Optical amplification system and optical amplification method

Abstract

In order to reduce power consumption, an optical amplification system (6) is provided with: a plurality of optical output means (22) and a plurality of optical amplification means (14); a power consumption measurement means (51) for measuring each power consumption as consumed by the plurality of optical output means (22); an excitation light measurement means (25) for measuring the intensity of excitation light; a first optical signal measurement means (21) for measuring a first intensity of an optical signal before amplification by the optical amplification means (14); a second optical signal measurement means (24) for measuring a second intensity of the optical signal after amplification by the optical amplification means (14); a first calculation means (52) for calculating the radiation efficiency of the optical output means (22) on the basis of the power consumption and the intensity of the excitation light; a second calculation means (52) for calculating the excitation efficiency of the optical amplification means (14) on the basis of the first intensity, the second intensity, and the intensity of the excitation light; and, a connection means (23) for connecting each of the optical output means (22) and each of the optical amplification means (14) on the basis of radiation efficiency and excitation efficiency.

Description

[Technical field]

[0001] The present invention relates to, for example, an optical amplification system capable of amplifying an optical signal by a plurality of optical amplifiers. [Background technology]

[0002] In recent years, methods for amplifying optical signals propagating through each core in a multi-core optical fiber have been known. For example, Patent Document 1 discloses a technique for controlling the output power of a laser beam to pump the cores of a multi-core optical fiber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2020-513162 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a multi-core optical fiber, even if pump light of the same intensity is input to multiple cores, the amount of amplification between cores varies due to errors in the core arrangement and manufacturing process. Also, in the light sources that output pump light, even if the same amount of power is supplied to multiple light sources, the intensity of the pump light output from the light sources may differ due to errors in the light sources that occur during manufacturing.

[0005] As described above, even if each of the multiple cores and each of the light sources have the same specifications, their characteristics such as amplification amount differ from one another. For example, when trying to excite a core with a low amplification amount using a light source that outputs low-intensity excitation light, there is a problem that power consumption is high.

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an optical amplification system etc. capable of reducing power consumption. [Means for solving the problem]

[0007] The optical amplification system of the present invention comprises: A plurality of optical output means for outputting excitation light; a plurality of optical amplifiers for amplifying optical signals in response to the pump light; a power consumption measuring means for measuring the power consumption of each of the plurality of light output means; an excitation light measuring means for measuring an intensity of the excitation light output from each of the plurality of light output means; a first optical signal measuring means for measuring a first intensity of the optical signal before being amplified by the optical amplifying means; a second optical signal measuring means for measuring a second intensity of the optical signal after being amplified by the optical amplifying means; a first calculation means for calculating a radiation efficiency of the light output means based on the power consumption and the intensity of the excitation light; a second calculation means for calculating an excitation efficiency of the optical amplification means based on the first intensity, the second intensity, and the intensity of the excitation light; a connection means for connecting each of the optical output means and each of the optical amplifying means based on the radiation efficiency and the excitation efficiency; Equipped with.

[0008] Alternatively, the optical amplification method of the present invention comprises: A plurality of light output means outputs excitation light; amplifying an optical signal in response to the pump light by a plurality of optical amplifiers; measuring power consumption of each of the plurality of light output means; measuring the intensity of the excitation light output from each of the plurality of light output means; measuring a first intensity of the optical signal before being amplified by the optical amplifier; measuring a second intensity of the optical signal after being amplified by the optical amplifier; calculating a radiation efficiency of the light output means based on the power consumption and the intensity of the excitation light; calculating an excitation efficiency of the optical amplification means based on the first intensity, the second intensity, and the intensity of the excitation light; Each of the optical output means and each of the optical amplifying means are connected based on the radiation efficiency and the excitation efficiency.

[0009] Alternatively, the storage medium of the present invention comprises: A plurality of light output means outputs excitation light; amplifying an optical signal in response to the pump light by a plurality of optical amplifiers; measuring power consumption of each of the plurality of light output means; measuring the intensity of the excitation light output from each of the plurality of light output means; measuring a first intensity of the optical signal before being amplified by the optical amplifier; measuring a second intensity of the optical signal after being amplified by the optical amplifier; calculating a radiation efficiency of the light output means based on the power consumption and the intensity of the excitation light; calculating an excitation efficiency of the optical amplification means based on the first intensity, the second intensity, and the intensity of the excitation light; The optical amplifier stores a program for causing an information processing device to execute a process of connecting each of the optical output means and each of the optical amplifiers based on the radiation efficiency and the excitation efficiency. Effect of the Invention

[0010] According to the present invention, it is possible to provide an optical amplification system, an optical amplification method, and a storage medium that are capable of reducing power consumption. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing an example of the configuration of an optical amplification system according to a first embodiment of the present invention. [Diagram 2] 4 is a flowchart showing an operation of the optical amplification system in the first embodiment of the present invention. [Diagram 3] 10 is a flowchart showing the operation of a modified example of the optical amplification system in the first embodiment of the present invention. [Figure 4]FIG. 2 is a diagram for explaining a modified example of the optical amplification system in the first embodiment of the present invention. [Diagram 5] FIG. 11 is a block diagram showing an example of the configuration of an optical amplification system according to a second embodiment of the present invention. [Figure 6] 10 is a flowchart showing an operation of the optical amplification system in the second embodiment of the present invention. [Figure 7] FIG. 11 is a diagram for explaining a modified example of the optical amplification system in the second embodiment of the present invention. [Figure 8] 10 is a flowchart showing the operation of a modified example of the optical amplification system in the second embodiment of the present invention. [Figure 9] FIG. 13 is a block diagram showing an example of the configuration of an optical amplification system according to a third embodiment of the present invention. [Figure 10] FIG. 13 is a block diagram showing an example of the configuration of an optical amplification system according to a fourth embodiment of the present invention. [Figure 11] FIG. 13 is a diagram for explaining an optical amplification system according to a fourth embodiment of the present invention. [Figure 12] 13 is a flowchart showing an operation of the optical amplification system in the fourth embodiment of the present invention. [Figure 13] FIG. 13 is a block diagram showing an example of the configuration of an optical communication system according to a fifth embodiment of the present invention. [Figure 14] FIG. 13 is a block diagram showing an example of the configuration of an optical amplification system according to a sixth embodiment of the present invention. [Figure 15] 13 is a flowchart showing an operation of the optical amplification system in the sixth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] <First embodiment> An optical amplification system 1 in the first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a configuration example of the optical amplification system 1. As shown in Fig. 1, the optical amplification system 1 includes multiplexing means 11A, 11B, and 11C, a bundle fiber 12, a demultiplexer 13, a multi-core EDF (Erbium Doped Fiber) 14, and a bundle fiber 15. These components are connected to each other via optical fibers.

