JP6155660B2 - Optical submarine repeater and optical submarine repeater mounting method - Google Patents

Description

  The present invention relates to an optical submarine repeater and an optical submarine repeater mounting method.

  An optical submarine repeater is a device laid on the seabed for the purpose of relaying optical signals such as telephone lines. In general, the length of a signal line laid on the seabed between land is very long. For this reason, the number of optical submarine repeaters necessary for relaying signals between land is also large. Therefore, in order to reduce the cost of the entire optical submarine repeater system, it is necessary to reduce the manufacturing cost of the optical submarine repeater.

  In addition, the optical submarine repeater needs to reduce the size of the casing that constitutes the optical submarine repeater in order to reduce the wave resistance and water pressure load of the cable. Also, optical submarine repeaters reduce the size of the housing that composes optical submarine repeaters in order to reduce the installation space and increase the signal line density as a system when multiplexing signal systems There is a need to do. Furthermore, in the optical submarine repeater, it is necessary to simplify the circuit configuration in the casing that constitutes the optical submarine repeater in consideration of workability at the time of failure or periodic maintenance.

  Various techniques relating to such a background are known (see, for example, Patent Documents 1 to 4).

  For example, Patent Document 1 describes an optical amplification repeater applied to a system in which an optical transmission line and a power supply cable for series constant current power supply are laid between first and second terminal stations. . Specifically, an optical circuit portion including the optical amplification means, an electric circuit portion including a drive / control means for driving or controlling the optical amplification means, a power supply means for supplying power to the drive / control means, It comprises a pressure-resistant housing and means for insulating the electric circuit portion and the power feeding means from the pressure-resistant housing.

  Further, for example, Patent Document 2 describes an optical submarine repeater having an efficient mounting structure. Specifically, it is composed of two optical circuit casings including a central optical fiber, two electric circuit casings that can be overlapped on both sides thereof, and two units in which both are arranged.

  Further, for example, Patent Document 3 describes an optical submarine cable transmission system capable of landing a branched optical cable from a submerged branch device beyond the transmission distance of a submarine repeater. Specifically, the optical submarine cable transmission system includes first and second terminal devices installed on land, optical submarine cables connecting the first and second terminal devices, and optical submarine cables at predetermined intervals. And a plurality of submarine repeaters inserted in the middle. The optical submarine cable transmission system further includes a submarine branching device inserted in the middle of the optical submarine cable, a third terminal device installed on land, a branch optical cable connecting the submarine branching device and the third terminal device, and Is included. An optical amplifying circuit including a rare earth doped fiber and an optical isolator is provided in the undersea branching device, and a pumping light source for supplying pumping light to the rare earth doped fiber is provided in the third terminal device.

  Further, for example, Patent Document 4 efficiently accommodates the connection portion between the optical gain equalizer and the optical fiber of the optical submarine cable according to the amplification characteristics of the optical submarine repeater and the transmission characteristics of the optical submarine cable. The structure of the optical component container for an optical submarine cable is described. Specifically, it has an optical component storage that can be detached from the seawater pressure resistant cylinder, and this optical component storage is further divided by a central axis. An optical gain equalizer is mounted on one of the divided optical component storage units. On the other side of the divided optical component housing portion, a connection portion between the optical fiber of the optical gain equalizer and the optical fiber of the optical submarine cable is mounted, and the optical fiber can be pulled out to the opposite side in each optical component housing body. It has a groove and a structure that holds the optical submarine cable.

Japanese Patent Laid-Open No. 06-237225 JP 07-336309 A JP 09-258082 A JP 2005-215413 A

  FIG. 3 shows a configuration of a general optical submarine repeater 9. In the general optical submarine repeater 9 shown in the figure, an electric circuit 91 that generates pumping light and an optical circuit 92 through which a transmitted optical signal passes are mixedly mounted on a casing 90. The electric circuit 91 includes, for example, an LD (laser diode) and a control circuit. The optical circuit 92 includes optical components such as 3 dB-CPL (3 dB coupler) and WDM-CPL (WDM coupler).

