JP6755215B2 - Optical line switching device - Google Patents

Description

The present invention relates to an optical line switching device.

For example, Patent Document 1 below proposes a line switching device that controls an optical line switching device to switch a communication light distribution path from a first optical fiber line to a second optical fiber line. In this line switching device, the communication service can be maintained by duplicating a single-core optical fiber line and switching to the second optical fiber line when an abnormality occurs in the communication of the first optical fiber line. There is.

JP-A-2015-226108

It is desired that the line switching device as proposed in Patent Document 1 can be applied to, for example, a tape fiber which is a multi-core optical fiber line. However, when the above-mentioned line switching device is simply applied to the tape fibers, the coupling efficiency due to the difference in the geometric shape in each tape fiber (for example, the deviation of the core spacing between the tape fibers) There is concern about a decline. Further, in the line switching device as described above, it is also required to prevent communication interruption and occurrence of interference when switching lines.

An object of the present invention is to provide an optical communication switching device capable of suppressing a decrease in coupling efficiency and preventing communication interruption and interference even when used for a tape fiber.

The optical line switching device according to one aspect of the present invention includes a communication state between the ONU and the first OLT via the first optical fiber group, and an ONU via a part of the first optical fiber group and the second optical fiber group. An optical line switching device that switches the communication state between the and the second OLT, and is a part of the first optical fiber group, a third optical fiber group that relays the second optical fiber group, and a tape included in the first optical fiber group. The first optical leakage coupling portion that optically couples the core propagation mode and the spatial propagation mode of each optical fiber of the first optical fiber group by bending the fiber, and each optical fiber included in the spatial propagation mode and the third optical fiber group. Based on the optical transfer unit that photocouples the core propagation mode of the above, the optical detection unit that detects light via the third optical fiber group and the optical transfer unit, and the light intensity detected by the optical detection unit, the first The centering mechanism control unit that adjusts the optical coupling state between the optical fiber group and the third optical fiber group and the communication between the ONU and one of the first OLT and the second OLT are cut off, and at the same time, the ONU and the first OLT and A line switching unit for opening communication with any one of the second OLTs is provided.

According to the present invention, it is possible to provide an optical communication switching device capable of suppressing a decrease in coupling efficiency and preventing communication interruption and interference even when used for a tape fiber.

FIG. 1 is a block diagram showing an optical line switching device according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the first optical fiber group. FIG. 3A is a schematic diagram showing an optical coupling portion according to the first embodiment, and FIG. 3B is a schematic diagram showing a part of FIG. 3A from different angles. is there. FIG. 4 is a schematic view showing a connection switching unit. FIG. 5A is a schematic diagram showing a line blocking portion and a first optical fiber group, and FIG. 5B is a schematic diagram showing a state in which the first optical fiber group is blocked by the line blocking portion. It is a figure. FIG. 6 is a block diagram showing an optical line switching device according to the second embodiment. FIG. 7A is a schematic view showing a state in which the second optical fiber group is blocked by the second line blocking portion, and FIG. 7B is a schematic view showing a state in which the second optical fiber group is blocked by the first line blocking portion. It is a schematic diagram which shows the state which the group is blocked. FIG. 8 is a schematic view showing a line branch portion. FIG. 9 is a block diagram showing an optical line switching device according to a third embodiment. FIG. 10 is a schematic view showing the optical coupling portion according to the third embodiment. FIG. 11 is a block diagram showing an optical line switching device according to a fourth embodiment. FIG. 12 is a schematic view showing the optical coupling portion according to the fifth embodiment. FIG. 13 is a schematic view showing the optical coupling portion according to the sixth embodiment.

[Explanation of Embodiments of the Invention]
First, the contents of the embodiments of the present invention will be listed and described.

In one embodiment of the present invention, the communication state between the ONU and the first OLT via the first optical fiber group, and the ONU and the second OLT via a part of the first optical fiber group and the second optical fiber group An optical line switching device that switches the communication state by bending a part of the first optical fiber group, the third optical fiber group that relays the second optical fiber group, and the tape fiber included in the first optical fiber group. The first optical leakage coupling part that optically couples the core propagation mode and the spatial propagation mode of each optical fiber of the first optical fiber group, the spatial propagation mode, and the core propagation mode of each optical fiber included in the third optical fiber group. The first optical fiber group and the first optical fiber group based on the optical transfer unit that photocouples the optical fiber, the optical detection unit that detects the light via the third optical fiber group and the optical transfer unit, and the light intensity detected by the optical detection unit. 3 At the same time as blocking communication between the centering mechanism control unit that adjusts the optical coupling state with the optical fiber group and one of the ONU and the first OLT and the second OLT, any one of the ONU and the first OLT and the second OLT. It is an optical line switching device including a line switching unit for opening communication with the other.

In this optical line switching device, side input / output technology is adopted in the communication between the ONU and the second OLT, and the first optical fiber group and the third optical fiber group are the first optical leakage coupling portion and the third optical fiber group. They are photobonded to each other via an optical transfer unit. Here, based on the intensity of the light passing through the third optical fiber group and the optical transfer unit detected by the optical detection unit, the centering mechanism control unit uses the light of the first optical fiber group and the third optical fiber group. The binding state is being adjusted. As a result, even when used for a tape fiber, it is possible to suppress a decrease in coupling efficiency due to a difference in the geometric shape of each optical fiber group. In addition, the line switching unit blocks communication between the ONU and one of the first OLT and the second OLT, and at the same time opens communication between the ONU and one of the first OLT and the second OLT. , Communication interruption and interference in the optical line switching device can be satisfactorily suppressed.

The optical line switching device further includes a fourth optical fiber group connected to the optical detection unit, and the line switching unit includes the connection of the third optical fiber group and the fourth optical fiber group, and the third optical fiber group and the third optical fiber group. It may have a connection switching part which switches between the connection of 2 optical fiber groups. In this case, when adjusting the optical coupling state between the first optical fiber group and the third optical fiber group, the light output from the ONU and passing through the third optical fiber group is selectively input to the fourth optical fiber group. it can.

The optical line switching device further includes a fourth optical fiber group connected to the optical detection unit and a line branching portion for branching the third optical fiber group into the second optical fiber group and the fourth optical fiber group. , The line switching unit may bend either one of the first optical fiber group and the second optical fiber group, and at the same time, eliminate the bending of the other of the first optical fiber group and the second optical fiber group.

