JP4139825B2 - Optical signal level measuring jig and optical signal level measuring method in optical transmission line - Google Patents

Description

  The present invention relates to a jig used for measuring the optical signal level of an optical fiber and a method for measuring the optical signal level of an optical transmission line using a measuring jig.

  In recent years, FTTH (Fiber To The Home) that directly draws an optical fiber from a station building to a terminal user has been installed in order to spread a high-speed broadband service for communication. As a recent trend of FTTH, the optical fiber is branched from the one-to-one SS (single star) system in which the optical fibers are individually drawn one by one, and the optical signal is distributed via an optical splitter that mixes the upstream and downstream. To one-to-many PDS (passive double star) system. As a result, the number of locations connecting optical fibers, such as closures provided in underground cable routes, branch line closures and drop closures provided in overhead cable routes, has increased from the station building to end users.

  By the way, there are fusion splicing and mechanical splice (mechanical splicing) for optical fiber connection, and mechanical splice is the mainstream because of cost advantage, but generally the defect occurrence rate is higher than that of splicing splicing. When an opening failure due to an optical fiber connection failure occurs, it is complicatedly entangled with causes such as a device failure or a network setting failure, making it difficult to identify the cause. In addition, it is necessary to perform complicated and time-consuming trouble point exploration work from the final end using expensive equipment, and a large amount of reworking work occurs. Therefore, it is very important to confirm the line state by measuring the optical signal level of the upstream optical fiber before connecting the optical fiber at the connection position of the optical fiber. In the PDS system, since the optical fiber is multi-branched by the optical splitter, if there is a problem with the connection of the optical fiber to the optical splitter and the optical splitter, the influence will increase to the downstream side. It is important to measure the optical signal level before and after the splitter.

  In other words, when establishing an optical transmission line from the station building to the end user, the design is such that the transmission loss is within the dynamic range. It is important to check whether or not

  Here, transmission loss (dB) = 0.37 × L + 0.5 × Nc + 0.07 × Ns + 0.1 × Nm + Br + system margin is obtained. However, L: transmission path distance (km), Nc: connector connection location, Ns: fusion connection location, Nm: mechanical splice connection location, Br: coupler insertion loss, system margin: 1 dB.

  The coupler insertion loss Br is 2 branches: 3.5 dB, 4 branches: 7.0 dB, 8 branches: 10.5 dB.

  Incidentally, the average connection loss due to the fusion splicing mainly used for the permanent connection of the trunk line system is around 0.1 dB, the average connection loss due to the mechanical splice mainly used for the permanent connection of the access network is The average connection loss by an optical connector employed for permanent connection that requires attachment / detachment, such as a terminal of an apparatus, is about 0.3 dB.

On the other hand, in order to confirm the line state of the optical fiber, in order to measure the optical signal level, it is necessary to perform a fusion splicing with a small connection loss (see, for example, Patent Document 1). Specifically, an optical fiber whose optical signal level is to be measured is fused and connected to an optical fiber of an optical connector with an optical fiber cord specified in JIS C 5970, and the optical connector of the optical connector with an optical fiber cord is connected. An optical power meter is connected to measure the optical signal level.
JP 2004-317945 A

  By the way, as described above, an optical fiber whose optical signal level is to be measured and an optical fiber of an optical connector with an optical fiber cord are connected by a fusion splicing with a small connection loss, and the optical signal level is measured by an optical power meter. In addition to the expensive equipment for fusing optical fibers, the connection work requires a lot of time, and the construction period is prolonged and the construction cost is increased. For this reason, the measurement work of the optical signal level at the connection point may be omitted. As a result, if a poor opening occurs after the construction of the optical transmission path, as described above, it becomes difficult to identify the cause, and the failure point search A large amount of rework work such as work will occur. In addition, it is necessary to match the optical fiber axis centers with a fixed pressing force and fuse them while excluding dust and the like, and in the outside world, especially in the overhead cable route It is difficult to make a fusion splice. Furthermore, after the measurement of the optical signal level is completed, in order to connect the optical fiber to the downstream optical fiber, the fusion spliced part between the measured optical fiber and the optical fiber of the optical connector with the optical fiber cord must be removed. The work is complicated.