  As shown in FIG. 3, in a general optical submarine repeater, an electric circuit 91 and an optical circuit 92 are mounted in the same casing 90 to constitute an optical amplifier as one subsystem. Here, the case where the optical submarine repeater 9 has the above-mentioned one subsystem is shown, but in general, the optical submarine repeater may be configured by the plurality of subsystems described above. For this reason, the general optical submarine repeater has a problem in that the size of the housing becomes large.

  Moreover, since a general optical submarine repeater manufactures a housing using a special metal material such as BeCu, there is a problem that the manufacturing cost increases. Further, as shown in FIG. 3, in a general optical submarine repeater, an electric circuit 91 and an optical circuit 92 are mounted in the same casing. For this reason, it is necessary to inspect and adjust whether or not to operate as an optical amplifier after the assembly of the optical submarine repeater is completed, which has a problem of affecting workability and deteriorating work efficiency. It was. Furthermore, in general optical submarine repeaters, when the above subsystems are mounted in a small housing such as a joint box, there is not enough space for mounting, so more than two subsystems cannot be mounted. There was a problem that subsystems could not be created.

  An object of the present invention is to provide an optical submarine repeater and a method for mounting an optical submarine repeater circuit that solve the above-described problems.

In order to solve the above-described problem, according to a first embodiment of the present invention, an optical submarine repeater, which is a first housing mounted with an electrical circuit including a circuit for generating excitation light and a surge protection circuit, is provided. A cable that connects the electrical circuit and the optical circuit, including a second housing mounted with an optical circuit that transmits the transmitted optical signal, a signal fiber, an electrical signal line, and a fiber that transmits excitation light With.

According to a second aspect of the present invention, there is provided a method for mounting an optical submarine relay circuit, the step of mounting an electrical circuit including a circuit for generating excitation light and a surge protection circuit on a first housing, and transmission. A step of mounting an optical circuit for transmitting an optical signal on the second housing, and connecting the electric circuit and the optical circuit with a signal fiber, an electric signal line, and a cable containing a fiber for transmitting excitation light. Including stages.

  The above summary of the invention does not enumerate all necessary features of the present invention. Also, a sub-combination of these feature groups can also be an invention.

  As is apparent from the above description, according to the present invention, it is possible to reduce the size of a device including a small casing on which an electric circuit is mounted and a small casing on which an optical circuit is mounted. Further, according to the present invention, the manufacturing cost of such a device can be reduced.

It is a block diagram which shows the structure of the optical submarine repeater which concerns on one Embodiment. It is a block diagram of the optical submarine repeater which concerns on other embodiment. It is a block diagram which shows the structure of the general optical submarine repeater 9. FIG.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are described below. However, this is not always essential for the solution of the invention.

  FIG. 1 is a configuration diagram illustrating a configuration of an optical submarine repeater according to an embodiment. In the figure, the optical submarine repeater 1 of this embodiment is mounted on a housing 10 configured as a joint box, and includes an electric circuit 11 including a circuit for generating excitation light and a surge protection circuit.

  Further, the optical submarine repeater 1 of the present embodiment includes an optical circuit 12 that is mounted on a housing 20 configured as a joint box and transmits transmitted optical signals.

  Furthermore, the optical submarine repeater 1 of this embodiment includes a cable 30 that connects the electric circuit 11 and the optical circuit 12. In addition to the signal fiber and the electric signal line used for the optical submarine repeater, the cable 30 transmits the excitation light from the electric circuit 11 to an EDF (Erbium doped fiber) (described later) of the optical circuit 12. Assume that the fiber to be transmitted is mounted.

  As shown in FIG. 1, in the present embodiment, as an electric circuit 11, a control circuit 111, LD1 (112), LD2 (113) operating as an excitation LD (laser diode), and PBC (polarization combining coupler) The case where an electric circuit provided with 114 is used is described. However, in general, the electric circuit 11 is not limited by the above circuit, and may be a circuit having another configuration as long as it includes a circuit that generates excitation light and a surge protection circuit.