The optical line switching device further includes a centering light source unit that outputs light for centering, and a fifth optical fiber group that connects the centering light source unit and the line switching unit, and the line switching unit is a third. The connection between the optical fiber group and the 5th optical fiber group and the connection between the 3rd optical fiber group and the 2nd optical fiber group are switched, and the optical detection unit adjusts the connection via the 5th optical fiber group and the 3rd optical fiber group. You may detect the light of mind. In this case, for example, the light from the ONU toward the second OLT can be selectively input to the second optical fiber group. In addition, by using the centering light source unit, the centering operation of the first optical fiber group and the third optical fiber group can be performed regardless of the communication state.

The optical line switching device includes a centering light source unit that outputs light for centering, a fifth optical fiber group that connects the centering light source unit and the line switching unit, a second optical fiber group, and a fifth optical fiber group. The line switching unit further comprises a line branching portion for merging the light fibers, and the line switching unit bends either one of the first optical fiber group and the second optical fiber group, and at the same time bends the other of the first optical fiber group and the second optical fiber group. The light for alignment may be detected via the fifth optical fiber group and the third optical fiber group by eliminating the bending of the light. In this case, by using the centering light source unit, the centering operation of the first optical fiber group and the third optical fiber group can be performed regardless of the communication state.

The optical line switching device is provided on the ONU side of the first optical leakage coupling portion, and is a second optical leakage coupling that optically couples the core propagation mode and the spatial propagation mode of each optical fiber included in the first optical fiber group. Further, the light detection unit may detect the light for centering through the first light leakage coupling unit and the second light leakage coupling unit.

The wavelength of the light output from the centering light source unit may be longer than 1625 nm. In this case, it is possible to prevent the light output from the centering light source unit from interfering with the light for communicating between the ONU and the first OLT or the second OLT.

The optical line switching device further includes a bending angle adjusting portion for increasing the bending angle of the first optical fiber group in the first optical leakage coupling portion when the communication between the ONU and the first OLT is cut off, and the bending angle is adjusted. The portion may be provided between the ONU and the first light leakage coupling portion. In this case, the proportion of light leaking from the first optical fiber group at the first optical leakage coupling portion can be increased. As a result, light having sufficient intensity is transmitted from the ONU to the second OLT, so that communication failure between the ONU and the second OLT can be suppressed.

When the optical line switching device includes a second optical leakage coupling portion, the optical line switching device of the first optical fiber group in the first optical leakage coupling portion when the communication between the ONU and the first OLT is interrupted. A bending angle adjusting portion for increasing the bending angle may be further provided, and the bending angle adjusting portion may be provided between the first light leakage coupling portion and the second light leakage coupling portion. In this case, the proportion of light leaking from the first optical fiber group at the first optical leakage coupling portion can be increased. As a result, light having sufficient intensity is transmitted from the ONU to the second OLT, so that communication failure between the ONU and the second OLT can be suppressed.

The bending angle adjusting portion may be arranged so as to be farther from the first light leakage coupling portion as the allowable bending radius of the first optical fiber group is larger. In this case, the bending angle of the first optical fiber group at the first optical leakage coupling portion can be appropriately set according to the allowable bending radius of the first optical fiber group.

[Details of Embodiments of the present invention]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same code will be used for the same element or the element having the same function, and duplicate description will be omitted.

(First Embodiment)
FIG. 1 is a block diagram showing an optical line switching device according to the first embodiment. As shown in FIG. 1, the optical line switching device 1 includes a first optical fiber group F1, a second optical fiber group F2, a third optical fiber group F3, a fourth optical fiber group F4, and an ONU2 (Optical). A Network Unit), a first OLT 3 (Optical Line Terminal), a second OLT 4, an optical coupling unit 5, an optical detection unit 6, a centering mechanism control unit 7, and a line switching unit 8. The optical line switching device 1 includes a communication state between the ONU 2 and the first OLT 3 via the first optical fiber group F1, and the ONU 2 and the second optical fiber group F1 via a part F1a of the first optical fiber group F1 and the second optical fiber group F2. It is a device that switches the communication state with 2OLT4. The optical line switching device 1 is a device that switches the communication state by using the side optical input / output technology (details will be described later).

FIG. 2 is a schematic cross-sectional view of the first optical fiber group F1. As shown in FIG. 2, the first optical fiber group F1 is a tape fiber including a multi-core optical fiber, and includes four optical fibers 11 to 14 and a tape portion 15 for bundling the optical fibers 11 to 14. Have. The optical fiber 11 has a core 11a having a circular cross section, a clad 11b having a circular cross section surrounding the core 11a, and a resin cover 11c surrounding the clad 11b. Each of the resin cover 11c and the tape portion 15 has translucency, and is formed of, for example, acrylic resin. The optical fibers 12 to 14 also have the same configuration as the optical fiber 11. The core spacing S between the optical fibers in the first optical fiber group F1 is, for example, 0.21 mm to 0.29 mm. Each of the second to fourth optical fiber groups F2 to F4 is a tape fiber containing four optical fibers as in the first optical fiber group F1. Each of the first to fourth optical fiber groups F1 to F4 may have different core spacings S and the like due to differences in geometric shapes.

Returning to FIG. 1, the ONU2 is a subscriber-side transmission device, for example, an optical line termination device provided in the subscriber's home. On the other hand, each of the first OLT 3 and the second OLT 4 is a transmission device on the operator side, and is, for example, an optical line termination device provided in the station building. The ONU2 is connected to the first OLT 3 via the first optical fiber group F1 which is an active optical fiber line. Further, the ONU2 includes a part F1a of the first optical fiber group F1, a second optical fiber group F2 which is a detour optical fiber line, and a part F1a of the first optical fiber group F1 and a second optical fiber group F2. It may be connected to the second OLT 4 via the relay third optical fiber group F3. In the first embodiment, the first OLT 3 is the main OLT and the second OLT 4 is the sub OLT. The "connection" in the present specification may be at least optically connected and may not be physically connected.

FIG. 3A is a schematic view showing the optical coupling portion 5 according to the first embodiment, and FIG. 3B is a schematic view showing a part of FIG. 3A from different angles. Is. As shown in FIGS. 3A and 3B, the optical coupling unit 5 has a light leakage coupling unit 21 (first light leakage coupling unit) and a light transfer unit 22.