[0013] When there is no need to distinguish between the multiplexing means 11A, 11B, and 11C, in the following description, each of the multiplexing means 11A, 11B, and 11C will be referred to as multiplexing means 11. Pumping light input from a connection means 23 described below and an optical signal from another optical communication device are input to the multiplexing means 11. The multiplexing means 11 also multiplexes the optical signal and the pumping light, and outputs the multiplexed signal to the bundle fiber 12. The multiplexing means 11 is, for example, an optical coupler.

[0014] The bundle fiber 12 outputs the multiplexed light of the pumping light and the optical signal output from the multiplexing means 11 to one multi-core optical fiber. At this time, the bundle fiber 12 outputs the multiplexed light of the pumping light and the optical signal to a different core (not shown) for each multiplexing means 11. Note that the above-mentioned core refers to one included in the multi-core optical fiber. For example, when multiplexing means 11A, 11B, and 11C are present as shown in FIG. 1, the multiplexed light output from the multiplexing means 11A, the multiplexed light output from the multiplexing means 11B, and the multiplexed light output from the multiplexing means 11C are output toward different cores by each of the multiplexing means 11A, 11B, and 11C.

[0015] The demultiplexer 13 is, for example, an isolator. The demultiplexer 13 prevents light generated inside and outside the optical amplification system 1 from being input from the bundle fiber 15 side to the bundle fiber 12 side. The demultiplexer 13 may be a wavelength filter. In this case, the demultiplexer 13 can prevent light having a wavelength other than the wavelengths set in advance as the transmission band (for example, light other than the optical signal and the pump light) from being input to the multi-core EDF 14.

[0016] The multi-core EDF 14 is an optical fiber having multiple cores. Each core in the multi-core EDF 14 amplifies the optical signal according to the pump light multiplexed with the optical signal. The multi-core EDF 14 outputs the optical signal amplified in each core to the bundle fiber 15. Note that the cores included in the multi-core EDF 14 correspond to optical amplifying means. Also, the multi-core EDF 14 corresponds to multiple optical amplifying means.

[0017] The bundle fiber 15 outputs a plurality of optical signals from the multi-core EDF 14 to different optical fibers.

[0018] Moreover, the optical amplification system 1 further comprises a first optical signal measuring means 21 , optical output means 22 A, 22 B, 22 C, a connecting means 23 , a second optical signal measuring means 24 , and an excitation light measuring means 25 .

[0019] The first optical signal measuring means 21 is connected to each of the multiplexing means 11A, 11B, and 11C and to the management unit 30 described later. The first optical signal measuring means 21 measures the intensity of the optical signal before being amplified by the multi-core EDF 14. The intensity of the optical signal before being amplified by the multi-core EDF 14 corresponds to the first intensity described later. The first optical signal measuring means 21 receives an optical signal branched by an optical branching unit (not shown) provided in the optical fiber in front of the multiplexing means 11. The first optical signal measuring means 21 measures the intensity of the optical signal before being amplified by the multi-core EDF 14 based on the intensity of the received optical signal. For example, when a plurality of optical fibers are connected to each multiplexing means 11 as shown in FIG. 1, the first optical signal measuring means 21 measures the intensity of the optical signal for each optical fiber. The first optical signal measuring means 21 outputs the measured intensity of the optical signal to the management unit 30 described later.

[0020] When there is no need to distinguish between the optical output means 22A, 22B, and 22C, in the following description, each of the optical output means 22A, 22B, and 22C will be referred to as optical output means 22. The optical output means 22 is, for example, a laser diode. The multiple optical output means 22 are connected to a connection means 23, an excitation light measurement means 25, and a management unit 30. The multiple optical output means 22 output multiple excitation lights. The excitation lights output from the optical output means 22 are input to each of the multiplexing means 11 via the connection means 23.

[0021] The connection means 23 connects each of the multiple optical output means 22 to each of the multi-core EDF 14 via each of the multiple multiplexing means 11, the bundle fiber 12, and the demultiplexer 13. Specifically, the connection means 23, the multiplexing means 11, the bundle fiber 12, and the demultiplexer 13 connect each of the multiple optical output means 22 to each of the multi-core EDF 14. Since the cores in the multi-core EDF 14 to which each multiplexing means 11 is connected are fixed, the connection means 23 can switch the connection relationship between the cores in the multi-core EDF 14 and the optical output means 22 by switching the connection relationship between each multiplexing means 11 and each optical output means 22. For example, the connection means 23 can switch the connection destination of the optical output means 22A from one core to another core in the multi-core EDF 14. The connection means 23 is, for example, a matrix switch.

[0022] The second optical signal measuring means 24 is connected to the bundle fiber 15 and the management unit 30. The second optical signal measuring means 24 measures the intensity of the optical signal after being amplified by the multi-core EDF 14. The intensity of the optical signal after being amplified by the multi-core EDF 14 corresponds to a second intensity described later. The second optical signal measuring means 24 receives an optical signal branched by an optical branching unit (not shown) provided in an optical fiber at the rear stage of the bundle fiber 15. The second optical signal measuring means 24 measures the intensity of the optical signal after being amplified by the multi-core EDF 14 based on the intensity of the received optical signal. For example, when a plurality of optical fibers are connected to the bundle fiber 15 as shown in FIG. 1, the second optical signal measuring means 24 measures the intensity of the optical signal for each optical fiber. The second optical signal measuring means 24 outputs the measured intensity of the optical signal to the management unit 30 described later.

