Light source device, light device, and control light generating method

Abstract

Since it is difficult to constantly monitor a large number of unused fiber optic transmission lines in an optical submarine cable system, a light source device according to the present invention comprises: a light generation means for generating amplified spontaneous emission light; a light control means for controlling the band and power of the amplified spontaneous emission light and generating waveform shaping spontaneous emission light; and an optical branching means for branching the waveform shaping spontaneous emission light into a plurality of branched light beams.

Description

[Technical field]

[0001] The present invention relates to a light source device, an optical device, a control light generating method, and a monitor light generating method, and more particularly to a light source device, an optical device, a control light generating method, and a monitor light generating method used in an optical submarine cable system. [Background technology]

[0002] Optical submarine cable systems that connect continents with optical fibers play an important role as infrastructure supporting international communication networks. Optical submarine cable systems consist of submarine cables that accommodate optical fibers, submarine repeaters equipped with optical amplifiers, submarine branching devices that branch optical signals, and terminal equipment installed at landing stations.

[0003] In an optical submarine cable system, remote fiber test equipment (RFTE) is used to monitor unused optical fibers (dark fibers) for abnormalities. When an optical time domain reflectometry (OTDR) method is adopted, the RFTE sends out an optical pulse from one end of the optical fiber and measures the change in intensity of the backscattered light that returns through the optical fiber in the opposite direction to the direction in which the optical pulse was sent. In this case, when only an optical pulse is sent out, the power of the submarine repeater changes instantly from a no-input state, causing an optical surge. An example of a technology for avoiding the occurrence of such an optical surge is described in Patent Document 1.

[0004] The related optical network system described in Patent Document 1 includes a plurality of optical signal distribution devices, a plurality of optical lines connecting the plurality of optical signal distribution devices, and a network management server. Each optical signal distribution device includes an optical cross-connect device. A WDM multiplexing device that multiplexes signal light of different wavelengths to generate WDM signal light, a WDM demultiplexing device that demultiplexes the WDM signal light into signal light of individual wavelengths, a line measurement device, and a dummy light source are connected to the optical cross-connect device. Here, the network management server controls the optical cross-connect device of the optical signal distribution device to output dummy light output from the dummy light source to an optical amplification line that does not transmit signal light.

[0005] With this configuration, according to the related optical network system, it is possible to suppress the occurrence of optical surges when setting up optical paths by supplying dummy light to unused optical lines.

[0006] Furthermore, a related technique is described in Patent Document 2. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-196938 A [Patent Document 2] International Publication No. 2019 / 151067 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, in the related optical network system described in Patent Document 1, the output destination of the dummy light is switched by controlling the optical cross-connect device. Therefore, it is not possible to simultaneously keep a plurality of optical fiber transmission lines in a state in which optical pulses can be introduced. In addition, when there are many optical fiber transmission lines to be monitored, it takes a long time to monitor all the optical fiber transmission lines.

[0009] Thus, there has been a problem in that it is difficult to constantly monitor a large number of unused optical fiber transmission lines in an optical submarine cable system.

[0010] An object of the present invention is to provide a light source device, an optical device, a control light generating method, and a monitoring light generating method that solve the problem that it is difficult to constantly monitor a large number of unused optical fiber transmission lines in an optical submarine cable system. [Means for solving the problem]

[0011] The light source device of the present invention includes a light generating means for generating amplified spontaneous emission light, a light control means for controlling the bandwidth and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light, and a light branching means for branching the waveform-shaped spontaneous emission light into a plurality of branch lights.

[0012] The control light generating method of the present invention generates amplified spontaneous emission light, controls the band and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light, and branches the waveform-shaped spontaneous emission light into a plurality of branch lights. Effect of the Invention

[0013] According to the light source device, optical device, control light generating method, and monitor light generating method of the present invention, a large number of unused optical fiber transmission lines can be constantly monitored in an optical submarine cable system. [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a configuration of a light source device according to a first embodiment of the present invention. [Diagram 2] FIG. 5 is a block diagram showing a configuration of a light source device according to a second embodiment of the present invention. [Diagram 3] FIG. 11 is a block diagram showing a configuration of a light source device according to a third embodiment of the present invention. [Figure 4A]13 is a diagram showing the spectrum of waveform-shaped spontaneous emission light generated by a light control unit included in a light source device according to a second embodiment of the present invention. FIG. [Figure 4B] FIG. 11 is a diagram showing the spectrum of waveform-shaped spontaneous emission light generated by a light control unit included in a light source device according to a third embodiment of the present invention. [Diagram 5] FIG. 11 is a block diagram showing the connection relationship between a light source device and an interface device according to a second embodiment of the present invention. [Figure 6A] FIG. 11 is a block diagram showing another connection relationship between the light source device and the interface device according to the second embodiment of the present invention. [Figure 6B] FIG. 11 is a block diagram showing the connection relationship between a light source device and an interface device according to a third embodiment of the present invention. [Figure 7] FIG. 11 is a block diagram showing a configuration of an optical device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] [First embodiment] 1 is a block diagram showing the configuration of a light source device 100 according to a first embodiment of the present invention. The light source device 100 has a light generation section (light generation means) 110, a light control section (light control means) 120, and a light branching section (light branching means) 130. The light source device 100 is preferably used in an optical submarine cable system.