The optical leakage coupling portion 21 is a portion that photocouples the core propagation mode and the spatial propagation mode of each optical fiber 11 to 14 included in the first optical fiber group F1 by bending the first optical fiber group F1. The core propagation mode indicates a state in which light propagates in the core of each optical fiber, and the spatial propagation mode indicates a state in which light propagates in space. The light leakage coupling portion 21 has a pressing member 23 having a circular cross section and a transparent block 24 provided with a recess 24a that can be fitted on the side surface of the pressing member 23. The first optical fiber group F1 is arranged between the pressing member 23 and the transparent block 24. Therefore, when the pressing member 23 is fitted into the recess 24a, the first optical fiber group F1 which is a tape fiber is sandwiched between the pressing member 23 and the transparent block 24 and bent. In the first optical fiber group F1 bent by the light leakage coupling portion 21, a part on the ONU2 side of the light leakage coupling portion 21 is designated as F1a, and a portion on the first OLT3 side of the light leakage coupling portion 21 is designated as F1a. The other part is F1b. Further, the transparent block 24 has a refractive index higher than that of the resin cover 11c and the tape portion 15, and is formed of, for example, optical glass or polycarbonate.

Here, the movement of light output from the ONU 2 to the first optical fiber group F1 when the first optical fiber group F1 is bent by the optical leakage coupling portion 21 will be described. First, a part of the light output from ONU2 and circulating in the optical fibers 11 to 14 leaks to the outside from the bending point of the first optical fiber group F1. The leaked light L1 propagates in the transparent block 24. Then, the light L1 propagating in the transparent block 24 leaks to the external space from the slope 24b of the transparent block 24 facing a part F1b of the first optical fiber group. As a result, the core propagation mode of light changes to the spatial propagation mode. A non-reflective film may be provided on the slope 24b.

The optical transfer unit 22 is an optical system that photocouples the spatial propagation mode to the core propagation mode of each optical fiber included in the third optical fiber group F3. The optical transfer unit 22 has plano-convex lenses 25 and 26 and a condensing lens 27 connected to the third optical fiber group F3. The lens 25 is located closer to the light leakage coupling portion 21 than the lens 26 and the condensing lens 27, and is a lens that adjusts the traveling direction of the light L1 leaked from the light leakage coupling portion 21 into the space. The lens 26 is located between the lens 25 and the condensing lens 27, and is a lens that adjusts the traveling direction of the light L2 adjusted by the lens 25 in the direction of reaching the condensing lens 27. The condensing lens 27 is connected to each optical fiber included in the third optical fiber group F3, and is a lens that condenses the light from the lens 26 to the core of each optical fiber. At least one of the lens 26 and the condensing lens 27 is a biaxial translation mechanism (alignment mechanism), and is provided so as to be driveable by a drive mechanism (not shown). The two axes are directions that intersect the traveling direction of light.

Specifically, the light L1 leaked from the slope 24b of the transparent block 24 in the light leakage coupling portion 21 to the external space first reaches the lens 25. Next, the light L2 whose traveling direction is adjusted by the lens 25 reaches the lens 26. Next, the light L3 whose traveling direction is further adjusted by the lens 26 reaches the condensing lens 27. When the light L3 reaching the condensing lens 27 is input to the core of each optical fiber of the third optical fiber group F3, the spatial propagation mode of light changes to the core propagation mode. At least one of the lens 26 and the condensing lens 27 translates along two axes according to the control of the centering mechanism control unit 7. As a result, the amount of loss in the change from the spatial propagation mode of light to the core propagation mode can be adjusted to be low.

Returning to FIG. 1, the photodetector 6 is a portion that detects light via the third optical fiber group F3. In the first embodiment, the optical detection unit 6 is connected to the fourth optical fiber group F4 connected to the connection switching unit 31 (details will be described later) of the line switching unit 8. The photodetector 6 is output from ONU2 and passes through a part F1b of the first optical fiber group F1, an optical coupling unit 5, a third optical fiber group F3, a line switching unit 8, and a fourth optical fiber group F4. This is the part that detects the strength of. The photodetector 6 is, for example, a photosensor that detects the intensity of light output from the optical fiber of the fourth optical fiber group F4.

The centering mechanism control unit 7 is a portion that adjusts the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3 based on the light intensity detected by the light detection unit 6. The centering mechanism control unit 7 is, for example, a CPU (Central Processing Unit) mounted on the drive mechanism. The centering mechanism control unit 7 adjusts at least one of the positions of the lens 26 and the condensing lens 27 of the optical coupling unit 5 based on the detection result of the light detection unit 6. As a result, the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3 is optimized. The optimization of the optical coupling state is, for example, maximizing the coupling efficiency between each optical fiber 11 to 14 of the first optical fiber group F1 and each optical fiber of the third optical fiber group F3. For example, the centering mechanism control unit 7 maximizes the coupling efficiency by adjusting the position of each optical fiber of the third optical fiber group F3.

The line switching unit 8 is a portion that blocks communication between the ONU 2 and any one of the first OLT 3 and the second OLT 4, and at the same time opens communication between the ONU 2 and any one of the first OLT 3 and the second OLT 4. The line switching unit 8 has a connection switching unit 31 and a line blocking unit 32.

FIG. 4 is a schematic view showing the connection switching unit 31. The connection switching unit 31 is an active element having a first condensing lens 34 and a second condensing lens 35 that are photocoupled to each other. The first condensing lens 34 includes lenses 34a to 34d connected to the optical fiber of the third optical fiber group F3, and lenses 34e to 34h not connected to any part in the optical line switching device 1. doing. The lenses 34a to 34d and the lenses 34e to 34h are alternately arranged along a direction orthogonal to the traveling direction of light. The second condensing lens 35 has lenses 35a to 35d connected to the optical fiber of the second optical fiber group F2 and lenses 35e to 35h connected to the optical fiber of the fourth optical fiber group F4. .. The lenses 35a to 35d and the lenses 35e to 35h are arranged alternately with each other along the above-mentioned direction orthogonal to the traveling direction of light, similarly to the first condensing lens 34. The second condensing lens 35 is movable in the above direction with respect to the first condensing lens 34.

