JPS63284447A - Testing method for characteristic evaluation of light beam path - Google Patents

Abstract

PURPOSE:To test characteristic evaluation economically by connecting the connector of an optical coupler with the connector of a light beam path at the time of a test, and inserting a test system into the light beam path. CONSTITUTION:A test system 6 is independent of the optical fiber 4 and inserted in some part of the optical fiber 4 only at the time of the test. An area encircled with a broken line A is a switching area and connectors 13 and 14 of the optical fiber 4 are connected normally to connectors 10 and 11 of a jumper line 12. When the test is conducted, on the other hand, the connector 10 of the jumper line 12 connected to the connector 13 of the optical fiber 4 is switched to the connector 8 of the optical coupler of a test system 5 and the connector 11 of the optical jumper line 12 connected to the connector 14 of the optical fiber 4 is switched similarly to the connector 9 of the optical coupler 7 of the test system 5. Consequently, there is no need to provide an expensive testing optical parts in the light beam path as usual, so the characteristic evaluation of the light beam path is tested very economically.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for testing the characteristics of an optical line such as an optical fiber.

(Prior Art) In recent years, optical communication systems using optical fibers as optical lines have been widely used. In such optical communication systems, it is common practice to insert a test system in the middle of the optical line in order to monitor various optical losses in the optical line. Electrical/optical converter (Elo) 1 and optical/electrical converter (0/E) 2
When an optical coupler 3 is connected to an optical fiber 4, an optical coupler 3 is permanently installed in the middle of the optical fiber 4, and during testing, the coupler 3 is connected to a testing device, such as a pulse tester (
By connecting to the optical fiber (OTDR) 5, optical loss in the middle of the optical fiber 4 is measured.

(Problems to be Solved by the Invention) However, in the conventional test method, as mentioned above, the optical coupler 3, which is unnecessary for actual communication and is expensive, is permanently installed in the optical path. There are disadvantages.

In particular, in the case of multi-core optical fibers, the number of optical couplers 3 required is equal to the number of cores (for example, in the case of a 100-core cable, 100 optical couplers are required), so the cost increases significantly.

The present invention has been made in view of the above-mentioned conventional problems, and is a method for testing optical lines used in optical communication, which eliminates the need to permanently install expensive optical components that are unnecessary for communication in the optical line. The purpose of this invention is to provide an optical line testing method that enables economical performance of characteristic evaluation tests such as optical loss tests.

(Means for Solving the Problems) The present invention does not permanently install an optical component for testing and use, such as an optical coupler, in the middle of the optical path, but instead connects the optical coupler connected to the test equipment to the optical path only during testing. This is based on the recognition that if the optical coupler is inserted inside, one optical coupler is sufficient and the test can be carried out economically.

That is, in order to achieve the above object, according to the present invention, in a test method for inserting a test system into an optical line under test and evaluating the characteristics of the optical line, the test system is connected to a test device and the test device. and an optical coupler having connectors at both ends, and a connector is provided at at least one location on the optical line, and the connector of the optical coupler and the connector of the optical line are connected during testing. Therefore, we decided to insert a test system into the optical path.

(Function) The test system consists of a test device and an optical coupler, such as an optical coupler, connected to the test device, and a pair of connectors is provided at least at one location on the optical path to enable splitting. At times, the above optical coupler is inserted between the connectors of the optical line, and the connectors at both ends are connected to the connectors of the optical line, respectively.

At this time, if a connector switching device is used, the switching connection between the connectors can be performed in an extremely short time, so that the work efficiency at the time of switching is also improved.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

FIGS. 1 and 2 schematically represent a measurement system which is a first embodiment of the optical line testing method of the present invention. In addition, in the figure, the same components as in FIG. 1O are denoted by the same reference numerals.

In the figure, a test system 6 for measuring optical loss is composed of a pulse tester (OTDR) 5, which is a test device, and an optical coupler 7. Then, the bow of this optical coupler 7) 7a
and 7b are connected to connectors 8.9, respectively, and 0TDR5 is connected to the branch port 7c of the optical power bluff. On the other hand, there are connectors 1 at both ends in the middle of the optical fiber 4.
An optical jumper line 12 having a diameter of 0.11 is interposed.

Specifically, among the two connectors 13 and 14 arranged on the optical fiber 4, the connector 1j is the connector 10 of the optical jumper line 12, and the connector 14 of the optical fiber 4 is the connector 11 of the optical jumper line 12. are connected to each other.