  The present invention has been made in view of such problems, and is an optical signal level measurement treatment that can temporarily connect an optical fiber with an optical fiber of an optical power meter or an optical connector with an optical fiber cord with low loss. Prior to the main connection of the optical fiber, the optical fiber is temporarily connected to the optical fiber of the optical power meter or the optical connector with the optical fiber cord with low loss, and the optical signal level can be measured easily and in a short time. It is an object of the present invention to provide a method for measuring the optical signal level of an optical transmission line that can grasp the line state of the optical transmission line.

  The optical signal level measurement jig of the present invention temporarily connects an optical fiber to an optical power meter or to an optical fiber of an optical connector with an optical fiber cord connected to the optical power meter with low loss. A measuring jig, comprising a base, a gripping member of an optical fiber core wire slidably provided at one end of the base, and a connector member provided at the other end of the base, The connector member prevents a holder provided on the base, a self-alignment ferrule disposed on the holder via a spring, a connection nut attached to the holder, and the ferrule and the connection nut from coming off. And a frame with a guide key screwed to the holder, and a gripping member that grips the optical fiber core wire is slid by a distance corresponding to the length of the ferrule, thereby An optical connector with an optical fiber cord is inserted through the inner hole of the ferrule and the tip of the optical fiber is opposed to a sensor of an optical power meter screwed to the connection nut, or is screwed to the connection nut. The optical fiber is butted against the tip of the optical fiber.

  In the present invention, the connector member is manufactured with reference to the F01 type single-core optical fiber connector defined in JIS.

  In the present invention, the ferrule having a self-alignment property is not particularly limited, and examples thereof include a ferrule made of crystallized glass.

  According to the present invention, the optical fiber core wire is gripped by the gripping member, the gripping member is pushed by a distance corresponding to the length of the ferrule, the optical fiber is inserted into the inner hole of the ferrule, and the light that is screwed to the connector member. The optical fiber of the optical connector with an optical fiber cord that faces the sensor of the power meter or is connected to the optical power meter and screwed to the connector member is abutted. At this time, the ferrule has a self-alignment property, so that the optical fiber can be held concentrically in the inner hole of the ferrule. Further, since the optical fiber is pushed by a distance corresponding to the length of the ferrule, it does not protrude from the tip of the ferrule until it reaches the sensor of the optical power meter, and the sensor is not damaged.

  As a result, it is possible to temporarily connect the optical fiber held by the jig directly to the optical power meter with low loss without causing an axis deviation and without damaging the sensor. In addition, the optical fiber of the optical connector with the optical fiber cord can be abutted against the optical fiber, and the optical fiber of the optical connector with the optical fiber cord can be temporarily connected with low loss. Therefore, the optical signal level of the optical fiber can be measured with an optical power meter directly or via an optical connector with an optical fiber cord with low loss.

  In the present invention, when a groove having a V-shaped cross section facing the insertion hole of the holder is formed on the upper surface of the base along the optical fiber arrangement direction, the optical fiber is smoothly moved along the V-shaped groove. The optical fiber can be inserted into the inner hole of the ferrule and the optical fiber is abutted with the optical fiber of the optical connector with the optical fiber cord with a constant pressing force, and is grasped by the bending of the optical fiber within the range of the V-shaped groove. Can be preferred.

  In the present invention, when a dimensional scale is attached to the upper surface of the base along the optical fiber arrangement direction, the length of the ferrule is increased by pushing the gripping member with the end face of the optical fiber core line aligned with the dimensional scale. The optical fiber can be inserted through the ferrule by a distance corresponding to the length, and the work is facilitated as compared with the case where a small-diameter optical fiber is placed along the end face of the ferrule, which is preferable.

The method for measuring the optical signal level in the optical transmission line of the present invention is based on the upstream side prior to the fusion splicing or mechanical splicing of the optical fiber at the connection point of the optical fiber when laying the optical fiber from the office building to the end user. 4. An optical connector with an optical fiber cord, wherein the optical fiber is temporarily connected to the optical power meter with a low loss via the measurement jig according to claim 1 or connected to the optical power meter. The optical signal level is measured by temporarily connecting to the optical fiber with a low loss via the measuring jig according to any one of claims 1 to 3 .

  According to the present invention, prior to the main connection of the optical fiber, the upstream optical fiber is temporarily connected to the optical power meter directly with a low loss through the measurement jig at the connection position of the optical fiber, or upstream. The optical fiber on one side is temporarily connected to the optical fiber of the optical connector with one optical fiber cord through a measurement jig with low loss, and the optical connector with the other optical fiber cord is connected to the optical power meter. The optical signal level of the optical fiber is measured.