In FIG. 4, the lenses 34a to 34d are optically coupled to the lenses 35e to 35h, respectively. Therefore, the third optical fiber group F3 is connected to the fourth optical fiber group F4 via the connection switching unit 31. Here, by moving the second condensing lens 35, the lenses 34a to 34d can be photocoupled with the lenses 35a to 35d. At this time, the third optical fiber group F3 is connected to the second optical fiber group F2 via the connection switching unit 31. By moving the second condensing lens 35 in this way, it is possible to switch between the connection of the third optical fiber group F3 and the fourth optical fiber group F4 and the connection of the third optical fiber group F3 and the second optical fiber group F2. it can. In other words, by using the connection switching unit 31, the light output from the third optical fiber group F3 can be output to only one of the second optical fiber group F2 and the fourth optical fiber group F4.

FIG. 5A is a schematic view showing the line blocking portion 32 and the first optical fiber group F1, and FIG. 5B is a schematic diagram in which the first optical fiber group F1 is blocked by the line blocking portion 32. It is a schematic diagram which shows the state. The line blocking portion 32 shown in FIGS. 5A and 5B is a portion that cuts off the other portion F1b of the first optical fiber group F1. The line blocking portion 32 has a circular cross section and has pressing members 32a to 32c and pressing members 32d and 32e arranged in order. The pressing members 32a to 32e can move in the direction orthogonal to the first and second optical fiber groups F1 and F2. In this direction, the first optical fiber group F1 is located between the pressing members 32a to 32c and the pressing members 32d and 32e. That is, the pressing members 32a to 32c and the pressing members 32d and 32e are separated from each other with the first optical fiber group F1 in the above direction.

When the first optical fiber group F1 is cut off by the line blocking portion 32, the pressing members 32a to 32c and the pressing members 32d and 32e move in a direction in contact with the first optical fiber group F1. Then, as shown in FIG. 5B, the pressing members 32a to 32e come into contact with the first optical fiber group F1. As a result, the first optical fiber group F1 is sandwiched between the pressing members 32a to 32c and the pressing members 32d and 32e and is bent.

The line blocking unit 32 cuts off the first optical fiber group F1 at the same time as the third optical fiber group F3 is connected to the second optical fiber group F2 via the connection switching unit 31. In other words, the connection switching unit 31 opens the connection state between the ONU 2 and the second OLT 4, and at the same time, the line cutoff unit 32 cuts off the connection state between the ONU 2 and the first OLT 3. In this way, the line switching unit 8 having the connection switching unit 31 and the line blocking unit 32 opens one of the first optical fiber group F1 and the second optical fiber group F2 and shuts off the other, thereby causing the ONU 2 and the second. The connection state with only one of 1OLT3 and 2nd OLT4 is secured.

According to the optical line switching device 1 according to the first embodiment described above, the side input / output technology is adopted in the communication between the ONU 2 and the first OLT 3, and the first optical fiber group F1 and the third are used. The optical fiber group F3 is photocoupled to each other via an optical coupling portion 5 having a light leakage coupling portion 21 and a phototransfer coupling portion 22. Here, based on the intensity of the light passing through the third optical fiber group F3 and the optical transfer unit 22 detected by the optical detection unit 6, the centering mechanism control unit 7 uses the first optical fiber group F1 and the third light. The optical coupling state with the fiber group F3 is adjusted. As a result, even when the tape fiber is used, it is possible to suppress a decrease in coupling efficiency due to a deviation in the core spacing in each tape fiber.

In addition, the line switching unit 8 cuts off the communication between the ONU 2 and one of the first OLT 3 and the second OLT, and at the same time opens the communication between the ONU 2 and any one of the first OLT 3 and the second OLT 4. For example, while the centering mechanism control unit 7 is adjusting the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3, ONU2 keeps the communication between ONU2 and the first OLT3 open. The communication between the light and the second OLT4 can be held in a cut-off state. As a result, it is possible to satisfactorily suppress the occurrence of communication interruption in the optical line switching device 1. Further, after the adjustment of the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3 by the centering mechanism control unit 7 is completed, the line switching unit 8 immediately moves between ONU2 and the first OLT3. Communication between ONU2 and the second OLT4 can be opened at the same time as blocking the communication. As a result, the occurrence of communication interference in the optical line switching device 1 can be satisfactorily suppressed.

The optical line switching device 1 includes a fourth optical fiber group F4 connected to the optical detection unit 6, and the line switching unit 8 connects the third optical fiber group F3 and the fourth optical fiber group F4 and the third optical fiber group F4. It has a connection switching unit 31 for switching between the connection of the fiber group F3 and the connection of the second optical fiber group F2. Therefore, when adjusting the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3, the light output from the ONU 2 and passing through the third optical fiber group F3 is transferred to the fourth optical fiber group F4. Can be entered selectively. Therefore, it is possible to better suppress the interruption of communication and the occurrence of interference in the optical line switching device 1.

(Second Embodiment)
Hereinafter, the optical line switching device according to the second embodiment will be described. In the description of the second embodiment, the description overlapping with the first embodiment is omitted, and the part different from the first embodiment is described. That is, the description of the first embodiment may be appropriately used for the second embodiment to the extent technically possible.

FIG. 6 is a block diagram showing an optical line switching device according to the second embodiment. As shown in FIG. 6, the line switching unit 8A of the optical line switching device 1A does not include the connection switching unit 31, and is provided with the first line blocking unit 32A and the second line blocking unit 33. .. In addition, the optical line switching device 1A includes a line branching portion 41 that branches the third optical fiber group F3 into the second optical fiber group F2 and the fourth optical fiber group F4.

The first line blocking section 32A is a portion that blocks or opens the other section F1b of the first optical fiber group F1, similarly to the line blocking section 32. Further, the second line blocking portion 33 is a portion that cuts off or opens the second optical fiber group F2. The first line cutoff unit 32A and the second line cutoff unit 33 operate complementary to each other. Therefore, when one of the first line cutoff section 32A and the second line cutoff section 33 cuts off the corresponding tape fiber, the other of the first line cutoff section 32A and the second line cutoff section 33 is the corresponding tape. The fiber is open. The first line cutoff portion 32A and the second line cutoff portion 33 may be integrated.