[0023] The excitation light measuring means 25 is connected to the connection means 23, each of the plurality of optical output means 22, and the management unit 30. The excitation light measuring means 25 measures the intensity of the excitation light output from each of the plurality of optical output means 22. The excitation light measuring means 25 receives the excitation light branched by an optical branching unit (not shown) provided in the optical fiber between the optical output means 22. The excitation light measuring means 25 measures the intensity of the excitation light output from the optical output means 22 based on the intensity of the received excitation light. For example, when a plurality of optical output means 22 are provided as shown in FIG. 1, the excitation light measuring means 25 measures the intensity of the excitation light for each optical output means 22. The excitation light measuring means 25 outputs the measured intensity of the excitation light to the management unit 30 described later.

[0024] The optical amplification system 1 further includes a management unit 30. The management unit 30 includes a controller 31, a power calculator 32, an efficiency calculator 33, and a database .

[0025] The controller 31 instructs the connection means 23 on the connection relationship between the multiple optical output means 22 and the multiple cores in the multi-core EDF 14. The connection means 23 connects the multiplexing means 11 connected to the cores in the multi-core EDF and the optical output means 22 according to the instruction from the controller. The above-mentioned connection relationship indicates a combination of the cores in the multi-core EDF 14 and the optical output means 22 that are connected to each other.

[0026] Power calculator 32 measures the power consumption consumed by each of the plurality of light output means 22. Power calculator 32 corresponds to the power consumption measuring means. The light output means 22 described above outputs excitation light with an intensity according to the magnitude of the input power. Power calculator 32 calculates the power input to each light output means 22 as the power consumption. Power calculator 32 may measure the current input to light output means 22 or the voltage applied to light output means 22 instead of power.

[0027] Efficiency calculator 33 calculates the radiation efficiency of light output means 22 based on the power consumption consumed by light output means 22 and the intensity of excitation light output from light output means 22. Efficiency calculator 33 corresponds to the first calculation means. For example, efficiency calculator 33 calculates the ratio of the intensity of excitation light to the power consumption as the radiation efficiency. Light output means 22 with high radiation efficiency can output excitation light of higher intensity with less power consumption.

[0028] The efficiency calculator 33 calculates the pumping efficiency of the multi-core EDF 14 based on the first intensity, the second intensity, and the intensity of the pumping light. The efficiency calculator 33 corresponds to the second calculation means. The efficiency calculator 33 obtains the intensity (first intensity) of the optical signal before being amplified by the multi-core EDF 14 from the first optical signal measurement means 21. The efficiency calculator 33 also obtains the intensity (second intensity) of the optical signal after being amplified by the multi-core EDF 14 from the second optical signal measurement means 24. The efficiency calculator 33 calculates the ratio of the second intensity to the first intensity as the amplification factor of the core. The efficiency calculator 33 calculates the amplification factor of each of the multiple cores.

[0029] Furthermore, the efficiency calculator 33 acquires the intensity of the excitation light output from each of the multiple light output means 22 from the excitation light measuring means 25. The efficiency calculator 33 calculates the ratio of the amplification factor of the core to the intensity of the excitation light input to the core as the excitation efficiency of the core.

[0030] The efficiency calculator 33 may obtain the ratio of the amplification factor of a core to the power consumption in the optical output means 22 that outputs the excitation light input to the core as the excitation efficiency of the core. In this case, the controller 31 causes the excitation light from one optical output means 22 to be output sequentially to different cores. The efficiency calculator 33 obtains the intensity (first intensity) of the optical signal before the excitation light is amplified in the core to which the excitation light is input, and the intensity (second intensity) of the optical signal after the excitation light is amplified in the core to which the excitation light is input. Furthermore, the efficiency calculator 33 obtains the power consumption consumed by the optical output means 22. The efficiency calculator 33 obtains the ratio of the second intensity to the first intensity as the amplification factor of the core. Furthermore, the efficiency calculator 33 obtains the ratio of the amplification factor of the core to the power consumption in the optical output means 22 as the excitation efficiency of the core. The controller 31 obtains the radiation efficiency of each optical output means 22 and the pumping efficiency of each core in the multi-core EDF 14 from the efficiency calculator 33. The controller 31 associates the cores with the lowest pumping efficiency in order of the radiation efficiency of each of the optical output means 22. For example, the controller 31 associates the optical output means 22 with the highest radiation efficiency and the core with the lowest pumping efficiency. The controller 31 also associates the optical output means 22 with the second highest radiation efficiency and the core with the second lowest pumping efficiency. The controller 31 outputs the correspondence between the cores and the optical output means 22 to the connection means 23. The connection means 23 connects the optical output means 22 and the cores according to the input correspondence. The controller 31 is also provided to be able to communicate with each component in the optical amplification system 1.

[0031] The database 34 acquires the radiation efficiency for each light output means 22 and the excitation efficiency for each core in the multi-core EDF 14 from the efficiency calculator 33. The database 34 may also acquire and store the correspondence between the light output means 22 and the cores from the controller 31. The database 34 may also store other information.

[0032] Next, the operation of the optical amplification system 1 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the operation of the optical amplification system 1.

[0033] The power calculator 32 measures the power consumption consumed by the optical output means 22 (S101). The pump light measuring means 25 measures the intensity of the pump light output from the optical output means 22 (S102). The first optical signal measuring means 21 measures the intensity (first intensity) of the optical signal before being amplified in the cores (S103). The second optical signal measuring means 24 measures the intensity of the optical signal after being amplified in the multi-core EDF 14 (S104). Note that the order of the processes of S101 to S104 may be reversed, and the processes of S101 to S104 may be performed in parallel.

[0034] The efficiency calculator 33 calculates the radiation efficiency of the light output means 22 based on the power consumption and the intensity of the excitation light (S105). The efficiency calculator 33 also calculates the excitation efficiency of the core based on the first intensity, the second intensity, and the intensity of the excitation light (S106). Note that the order of the processes of S105 and S106 may be reversed, or the processes of S105 and S106 may be performed in parallel.

