optical signal at the end of the target optical fiber.

  Similar to the branch coupler 122, the branch coupler 126 has both a function as a duplexer and a function as a multiplexer.

  In the present embodiment, the branch coupler 126 outputs light having a wavelength of 1310 nm supplied from the light source 127 to the first branch port 126a from the common port 126c. Further, the branch coupler 126 outputs light having a wavelength of 1310 nm supplied from the target optical fiber via the transmission optical fiber and the optical connector C2 to the common port 126c from the second branch port 126b. Note that the branching ratio of the branching coupler 126 is set to 3 dB in the vicinity of the wavelength region of 1310 nm, for example. However, any branch coupler having any known branch ratio can be used as the branch coupler 126.

  The light source 127 generates pulsed light having a wavelength of 1310 nm used for the optical pulse test, and supplies the generated pulsed light to the first branch port 126a of the branch coupler 126 via the transmission optical fiber. The pulse width of the pulsed light generated by the light source 127 can take a value from 20 ns to 4 μs, for example, similarly to the light source 123, and the user can select an optimum pulse in the optical pulse test via the control unit. The width can be selected.

  The light source 127 generates a modulated optical signal having a modulation frequency of 270 Hz used for a light source test for the target optical fiber using light having a wavelength of 1310 nm, and the generated modulated optical signal is a first branch port 126a of the branch coupler 126. Can also be supplied.

  The WDM coupler 124 is an optical coupler using a wavelength division multiplexing system, and has a function as a demultiplexer and a function as a multiplexer, similarly to the WDM coupler 110.

  In the present embodiment, the WDM coupler 124 includes light having a wavelength of 1650 nm supplied from the branch coupler 122 to the first branch port 124a provided therein and the branch coupler 126 to the second branch port 124b provided therein. It is used to supply the supplied light having a wavelength of 1310 nm to the avalanche photodiode 125 with low loss.

  The avalanche photodiode 125 is a photodiode with high light receiving sensitivity utilizing a photoelectric effect and an avalanche multiplication phenomenon.

  In the present embodiment, the avalanche photodiode 125 is supplied from the branch coupler 126 via the WDM coupler 124 and the intensity at each time of the light of wavelength 1650 nm supplied from the branch coupler 122 via the WDM coupler 124. It is used to detect the intensity of light of wavelength 1310 nm at each time.

  More specifically, the avalanche photodiode 125 is emitted from the light source 123 in the optical pulse test using pulsed light having a wavelength of 1650 nm, and is supplied with the branch coupler 122, the bandpass filter 121, the WDM coupler 110, and the optical connector C1. The backscattered light of the pulse light supplied to the target optical fiber via the optical fiber, and the backscattered light supplied via the WDM coupler 110, the bandpass filter 121, the branch coupler 122, and the WDM coupler 124 is received. At each time, an electric signal (current) corresponding to the intensity of the backscattered light is output.

  Similarly, the avalanche photodiode 125 is a pulsed light emitted from the light source 127 and supplied to the target optical fiber via the branch coupler 126 and the optical connector C2 in an optical pulse test using a pulsed light having a wavelength of 1310 nm. And backscattered light supplied via the branch coupler 126 and the WDM coupler 124 is received, and an electric signal (current) corresponding to the intensity of the backscattered light is output at each time. To do.

  The backscattered light is scattered light that propagates in a direction opposite to the propagation direction of the pulsed light among the scattered light that is generated when the pulsed light supplied to the target optical fiber is scattered at each position of the target optical fiber. Refers to that.

  The electrical signal at each time output from the avalanche photodiode 125 is digitized by a data acquisition unit (not shown) and transmitted to the control unit. The control unit detects the presence or absence of a physical failure such as disconnection or increased loss in the target optical fiber, and the location where the physical failure has occurred, by analyzing the magnitude of the electrical signal at each time. be able to.