FIG. 7A is a schematic view showing a state in which the second optical fiber group F2 is blocked by the second line blocking section 33, and FIG. 7B is a schematic view showing a state in which the second optical fiber group F2 is blocked by the first line blocking section 32A. It is a schematic diagram which shows the state which 1 optical fiber group F1 is cut off. As shown in FIGS. 7A and 7B, the first line blocking portion 32A has only the pressing members 32a to 32c, and the second line blocking portion 33 has a circular cross-sectional shape and is arranged in order. It has the pressed members 33a to 33c. Further, any one of the first line cutoff portion 32A and the second line cutoff portion 33 includes pressing members 36a and 36b having a circular cross section and arranged in order. The pressing members 32a to 32c, 33a to 33c, 36a, and 36b are movable in a direction orthogonal to the first and second optical fiber groups F1 and F2. In this direction, the pressing members 36a and 36b are located between the pressing members 32a to 32c and the pressing members 33a to 33c. Further, in this direction, the first optical fiber group F1 is located between the pressing members 32a to 32c and the pressing members 36a and 36b, and the second optical fiber group F2 is located between the pressing members 33a to 33c and the pressing member. It is located between 36a and 36b.

For example, when the state in which the second optical fiber group F2 is cut off changes to the state in which the first optical fiber group F1 is cut off, the pressing members 32a to 32c and the pressing members 36a and 36b mutually receive the first light. It moves in the direction in contact with the fiber group F1. As a result, the pressing members 36a and 36b that were in contact with the second optical fiber group F2 in FIG. 7A are separated from the second optical fiber group F2, and as shown in FIG. 7B, the pressing members 36a and 36b are separated from each other. 1 Contact with the optical fiber group F1. As a result, the first optical fiber group F1 is sandwiched between the pressing members 32a to 32c and the pressing members 36a and 36b and is bent. On the other hand, the pressing members 33a to 33c that were in contact with the second optical fiber group F2 in FIG. 7A are separated from the second optical fiber group F2. As a result, the bending of the second optical fiber group F2 is eliminated, and the second optical fiber group F2 is opened. In this way, the line switching unit 8A having the first line blocking unit 32A and the second line blocking unit 33 opens one of the first optical fiber group F1 and the second optical fiber group F2 and blocks the other. , ONU2 and one of the first OLT3 and the second OLT4 are secured.

FIG. 8 is a schematic view showing the line branch portion 41. The line branch portion 41 has passive elements 41a to 41d connected to each optical fiber of the third optical fiber group F3. Each of the passive elements 41a to 41d is connected to the corresponding optical fiber of the second optical fiber group F2 and the corresponding optical fiber of the fourth optical fiber group F4. The passive elements 41a to 41d are, for example, an optical fiber coupler or a spectroscopic filter. Even if the intensity of the light input to the second optical fiber group F2 via the line branch portion 41 is significantly higher than the intensity of the light input to the fourth optical fiber group F4 via the line branch portion 41. Good. For example, the ratio of the intensity of light input to the second optical fiber group F2 via the line branch portion 41 to the intensity of light input to the fourth optical fiber group F4 via the line branch portion 41 is 9. It may be about 1.

The optical line switching device 1A according to the second embodiment also has the same effects as those of the first embodiment. Further, by using the line branching unit 41 instead of the connection switching unit 31, the mechanism for driving the connection switching unit 31 can be omitted, unlike the first embodiment. Therefore, with a configuration simpler than that of the first embodiment, light detection by the photodetector 6 and communication between the ONU 2 and the second OLT 4 can be realized. In addition, the ONU2 and the second OLT4 can be communicated with each other while adjusting the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3.

Further, the line switching unit 8A bends either one of the first optical fiber group F1 and the second optical fiber group F2 by the first line blocking unit 32A and the second line blocking unit 33, and at the same time, the first optical fiber group. The bending of the other of F1 and the second optical fiber group F2 is eliminated. In this case, it is possible to easily block the communication between the ONU and one of the first OLT and the second OLT, and open the communication between the ONU and the other of the first OLT and the second OLT.

(Third Embodiment)
Hereinafter, the optical line switching device according to the third embodiment will be described. In the description of the third embodiment, the description overlapping with the first and second embodiments will be omitted, and the parts different from the first and second embodiments will be described. That is, the description of the first and second embodiments may be appropriately used in the third embodiment to the extent technically possible.

FIG. 9 is a block diagram showing an optical line switching device according to a third embodiment. As shown in FIG. 9, the optical line switching device 1B includes a fifth optical fiber group F5 and a centering light source unit 51. Instead, the optical line switching device 1B does not include the fourth optical fiber group F4, unlike the first and second embodiments.

The centering light source unit 51 is a light emitting element that outputs light for centering. The presence or absence of light output by the centering light source unit 51 is controlled by the centering mechanism control unit 7A. For example, during the alignment of the first optical fiber group F1 and the third optical fiber group F3 (that is, during the adjustment of the optical coupling state), the alignment light source unit 51 outputs light. Further, after the alignment of the first optical fiber group F1 and the third optical fiber group F3, the optical output of the alignment light source unit 51 is stopped by the control of the alignment mechanism control unit 7A. The wavelength of the centering light output from the centering light source unit 51 is longer than the wavelength of the communication light, for example, longer than 1625 nm. As a result, interference between the centering light and the communication light can be satisfactorily prevented. The ONU2 or the like may include, for example, a band reflection filter that reflects light for alignment. This band reflection filter is a filter that reflects light having a wavelength of about 1625 nm, for example, centered on 1650 nm.

The fifth optical fiber group F5 is a light source fiber that connects the centering light source unit 51 and the line switching unit 8. More specifically, each optical fiber of the fifth optical fiber group F5 is connected to the lenses 35e to 35h of the corresponding connection switching unit 31 (see FIG. 4). Therefore, the connection switching unit 31 according to the third embodiment switches between the connection of the third optical fiber group F3 and the fifth optical fiber group F5 and the connection of the third optical fiber group F3 and the second optical fiber group F2. ..

The light detection unit 6A according to the third embodiment detects the intensity of the centering light output from the centering light source unit 51. More specifically, the optical detection unit 6A detects the intensity of the light for alignment via the fifth optical fiber group F5, the connection switching unit 31, the third optical fiber group F3, and the optical coupling unit 5A. In addition, the photodetector 6A is not provided in the ONU2 and is provided apart from the first optical fiber group F1. Therefore, the optical coupling unit 5A in the third embodiment is provided with a mechanism for leaking at least a part of the centering light output from the centering light source unit 51.