[0035] The controller 31 outputs the correspondence between the light output means 22 and the cores based on the radiation efficiency and the excitation efficiency to the connection means 23 (S107). Furthermore, the connection means 23 connects each of the cores to each of the light output means 22 (S108). After the process of S107, the management unit 30 may adjust the power supplied to the light output means 22 so that the second intensity measured by the second optical signal measuring means 24 becomes a predetermined target value.

[0036] As described above, the optical amplification system 1 includes a plurality of optical output means 22, a plurality of cores (a plurality of multi-core EDFs 14), a power calculator 32, an excitation light measuring means 25, a first optical signal measuring means 21, a second optical signal measuring means 24, an efficiency calculator 33, and a connecting means 23. The plurality of cores correspond to the plurality of multi-core EDFs 14. The power calculator 32 corresponds to the power consumption measuring means. Moreover, the efficiency calculator 33 corresponds to the first calculating means and the second calculating means. Moreover, the plurality of optical output means 22 output excitation light. The plurality of cores amplify an optical signal according to the excitation light. The power calculator 32 measures each of the power consumptions consumed by the plurality of optical output means 22. The first optical signal measuring means 21 measures a first intensity of the optical signal before being amplified in the core. The second optical signal measuring means 24 measures a second intensity of the optical signal after being amplified in the core. The efficiency calculator 33 calculates the radiation efficiency of the optical output means 22 based on the power consumption in the optical output means 22 and the intensity of the excitation light. Moreover, the efficiency calculator 33 calculates the excitation efficiency of the core based on the first intensity, the second intensity, and the intensity of the excitation light. Moreover, the connection means 23 connects each of the light output means 22 and each of the cores based on the radiation efficiency and the excitation efficiency.

[0037] In a general optical communication system, all optical signals need to be amplified to a predetermined intensity or more. Therefore, when a core with low excitation efficiency is connected to an optical output means with low radiation efficiency, it is necessary to supply a significantly large amount of power to the optical output means in order to amplify an optical signal propagating through the core to a predetermined intensity. On the other hand, in the optical amplification system 1, each of the multiple optical output means 22 and each of the multiple cores are connected by the connection means 23 based on the radiation efficiency and the excitation efficiency. As a result, the optical amplification system 1 can connect, for example, a core with high radiation efficiency among the multiple optical output means 22 and a core with low excitation efficiency, and connect a core with low radiation efficiency among the multiple optical output means 22 and a core with high excitation efficiency. As a result, in the optical amplification system 1, it is not necessary to supply a significantly large amount of power to one optical output means 22, so that power consumption can be suppressed.

[0038] Next, a description will be given of the optical amplification system 1A. The optical amplification system 1A is a modified example of the optical amplification system 1. The optical amplification system 1A has a similar configuration to the optical amplification system 1 shown in FIG.

[0039] The operation of the optical amplification system 1 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the operation of the optical amplification system 1.

[0040] The pumping light measuring means 25 measures the intensity of the pumping light when the amplification factor of each core reaches the target value as a target value (S101A). Specifically, the controller 31 adjusts the power consumption supplied to the light output means 22, while the efficiency calculator 33 calculates the amplification factor of the core to which the light output means 22 supplies the pumping light. The controller 31 acquires the intensity of the pumping light at the time when the amplification factor reaches a threshold value from the pumping light measuring means 25. For example, the controller 31 acquires that the intensity of the pumping light when the amplification factor of the first core among the multiple cores reaches the target value is 0.39 W. In the case where there are four cores, the controller 31 further acquires that the intensity of the pumping light when the second core, the third core, and the fourth core reach their target values ​​are 0.41 W, 0.42 W, and 0.53 W, respectively.

[0041] The power calculator 32 measures the power consumption for each optical output means 22 to output pump light having the intensity of each target value (S102A). Specifically, as shown in Fig. 4, the power calculator 32 measures the power consumed by the optical output means 22 to output pump light of the intensity required for the amplification factor of each core to reach the target value. Fig. 4 is a diagram showing the correspondence between each core and the optical output means 22 when the multi-core EDF 14 has four cores and the optical amplification system 1 has four optical output means 22. Fig. 4 shows that the power consumption required for the fourth core to set the amplification factor of the fourth core to the target value is 2.019 W, for example.

[0042] Controller 31 selects the correspondence between the cores and the light output means 22 that minimizes the sum of the power consumptions (S103A). For example, in the example of Fig. 4, the sum of the power consumptions is minimized when first light output means 221 is associated with the fourth core, second light output means 222 is associated with the first core, third light output means 223 is associated with the third core, and fourth light output means 224 is associated with the second core.

[0043] Controller 31 outputs the selected correspondence to connection means 23 (S104A). Connection means 23 then connects each of the cores to each of the optical output means 22 according to the output correspondence (S105A). In the above example, first optical output means 221 is connected to the fourth core, second optical output means 222 is connected to the first core, third optical output means 223 is connected to the third core, and fourth optical output means 224 is connected to the second core.

[0044] <Second embodiment> An optical amplification system 2 in the second embodiment will be described with reference to Fig. 5. Fig. 5 is a block diagram showing a configuration example of the optical amplification system 2. As shown in Fig. 5, the optical amplification system 2 includes multiplexing means 11A, 11B, and 11C, a bundle fiber 12, a demultiplexer 13, a multi-core EDF (Erbium Doped Fiber) 14, and a bundle fiber 15, similar to the optical amplification system 1. The optical amplification system 2 further includes a cladding light output means 41 and a multiplexer 42.

[0045] The optical output means for cladding 41 outputs pumping light to be input to the cladding of the multi-core EDF 14. The multiplexer 42 inputs the pumping light from the optical output means for cladding 41 to an optical fiber between the multi-core EDF 14 and the bundle fiber 15. As a result, the pumping light from the optical output means for cladding 41 is input to the cladding of the multi-core EDF 14.

[0046] Next, the operation of the optical amplification system 2 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the operation of the optical amplification system 2. The controller 31 issues an instruction to the optical output means 22 and the cladding optical output means 41 to stop output of pumping light from the optical output means 22 and output pumping light from the cladding optical output means 41 (S201). As a result, the multi-core EDF 14 amplifies the optical signal propagating through each core by only the cladding.