  FIG. 4A shows an example of the waveform of the pulsed light output from the light source 123 (or the light source 127) in the optical pulse test, and the pulsed light when there is no physical obstacle such as a scratch in the target optical fiber. It is a timing chart which shows the waveform example of the backscattered light which arises, and the waveform example of the electric signal output from the avalanche photodiode 125 which received this backscattered light.

  As shown in (a) of FIG. 4, when there is no physical obstacle such as a scratch in the target optical fiber, the backscattered light decreases as the elapsed time from the emission time of the pulsed light increases, The pulsed light has a peak corresponding to the reflected light reflected at the end of the target optical fiber.

  FIG. 4B shows an example of the waveform of the pulsed light output from the light source 123 (or the light source 127) in the optical pulse test, and when there is a physical failure such as a scratch in the target optical fiber, It is a timing chart which shows the waveform example of the backscattered light which arises, and the waveform example of the electric signal output from the avalanche photodiode 125 which received this backscattered light.

  As shown in FIG. 4B, when a physical obstacle such as a scratch exists in the target optical fiber, the backscattered light has a peak corresponding to the reflected light reflected by the physical obstacle, a pulse The light has a peak corresponding to the reflected light reflected at the end of the target optical fiber.

  The control unit detects a time interval from when the pulsed light is emitted by the light source 123 until the peak due to the physical failure is observed, and based on the detected time interval, the physical failure in the target optical fiber is detected. Can be calculated.

  The optical power measuring device 130 is configured to detect the power of signal light extracted from the target optical fiber. More specifically, the optical power measuring device 130 in the optical power measurement test, the upstream signal light (wavelength 1310 nm) from the ONU 51 to the OLT 52 and the downstream signal light (wavelength 1550 nm) from the OLT 52 to the ONU 51. ), For example, as shown in FIG. 3, may be configured by a WDM coupler 131, a filter 132, a photodiode (PD: Photodiode) 133, a filter 134, and a photodiode 135. it can. The filter 132 and the photodiode 133 are configured to detect the power of signal light having a wavelength of 1310 nm, and the filter 134 and the photodiode 135 are configured to detect the power of signal light having a wavelength of 1550 nm. is there. Further, the WDM coupler 131 has a configuration used when detecting the power of any signal light.

  The WDM coupler 131 is an optical coupler using a wavelength division multiplexing system, and has a function as a demultiplexer and a function as a multiplexer, similarly to the WDM coupler 110. However, unlike the WDM coupler 110, the WDM coupler 131 demultiplexes the signal light input from the common port 131c included in the WDM coupler 131, and the first demultiplexed light having high transparency in the wavelength region including 1310 nm. The first branch port 131a provided and the second demultiplexed light having high transparency in the wavelength region including 1550 nm are output from the second branch port 131b provided therein.

  Further, as shown in FIG. 3, in the present embodiment, the common port 131c is connected to the second branch port 110b of the WDM coupler 110, and the first branch port 131a is connected to the filter 132. The second branch port 131b is connected to the filter 134.

  The filter 132 selectively transmits signal light having a center wavelength of 1310 nm out of signal light supplied from the first branch port 131a of the WDM coupler 131 via the transmission optical fiber, and transmits the signal light after transmission. This is supplied to the photodiode 133.

  The photodiode 133 receives the signal light supplied from the filter 132 and outputs an electric signal (current) corresponding to the power of the received signal light. The output electrical signal is digitized by a data acquisition unit (not shown) and transmitted to the control unit. The control unit can calculate the power of the signal light having a wavelength of 1310 nm supplied from the target optical fiber via the WDM coupler 110, the WDM coupler 131, and the filter 132, based on the magnitude of the electric signal.

  The filter 134 selectively transmits signal light having a center wavelength of 1550 nm out of signal light supplied from the second branch port 131b of the WDM coupler 131 via the transmission optical fiber, and transmits the signal light after transmission. This is supplied to the photodiode 135.