  In the present embodiment, the case where an optical circuit provided with 3 dB-CPL 121, WDM-CPL (122, 123), and EDF (124, 125) is used as the optical circuit 12 is described. However, in general, the optical circuit 12 may be any other circuit as long as it is a circuit through which the transmitted optical signal passes, and is not limited by the above circuit.

  Hereinafter, the function of the optical submarine repeater 1 will be described. The optical submarine repeater 1 is configured such that the electrical circuit 11 is mounted on a housing 10 that is a small joint box, and the optical circuit 12 is mounted on a housing 20 that is a small joint box. The cable 30 connecting the electric circuit in the housing 10 and the optical circuit 12 in the housing 20 includes a fiber for transmitting excitation light in addition to the signal fiber and the electric signal line, and includes the optical circuit 12. Excitation light is supplied to the EDF (124, 125).

  As described above, the optical submarine repeater 1 is configured as a circuit in a separate small casing in which the electric circuit 11 and the optical circuit 12 are separated. As a result, the housing that is the joint box can be downsized. This downsizing makes it possible to increase the water pressure resistance, so there is no need to construct the case using a special metal such as BeCu (beryllium copper alloy) used in the equipment of a large case. As a result, the manufacturing cost of the device can be reduced.

  Further, a larger number of subsystems composed of the electric circuit and the optical circuit can be mounted in the miniaturized joint box. Furthermore, in the optical submarine repeater 1, the electric circuit 11 and the optical circuit 12 can be manufactured separately, and both circuits can be inspected separately. It can be simplified.

  The operation of the optical submarine repeater 1 will be described below. As shown in FIG. 1, an electric signal enters the casing 10 which is a joint box on the electric circuit 11 side from the (+) side, and LD1 (112) and LD2 (113) which are excitation LDs in the control circuit 111 are connected. Drive. Excitation light is output from the driven LD1 (112) and LD2 (113), and the excitation light enters the PBC 114. Further, the excitation light passes through a cable 30 laid between the housing 10 and the housing 20 that is a joint box, and enters the housing 20 that is a joint box on the optical circuit 12 side.

  The excitation light that has entered the housing 20 that is a joint box on the optical circuit 12 side passes through the 3 dB-CPL 121 and is branched into two optical paths, and enters the WDM-CPL 122 and the WDM-CPL 123. Here, the signal light transmitted to the device via the signal fiber and the pumping light are multiplexed by the WDM-CPL 122 and the WDM-CPL 123. Further, the combined excitation light passes through the EDF 125. As a result, the signal light transmitted through the signal fiber is optically amplified.

  According to the optical submarine repeater according to the present embodiment, the electrical circuit 11 and the optical circuit 12 that are constituent elements are separately mounted to be mounted on the small casing 10 and the casing 20 that are joint boxes. There is an effect that becomes possible. In addition, according to the optical submarine repeater according to the present embodiment, the waterproof pressure strength can be increased by downsizing the housing 10 and the housing 20. As a result, there is no need to construct a large casing using a special metal such as BeCu (beryllium copper alloy), so that the manufacturing cost can be reduced. Furthermore, according to the optical submarine repeater according to the present embodiment, the electrical circuit 11 and the optical circuit 12 can be separately manufactured and inspected in the middle of manufacturing, so that the productivity can be improved. Yes.

  FIG. 2 is a configuration diagram of an optical submarine repeater according to another embodiment. In the figure, the optical submarine repeater 2 of the present embodiment includes an electric circuit 21 mounted on a housing 10 configured as a joint box. Moreover, the optical submarine repeater 2 of this embodiment is provided with the optical circuit 22 mounted in the housing | casing 20 comprised as a joint box. Furthermore, the optical submarine repeater 2 of this embodiment includes a cable 40 that connects the electric circuit 21 and the optical circuit 12. The cable 40 is mounted with a fiber for transmitting excitation light from the electric circuit 21 to an EDF (described later) of the optical circuit 22 in addition to a signal fiber and an electric signal line commonly used for an optical submarine repeater.