[0047] The second optical signal measuring means 24 measures the intensity (second intensity) of the optical signal after being amplified (S202). For example, when there are four cores, the second optical signal measuring means 24 measures that the intensity of the optical signal amplified in the first core is 19.03 dBm, the intensity of the optical signal amplified in the second core is 18.7 dBm, the intensity of the optical signal amplified in the third core is 18.37 dBm, and the intensity of the optical signal amplified in the fourth core is 17.95 dBm.

[0048] The controller 31 adjusts the pump light output from each optical output means 22 so that the second intensity reaches the target value (S203). In the above example, the second optical signal measuring means 24 adjusts the power supplied to each optical output means 22 so that the intensity (second intensity) of the optical signal after amplified in all the cores becomes 19.03 dBm. The second optical signal measuring means 24 may adjust the power supplied to each optical output means 22 so that the intensity (second intensity) of the optical signal after amplified in all the cores reaches the target value, with a value exceeding 19.03 dBm (the intensity of the optical signal amplified in the first core) as the target value.

[0049] The power calculator 32 measures the power consumption in the optical output means 22 when the second intensity reaches the target value. Fig. 7 shows the power consumption measured by the power calculator 32. For example, Fig. 7 shows that in the above example, when pump light from the first optical output means is input to the second core, in order to make the intensity of the optical signal after being amplified in the second core match the target value, it is necessary to supply a power consumption of 77.6 mw to the first optical output means.

[0050] Controller 31 selects the correspondence between the cores and the light output means 22 that minimizes the sum of the respective power consumptions. In the example shown in Fig. 7, the sum of the respective power consumptions is minimized when the first light output means 22 is associated with the fourth core, the second light output means 22 is associated with the third core, the third light output means 22 is associated with the first core, and the fourth light output means 22 is associated with the second core.

[0051] Controller 31 outputs the selected correspondence to connection means 23 (S206). Connection means 23 connects each of the cores to each of the optical output means 22 according to the input correspondence. In the above example, connection means 23 connects first optical output means 22 to the fourth core, connects second optical output means 22 to the third core, connects third optical output means 22 to the first core, and connects fourth optical output means 22 to the second core (S207).

[0052] Next, the optical amplification system 2A will be described. The optical amplification system 2A is a modified example of the optical amplification system 2. The optical amplification system 2A has a similar configuration to the optical amplification system 2 shown in FIG. 5. Moreover, the operation of the optical amplification system 2A is similar to the operation of the optical amplification system 1. Specifically, the optical amplification system 2A operates according to the flowchart shown in FIG.

[0053] Next, a description will be given of an optical amplification system 2B, which is a modified example of the optical amplification system 2. The optical amplification system 2A has a similar configuration to the optical amplification system 2 shown in FIG.

[0054] The operation of the optical amplification system 2B will be described. The power calculator 32 measures the power consumption consumed by the optical output means 22 (S201B). The pumping light measuring means 25 measures the intensity of the pumping light output from the optical output means 22 (S202B). The controller 31 issues an instruction to the optical output means 22 and the cladding optical output means 41 to stop the output of the pumping light from the optical output means 22 and output the pumping light from the cladding optical output means 41 (S203B). The first optical signal measuring means 21 measures the intensity (first intensity) of the optical signal before being amplified in the core (S204B). The second optical signal measuring means 24 measures the intensity of the optical signal after being amplified in the multi-core EDF 14 (S205B). The order of the processes of S201B and S202B may be reversed, or the processes of S201B and S202B may be performed in parallel. Furthermore, the order of the processes of S204 and S205B may be reversed, and the processes of S204B and S205B may be performed in parallel.

[0055] The efficiency calculator 33 calculates the radiation efficiency of the light output means 22 based on the power consumption and the intensity of the excitation light (S206B). The efficiency calculator 33 also calculates the amplification factor of the core based on the first intensity and the second intensity (S207B). The order of the processes of S206B and S207B may be reversed, or the processes of S206B and S207B may be performed in parallel.

[0056] The controller 31 selects a correspondence between the cores and the optical output means 22 based on the amplification factor and radiation efficiency of each core by the cladding (S208B). Specifically, the controller 31 associates the cores with the lowest amplification factor by the cladding in order of the highest radiation efficiency for each of the multiple optical output means 22. For example, the controller 31 associates the optical output means 22 with the highest radiation efficiency and the core with the lowest amplification factor. The controller 31 also associates the optical output means 22 with the second highest radiation efficiency and the core with the second lowest amplification factor. The controller 31 outputs the correspondence between the cores and the optical output means 22 to the connection means 23 (S209B). The connection means 23 connects the optical output means 22 and the cores according to the input correspondence (S210B).

[0057] <Third embodiment> An optical amplification system 3 in the third embodiment will be described with reference to Fig. 9. Fig. 9 is a block diagram showing a configuration example of the optical amplification system 3. As shown in Fig. 5, the optical amplification system 2 includes multiplexing means 11A, 11B, and 11C, a bundle fiber 12, a demultiplexer 13, a multi-core EDF (Erbium Doped Fiber) 14, a bundle fiber 15, a cladding optical output means 41, and a multiplexer 42, similar to the optical amplification system 1. The optical amplification system 3 includes an additional optical output means 22 and multiplexers 16A, 16B, and 16C.

[0058] The additional optical output means 22D is a pumping light source capable of outputting pumping light. The additional optical output means 22D is not connected to any of the multiple cores (multiple multi-core EDFs 14). On the other hand, the optical output means 22A, 22B, and 22C are connected to any of the multiple cores.