In the configuration of such a measurement system, the test system 6 includes an optical fiber 4
It is independent from the optical fiber 4, and is inserted into the optical fiber 4 only during testing. That is, in the figure, the area surrounded by the broken line A is the switching area, and is normally connected to the connectors 13, 14, and 10, 11 of the optical fiber 4, respectively, as shown in FIG. On the other hand, during the test, as shown in FIG.
0 to the connector 8 of the optical coupler of the test system 5, and similarly, switch the connector 11 of the optical jumper wire 12 connected to the connector 14 of the optical fiber 4 to the connector 9 of the optical power bluff of the test system 5. . At this time, as the above-mentioned connectors 8.9.10 and ratio 13.14, the fitting pin type shown in Fig. 3 (a) and 3) is used, and the connector switching device shown in Fig. 4 is used. When used, the switching operation described above can be performed in an extremely short time, improving work efficiency during switching.

Figure 3 shows an example of a mating pin type five-core connector 15.
Two fitting portions 15b are formed extending from both side walls of the end portion of the base portion 15a of the connector 15, and each of these fitting portions 15b has a pin hole for fitting a fitting pin 16 thereinto. 1
5c is drilled. In addition, the front end surface of the fitting portion 15b (
15b" is the end surface 15a' of the base 15a.
It is retreating backwards by a length X. Moreover, the fitting part 15
The length of pin 16 is behind b! longer than (length L>f
f1) A space is formed.

FIG. 4 shows the connector 1 shown in FIG. 2 from the state in which the connector 13 and connector 10 shown in FIG.
A connector switching device 20 for switching the state in which the connector 3 and the connector 8 are connected is shown. In addition, connector 8
．． 10 and 13 are the connectors 1 shown in FIG. 3 above.
In Figure 0, which uses the same structure as 5, the connector switching device 20 is composed of bases 2 and 1, a pin pushing mechanism 22 and a connector moving mechanism 23 mounted on the base 21. . A connector accommodating groove 24 is formed in the base 21 and extends from the minus side 21a to the other side 21b. This groove 24 is formed on one side 21a from the center position of the base 21.
A groove 24a extends to the other side 21b and has a groove width sufficient for fitting the connector 13, and a groove 24a extends to the other side 21b and has a groove width for three connectors, and is symmetrical about the central axis along the longitudinal direction of the groove 24. It consists of a groove 24b. Then, in the groove 24b, the connector 10 is installed opposite to the connector 13 that is inserted into the groove 24a, as will be described later, and the connector 8 is installed in close contact with one side of the connector 10 on the side of the connector moving mechanism 23 (described later). On the other side of the connector 10, there is further a connector 1.
There is still space left to accommodate individuals. Pin extrusion mechanism 22
is composed of an extrusion block 22a and a driving device ff22b, and is arranged in a space 21c communicating with the groove 24a. The extrusion block 22a has an integrally formed arm 22.
The distal end of the arm 22a' projects from the space 21c into the groove 24a. The extrusion block 22a is movable along the longitudinal direction of the groove 24a by a drive device 22b, and as described later, the arm 22a.

Connect the tip of the connector 13 to the pin hole (connector 1 in Figure 3).
One end of the pin 26 is engaged with the other end of the pin 26 inserted into the hole (corresponding to the pin hole 15c of No. 5), and the pin 26 is moved in the direction of being pushed into the pin hole.

On the other hand, the connector moving mechanism 23 is disposed in a space 21d formed below the groove 24b in communication with the groove 24b, and between a moving table 23a that can come into close contact with the connector 8, and the bottom surface of the space 21d and the moving table 23a. It is comprised of an elastic member, for example, a compression spring 23b, which is interposed between and urges the moving table 23a upward in the figure (in a direction perpendicular to the optical axis of the optical fiber 4). Furthermore, the movable table 23a has a locking portion 23 at its bottom so that when the compression spring 23b is expanded, that is, moved upward, the movable table 23a stops at a position where its upper surface is flush with the bottom surface of the groove 24a.
a° is formed.