  The photodiode 135 receives the signal light supplied from the filter 134 and outputs an electric signal (current) corresponding to the power of the received signal light. The output electrical signal is digitized by a data acquisition unit (not shown) and transmitted to the control unit. The control unit can calculate the power of the signal light having a wavelength of 1550 nm supplied from the target optical fiber via the WDM coupler 110, the WDM coupler 131, and the filter 134 based on the magnitude of the electric signal.

  In this embodiment, since the optical power measuring device 130 is connected to the WDM coupler 110 via an optical connector (shown as a white rectangle in FIG. 3), the optical power measuring device 130 is connected to the optical line testing apparatus 10. Can be easily removed. Therefore, for users who do not use optical power measurement, custom-made such as shipping with a simple configuration with the optical power measuring device 130 removed can be easily realized.

  Further, in the present embodiment, the optical line test system 1 can be realized with a simple configuration as compared with the optical line test system described in Non-Patent Document 1 that requires a measuring instrument termination rack selection device. Accordingly, since the failure rate in the optical line test system 1 is reduced, the reliability of the optical line test system 1 is improved.

As described above, the optical fiber line testing system 1 according to the present invention, _{n i} pieces of light roadside port DPAi_1～DPAi_n _i connected to the optical fiber group, and, connected to one of said _{n i} pieces of light roadside port m stand and child fiber selector 20b1~20bm with tester-side port DPBi being (1 ≦ i ≦ m, m and _{n i} is an arbitrary natural number), n pieces connected to the optical fiber group of rays roadside port PPAm + 1 PPAm + n (n is an arbitrary natural number), m optical line side ports PPA1 to PPAm connected to the tester side ports of each of the m child fiber selectors 20b1 to 20bm, and these n + m optical line sides One parent fiber selector 20a having a single tester side port PPB connected to any of the ports, and the parent fiber selector 20a An optical line testing apparatus 10 connected to one tester side port PPB, an optical fiber group connected to each of the child fiber selectors 20b1 to 20bm, and an optical fiber connected to the parent fiber selector 20a And an optical line testing apparatus 10 for testing a target optical fiber selected from the group.

  According to the optical line test system 1 according to the present invention configured as described above, the manufacturing cost and the maintenance cost of the optical line test system 1 can be reduced.

<Modification 1>
The configuration of the optical measuring device 100 included in the optical line test system 1 according to the present embodiment is not limited to the above-described example. Here, an optical measuring device 100 according to a first modification of the present embodiment will be described with reference to FIG.

  The optical pulse tester 120 in the optical measuring device 100 according to this modification performs an optical pulse test using light having a wavelength of 1550 nm in addition to an optical pulse test using light having a wavelength of 1650 nm and light having a wavelength of 1310 nm. It is the structure which can do. For example, as shown in FIG. 5, the optical pulse tester 120 in the present modification includes the bandpass filter 121, the branch coupler 122, the light source 123, the WDM coupler 124, the avalanche photodiode 125, and the branch coupler 126 that have already been described. In addition, the light source 128, the WDM coupler 129, the filter 140, and the avalanche photodiode 141 can be provided.

  In this modification, the filter 140 and the avalanche photodiode 141 are configured to perform an optical pulse test using light having a wavelength of 1550 nm, and the light source 128, the branch coupler 126, and the WDM coupler 129 are configured to emit light having a wavelength of 1550 nm. This is a configuration used in both the optical pulse test used and the optical pulse test using light having a wavelength of 1310 nm. In this modification, the WDM coupler 124 and the avalanche photodiode 125 are also used for an optical pulse test using light having a wavelength of 1310 nm.

  The light source 128 generates pulse light having a wavelength of 1310 nm and pulse light having a wavelength of 1550 nm used for the optical pulse test, and supplies the generated pulse light to the first branch port 126a of the branch coupler 126 via a transmission optical fiber. . Like the light source 123, the pulse width of the pulsed light generated by the light source 128 can take a value from 20 ns to 4 μs, for example, and the user can select the optimum pulse in the optical pulse test via the control unit. The width can be selected.