  As a result, it is possible to measure the optical signal level by a simple operation as compared with the case of measuring the optical signal level of the optical fiber by fusion splicing, and by greatly reducing the number of work steps. Therefore, since it is possible to reliably grasp the connection failure at the connection point of the optical fiber without taking time, the measurement of the optical signal level is surely performed, and the revisit to the user when the connection failure occurs, This eliminates complicated and time-consuming work such as exploring failure points.

  Here, the loss due to the temporary connection of the optical fiber is about 1 dB so as not to cause a large measurement error in the dynamic range of the optical transmission line with reference to the connection loss of the fusion splicing, mechanical splice, and optical connector. Is preferred.

The method of measuring the optical signal level in the optical transmission line of the present invention is based on the optical splitter before connecting the optical fiber to the optical splitter at the branching point of the optical fiber when laying the optical fiber from the office building to the end user. The optical fiber on the upstream side is temporarily connected to the optical power meter with a low loss via the measurement jig according to any one of claims 1 to 3 , or with an optical fiber cord connected to the optical power meter The optical signal level is measured by temporarily connecting to the optical fiber of the optical connector with a low loss via the measuring jig according to any one of claims 1 to 3 , while the optical signal is connected after the optical fiber is connected to the optical splitter. and temporarily connected with low loss in the optical power meter and optical fiber on the downstream side of the splitter via a measuring jig according to any one of claims 1 to 3, or is connected to an optical power meter Is characterized in measuring the optical signal level is temporarily connected with low loss through the measurement jig according to any one of the optical fibers of the optical fiber cord with the optical connector according to claim 1 to 3 .

  According to the present invention, the optical fiber on the upstream side of the optical splitter is temporarily connected to the optical power meter via the measurement jig at a low loss prior to the main connection of the optical fiber to the optical splitter at the branch point of the optical fiber. Or connect temporarily to the optical fiber of one optical fiber cord-attached optical connector via a measurement jig with low loss, and connect the other optical connector with an optical fiber cord to an optical power meter, The optical signal level of the optical fiber upstream is measured. Also, after connecting the optical fiber to the optical splitter, the optical fiber downstream of the optical splitter is temporarily connected to the optical power meter directly through the measurement jig with low loss, or one optical connector with an optical fiber cord Is temporarily connected to the optical fiber through a measurement jig with low loss, and the other optical connector with an optical fiber cord is connected to the optical power meter to measure the optical signal level of the optical fiber downstream of the optical splitter. .

  As a result, it is possible to measure the optical signal level by a simple operation as compared with the case of measuring the optical signal level of the optical fiber by fusion splicing, and by greatly reducing the number of work steps. Therefore, it is possible to reliably grasp the connection failure of the optical fiber to the optical splitter and the failure of the optical splitter without taking time, so that the measurement of the optical signal level is performed reliably and when the connection failure occurs. Re-visiting users such as re-visiting users and complicated and time-consuming trouble point exploration can be eliminated.

  Here, the loss due to the temporary connection of the optical fiber is about 1 dB so as not to cause a large measurement error in the dynamic range of the optical transmission line with reference to the connection loss of the fusion splicing, mechanical splice, and optical connector. Is preferred.

  According to the optical signal level measuring jig of the present invention, an optical fiber can be temporarily connected to an optical fiber of an optical power meter or an optical connector with an optical fiber cord with low loss.

  Further, according to the method for measuring the optical signal level of the optical transmission line of the present invention, prior to the main connection of the optical fiber, the optical fiber is temporarily connected to the optical fiber of the optical power meter or the optical connector with the optical fiber cord with low loss. The optical signal level can be measured easily and in a short time, and the line state of the optical transmission line can be grasped.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIGS. 1 to 3 show an embodiment of a measuring jig 1 used in the method for measuring an optical signal level in an optical transmission line according to the present invention.

  The jig 1 includes a base 2, an optical fiber core gripping member 3 provided at one end of the base 2 via a gripping guide 21, and a mounting plate 22 at the other end of the base 2. Connector member 4 formed.

  The base 2 is formed in a substantially flat rectangular parallelepiped shape, and a plurality of parallel lines 2x extending in the longitudinal direction across the center line in the width direction are attached to the upper surface thereof. It can be used as a deflection gauge for optical fiber cores arranged along the direction.