[0059] A case where an additional optical output means 22D is connected to one of the multiple cores instead of one of the optical output means 22A, 22B, and 22C will be described. For example, it is assumed that the optical output means 22A, 22B, and 22C are connected to the first core, the second core, and the third core in the multi-core EDF 14, respectively. In this example, when the optical output means 22D is connected to the first core instead of the optical output means 22A, the multiplexer 16 multiplexes the pumping light output from the optical output means 22A and the pumping light output from the optical output means 22D, and outputs the multiplexed light to the core. At this time, the optical output means 22D gradually increases the intensity of the pumping light it outputs. On the other hand, the optical output means 22A gradually decreases the intensity of the pumping light it outputs, and stops outputting the pumping light. Incidentally, the optical output means 22A and the optical output means 22D are adjusted so that the intensity of the combined pumping light becomes the same as the intensity of the pumping light that the optical output means 22A has output to the first core.

[0060] As a result, pumping light can be supplied to the core from the new optical output means 22, so that, for example, a correspondence relationship between the new optical output means 22 and the core can be obtained in S107 of the operation of the optical amplification system 1. Similarly, a correspondence relationship between the new optical output means 22 and the core can be obtained in S103A of the optical amplification system 1A, S206 of the optical amplification system 2, and S208B of the optical amplification system 2B. Therefore, according to the third embodiment, power consumption can be reduced by taking into consideration the new optical output means 22 other than the optical output means 22 already outputting pumping light.

[0061] <Fourth embodiment> An optical amplification system 4 in the fourth embodiment will be described with reference to Fig. 10. Fig. 10 is a block diagram showing a configuration example of the optical amplification system 4. As shown in Fig. 10, the optical amplification system 4 includes multiplexing means 11A, 11B, and 11C, a bundle fiber 12, a demultiplexer 13, a multi-core EDF (Erbium Doped Fiber) 14, a bundle fiber 15, a cladding optical output means 41, a multiplexer 42, an additional optical output means 22, and multiplexers 16A, 16B, and 16C, similar to the optical amplification system 3. The optical amplification system 4 differs from the optical amplification system 3 in that it further includes an update determination means 35 in the database 34.

[0062] In the optical amplification system 4, the database 34 has a graph showing the correlation between the power consumption of each optical output means 22 and the intensity of the pumping light output from each optical output means 22. For example, the database 34 has graph A shown in Fig. 11. Fig. 11 is a graph showing the correlation between the power consumption of the optical output means 22 and the intensity of the pumping light.

[0063] Update determination means 35 monitors the power consumption and the intensity of the excitation light of light output means 22, and outputs a notification including the amount of change in power consumption to database 34. Furthermore, when the amount of change in power consumption exceeds a predetermined threshold, update determination means 35 instructs database 34 to update the correlation between power consumption and the intensity of the excitation light.

[0064] Specifically, the update determination means 35 acquires, for example, that the power consumption of the optical output means 22 is 110 mw and the intensity of the pump light is 10 dBm. At this time, the update determination means 35 refers to the graph of FIG. 11 stored in the database 34 and acquires the power consumption corresponding to the intensity (10 dBm) of the pump light. The update determination means 35 acquires, for example, from the database 34 that the power consumption corresponding to the intensity (10 dBm) of the pump light is 110 mw. At this time, the update determination means 35 outputs to the database 34 a notification including that the amount of change in power consumption is 10%. Furthermore, if the update determination means 35 has a threshold of the amount of change of 5%, the amount of change in power consumption exceeds the threshold, and therefore issues an instruction to update the correlation between the power consumption and the intensity of the pump light.

[0065] The database 34 updates the correlation between the power consumption and the intensity of the excitation light based on the change in power consumption notified by the update determination means 35. Specifically, when the amount of change in power consumption is 10%, the database 34 adds an increase of 10% to the power consumption value in the correlation in the database 34. For example, by adding an increase of 10% to the power consumption in graph A in FIG. 11, graph A is updated to graph B.

[0066] Next, an example of the operation of the optical amplification system 4 will be described with reference to FIG.

[0067] The update determination means 35 monitors the power consumption and the intensity of the pump light for each optical output means 22 (S401). The update determination means 35 determines whether the amount of change in power consumption exceeds the threshold value (S402). If the amount of change in power consumption does not exceed the threshold value (No in S402), the update determination means 35 repeats the process of S401. On the other hand, if the amount of change in power consumption exceeds the threshold value (Yes in S402), the database 34 updates the correlation between the power consumption and the intensity of the pump light based on the change in power consumption (S403). Note that the above-mentioned processes of S401 to S403 may be executed in parallel with the operation of the above-mentioned optical amplification systems 1, 1A, 2, 2A, 2B, and 3.

[0068] Next, the optical amplification system 4A will be described. The optical amplification system 4A is a modified example of the optical amplification system 4. The optical amplification system 4A has a similar configuration to the optical amplification system 4 shown in Fig. 10. Moreover, the operation of the optical amplification system 4 is similar to that of the optical amplification system 3. In addition to the operation of the optical amplification system 3, the optical amplification system 4A performs the following operations.

[0069] In the explanation of the optical amplification system 3, the case where the connection between the optical output means 22A and the cores is cut off and the additional optical output means 22D is connected to one of the multiple cores has been explained. In this case, the update determination means 35 instructs the database 34 to update the correlation between the power consumption of the optical output means 22A that has stopped outputting the pumping light and the intensity of the pumping light after the additional optical output means 22D is connected to one of the multiple cores.

[0070] The database 34 transfers the instruction from the update determination means 35 to the controller 31. The controller 31 instructs the light output means 22A to output the excitation light again. As a result, among the multiple light output means 22, the light output means 22A that has stopped outputting the excitation light outputs the excitation light again.

[0071] Database 34 updates the above-mentioned correlation based on the power consumption consumed by light output means 22A and the intensity of the excitation light output by light output means 22A. At this time, by light output means 22A sequentially changing the intensity of the excitation light, database 34 can obtain the power consumption corresponding to each intensity of the excitation light and update the correlation to a new one.

[0072] <Fifth embodiment> Next, an optical communication system 400 will be described with reference to Fig. 13. Fig. 13 is a schematic diagram of an optical communication system 400 including a plurality of optical amplification systems 1. The optical amplification system 1 has the configuration shown in Fig. 1.