FIG. 10 is a schematic view showing a light coupling unit 5A and a photodetection unit 6A according to the third embodiment. As shown in FIG. 10, in the optical coupling portion 5A, in addition to the light leakage coupling portion 21 and the optical transfer portion 22, the light leakage coupling portion 61 (second light leakage) located on the ONU2 side of the light leakage coupling portion 21 It has a joint). Similar to the optical leakage coupling portion 21, the optical leakage coupling portion 61 has a core propagation mode and a spatial propagation mode of each optical fiber 11 to 14 included in the first optical fiber group F1 due to bending of the first optical fiber group F1. Is the part that photocouples. The light leakage coupling portion 61 has a pressing member 62 having a circular cross section and a transparent block 63 provided with a recess 63a that can be fitted on the side surface of the pressing member 62. The first optical fiber group F1 is arranged between the pressing member 62 and the transparent block 63. The cross-sectional diameter of the pressing member 62 is larger than the cross-sectional diameter of the pressing member 23. This is because, as described above, the wavelength of the centering light is longer than the wavelength of the communication light. By setting the cross-sectional diameter of the pressing member 62 in this way, the light for dimming is likely to leak from the light leakage coupling portion 61 to the external space.

Here, the movement of the light for dimming until it reaches the photodetector 6A via the light leakage coupling portions 21 and 61 will be described. First, the light output from the centering light source unit 51 passes through the fifth optical fiber group F5, the connection switching unit 31, the third optical fiber group F3, and the optical transfer unit 22, and the transparent block 24 of the optical leakage coupling unit 21. Is entered in. At least a part of the light propagating in the transparent block 24 is input to the optical fibers 11 to 14 of the first optical fiber group F1. A part of the light input to these optical fibers 11 to 14 leaks to the outside from the bending point of the first optical fiber group F1 in the optical leakage coupling portion 61. The leaked light propagates in the transparent block 63. Then, the light propagating in the transparent block 63 leaks from the slope 63b of the transparent block 63 facing the light leakage coupling portion 21 to the external space and is input to the light detection unit 6A.

In the optical line switching device 1B according to the third embodiment, the same effects as those of the first and second embodiments are exhibited except that the light from the second OLT4 to the ONU2 is used. In addition, by using the centering light source unit 51, the centering operation of the first optical fiber group F1 and the third optical fiber group F3 can be performed regardless of the communication state.

The wavelength of the light output from the centering light source unit 51 is longer than 1625 nm. Therefore, it is possible to suppress the interference between the light output from the centering light source unit 51 and the light for communicating the ONU2 with the first OLT3 or the second OLT4.

(Fourth Embodiment)
Hereinafter, the optical line switching device according to the fourth embodiment will be described. In the description of the fourth embodiment, the description overlapping with the first to third embodiments will be omitted, and the parts different from the first to third embodiments will be described. That is, the description of the first to third embodiments may be appropriately used in the fourth embodiment to the extent technically possible.

FIG. 11 is a block diagram showing an optical line switching device according to a fourth embodiment. As shown in FIG. 11, the optical line switching device 1C includes a line switching unit 8A and a line branching unit 71 for merging the second optical fiber group F2 and the fifth optical fiber group F5. 3 Different from the embodiment. The line branch portion 71 has the same configuration and function as the line branch portion 41 in the second embodiment. That is, the line branch portion 71 can be regarded as the same as the line branch portion 41. The optical line switching device 1C according to the fourth embodiment also has the same effects as those of the third embodiment. Further, by using the line branch portion 71 instead of the connection switching portion 31, the mechanism for driving the connection switching portion 31 can be omitted, unlike the third embodiment. Therefore, with a configuration simpler than that of the third embodiment, it is possible to realize light detection by the photodetector 6A and communication between ONU2 and the second OLT4. In addition, the ONU2 and the second OLT4 can be communicated with each other while adjusting the optical coupling state between the first optical fiber group F1 and the third optical fiber group F3.

(Fifth Embodiment)
Hereinafter, the optical line switching device according to the fifth embodiment will be described. In the description of the fifth embodiment, the description overlapping with the first to fourth embodiments will be omitted, and the parts different from the first to fourth embodiments will be described. That is, the description of the first to fourth embodiments may be appropriately used in the fifth embodiment to the extent technically possible.

12 (a) and 12 (b) are schematic views showing the optical coupling portion 5B according to the fifth embodiment. More specifically, FIG. 12A shows a state in which ONU2 and the first OLT3 are communicating, and FIG. 12B shows a state in which ONU2 and the second OLT4 are communicating. There is. The optical line switching device according to the fifth embodiment has the same configuration as the optical line switching device 1 according to the first embodiment, except that the optical line switching device 5B is provided instead of the optical coupling unit 5. ..

As shown in FIG. 12A, the optical coupling portion 5B is different from the optical coupling portion 5 shown in FIG. 3A, and the bending angle adjusting portion 81 located between the light leakage coupling portion 21 and the ONU2 is located. Has. The bending angle adjusting portion 81 is a member that increases the bending angle of the first optical fiber group F1 in the light leakage coupling portion 21 when the communication between the ONU 2 and the first OLT 3 is cut off, and has a cross section similar to that of the pressing member 23. It has a circular shape. The cross-sectional diameter of the bending angle adjusting portion 81 is substantially the same as, for example, the cross-sectional diameter of the pressing member 62. The bending angle adjusting portion 81 is arranged on the transparent block 24 side of the first optical fiber group F1. Like the pressing member 23, the bending angle adjusting portion 81 is provided so as to be movable in a direction intersecting with the first optical fiber group F1. The moving distance of the bending angle adjusting unit 81 in the direction is set to a predetermined value. As shown in FIG. 12B, when the communication between the ONU 2 and the first OLT 3 is cut off, the bending angle adjusting portion 81 moves to the first optical fiber group F1 side, so that the first optical fiber group F1 Bends. Specifically, when the communication between the ONU 2 and the first OLT 3 is cut off, the bending angle adjusting portion 81 bends a part F1a of the first optical fiber group F1 in the vicinity of the light leakage coupling portion 21. The bending angle adjusting unit 81 may increase the bending angle at the same time that the communication between the ONU 2 and the first OLT 3 is cut off, or the bending angle is adjusted after the communication between the ONU 2 and the first OLT 3 is cut off. It may be increased. The bending angle of the first optical fiber group F1 in the light leakage coupling portion 21 is an angle formed by a part F1a side of the first optical fiber group F1 that bends in the light leakage coupling portion 21. The bending angle in the fifth embodiment is determined by, for example, the bending angle of the first optical fiber group F1 of the first embodiment (FIG. 3 (FIG. 3)) by bending a part F1a of the first optical fiber group F1 by the bending angle adjusting unit 81. It is larger than (see a)).