  The holding member 3 is formed in a rectangular parallelepiped shape with urethane rubber, and a slit 3a is formed on the center line in the width direction. For this reason, when the optical fiber core line arranged along the longitudinal direction of the base 2 is inserted into the slit 3 a of the gripping member 3, it can be held so as not to move by the elastic force of the gripping member 3.

  The connector member 4 is manufactured with reference to the F01 type single-core optical fiber connector specified in JIS C 5970, and is loosely fitted in a mounting hole 22a (see FIG. 2) formed in the mounting plate 22 of the base 2. A flanged holder 41 in which an insertion hole 41a of the optical fiber f is formed, and a ferrule 43 having a self-alignment property inserted into the flanged holder 41 via a spring 42, for example, a crystallized glass ferrule, The connection nut 44 attached to the flanged holder 41 and the frame 45 with a guide key having a female screw 451 that can be screwed into the male screw 411 of the flanged holder 41 prevent the ferrule 43 and the connection nut 44 from coming out. The guide key frame 45 can be screwed to the flanged holder 41. (See FIG. 3).

  Examples of the ferrule 43 having self-alignment properties include a crystallized glass ferrule related to the manufacture and sale of Nippon Electric Glass. The ferrule 43 has an inner hole 43a that is located on the center of the ferrule 43 and penetrates from one end to the other end. A flare portion 43b that guides the optical fiber f to the inner hole 43a is formed at one end. At the other end, a chamfer 43c is formed at the outer peripheral edge. Further, a flange member 431 is fixed to one end portion of the ferrule 43.

  Here, in the crystallized glass ferrule of the embodiment, the outer diameter is 2.499 mm ± 0.0005 mm, the inner diameter of the inner hole 43a through which the optical fiber f is inserted is 0.126 mm + 0.001 / −0 mm, The concentricity tolerance is set so that the center is located in a circle having a diameter of 0.0014 mm centered on the center of the outer periphery.

  Using the jig 1 configured in this manner, the optical fiber f is abutted against the optical fiber f of the optical connector 6 with an optical fiber cord (see FIG. 4) stipulated in JIS C 5970 and temporarily connected. It measured based on the optical fiber loss test prescribed | regulated to JISC6823,6826. The test results are shown in FIG.

  Whether the test result is when an optical connector with an optical fiber cord manufactured by A company is used or when an optical connector with an optical fiber cord manufactured by B company is used, the connection loss is within the range of 1 dB. Thus, it is clear that the optical fiber f is temporarily connected with low loss without causing an axis deviation or an axis inclination (see FIGS. 6A and 6B).

When connecting the optical fiber f, the loss due to the axial deviation of the optical fiber f is obtained by Loss = 4.34 (d / (W / 2)) ² .

  Here, d indicates the amount of axial deviation of the optical fiber f, and W indicates the outer diameter of the optical fiber f. When the amount of axial misalignment in a crystallized glass ferrule having a concentricity of 0.7 μm or less is maximum, the calculated connection loss is 0.5 dB.

  Next, a procedure for temporarily connecting the optical fiber f using the jig 1 configured as described above and measuring the optical signal level will be described with reference to FIGS.

  First, an optical connector 5 defined in JIS C 5970 and an optical connector 6 with an optical fiber cord are prepared, and one optical connector 61 of the optical connector 6 with an optical fiber cord is attached to an optical power meter 7 (type 211A manufactured by Gray Technos). And the optical connector 5 is connected to the other optical connector 61. Next, the connection nut 44 of the connector member 4 in the jig 1 is coupled to the optical connector 5.

  Here, in the middle of the optical connector 5, the front end face of the ferrule in the optical connector 6 with the optical fiber cord and the front end face of the ferrule 43 of the connector member 4 in the jig 1 are abutted.

  On the other hand, although not shown in detail for the optical fiber cord of the optical fiber f whose optical signal level is to be measured, the optical fiber f is exposed by peeling the core wire in advance with a fiber stripper and using a fiber cutter. Then, the end face is cut so that there is no chipping or burrs, and the length of the exposed optical fiber f is a length corresponding to the mechanical splice, for example, 12.5 mm.