  The light source 128 generates a modulated optical signal having a modulation frequency of 270 Hz, which is used for a light source test for the target optical fiber, using light having a wavelength of 1310 nm or light having a wavelength of 1550 nm. One branch port 126a can also be supplied.

  The WDM coupler 129 is an optical coupler using a wavelength division multiplexing system, and has a function as a demultiplexer and a function as a multiplexer, similarly to the WDM coupler 110. Further, the WDM coupler 129 demultiplexes light input from the common port 129c provided therein, and from the first branch port 129a provided with the first demultiplexed light having high transparency in a wavelength region including 1550 nm. The second demultiplexed light having high transparency in the wavelength region including 1310 nm is output from the second branch port 129b provided with itself.

  As shown in FIG. 5, in this modification, the common port 129 c is connected to the second branch port 126 b of the branch coupler 126, and the first branch port 129 a is connected to the filter 140. The second branch port 129b is connected to the second branch port 124b of the WDM coupler 124 via a transmission optical fiber and an optical connector.

  In this modification, when an optical pulse test using pulsed light having a wavelength of 1310 nm is performed, the rear of pulsed light having a wavelength of 1310 nm emitted from the light source 128 and supplied to the target optical fiber via the branch coupler 126 and the optical connector C2. The scattered light is supplied to the avalanche photodiode 125 via the branch coupler 126, the WDM coupler 129, and the WDM coupler 124.

  The filter 140 selectively transmits light having a center wavelength of 1550 nm out of light supplied from the first branch port 129a of the WDM coupler 129 via the transmission optical fiber, and transmits the light after transmission through the avalanche beam. This is supplied to the photodiode 141.

  Similar to the avalanche photodiode 125, the avalanche photodiode 141 is a photodiode with high light receiving sensitivity using the photoelectric effect and the avalanche multiplication phenomenon. In this modification, the avalanche photodiode 141 is used to detect the intensity of light having a wavelength of 1550 nm supplied from the branch coupler 126 via the WDM coupler 129.

  More specifically, the avalanche photodiode 141 is a wavelength emitted from the light source 128 and supplied to the target optical fiber via the branch coupler 126 and the optical connector C2 in an optical pulse test using pulsed light having a wavelength of 1550 nm. Backscattered light of 1550 nm pulse light, which receives backscattered light supplied via the branch coupler 126, the WDM coupler 129, and the filter 140, and corresponds to the intensity of the backscattered light at each time. Outputs an electrical signal (current). The electrical signal at each time output from the avalanche photodiode 141 is digitized by a data acquisition unit (not shown) and transmitted to the control unit. The control unit detects the presence or absence of a physical failure such as disconnection or increased loss in the target optical fiber, and the location where the physical failure has occurred, by analyzing the magnitude of the electrical signal at each time. be able to.

<Modification 2>
Below, the optical measuring device 100 with which the optical-line test system 1 which concerns on the 2nd modification of this embodiment is provided is demonstrated with reference to FIG.

  The optical pulse tester 120 in the optical line test system 1 according to this modification is a configuration for performing an optical pulse test using light having a wavelength of 1650 nm. For example, as shown in FIG. While including the branch coupler 122, the light source 123, the WDM coupler 124, and the avalanche photodiode 125, the branch coupler 126, the light source 127, the light source 128, the WDM coupler 129, the filter 140, and the avalanche photodiode 141 that have already been described. It can be set as the structure which is not equipped with any of these. The configuration of the optical power measuring device 130 in this modification is the same as the configuration already described.

  In the present modification, since the number of target optical fibers connected to the optical measuring instrument 100 is one, the optical line test system 1 according to the present modification can be configured without the optical switch 11. The target optical fiber selected by the parent fiber selector 20 can be directly connected to the common port 110c of the WDM coupler 110.