[0017] The light generating section 110 generates amplified spontaneous emission light. The light controlling section 120 controls the band and power of this amplified spontaneous emission light to generate waveform-shaped spontaneous emission light. The light branching section 130 then branches this waveform-shaped spontaneous emission light into a plurality of branch lights.

[0018] In this manner, in the light source device 100 of this embodiment, the light branching unit 130 branches the waveform-shaped spontaneous emission light generated by the light generating unit 110 and the light control unit 120 into a plurality of branched lights. Therefore, it is possible to simultaneously supply a plurality of branched lights as dummy lights to a plurality of unused optical fiber transmission lines. As a result, it is possible to simultaneously bring a plurality of optical fiber transmission lines into a state in which an optical pulse can be introduced, so that it is possible to monitor unused optical fibers (dark fibers) without causing an optical surge. That is, according to the light source device 100 of this embodiment, it is possible to constantly monitor a plurality of unused optical fiber transmission lines in an optical submarine cable system.

[0019] Here, the light generating unit 110 can be configured to include an optical waveguide containing a rare earth element in its core, and an excitation laser that generates excitation light for exciting the rare earth element. Specifically, for example, the light generating unit 110 can be an ASE (Amplified Spontaneous Emission) light source in which an amplifier (Erbium Doped Fiber Amplifier: EDFA) using an erbium doped fiber in the optical waveguide is in a no-input signal state. Note that the amplified spontaneous emission (ASE) generated by the light generating unit 110 is amplified spontaneous emission light with a continuous and broad optical spectrum.

[0020] The optical control unit 120 can be configured to include a wavelength selective switch (WSS). The wavelength selective switch (WSS) can adjust the amount of attenuation of the power of the input light for each wavelength. By configuring the wavelength selective switch (WSS) as a one-input, one-output configuration, it is possible to obtain output light with the waveform of the input light arbitrarily shaped.

[0021] The optical control unit 120 can control the band of the amplified spontaneous emission light to a range including the entire wavelength band of the wavelength multiplexed signal light propagating through the optical submarine cable system. The optical control unit 120 can be configured to control the power of the amplified spontaneous emission light so that the power of each branched light branched by the optical branching unit 130 matches the total input power of the submarine repeaters that make up the optical submarine cable system. The optical control unit 120 may output the power of the amplified spontaneous emission light without limiting it.

[0022] Typically, a multi-branch optical splitter can be used as the optical branching unit 130 .

[0023] Next, a control light generating method according to this embodiment will be described.

[0024] In the control light generating method according to the present embodiment, first, an amplified spontaneous emission light is generated. Then, the band and power of the amplified spontaneous emission light are controlled to generate a waveform-shaped spontaneous emission light. After that, the waveform-shaped spontaneous emission light is branched into a plurality of branch lights.

[0025] Here, generating the amplified spontaneous emission light may include exciting a rare earth element contained in the core of the optical waveguide with pump light, and generating the waveform-shaped amplified spontaneous emission light may include adjusting the power of the amplified spontaneous emission light for each wavelength.

[0026] As described above, according to the light source device 100 and the control light generating method of this embodiment, a large number of unused optical fiber transmission lines can be constantly monitored in an optical submarine cable system.

[0027] Second Embodiment Next, a second embodiment of the present invention will be described. Fig. 2 shows the configuration of a light source device 200 according to this embodiment. The light source device 200 further includes a first connection unit (first connection means) 240 in addition to a light generation unit (light generation means) 110, a light control unit (light control means) 120, and a light branching unit (light branching means) 130. The light source device 200 is preferably used in an optical submarine cable system.

[0028] The light generating section 110 generates amplified spontaneous emission light. The light controlling section 120 controls the band and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light. The light branching section 130 branches the waveform-shaped spontaneous emission light into a plurality of branch lights.