  When such preparation is completed, the optical fiber cord to be measured is gripped, and the optical fiber f is inserted into the insertion hole of the flange member 431 to which the ferrule 43 is fixed through the insertion hole 41a of the flanged holder 41. On the other hand, the optical fiber core wire is inserted into the slit 3a of the gripping member 3, and the optical fiber core wire is held. After that, the optical fiber f reaches the tip surface through the inner hole 43a of the ferrule 43 by gradually pushing out toward the front in a state where the optical fiber core wire is held by the holding member 3, and the optical fiber cord-attached light The optical fiber f fixed to the inner hole of the ferrule of the optical connector 61 in the connector 6 with an adhesive in a concentric state with the center of the inner hole. Then, the optical fiber core wire is further pushed in slightly so that the end faces come into surface contact with the optical fiber f of the optical fiber cord-attached optical connector 6 with a constant pressing force. At this time, the fact that the end faces of the optical fibers f are brought into surface contact with a constant pressing force is that the optical fiber core wire is bent within a range of a line 2x as a bending gauge attached to the upper surface of the base 2. To grasp. That is, an excessive pressing force acts on the optical fiber f to prevent the tip surface of the optical fiber f from being chipped or broken.

  When the temporary connection of the optical fiber f is completed, the optical power meter 7 may be operated to measure the optical signal level of the optical fiber f. Here, as described above, the optical signal level at the measurement point has already been grasped, and by comparing the optical signal level with the measured optical signal level, the upstream optical fiber f can be connected. It is possible to grasp whether or not there is a problem.

  As a result, the optical signal level of the upstream optical fiber f can be easily measured prior to the main connection of the optical fiber f, and the connection failure at the connection point of the optical fiber f can be reliably grasped. In addition, compared with the case where the optical signal level is measured by fusion splicing of the optical fiber f, it is possible to greatly reduce the number of work steps and improve the certainty of the construction. In addition, it is possible to eliminate rework such as revisiting the user when connection failure occurs and complicated and troublesome fault point search.

  In the above-described embodiment, the case where the optical signal level at the connection point of the optical fiber f is measured has been described. However, the embodiment can also be applied to the case where the optical signal level is measured at a branch point where the optical fiber f is branched. .

  That is, one optical connector 61 of the optical connector 6 with an optical fiber cord is connected to the optical power meter 7, the optical connector 5 is connected to the other optical connector 61, and the connector member 4 in the jig 1 is connected to the optical connector 5. After connecting the connection nut 44, the upstream optical fiber f connected to the optical splitter is temporarily connected to the optical fiber f of the optical connector 6 with an optical fiber cord through the jig 1 with low loss. Measure the optical signal level. Similarly, after the upstream optical fiber f is connected to the optical splitter, the downstream optical fiber f is connected to the optical splitter, and the optical signal level of the connected downstream optical fiber f is measured. It is possible to grasp the failure of the splitter or the failure of the branch connection portion.

  7 to 9 show another embodiment of the optical signal level measuring jig 1 of the present invention.

  The jig 1 also includes a base 2, an optical fiber core gripping member 3 provided at one end of the base 2 via a gripping guide 21, and a connector member 4 provided at the other end of the base 2. , Is composed of.

  The base 2 is a flat cuboid having a rectangular parallelepiped cutout A in one half, and the upper surface of the other half is located at the center in the width direction from the inner end edge in the longitudinal direction to the outer end. A groove 2y having a V-shaped cross section extending toward the edge is formed, and a dimension label 22 with the outer edge as a reference is attached. A guide hole 2a penetrating in the vertical direction is formed in the longitudinal direction in the half portion where the notch A is formed, and a protrusion 211 provided on the lower surface of the grip guide 21 is formed in the guide hole 2a. It is mated. The protrusion 211 of the gripping guide 21 is screwed from the bottom surface side of the base 2 to prevent the gripping guide 21 from falling off the base 2.

  A notch ball 23 is provided on the lower surface of the gripping guide 21, while a fitting recess 2b into which the notch ball 23 can be fitted on the upper surface of one half of the base 2 on which the notch A is formed. The notch ball 23 is fitted into the fitting recess 2b, whereby the stroke of the grip guide 21 can be regulated. Specifically, when the notch ball 23 of the grip guide 21 is slid from the state where the notch ball 23 is fitted to the fitting recess 2b on the one end side to the position where the notch ball 23 is fitted to the fitting recess 2b on the other end side, the grip guide 21 is set to move by a distance corresponding to the length of the ferrule 43 including the flange member 431.