  Thus, since the optical switch 11 is omitted in the optical line test system 1 according to this modification, the manufacturing cost and the maintenance cost can be further reduced.

[Second Embodiment]
FIG. 7 is a block diagram showing a configuration of the optical line test system 1 according to the second embodiment. As shown in FIG. 7, the optical line test system 1 according to the present embodiment is similar to the optical line test system 1 according to the first embodiment, and includes a parent fiber selector 20a, m child fiber selectors 20b1 to 20bm, and The optical line test apparatus 10 is provided.

  The differences between the optical line test system 1 according to the present embodiment and the optical line test system 1 according to the first embodiment are as follows.

  (1) In the first embodiment, the parent fiber selector 20a includes a single tester side port PPB, whereas in the present embodiment, the parent fiber selector 20a includes two tester side ports PPB1. -A point provided with PPB2.

  (2) In the first embodiment, the tester side port PPB of the parent fiber selector 20a is connected to the two optical connectors (optical line side ports) C1 to C2 of the optical measuring device 100 via the optical switch 11. On the other hand, in this embodiment, the two tester side ports PPB1 to PPB2 of the parent fiber selector 20a are respectively connected to the two optical connectors (optical line side ports) of the optical measuring device 100 without going through the optical switch 11. Points connected to C1 and C2.

  Thus, the optical switch 11 can be omitted by using the parent fiber selector 20a having the two tester side ports PPB1 and PPB2. More generally speaking, if the master fiber selector 20a having the same number of tester side ports PPB1 to PPB2 as the optical connectors of the optical measuring device 100 is used, the optical switch 11 can be omitted. As a result, the optical line testing apparatus 10 can be further downsized. In addition, the optical line test system 1 which concerns on this embodiment can be implemented similarly to the optical line test system 1 which concerns on 1st Embodiment except the difference mentioned above. For example, as the configuration of the optical measuring device 100, the one shown in FIG. 3 or the one shown in FIG. 5 may be used.

  However, if the configuration in which the two tester side ports PPB1 to PPB2 of the parent fiber selector 20a are simultaneously connected to the two optical connectors C1 to C2 of the optical measuring device 100 is adopted, another optical line is used for a test on a certain optical line. There may be a problem that propagating communication light has an effect. For example, when the optical measuring device 100 is configured as shown in FIG. 5, there arises a problem that communication light having a wavelength of 1310 nm propagating through another optical line affects the optical pulse test of 1650 nm regarding a certain optical line. This is because communication light having a wavelength of 1310 nm incident on the optical measuring device 100 from the optical connector C2 reaches the APD 125 even when the optical pulse test of 1650 nm is performed (see FIG. 5).

  In order to avoid such a problem, it is desirable to add a function of blocking communication light incident on one of the optical connectors C1 and C2. In particular, when the optical measuring device 100 is configured as shown in FIG. 5, it is desirable to add a function of blocking communication light having a wavelength of 1310 nm incident on the optical connector C2 during the 1650 nm optical pulse test.

  A configuration example of the parent fiber selector 20a having such a function is shown in FIG. In the drawing, PFA1 to PFAm + n indicate optical line side fibers (fixed fibers) connected to the optical line side ports PPA1 to PPAm + n, respectively. PFB1 to PFB2 indicate tester side fibers (moving fibers) connected to the tester side ports PPB1 to PPB2, respectively.

  The parent fiber selector 20a shown in FIG. 11C includes a fiber moving mechanism (not shown) that moves the tester-side fibers PFB1 and PFB2. By this fiber movement mechanism, the tester side fiber corresponding to the selected test function among the tester side fibers PFB1 to PFB2 is the optical line side fiber corresponding to the selected optical line among the optical line side fibers PFA1 to PFAm + n. And placed on a common V-shaped groove. Further, the parent fiber selector 20a shown in FIG. 11C includes pressing tools 205a to 205b. The pressing tools 205a to 205b correspond to the end of the tester side fiber corresponding to the selected test function among the tester side fibers PFB1 to PFB2, and to the selected optical fiber among the optical line side fibers PFA1 to PFAm + n. The end of the optical line side fiber is connected.