[0073] In the optical communication system 400, an optical signal transmitted from the transmitter 100 is relayed by a plurality of optical amplification systems 1 and received by the receiver 200. Although Fig. 13 shows that two optical amplification systems 1 are provided between the transmitter 100 and the receiver 200, other optical devices (such as a filter or an optical amplification device) may be further provided.

[0074] The transmission path from the upstream optical amplification system 1 to the receiver 200 propagates a plurality of optical signals output from the multi-core EDF 14 (a plurality of multi-core EDFs 14) in the optical amplification system 1 provided on the upstream side.

[0075] The first optical signal measuring means 21 provided in the subsequent optical amplification system 1 is provided on the above-mentioned transmission path and measures the intensities of the multiple optical signals in the transmission path. The first optical signal measuring means 21 provided in the subsequent optical amplification system 1 corresponds to the third optical signal measuring means. The intensity measured by the first optical signal measuring means 21 provided in the subsequent optical amplification system 1 corresponds to the third intensity.

[0076] In the optical communication system 400, two optical amplification systems 1 are connected by a line 300. For example, the management units 30 of the two optical amplification systems 1 are connected so as to be able to communicate with each other. The management unit 30 provided in the optical amplification system 1 at the rear stage transmits the third intensity measured by the first optical signal measuring means 21 to the management unit 30 provided in the optical amplification system 1 at the front stage.

[0077] The management unit 30 in the front-stage optical amplification system 1 instructs the connection unit 23 to update the connection relationship between each of the optical output units 22 and each of the cores in the multi-core EDF 14. Specifically, the management unit 30 repeats the processes of S101 to S108 again. As a result, the connection unit 23 updates the connection relationship between each of the optical output units 22 and each of the cores in the multi-core EDF (multi-core EDF 14) when the third intensity has changed by a predetermined value or more.

[0078] When the optical amplification system 1A is provided instead of the optical amplification system 1, the processes of S101A to S105A are repeated so that the connection means 23 updates the connection relationship between each of the optical output means 22 and each of the cores in the multi-core EDF (multi-core EDF 14). Similarly, in the optical communication system 400, the optical amplification system 1 may be replaced by optical amplification systems 2, 2A, 2B, 3, and 4.

[0079] Modifications of the optical output means 22 in all the above embodiments will be described. In the above description, one optical output means 22 is, for example, one laser diode. On the other hand, the multiple optical output means 22 may output pumping light to multiple cores (multiple multi-core EDFs 14) in the multi-core EDF 14 by branching light output from one light source. In this case, the intensity of the pumping light input to each core is adjusted by the branching ratio with respect to the light from the light source. In addition, the optical output means 22 may output pumping light to the cores (multi-core EDFs 14) in the multi-core EDF 14 by multiplexing light output from multiple light sources.

[0080] Sixth embodiment Next, an optical communication system 400 will be described with reference to Fig. 14. Fig. 14 is a schematic diagram of an optical amplification system 6. As shown in Fig. 14, the optical amplification system 6 includes a plurality of optical amplification means (multi-core EDFs 14A, 14B, 14C), a first optical signal measurement means 21, optical output means 22A, 22B, 22C, a connection means 23, a second optical signal measurement means 24, an excitation light measurement means 25, and a management unit 50. The management unit 50 includes a power consumption measurement means 51, a first calculation means 52, and a second calculation means 53. When it is not necessary to distinguish between the optical amplification means (multi-core EDFs 14A, 14B, 14C), each of the optical amplification means (multi-core EDFs 14A, 14B, 14C) will be referred to as an optical amplification means 14 in the following description. Furthermore, in the following description, when there is no need to distinguish between light output means 22A, 22B, and 22C, each of light output means 22A, 22B, and 22C will be referred to as light output means 22.

[0081] The optical output means 22 output pump light. The multi-core EDFs 14 amplify optical signals in response to the pump light. The power consumption measuring means 51 measures the power consumption of each of the optical output means 22.

[0082] The pumping light measuring means 25 measures the intensity of the pumping light output from each of the multiple optical output means 22. The first optical signal measuring means 21 measures a first intensity of the optical signal before it is amplified by the multi-core EDF 14. The second optical signal measuring means 24 measures a second intensity of the optical signal after it is amplified by the multi-core EDF 14.

[0083] The first calculation means 52 calculates the radiation efficiency of the light output means 22 based on the power consumption measured by the power consumption measurement means 51 and the intensity of the excitation light measured by the excitation light measurement means 25. The second calculation means 53 calculates the excitation efficiency of the multi-core EDF 14 based on the first intensity, the second intensity, and the intensity of the excitation light.

[0084] The connection means 23 connects each of the optical output means 22 to each of the multi-core EDFs 14 based on radiation efficiency and excitation efficiency.

[0085] Next, the operation of the optical amplification system 6 will be described with reference to Fig. 15. Fig. 15 is a flowchart showing the operation of the optical amplification system 6.

[0086] The power consumption measuring means 51 measures the power consumption consumed by the optical output means 22 (S601). The excitation light measuring means 25 measures the intensity of the excitation light output from the optical output means 22 (S602). The first optical signal measuring means 21 measures the intensity (first intensity) of the optical signal before it is amplified in the core (S603). The second optical signal measuring means 24 measures the intensity of the optical signal after it is amplified in the multi-core EDF 14 (S604). Note that the order of the processes of S601 to S604 may be reversed, and the processes of S601 to S604 may be performed in parallel.

[0087] The first calculation means 52 calculates the radiation efficiency of the light output means 22 based on the power consumption and the intensity of the excitation light (S605). The second calculation means 53 calculates the excitation efficiency of the core based on the first intensity, the second intensity, and the intensity of the excitation light (S606). The order of the processes of S605 and S606 may be reversed, or the processes of S605 and S606 may be performed in parallel.

[0088] The controller 31 connects each of the cores to each of the light output means 22 based on the radiation efficiency and the pumping efficiency (S607).

[0089] As described above, the optical amplification system 6 includes a plurality of optical output means 22, a plurality of multi-core EDFs 14, a power consumption measuring means 51, an excitation light measuring means 25, a first optical signal measuring means 21, a second optical signal measuring means 24, a first calculating means 52, a second calculating means 53 and a connecting means 23.