  The holding member 3 is formed in a rectangular parallelepiped shape with urethane rubber, and a slit 3a is formed on the center line in the width direction. For this reason, when the optical fiber core line arranged along the longitudinal direction of the base 2 is inserted into the slit 3 a of the gripping member 3, it can be held so as not to move by the elastic force of the gripping member 3.

  Since the connector member 4 is not different from the connector member 4 of the above-described embodiment except that a stopper holder 46 in which a mounting plate and a holder with a flange are integrated is used, the same member is denoted by the same reference numeral. Detailed description thereof is omitted.

  The stopper holder 46 is formed with an insertion hole 46a at a position facing the V-shaped groove 2y of the base 2 when the stopper holder 46 is screwed to the distal end surface of the base 2. The optical fiber f disposed in the groove 2y can be guided into the insertion hole 46a of the stopper holder 46. The stopper holder 46 is formed with a male screw 461 that can be screwed into the female screw 451 of the frame 45 with a guide key.

  Using the jig 1 of this embodiment, the optical fiber f is abutted against and temporarily connected to the optical fiber f of the optical connector 6 with an optical fiber cord defined in JIS C 5970, and the loss is defined in JIS C 6823, 6826. Measured according to the optical fiber loss test. The test results are shown in FIG.

  According to the test results obtained by measuring each of the five types of optical connectors with optical fiber cords 10 times, the connection loss is a calculated connection loss of 0.5 dB obtained from an expression for determining the loss due to the axis deviation of the optical fiber f. It is apparent that the optical fiber f is temporarily connected with low loss without causing any axial deviation or axial inclination of the optical fiber f.

  In this case, the reason why the connection loss is reduced as compared with the case where the jig 1 of the previous embodiment is used is that the optical fiber f gripped by the gripping member 3 is only fixed, that is, the flange through the gripping guide 21. This is considered to be because the optical fiber f is abutted with a constant pressing force by moving it by a distance corresponding to the length of the ferrule 43 including the member 431.

Specifically, when the pressing force of the optical fiber f when the jig 1 of the present embodiment is used is measured, if the optical fiber f is in the V-shaped groove 2y, it is ² to 3 N / mm ² . Yes, the pressing pressure is greatly reduced compared to the JIS standard that stipulates that a low loss connection of 0.5 dB or less is obtained by pressing ferrules with a diameter of 2.5 mm at 7 to 11 N / mm ^2. ing.

  A procedure for temporarily connecting the optical fiber f using the jig 1 and measuring the optical signal level will be briefly described with reference to FIG.

  First, one optical connector 61 of the optical connector 6 with an optical fiber cord is connected to the optical power meter 7, the optical connector 5 is connected to the other optical connector 61, and the connector member 4 in the jig 1 is connected to the optical connector 5. The connecting nut 44 is coupled.

  Here, in the middle of the optical connector 5, the front end face of the ferrule in the optical connector 6 with the optical fiber cord and the front end face of the ferrule 43 of the connector member 4 in the jig 1 are abutted.

  On the other hand, after confirming that the grip guide 21 is positioned on the rear end side (the state shown in FIG. 10A), the optical fiber cord to be measured for the optical signal level is gripped, and the optical fiber core Is inserted into the slit 3 a of the gripping member 3 to hold the optical fiber core wire, and the optical fiber f is disposed in the V-shaped groove 2 y of the base 2, and its tip is immediately before the insertion hole 46 a of the stopper holder 46. To be located. Next, the grip guide 21 is pushed forward and moved to a position where the notch ball 23 is fitted into the front fitting recess 2b. Since the movement amount of the gripping guide 21 is a distance corresponding to the length of the ferrule 43 including the flange member 431, the tip of the optical fiber f held by the gripping member 3 fixed to the gripping guide 21 is also the same amount. It moves forward only, and reaches the vicinity of the tip of the inner hole 43a through the insertion hole of the flange member 431 in the ferrule 43. That is, since the tip of the optical fiber f is at a position facing the insertion hole 46a of the stopper holder 46 (position at a slight distance to the end face of the flange member 431 of the ferrule 43) before the grip guide 21 is moved, Even with the movement of the guide 21, the optical fiber f of the optical connector 6 with the optical fiber cord is not yet abutted. Thereafter, the optical fiber f reaches the distal end surface of the inner hole 43a of the ferrule 43 by gradually pushing it toward the front while holding the optical fiber core wire with the gripping member 3, and the optical connector 6 with the optical fiber cord. The optical connector 61 is in contact with the optical fiber f fixed to the inner hole of the ferrule of the optical connector 61 with an adhesive concentrically with the center of the inner hole. Then, the optical fiber core wire is further pushed slightly in such a manner that the tip surfaces come into surface contact with the optical fiber f of the optical connector 6 with an optical fiber cord with a constant pressing force, and within the range of the V-shaped groove 2y. Understand by bending. At this time, the front end surfaces of the optical fibers f are in surface contact with a constant pressing force without the front end surfaces of the optical fibers f being chipped or broken.