[0029] The first connection unit 240 is configured to introduce the multiple branched lights into the multiple interface devices 10 provided for the multiple optical transmission paths 20, respectively. Typically, the first connection unit 240 can be an optical adapter that connects optical fibers through which the branched lights propagate.

[0030] Each of the optical transmission paths 20 includes an optical fiber transmission path, and each optical fiber transmission path configures a fiber pair (FP) consisting of an optical fiber for an upstream line and an optical fiber for a downstream line. Here, each fiber pair (FP) is an unused optical fiber (dark fiber) through which no main signal light propagates. In other words, a transponder serving as a main signal source is not connected to each interface device 10.

[0031] The optical control unit 120 can be configured to control the bandwidth and power of the amplified spontaneous emission light in accordance with the number of interface devices 10. Specifically, when a large number (e.g., eight or more) of interface devices 10 are connected to each of a large number of fiber pairs (e.g., eight or more fiber pairs), the optical control unit 120 can be configured to output the power of the amplified spontaneous emission light without limiting it.

[0032] Next, a control light generating method according to this embodiment will be described.

[0033] In the control light generating method according to the present embodiment, first, amplified spontaneous emission light is generated. Then, the band and power of this amplified spontaneous emission light are controlled to generate waveform-shaped spontaneous emission light. After that, this waveform-shaped spontaneous emission light is branched into a plurality of branched lights. The configuration up to this point is the same as the control light generating method according to the first embodiment.

[0034] In the control light generating method according to the present embodiment, the branched light is further introduced into a plurality of interface devices provided for each of the plurality of optical transmission lines, respectively. In this case, when generating the waveform-shaped spontaneous emission light, the bandwidth and power of the amplified spontaneous emission light can be controlled according to the number of the interface devices.

[0035] As described above, according to the light source device 200 and the control light generating method of this embodiment, a large number of unused optical fiber transmission lines can be constantly monitored in an optical submarine cable system.

[0036] Third embodiment Next, a third embodiment of the present invention will be described. Fig. 3 shows the configuration of a light source device 300 according to this embodiment. The light source device 300 further includes a second connection section (second connection section) 340 in addition to a light generation section (light generation means) 110, a light control section (light control means) 120, a light branching section (light branching means) 130, and a first connection section (first connection means) 240. The light source device 300 is preferably used in an optical submarine cable system. Note that the same components as those of the light source device 200 according to the second embodiment are denoted by the same reference numerals, and detailed description thereof may be omitted.

[0037] The light generating section 110 generates amplified spontaneous emission light. The light controlling section 120 controls the band and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light.

[0038] The second connection unit 340 is configured to introduce the waveform-shaped spontaneous emission light into the operational interface device 12 included in the multiple interface devices. Typically, the second connection unit 340 can be an optical adapter that connects an optical fiber through which the waveform-shaped spontaneous emission light propagates.

[0039] Here, the operational interface device 12 corresponds to the operational optical transmission path 22 through which the main signal light propagates among the multiple optical transmission paths. In other words, the operational interface device 12 is in a state where a transponder serving as a main signal source is connected to it.

[0040] In this case, the optical control unit 120 can be configured to control the band and power of the amplified spontaneous emission light in accordance with the characteristics of the operational optical transmission line 22. This will be specifically described below with reference to the drawings.

[0041] 4A shows the spectrum of the waveform-shaped spontaneous emission light generated by the optical control unit 120 included in the light source device 200 according to the second embodiment. In this case, the waveform-shaped spontaneous emission light is branched by the optical branching unit 130 and then introduced into unused optical fibers (dark fibers) through which no main signal light propagates. In order to monitor unused optical fibers (dark fibers), the branched light may be introduced as dummy light to enable the introduction of optical pulses. Therefore, as shown in FIG. 4A, the optical control unit 120 outputs continuous waveform-shaped spontaneous emission light at full power without limiting the power of the amplified spontaneous emission light. As a result, each of the multiple branched lights branched by the optical branching unit 130 can have a required power.

[0042] On the other hand, when the waveform-shaped spontaneous emission light is introduced as dummy light into the operating optical transmission line through which the main signal light propagates, it is necessary to compensate for the wavelength dependence of the loss and gain in the optical amplifiers provided in the optical fiber transmission line and the undersea repeater that constitute the operating optical transmission line. Therefore, in the light source device 300 according to this embodiment, as shown in FIG. 4B, the optical control unit 120 is configured to control the band and power of the amplified spontaneous emission light according to the characteristics of the operating optical transmission line 22. Specifically, for example, the optical control unit 120 controls the band of the amplified spontaneous emission light to one of odd channels or even channels in a wavelength division multiplexing (WDM) system, and shapes the amplified spontaneous emission light into a comb-shaped waveform. Then, the power of the amplified spontaneous emission light generated by the light generation unit 110 (broken line in FIG. 4B) is controlled to about half, so that the power level can be controlled. By using the waveform-shaped spontaneous emission light shaped in this way, it is possible to adjust the optical signal to noise ratio (OSNR) at the receiving side to be constant for each channel.