  As shown in FIG. 2, in the present embodiment, as the electric circuit 21, the control circuits 111a and 111b, and LD1 (112a), LD2 (113a), LD3 (112b), and LD4 that operate as excitation LDs (laser diodes). (113b) is used. In addition to this, an electric circuit provided with PBCs (polarization combining couplers) 114a and 114b is used. However, in general, the electric circuit 21 is not limited by the above circuit, and may be a circuit having another configuration as long as it includes a circuit that generates excitation light.

  As shown in FIG. 2, in the present embodiment, 3 dB-CPL 121a, 121b, WDM-CPL (122a, 122b, 123a, 123b), and EDF (124a, 124b, 125a, 125b) are used as the optical circuit 22. Use the arranged optical circuit. However, in general, the optical circuit 22 may be any other circuit as long as it is a circuit through which the transmitted optical signal passes, and is not limited by the above circuit.

  The configuration of the optical submarine repeater 2 of the present embodiment shown in FIG. 2 is a configuration of an optical submarine repeater including two subsystems (4AMP configuration). That is, in the optical submarine repeater 2, the electric circuit 21 is constituted by the above-described four pumping LDs, and the paired LDs are multiplexed by PBC (114a, 114b) which is a PBC coupler. In this case, the excitation light output from the electric circuit 21 is supplied to the EDF (124a, 124b, 125a, 125b) of the optical circuit 22 via the cable 40 incorporating two fibers.

  As another embodiment, an optical submarine repeater having three or more subsystems (AMPs) configured by the above-described electric circuit and optical circuit can be configured. Moreover, the optical submarine repeater can be suitably applied to an apparatus that is difficult to collect once laid, and can be applied to an apparatus having a large size even if the casing is downsized.

DESCRIPTION OF SYMBOLS 1 Optical submarine repeater 2 Optical submarine repeater 10 Case 20 Case 11 Electrical circuit 21 Electrical circuit 12 Optical circuit 22 Optical circuit 30 Cable 40 Cable 111 Control circuit 112 LD1
113 LD2
114 PBC
121 3dB-CPL
122 WDM-CPL
123 WDM-CPL
124 EDF
125 EDF

Claims (7)

A first housing on which an electric circuit including a circuit for generating excitation light and a surge protection circuit is mounted;
A second housing mounted with an optical circuit for passing the transmitted optical signal;
An optical submarine repeater including a signal fiber, an electric signal line, and a fiber for transmitting the pumping light, and a cable connecting the electric circuit and the optical circuit. The electrical circuit and the optical circuit are one subsystem that functions as an optical signal amplification circuit, and a plurality of the electrical circuits constituting the plurality of subsystems are mounted on the first casing, The optical submarine repeater according to claim 1, wherein an optical circuit constituting a subsystem is mounted on the second casing. The optical submarine repeater according to claim 1 or 2, wherein each of the first casing and the second casing is a joint box. The optical submarine repeater according to any one of claims 1 to 3 , wherein the fiber that transmits the excitation light transmits the excitation light output from the electric circuit and supplies the excitation light to the optical circuit. The optical submarine repeater according to any one of claims 1 to 4 , wherein the electric circuit includes a control circuit, a laser diode, and a polarization combining coupler. The optical submarine repeater according to any one of claims 1 to 5 , wherein the optical circuit includes a 3 dB coupler, a WDM-coupler, and an amplification fiber, which are optical components. Mounting an electrical circuit including a circuit for generating excitation light and a surge protection circuit on the first housing;
Mounting an optical circuit for transmitting the transmitted optical signal in the second housing;
Wherein the electrical circuit and the optical circuit, the signal fiber, electrical signal lines, and a mounting method of an optical submarine repeater circuit comprising the steps of connecting a cable with a built-in fiber for transmitting the excitation light.

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