  When the temporary connection of the optical fiber f is completed, the optical power meter 7 may be operated to measure the optical signal level of the optical fiber f. Then, by comparing the required optical signal level at the measurement point with the measured optical signal level, it is possible to grasp whether or not there is a problem in the connection of the upstream optical fiber f.

  As a result, the optical signal level of the upstream optical fiber f can be easily measured prior to the main connection of the optical fiber f, and the connection failure at the connection point of the optical fiber f can be reliably grasped. In addition, compared with the case where the optical signal level is measured by fusion splicing of the optical fiber f, it is possible to greatly reduce the number of work steps and improve the certainty of the construction. In addition, it is possible to eliminate rework such as revisiting the user when connection failure occurs and complicated and troublesome fault point search.

  In the above-described embodiment, the case where the optical signal level at the connection point of the optical fiber f is measured has been described. However, the embodiment can also be applied to the case where the optical signal level is measured at a branch point where the optical fiber f is branched. .

  When the jig 1 according to this embodiment is used, the optical signal level of the optical fiber f can be directly connected to the optical power meter 7 without using the optical connector 6 with an optical fiber cord.

  That is, after connecting the connection nut 44 of the connector member 4 in the jig 1 to the optical power meter 7, the optical signal level is measured in the slit 3 a of the gripping member 3 located on the rear end side of the base 2. The optical fiber core wire is inserted and held, and the optical fiber f is disposed in the V-shaped groove 2 y of the base 2 with its tip positioned immediately before the insertion hole 46 a of the stopper holder 46. At this time, the boundary between the optical fiber f and the optical fiber core wire is positioned at the length of the optical fiber f using the dimension label 22. Specifically, when performing mechanical splicing, as described above, the optical fiber f and the optical fiber are placed at the 12.5 mm dimension scale position of the dimension label 22 by cutting the optical fiber f leaving 12.5 mm. Place the boundary with the core. In this way, by using the scale of the dimension label 22, the optical fiber core is smaller than the case where the tip of the optical fiber f that is extremely small in diameter and difficult to confirm is disposed so as to face the insertion hole 46 a of the stopper holder 46. Since the wire has a relatively large diameter and is easy to see, the optical fiber f can be easily arranged at the set position.

  Next, when the grip guide 21 is pushed forward and the tip of the optical fiber f is moved forward by a length corresponding to the length of the ferrule 43 including the flange member 431, the insertion of the flange member 431 in the ferrule 43 is performed. It reaches the vicinity of the tip of the inner hole 43a through the hole. In this case, although not shown in detail, the sensor surface of the optical power meter 7 is at a position away from the tip surface of the ferrule 43 in the connector member 4 of the jig 1 connected to the optical power meter. Even if the optical fiber f slightly protrudes from the front end surface of the ferrule 43 in the connector member 4 of the tool 1, it is set so as not to damage the sensor surface, and within a certain range in the front-rear direction from the front end surface of the ferrule 43. If the tip of the optical fiber f is positioned, the optical signal level can be measured. Therefore, as described above, the tip of the optical fiber f is moved forward by a length corresponding to the length of the ferrule 43 including the flange member 431 so that the tip of the optical fiber f is near the tip of the inner hole 43a of the ferrule 43. It is possible to measure the optical signal level in a state where it is positioned at the position. Moreover, since the tip of the optical fiber f is in the inner hole 43a of the ferrule 43 and does not protrude from the tip, it is possible to reliably prevent the sensor surface of the optical power meter from being damaged.