[0043] Next, a case where the operation is changed from a state in which a transponder serving as a main signal source is not connected to each interface device 10 to a state in which a transponder is connected to the operational interface device 12 will be described.

[0044] First, in a state where a transponder serving as a main signal source is not connected to each interface device 10, as shown in Fig. 5, a light source device 200 according to the second embodiment supplies branched light as dummy light to each of a plurality of optical transmission lines 20 via the interface device 10. Here, each optical transmission line 20 is an unused optical fiber (dark fiber) through which no main signal light propagates, and is, for example, a fiber pair (FP) consisting of an optical fiber for an uplink and an optical fiber for a downlink. With this configuration, a large number of unused optical fiber transmission lines can be constantly monitored.

[0045] Thereafter, as shown in Fig. 6A, when a transponder is connected to the operational interface device 12 of the interface devices and the operation is changed to a configuration in which the main signal light propagates through the operational optical transmission line 22, the connection between the light source device 200 and the operational interface device 12 is deleted. Then, an ASE light source device 500 including a light generating unit 110 and an optical control unit 120 is connected to the operational interface device 12. At this time, the light source device 300 according to the present embodiment may be used as the ASE light source device 500. With this configuration, the light source device 200 can be used to monitor the unused optical fiber transmission line, and the ASE light source device 500 or the light source device 300 can be used to compensate for the wavelength dependency of the loss and gain in the operational optical transmission line 22.

[0046] Thereafter, as shown in Fig. 6B, after a transponder is connected to each of the interface devices, the light source device 300 according to this embodiment can be connected to the operational interface device 12 to which the transponder is finally connected. The light source device 300 can be configured by changing the connection between the light control unit 120 and the optical branching unit 130 in the light source device 200 according to the second embodiment to a connection between the light control unit 120 and the second connection unit 340 (see Figs. 2 and 3). Therefore, it is possible to reuse the light source device 200 used for monitoring an unused optical fiber (dark fiber) as the light source device 300.

[0047] Next, a control light generating method according to this embodiment will be described.

[0048] In the control light generating method according to the present embodiment, first, an amplified spontaneous emission light is generated. Then, the band and power of the amplified spontaneous emission light are controlled to generate a waveform-shaped spontaneous emission light. After that, the waveform-shaped spontaneous emission light is branched into a plurality of branch lights.

[0049] In the control light generating method according to the present embodiment, the waveform-shaped spontaneous emission light is further supplied to an operational interface device included in a plurality of interface devices provided for each of a plurality of optical transmission lines. Here, the operational interface device corresponds to an operational optical transmission line through which the main signal light propagates among the plurality of optical transmission lines. In addition, when generating the waveform-shaped spontaneous emission light, the band and power of the amplified spontaneous emission light can be controlled according to the characteristics of the operational optical transmission line.

[0050] As described above, according to the light source device 300 and the control light generating method of this embodiment, it is possible to compensate for the wavelength dependence of loss and gain in an operational optical transmission line.

[0051] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described. Fig. 7 shows the configuration of an optical device 1000 according to this embodiment. The optical device 1000 includes a light source device 1100 and a plurality of interface devices 1200. The optical device 1000 is preferably used in an optical submarine cable system.

[0052] Any of the light source device 100 according to the first embodiment, the light source device 200 according to the second embodiment, and the light source device 300 according to the third embodiment can be used as the light source device 1100. Therefore, the light source device 1100 can generate a plurality of branched lights 1001. Each of the plurality of branched lights 1001 can be used as dummy lights for monitoring an unused optical fiber (dark fiber).

[0053] Each of the interface devices 1200 includes an optical multiplexing section (optical multiplexing means) 1210 that multiplexes one of the branched lights 1001 with a supervisory optical signal 1002. The supervisory optical signal 1002 may be, for example, an optical pulse used in an OTDR (Optical Time Domain Reflectometry) system.

[0054] Next, a method for generating monitor light according to this embodiment will be described.

[0055] In the monitoring light generating method according to the present embodiment, first, a plurality of branched lights are generated. Then, one of the plurality of branched lights is multiplexed with the monitoring optical signal. Here, when generating the plurality of branched lights, any one of the control light generating methods according to the first to third embodiments can be used.