  In the parent fiber selector 20a shown in FIG. 11 (c), it should be noted that the pressing tool 205a for pressing the tester side fiber PFB1 and the pressing tool 205b for pressing the tester side fiber PFB2 are individually provided. It is a point provided. These two pressing tools 205a-205b operate independently of each other. For example, during the 1650 nm optical pulse test, only the pressing tool 205a is operated to connect only the tester-side fiber PFB1 to the optical line-side fiber. As a result, the tester side fiber PFB2 and the optical line side fiber are not connected during the optical pulse test of 1650 nm. Therefore, during the optical pulse test of 1650 nm, communication light having a wavelength of 1310 nm incident on the optical connector C2 is blocked by the parent fiber selector 20a.

  In addition, although the structure which makes the parent fiber selector 20a bear the function which interrupts | blocks the communication light which injects into any one of optical connector C1-C2 was demonstrated here, it is not limited to this. That is, for example, even if a configuration in which an optical shutter S having such a function is added is adopted, the above-described problem (communication light having a wavelength of 1310 nm reaches the APD 125 during the 1650 nm optical pulse test and affects the test result. Problem).

  The configuration of the optical line test system 1 to which the optical shutter S is added is illustrated in FIG. The optical shutter S is for blocking communication light having a wavelength of 1310 nm that enters the optical connector C2 during the optical pulse test of 1650 nm. The optical shutter S may be realized by any optical element as long as it can switch whether to block or transmit communication light having a wavelength of 1310 nm. Therefore, from the optical switch 11 (see FIG. 1). Can also be reduced in size.

  In FIG. 8, the configuration in which the optical shutter S is provided in the optical line testing apparatus 10 is shown, but the configuration is not limited thereto. The optical shutter S is either (1) any point on the optical fiber connecting the tester side port PPB2 of the parent fiber selector 20a and the optical connector C2 of the optical measuring device 100, or (2) a tester of the parent fiber selector 20a. It can be inserted at any point on the tester side fiber PFB2 connected to the side port PPB2. That is, the optical shutter S may be provided inside the optical line testing device 10, may be provided between the optical line testing device 10 and the parent fiber selector 20a, or provided inside the parent fiber selector 20a. Also good.

[Additional Notes]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments and modifications can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

  The present invention can be suitably used for an optical line test system for testing an optical line such as an optical fiber constituting an access network.

DESCRIPTION OF SYMBOLS 1 Optical line test system 10 Optical line test apparatus 20a Parent fiber selector 20b1-20bm Child fiber selector 11 Optical switch 100 Optical measuring device 110 WDM coupler (optical coupler)
120 Optical Pulse Tester 122 Branch Coupler 123 Light Source 125 Avalanche Photodiode (Photodetector)
130 Optical Power Measuring Device 131 WDM Coupler 133 Photodiode 135 Photodiode

Claims (8)