A connector switching operation using such a device will be explained with reference to FIGS. 4 and 5. That is, first, the initial pin 25
The connectors 13 and 10 that have been fitted together are placed in the grooves 24a and 24b of the jig 21 of the switching device 20. At this time, the connector 8 to be switched to the lower part of the connector 10
are fixed together, and the moving table 23a is attached to the compression spring 23b.
If the connectors 10 and 8 are simultaneously placed in the groove 24b by pushing down against the pressure, the efficiency of the switching operation will be improved. After the connectors 10 and 8 are disposed in the groove 24b in this way, the upper surface of the moving table 23a comes into close contact with the lower part of the connector 8.Next, the pin 26 used for fitting the connector 13 and the connector 8 The pin hole 13c is inserted into the pin hole 13c by the pin pushing mechanism 22 from the rear of the fitting part 13b of the connector 13.
Insert into.

In other words, the driving equipment! The push-out block 22a, which engages with the end of the pin 26 by the push-out block 22b, is moved in the direction of the arrow A in FIG.
Move 6. Then, when the abutting surface 27 between the pins 25 and 26 becomes flush with the end surface 13a° of the optical fiber insertion portion 13a of the connector 13, the engagement between the connector 13 and the connector 10 is released. At this time, the moving mechanism 23
The moving table 23a pushes up the connectors 10 and 8 by the expansion of the compression spring 23b, and the connector 8 moves to the connector 1.
Stop at a position that is in line with 3. The pin 25 is inserted into the pin hole 10c of the connector 10 and rises together with the connector 10, and is housed in the upper space 24b. On the other hand, when the connectors 10 and 8 are raised, the pin 26
continues moving to the right. And the base 8 of the connector 8
It is preferable to determine the rising speed so that the pin 26 reaches the open end of the pin hole 8C of the fitting portion 8b of the connector 8 when the end surface 8a' of the connector 13 is aligned with the end surface 13a' of the connector 13. Specifically, if the moving time for one connector by the moving base 23a is Δt, and the moving speed of the pin 26 to the right is V, then the value of the moving speed V is set so as to satisfy the following formula: % formula % All you have to do is decide
However, in the above equation, Δt is a value determined by the weight of the moving table 23a in the moving mechanism 23, the spring constant of the compression spring 23b, etc. Note that the above equation is the speed while the pin 26 moves over the distance M2x shown in FIG. 5, and the speed in other areas may deviate from this equation.

In addition, in FIG. 4 above, the operation for switching the connector IO connected to the connector 13 in the switching area A shown in FIG. 1 to the connector 8 was explained. The operation of switching the previously used connector 11 to the connector 9 can also be performed using the same connector switching device as described above. It is efficient to perform these connector switching operations at the same time.

FIG. 6 is a schematic diagram of a measurement system showing a second embodiment of the optical line testing method of the present invention, in which a 2×2 optical coupler 30 is used in place of the optical power bluff shown in FIG. There is. in this case,
The optical jumper wire 12 as shown in FIG.
The 2×2 coupler 30, which may be formed at any location, is, for example, formed by fusion-bonding two optical fibers at a portion thereof, and has four ports 30a to 30d. Connectors 31 and 32 are provided on the boats 30a and 30b. 30 more boats
c is connected to the pulse tester (OTDR) 5,
A total reflection surface 33 is formed on the end face 0d.

When inserting such a test system in the middle of the optical fiber 4, the seventh
As shown in the figure, the connector 13 of the optical fiber 4 and the connector 31 of the optical coupler 30 are connected, and the connector 14 of the optical fiber 4 and the connector 32 of the optical coupler 30 are connected, respectively.

This connector switching operation can also be performed easily and in a short time by using the connector switching device as described above.

In Figure 7, during the test, an electrical-to-optical converter (Elo
) 1 is introduced into the boat 30a of the optical coupler 30 through the optical fiber 4 and the connectors 13 and 31,
Thereafter, the signal branches into boats 30c and 30d at the fused portion of the coupler 30, and is inputted from the boat 30c to the 0TDR5.

On the other hand, the signal branched to the boat 30d is totally reflected by the total reflection surface 33, and is then reflected between the boats 30a and 3 by the fused part of the coupler 30.
0b and from the boat 30b to the connector 32 and -
and is transmitted to the optical/electrical converter (0/E) 2 via the connector 14. At this time, when a 1:1 branching ratio is used as the 2×2 coupler 30, as shown in FIG. 0.5 of each is transmitted. Then, as shown in FIG. 8(b), the signal totally reflected by the total reflection surface 33 is branched to the boats 30a and 30b at a ratio of 1:1. Therefore, the signal transmitted from the electrical/optical converter (Elo) 1 to the optical/electrical converter (0/E) 2 is 0.25
The signal is attenuated to 1/4 compared to the input signal. Therefore,
Compared to the case where the tri coupler 7 shown in FIG. 1 is used, this has the advantage of not requiring jumper wires, but on the other hand, it is unavoidable that the signal attenuation rate becomes relatively large.