The bending angle adjusting portion 81 is provided so as to be movable along the extending direction of the first optical fiber group F1. The bending angle adjusting portion 81 is arranged so as to be separated from the light leakage coupling portion 21 as the allowable bending radius of the first optical fiber group F1 is larger. In other words, the bending angle adjusting portion 81 is arranged on the ONU2 side as the allowable bending radius of the first optical fiber group F1 becomes larger. For example, an optical fiber having an allowable bending radius of 15 mm and an optical fiber having an allowable bending radius of 30 mm have different proportions of light leaking depending on the bending angle.

The action and effect when the optical coupling portion 5B according to the fifth embodiment is used will be described below. From the viewpoint of improving the communication accuracy between the ONU 2 and the first OLT 3, the insertion loss of the first optical fiber group F1 is set to, for example, 2 dB or less. When the insertion loss of the first optical fiber group F1 is set in this way, when the ONU2 and the second OLT4 are communicated by using the optical leakage coupling portion 21, the coupling between the first optical fiber group F1 and the third optical fiber group F3 is performed. It can be inefficient. In this case, for example, the loss of light transmitted from the ONU 2 to the second OLT 4 may increase. As a result, a communication failure may occur between ONU2 and the second OLT4.

In order to prevent the occurrence of communication failure between ONU2 and the second OLT4, if the coupling efficiency between the first optical fiber group F1 and the third optical fiber group F3 is simply increased, the insertion loss of the first optical fiber group F1 is 2 dB. May be exceeded. As a result, the communication accuracy between the ONU 2 and the first OLT 3 deteriorates. As described above, there is a trade-off relationship between the insertion loss and the coupling efficiency.

On the other hand, in the fifth embodiment, when the communication between the ONU 2 and the first OLT 3 is cut off, the bending angle adjusting portion 81 increases the bending angle of the first optical fiber group F1 in the light leakage coupling portion 21. doing. Therefore, the proportion of light leaking from the first optical fiber group F1 in the light leakage coupling portion 21 can be increased. As a result, for example, even if the insertion loss of the first optical fiber group F1 is set to 2 dB or less, light having sufficient intensity is transmitted from the ONU 2 to the second OLT 4. Therefore, it is possible to suppress the occurrence of a communication failure between the ONU 2 and the second OLT 4 while preventing the deterioration of the communication accuracy between the ONU 2 and the first OLT 3. In addition, the bending angle adjusting portion 81 is arranged so as to be separated from the light leakage coupling portion 21 as the allowable bending radius of the first optical fiber group F1 is larger. Therefore, the bending angle of a part F1a of the first optical fiber group F1 in the light leakage coupling portion 21 can be appropriately set according to the allowable bending radius of the first optical fiber group F1.

As described above, the optical line switching device according to the fifth embodiment is the same as the optical line switching device 1 according to the first embodiment, except that the optical line switching device according to the first embodiment includes the optical coupling unit 5B instead of the optical coupling unit 5. It has a configuration. Therefore, in the fifth embodiment, in addition to the above-mentioned action and effect, the same action and effect as those in the above-mentioned first embodiment are exhibited.

(Sixth Embodiment)
Hereinafter, the optical line switching device according to the sixth embodiment will be described. In the description of the sixth embodiment, the description overlapping with the first to fifth embodiments will be omitted, and the parts different from the first to fifth embodiments will be described. That is, the description of the first to fifth embodiments may be appropriately used in the sixth embodiment to the extent technically possible.

13 (a) and 13 (b) are schematic views showing the optical coupling portion 5C according to the sixth embodiment. More specifically, FIG. 13A shows a state in which ONU2 and the first OLT3 are communicating, and FIG. 13B shows a state in which ONU2 and the second OLT4 are communicating. There is. The optical line switching device according to the sixth embodiment has the same configuration as the optical line switching device 1B according to the third embodiment, except that the optical line switching device 5C is provided instead of the optical coupling unit 5. ..

As shown in FIG. 13A, the optical coupling portion 5C is different from the light leakage coupling portion 21A of the optical coupling portion 5A shown in FIG. 9 and different from the light leakage coupling portion 21A. It includes a light leakage coupling portion 61A and a bending angle adjusting portion 81. In the light leakage coupling portion 21A, a part of the protruding portion forming the recess 24a of the transparent block 24A is cut out. Specifically, the protruding portion on the ONU2 side of the transparent block 24A is cut out. Similarly, in the light leakage coupling portion 61A, the protruding portion on the first OLT3 side of the transparent block 63A is cut out. Further, in the light leakage coupling portion 61A, the pressing member 62 is arranged closer to the pressing member 23 than the first optical fiber group F1, and the transparent block 63A is arranged closer to the transparent block 24A than the first optical fiber group F1. Has been done. The position of the photodetector 6A in the optical coupling unit 5C is different from the position of the photodetector 6A in the optical coupling unit 5A. Specifically, the position of the photodetector 6A in the optical coupling unit 5C is arranged closer to the transparent block 24 than the first optical fiber group F1.

In the sixth embodiment, the bending angle adjusting portion 81 is provided between the light leakage coupling portions 21A and 61A. As shown in FIG. 13B, when the communication between the ONU 2 and the first OLT 3 is cut off, the bending angle adjusting portion 81 makes a part F1a of the first optical fiber group F1 in the vicinity of the light leakage coupling portion 21A. bend. Further, the bending angle adjusting portion 81 is provided so as to be movable along the extending direction of the first optical fiber group F1 between the optical leakage coupling portions 21A and 61A.