M optical fiber-side selectors having ni optical line-side ports directly or indirectly connected to the optical line group, and tester-side ports connectable to any of the ni optical line-side ports; 1 ≦ i ≦ m, m and ni are arbitrary natural numbers)
N optical line side ports (n is an arbitrary natural number) connected to the optical line group, m optical line side ports connected to the tester side ports of each of the m child fiber selectors, and these one parent fiber selector having a single tester side port connectable to any of the n + m optical line side ports;
An optical line testing apparatus connected to a single tester side port of the parent fiber selector, an optical line group connected to each of the child fiber selectors, and an optical line connected to the parent fiber selector An optical line testing device for testing a target optical line selected from the group;
An optical line test system comprising: m−k + 2 optical wiring module racks that can store k fiber selectors (k is a natural number smaller than m), and m− except the k−1 child fiber selectors of the m child fiber selectors. For each of the k + 1 child fiber selectors, k-1 grandchild fiber selectors having a plurality of optical line side ports connected to the optical line group and a tester side port connected to the optical line side ports of the child fiber selectors And
Of the m sub-fiber selectors, the k-1 sub-fiber selectors are housed in one optical wiring module rack together with the optical line testing device, and the m-k + 1 sub-fiber selectors are included. Each is housed in each of the m−k + 1 optical wiring module racks together with the k−1 grandchild fiber selectors.
The optical line test system according to claim 1. L optical wiring module racks capable of storing k fiber selectors are provided (k is a natural number smaller than m, L is the smallest of natural numbers greater than (m + 1) / k),
Of the m sub-fiber selectors, k-1 sub-fiber selectors are housed in one optical wiring module frame together with the optical line testing device, and of the m sub-fiber selectors, m−k + 1 child fiber selectors, excluding k−1 child fiber selectors, are housed in L−1 optical wiring module racks.
The optical line test system according to claim 1. The optical line testing apparatus includes an optical coupler having a common port connected directly or indirectly to a single tester side port of the parent fiber selector, and an optical pulse connected to the first branch port of the optical coupler. An optical pulse tester for generating a pulsed light to be input to the target optical line and detecting a waveform of backscattered light of the pulsed light extracted from the target optical line; and an optical coupler An optical power measuring device connected to the second branch port, the optical power measuring device for measuring the power of the signal light extracted from the target optical line,
The optical line test system according to any one of claims 1 to 3, wherein The optical line testing device includes an optical line side port connected to a single tester side port of the parent fiber selector, and a first tester side port and a second one of which are connected to the optical line side port. An optical switch having a tester side port;
The optical pulse tester includes a first branch coupler having a common port connected to the first branch port of the optical switch via the optical coupler, and a first branch port connected to the first branch port of the first branch coupler. A first light source that generates pulsed light having a first wavelength, a second branch coupler in which a common port is connected to the second tester side port of the optical switch, and the second branch A second light source connected to the first branch port of the coupler, wherein the second light source generates a pulsed light having a second wavelength different from the first wavelength, and the first branch port includes the first branch A coupler connected to the second branch port of the coupler, the second branch port being connected to the second branch port of the second branch coupler, and a photodetector connected to the common port of the coupler. And pulsed light having the first wavelength. Backscattered light, and includes a photodetector for converting the pulsed light of the backscattered light having the second wavelength into an electric signal, and
The optical line test system according to claim 4, wherein: N _i-number of rays roadside port that is directly or indirectly connected to the optical line groups, and, m stand child fiber selector having either can be connected to the tester-side port of the n _i-number of beam roadside port And (1 ≦ i ≦ m, m and _ni are arbitrary natural numbers),
N optical line side ports (n is an arbitrary natural number) connected to the optical line group, m optical line side ports connected to the tester side ports of each of the m child fiber selectors, and these one parent fiber selector having x tester side ports (x is an arbitrary natural number) connectable to any of the n + m optical line side ports;
An optical line testing apparatus including an optical measuring device having x optical line side ports connected to each of x tester side ports of the parent fiber selector, wherein the optical line testing device is connected to each of the child fiber selectors. An optical line testing apparatus for testing a target optical line selected from the optical line group and the optical line group connected to the parent fiber selector;
An optical line test system comprising: X is 2;
The parent fiber selector has a blocking function for blocking communication light incident on one of the two optical line side ports of the optical measuring device,
The optical line test system according to claim 6. X is 2;
Further comprising a blocking means for blocking communication light incident on any one of the two optical line side ports of the optical measuring instrument,
The optical line test system according to claim 6.

Images