FIG. 9 shows a third embodiment of the present invention, and schematically represents a measurement system when the test method of the present invention is applied to a multicore cable. In this embodiment, the test system 40 consists of a 1×5 scan switch (having the function of selecting only one of the five cores) connected to the TDR5, a 41.5-core tape, and a 42.5-core combined waveform. Corrugator 43 and 5-core tape 42
5-core connectors 44 and 45 arranged at both ends of the connector.

On the other hand, an electrical/optical converter (Elo) 51 and an optical/electrical converter (0/E) 52 are connected by a 5-core optical fiber 53, and 5-core connectors 5 are connected at both ends of the optical fiber 53.
A five-core optical jumper wire 56 having a diameter of 4.55 is interposed between five-core connectors 57 and 58 disposed in the middle of the optical fiber 53.

Note that the area surrounded by the broken line B in the figure is the connector switching area.

In such a configuration, during testing, the connectors 54 at both ends of the optical jumper wire 56 are connected in the connector switching area B.
．． 55 to the connectors 44 and 45 of the test system 40, the test system 40 is inserted midway through the optical fiber 53. It is possible to use the connector switching device as described above at the time of this switching as well.

In the multicore cable test system described above, the insertion loss for the test light is made zero by using an optical multiplexer/demultiplexer instead of an optical coupler. In addition, it is possible to selectively measure 1 out of 5 cores using an optical scan switch.
The 0TDR makes it possible to sequentially measure multi-core cables.

(Effects of the Invention) As explained above, according to the present invention, in a test method for inserting a test system into an optical line under test and evaluating the characteristics of the optical line, the test system is connected to a test device and the test device. and an optical coupler that is connected to a Since the test system is inserted into the optical line by connecting the
Optical line characteristic evaluation tests can be carried out extremely economically.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams of a test system used in the optical line characteristic evaluation test method according to the first embodiment of the present invention, and Figure 3 is a conceptual diagram showing the structure of a connector used in the present invention. , FIG. 4 is a conceptual configuration diagram of a connector switching device, FIG. 5 is an explanatory diagram for explaining the connector switching operation, and FIGS. 6 and 7 are diagrams of an optical line according to a second embodiment of the present invention. The schematic diagram of the test system used in the characteristic evaluation test method, Figure 8, is the same as the above-mentioned 2.
FIG. 9 is a schematic diagram of the test system used in the optical line characteristic evaluation test method according to the third embodiment of the present invention. The figure is a schematic diagram of a test system used in a conventional optical line characteristic evaluation test method. 4...Optical fiber, 5...Pulse test 1m (OT
OR), 6... Test system, 7... Optical coupler, 8.9.
10.11.13.14.15... Connector, 16.
25.26...Mating bin, 20...Connector switching device, 30...2x2 optical coupler, 44.45.54.5
5.57.58...5-core connector.

Claims (2)

[Claims] (1) In a test method in which a test system is inserted into an optical line under test to evaluate the characteristics of the optical line, the test system is connected to a test device and an optical coupler connected to the test device and having connectors at both ends. At the same time, a pair of connectors is disposed at at least one location on the optical path, and a test system is installed in the optical path by connecting the connector of the optical coupler and the connector of the optical path during the test. A test method for evaluating the characteristics of an optical line, which is characterized by inserting an optical line. (2) When connecting a pair of connectors arranged at one location of the optical path and a connector of the optical coupler, the connector of the optical coupler is arranged in advance adjacent to one of the pair of connectors. disengaging the one connector from the other connector that engages with it, and moving the one connector away from the other connector at right angles to the optical axis of the optical path. , by moving the connector of the optical coupler together with the connector of the optical coupler and moving the connector of the optical coupler to the position before the movement of the one connector, thereby engaging the other connector and the connector of the optical coupler. 2. The optical line characteristic evaluation test method according to claim 1, wherein the optical line is connected.