[0090] In a general optical communication system, all optical signals need to be amplified to a predetermined intensity or more. Therefore, when a core with low excitation efficiency is connected to an optical output means with low radiation efficiency, it is necessary to supply a significantly large amount of power to the optical output means in order to amplify an optical signal propagating through the core to a predetermined intensity. On the other hand, in the optical amplification system 1, each of the multiple optical output means 22 and each of the multiple cores are connected by the connection means 23 based on the radiation efficiency and the excitation efficiency. As a result, the optical amplification system 1 can connect, for example, a core with high radiation efficiency among the multiple optical output means 22 and a core with low excitation efficiency, and connect a core with low radiation efficiency among the multiple optical output means 22 and a core with high excitation efficiency. As a result, in the optical amplification system 1, it is not necessary to supply a significantly large amount of power to one optical output means 22, so that power consumption can be suppressed.

[0091] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. [Explanation of symbols]

[0092] 1, 1A, 2, 2A, 2B, 3, 4, 4A, 6 Optical Amplification System 11, 11A, 11B, 11C Multiplexing means 12 Fiber bundle 13 Duplexer 14, 14A, 14B, 14C Multi-core EDF 15 Fiber bundle 16, 16A, 16B, 16C multiplexer 21 First optical signal measuring means 22 Optical output means 221 First light output means 222 Second light output means 223 Third light output means 224 fourth light output means 22A, 22B, 22C, 22D optical output means 23 Connection means 24 Second optical signal measuring means 25 Excitation light measurement means 30 Management Department 31 Controller 32 Power Calculator 33 Efficiency Calculator 34 Database 35 Update determination means 41 Light output means for cladding 42 Multiplexer 50 Management Department 51 Power consumption measurement means 52 First calculation method 53 Second calculation method 100 Transmitter 200 Receiver 300 lines 400 Optical Communication Systems

Claims

1. A plurality of optical output means for outputting excitation light; a plurality of optical amplifiers for amplifying optical signals in response to the pump light; a power consumption measuring means for measuring the power consumption of each of the plurality of light output means; an excitation light measuring means for measuring the intensity of the excitation light output from each of the plurality of light output means; a first optical signal measuring means for measuring a first intensity of the optical signal before being amplified by the optical amplifying means; a second optical signal measuring means for measuring a second intensity of the optical signal after being amplified by the optical amplifying means; a first calculation means for calculating a radiation efficiency of the light output means based on the respective power consumptions and the intensity of the excitation light; a second calculation means for calculating an excitation efficiency of the optical amplification means based on the first intensity, the second intensity, and the intensity of the excitation light; a connection means for connecting each of the optical output means and each of the optical amplifying means based on the radiation efficiency and the excitation efficiency; An optical amplification system comprising:

2. the plurality of optical amplifying means include cores in a multi-core optical fiber, the multi-core optical fiber has a clad that amplifies all of the optical signals propagating through the optical amplifying means; 10. The optical amplification system of claim 1.

3. The connection means is a first optical output unit among the plurality of optical output units and a first optical amplification unit among the plurality of optical amplification units; a second optical output means having a higher radiation efficiency than the first optical output means among the plurality of optical output means and a second optical amplifying means having a lower amplification amount by the clad than the first optical amplifying means among the plurality of optical amplifying means are connected to each other; 3. The optical amplification system of claim 2.

4. The connection means is a third optical output means of the plurality of optical output means and a third optical amplification means of the plurality of optical amplification means are connected to each other; a fourth optical output means having a higher radiation efficiency than the third optical output means among the plurality of optical output means and a fourth optical amplifying means having a lower excitation efficiency than the third optical amplifying means among the plurality of optical amplifying means are connected to each other; 3. An optical amplification system according to claim 1 or 2.

5. an additional optical output means that is not connected to any of the plurality of optical amplifying means and is capable of outputting new pump light; a multiplexing means for multiplexing the new pumping light output from the additional light output means and the pumping light output from any one of the plurality of light output means, and outputting the multiplexed light to any one of the plurality of optical amplifying means, the connection means connects both of the optical output means and the additional optical output means to one of the optical amplifying means via the multiplexing means; the additional light output means gradually increases the intensity of the new excitation light to be output, any one of the plurality of light output means gradually reduces the intensity of the excitation light output by itself and stops outputting the excitation light; An optical amplification system according to any one of claims 1 to 4.

6. a database storing a plurality of correlations between each of the power consumptions and each of the intensities of the excitation light; Among the plurality of light output means, the light output means which has stopped outputting the excitation light outputs the excitation light again, The database updates the correlation based on the power consumption consumed by the light output means and the intensity of the excitation light output by the light output means.

6. The optical amplification system of claim 5.

7. a database storing a plurality of correlations between each of the power consumptions and each of the intensities of the excitation light; The database updates the correlation based on the change in the power consumption. An optical amplification system according to any one of claims 1 to 5.

8. a transmission line for propagating the optical signals output from the optical amplifying means; a third optical signal measuring means provided on the transmission line and configured to measure a third intensity of the plurality of optical signals in the transmission line; the connection means updates a connection relationship between each of the optical output means and each of the optical amplifying means when the third intensity has changed by a predetermined value or more.

8. The optical amplification system of claim 7.

9. two of the plurality of optical output means output the pumping light to the plurality of optical amplifying means by branching light output from a single light source; An optical amplification system according to any one of claims 1 to 8.

10. A plurality of light output means outputs excitation light; amplifying an optical signal in response to the pump light by a plurality of optical amplifiers; measuring power consumption of each of the plurality of light output means; measuring the intensity of the excitation light output from each of the plurality of light output means; measuring a first intensity of the optical signal before being amplified by the optical amplifier; measuring a second intensity of the optical signal after being amplified by the optical amplifier; calculating a radiation efficiency of the light output means based on the power consumption and the intensity of the excitation light; calculating an excitation efficiency of the optical amplifying means based on the first intensity, the second intensity, and the intensity of the excitation light; connecting each of the optical output means and each of the optical amplifying means based on the radiation efficiency and the excitation efficiency; Optical amplification method.

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