  As described above, according to the present invention, it is possible to quickly establish an optical transmission line by preventing the occurrence of connection failure and the like, which can contribute to the construction of a high-speed network.

It is the front view and top view which show one Embodiment of the jig | tool for a measurement of the optical signal level of this invention. It is a disassembled perspective view of the jig | tool of FIG. It is sectional drawing which shows the connector member of the jig | tool of FIG. It is the schematic explaining the method of temporarily connecting an optical fiber using the jig | tool of FIG. 1 and measuring an optical signal level. It is an enlarged view which shows typically the temporary connection part of the optical fiber of FIG. It is a graph which shows the result of the loss test at the time of temporarily connecting an optical fiber using the jig | tool of FIG. It is the sectional view on the AA line of the top view which shows other embodiment of the jig | tool for the measurement of the optical signal level of this invention, a front view, a bottom view, and a front view. It is a disassembled perspective view of the jig | tool of FIG. It is sectional drawing which shows the connector member of the jig | tool of FIG. It is the schematic explaining the method of temporarily connecting an optical fiber using the jig | tool of FIG. 7, and measuring an optical signal level. It is the schematic explaining the method of temporarily connecting an optical fiber directly to an optical power meter using the jig | tool of FIG. 7, and measuring an optical signal level. It is a graph which shows the result of the loss test at the time of temporarily connecting an optical fiber using the jig | tool of FIG.

Explanation of symbols

1 Jig 2 Base 2x line (flexure gauge)
2y V-shaped groove 3 Holding member 4 Connector member 41, 46 Holder 42 Spring 43 Ferrule 43a Inner hole 431 Flange member 44 Connection nut 45 Frame with guide key 5 Optical connector 6 Optical connector with optical fiber cord 61 Optical connector 7 Optical power Meter f optical fiber

Claims (5)

  A measurement jig for temporarily connecting an optical fiber to an optical power meter or to an optical fiber of an optical connector with an optical fiber cord connected to the optical power meter with a low loss. An optical fiber core gripping member provided slidably on one end of the base, and a connector member provided on the other end of the base, the connector member comprising a holder provided on the base; A self-aligned ferrule disposed on the holder via a spring, a connection nut attached to the holder, a frame with a guide key screwed to the holder to prevent the ferrule and the connection nut from coming out, The optical fiber is inserted through the inner hole of the ferrule by sliding a gripping member that grips the optical fiber core wire by a distance corresponding to the length of the ferrule, A fiber tip is opposed to a sensor of an optical power meter screwed to the connection nut, or is abutted against an optical fiber tip of an optical connector with an optical fiber cord screwed to the connection nut. Measuring jig for optical signal level. V-shaped grooves according to claim 1 for measurement jig optical signal level, wherein a is formed along the arrangement direction of the optical fiber facing the insertion hole of the holder on the upper surface of the base . Claim 1 measuring jig of the optical signal level, wherein the size scale is attached along the arrangement direction of the optical fiber on the upper surface of the base. The upstream optical fiber according to any one of claims 1 to 3 , prior to fusion splicing or mechanical splicing of the optical fiber at a connection position of the optical fiber when laying the optical fiber from the office building to the end user. and a temporary connection with low loss in the optical power meter via the measuring jig, or the according to any of claims 1 to 3 in the optical fiber connected to the optical power meter optical fiber cord with the optical connector A method for measuring an optical signal level in an optical transmission line, wherein the optical signal level is measured by temporarily connecting with a low loss through a measuring jig. In the branch portion of the optical fiber when laying the optical fiber to the distal user from the station, prior to the connection of the optical fiber to the optical splitter, one of the optical fiber on the upstream side of the optical splitter claims 1 to 3 and temporarily connected with low loss in the optical power meter via the measuring jig according to, or any of the optical fiber of the connected to the optical power meter optical fiber cord with the optical connector according to claim 1 to 3 and temporarily connected with low loss through the measurement jig according to one of measuring the optical signal level, after the optical fiber to the optical splitter connected optical splitter downstream optical fiber of claim 1 to 3 Temporarily connect to the optical power meter through the measurement jig according to any one of the above, or the optical fiber of the optical connector with an optical fiber cord connected to the optical power meter Method of measuring the optical signal level in the optical transmission path, characterized in that Motomeko which temporarily connected with low loss through the measurement jig according to any one of 1 to 3 for measuring the optical signal levels.

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