When the optical coupling portion 5C according to the sixth embodiment is used, the same action and effect as those of the fifth embodiment are exhibited. In addition, as described above, the optical line switching device according to the sixth embodiment is the same as the optical line switching device 1B according to the third embodiment, except that the optical line switching device according to the sixth embodiment includes the optical coupling unit 5C instead of the optical coupling unit 5. It has a similar configuration. Therefore, in the sixth embodiment, in addition to the above-mentioned action and effect, the same action and effect as those in the above-mentioned third embodiment are exhibited.

The optical line switching device according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. For example, the first OLT 3 and the second OLT 4 may be the same OLT. In this case, the first optical fiber group F1 and the second optical fiber group F2 are connected to terminals different from each other in the OLT.

The number of optical fibers in each optical fiber group in the above embodiment is not limited to four. Each optical fiber group may include two or more, that is, a plurality of optical fibers. Further, in the above embodiment, the second to fifth optical fiber groups F2 to F5 are not necessarily tape fibers, but may be multi-core optical fiber lines. At least a part of the first optical fiber group F1 may be a tape fiber.

In the above embodiment, a system for monitoring the state of each optical fiber group may be introduced. In this case, monitoring light is input to each optical fiber group. This monitoring light has a longer wavelength than the communication light. In the third embodiment, the fourth embodiment, and the sixth embodiment, the monitoring light may be the light output from the centering light source unit 51. In this case, interference between the communication light and the monitoring light can be satisfactorily prevented.

The above embodiments may be combined as appropriate. For example, the second embodiment and the fifth embodiment may be combined, or the fourth embodiment and the sixth embodiment may be combined.

1,1A, 1B, 1C ... Optical line switching device, 2 ... ONU, 3 ... 1st OLT, 4 ... 2nd OLT, 5,5A, 5B, 5C ... Optical coupling unit, 6,6A ... Optical detection unit, 7,7A ... Alignment mechanism control unit, 8,8A ... Line switching unit, 11-14 ... Optical fiber, 21,21A ... Optical leakage coupling unit (first optical leakage coupling unit), 22 ... Optical transfer unit, 31 ... Connection switching unit , 32 ... Line cutoff, 32A ... First line cutoff, 33 ... Second line cutoff, 41 ... Line branch, 51 ... Centering light source, 61, 61A ... Light leakage coupling (second light leakage coupling) Part), 71 ... Line branching part, 81 ... Bending angle adjusting part, F1 ... First optical fiber group, F2 ... Second optical fiber group, F3 ... Third optical fiber group, F4 ... Fourth optical fiber group, F5 ... Fifth optical fiber group.

Claims (10)

An optical line that switches the communication state between the ONU and the first OLT via the first optical fiber group and the communication state between the ONU and the second OLT via a part of the first optical fiber group and the second optical fiber group. It is a switching device
A part of the first optical fiber group, a third optical fiber group relaying the second optical fiber group, and a third optical fiber group.
A first optical leakage coupling portion that photocouples the core propagation mode and the spatial propagation mode of each optical fiber of the first optical fiber group by bending the tape fiber included in the first optical fiber group.
An optical transfer unit that photocouples the spatial propagation mode and the core propagation mode of each optical fiber included in the third optical fiber group.
An optical detection unit that detects light via the third optical fiber group and the optical transfer unit, and
An alignment mechanism control unit that adjusts the optical coupling state between the first optical fiber group and the third optical fiber group based on the intensity of the light detected by the light detection unit.
With a line switching unit that blocks communication between the ONU and one of the first OLT and the second OLT, and at the same time opens communication between the ONU and any one of the first OLT and the second OLT. ,
An optical line switching device equipped with. A fourth optical fiber group connected to the photodetector is further provided.
1. The line switching unit includes a connection switching unit that switches between the connection of the third optical fiber group and the fourth optical fiber group and the connection of the third optical fiber group and the second optical fiber group. The optical fiber switching device described in 1. The fourth optical fiber group connected to the photodetector and
A line branch portion for branching the third optical fiber group into the second optical fiber group and the fourth optical fiber group, and
With more
The line switching unit bends either one of the first optical fiber group and the second optical fiber group, and at the same time, eliminates the bending of the other of the first optical fiber group and the second optical fiber group. Item 1. The optical line switching device according to item 1. A centering light source that outputs light for centering,
A fifth optical fiber group connecting the centering light source unit and the line switching unit, and
With more
The line switching unit switches between the connection of the third optical fiber group and the fifth optical fiber group and the connection of the third optical fiber group and the second optical fiber group.
The optical line switching device according to claim 1, wherein the optical detection unit detects the light for centering via the fifth optical fiber group and the third optical fiber group. A centering light source that outputs light for centering,
A fifth optical fiber group connecting the centering light source unit and the line switching unit, and
A line branch portion that joins the second optical fiber group and the fifth optical fiber group, and
With more
The line switching unit bends either one of the first optical fiber group and the second optical fiber group, and at the same time, eliminates the bending of the other of the first optical fiber group and the second optical fiber group.
The optical line switching device according to claim 1, wherein the optical detection unit detects the light for centering via the fifth optical fiber group and the third optical fiber group. Further provided is a second optical leakage coupling portion provided on the ONU side of the first optical leakage coupling portion and optically coupling the core propagation mode and the spatial propagation mode of each optical fiber included in the first optical fiber group. ,
The optical line switching device according to claim 4 or 5, wherein the photodetector detects the light for alignment through the first light leakage coupling portion and the second light leakage coupling portion. The wavelength of the light output from the centering light source unit is longer than 1625 nm.
The optical line switching device according to any one of claims 4 to 6. Further provided with a bending angle adjusting portion for increasing the bending angle of the first optical fiber group in the first light leakage coupling portion when the communication between the ONU and the first OLT is cut off.
The optical line switching device according to any one of claims 1 to 7, wherein the bending angle adjusting portion is provided between the ONU and the first optical leakage coupling portion. Further provided with a bending angle adjusting portion for increasing the bending angle of the first optical fiber group in the first light leakage coupling portion when the communication between the ONU and the first OLT is cut off.
The optical line switching device according to claim 6, wherein the bending angle adjusting portion is provided between the first light leakage coupling portion and the second light leakage coupling portion. The optical line switching device according to claim 8 or 9, wherein the bending angle adjusting portion is arranged so as to be separated from the first optical leakage coupling portion as the allowable bending radius of the first optical fiber group is larger.

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