[0056] With the above-described configuration, the optical device 1000 and monitor light generating method of this embodiment make it possible to constantly monitor a large number of unused optical fiber transmission lines in an optical submarine cable system.

[0057] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes.

[0058] (Supplementary Note 1) A light source device comprising: a light generating means for generating amplified spontaneous emission light; a light control means for controlling the bandwidth and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light; and a light branching means for branching the waveform-shaped spontaneous emission light into a plurality of branch lights.

[0059] (Supplementary Note 2) The light source device according to Supplementary Note 1, further comprising a first connection means configured to introduce the plurality of branched light beams into a plurality of interface devices provided for each of a plurality of optical transmission paths, respectively.

[0060] (Supplementary Note 3) The light source device according to Supplementary Note 2, wherein the light control means controls a band and a power of the amplified spontaneous emission light in accordance with the number of the plurality of interface devices.

[0061] (Supplementary Note 4) A light source device as described in Supplementary Note 2, further comprising a second connection means configured to introduce the waveform-shaped spontaneous emission light into an operational interface device included in the plurality of interface devices, the operational interface device corresponding to an operational optical transmission path among the plurality of optical transmission paths through which main signal light propagates.

[0062] (Supplementary Note 5) The light source device according to Supplementary Note 4, wherein the light control means controls a band and a power of the amplified spontaneous emission light in accordance with characteristics of the operational optical transmission line.

[0063] (Supplementary Note 6) The light source device according to any one of Supplementary Notes 1 to 5, wherein the light generating means comprises an optical waveguide containing a rare earth element in its core, and a pumping laser that generates pumping light for exciting the rare earth element.

[0064] (Supplementary Note 7) The light source device according to any one of Supplementary Notes 1 to 6, wherein the light control means includes a wavelength selection switch.

[0065] (Appendix 8) An optical device comprising a light source device according to any one of appendices 2 to 5 and a plurality of interface devices, each of the plurality of interface devices including an optical multiplexing means for multiplexing one of the plurality of branched lights with a supervisory optical signal.

[0066] (Appendix 9) A control light generating method for generating amplified spontaneous emission light, controlling a band and power of the amplified spontaneous emission light to generate waveform-shaped spontaneous emission light, and branching the waveform-shaped spontaneous emission light into a plurality of branch lights.

[0067] (Supplementary Note 10) The control light generating method according to Supplementary Note 9, wherein the plurality of branched lights are respectively introduced into a plurality of interface devices provided for a plurality of optical transmission paths.

[0068] (Supplementary Note 11) The control light generating method according to Supplementary Note 10, wherein generating the waveform-shaped spontaneous emission light includes controlling a bandwidth and a power of the amplified spontaneous emission light according to the number of the plurality of interface devices.

[0069] (Supplementary Note 12) A control light generation method according to Supplementary Note 9, further comprising the steps of: supplying the waveform-shaped spontaneous emission light to an operational interface device included in a plurality of interface devices provided for each of a plurality of optical transmission paths; and the operational interface device corresponding to an operational optical transmission path among the plurality of optical transmission paths through which a main signal light propagates.

[0070] (Supplementary Note 13) The control light generating method according to Supplementary Note 12, wherein generating the waveform-shaped spontaneous emission light includes controlling a bandwidth and power of the amplified spontaneous emission light according to characteristics of the operational optical transmission line.

[0071] (Supplementary Note 14) The control light generating method according to any one of Supplementary Notes 9 to 13, wherein generating the amplified spontaneous emission light includes exciting a rare earth element contained in a core of an optical waveguide with excitation light.

[0072] (Supplementary Note 15) The control light generating method according to any one of Supplementary Notes 9 to 14, wherein generating the waveform-shaped spontaneous emission light includes adjusting the power of the amplified spontaneous emission light for each wavelength.

[0073] (Supplementary Note 16) A supervisory light generating method for generating the plurality of branched lights by the control light generating method according to any one of Supplementary Notes 9 to 15, and multiplexing one of the plurality of branched lights with a supervisory optical signal.

[0074] 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]

[0075] 100, 200, 300 light source device 110 Light generation section 120 Light control unit 130 Optical branching section 240 First Connection 340 Second Connection 500 ASE light source device 10 Interface device 12 Operational Interface Device 20 Optical Transmission Line 22 Operational Optical Transmission Line 1000 optical equipment 1001 Branched Light 1002 Monitoring optical signal 1100 Light source device 1200 Interface Device 1210 Optical multiplexing section

Claims

1. a light generating means for generating amplified spontaneous emission light; an optical control means for controlling a band and a power of the amplified spontaneous emission light to generate a waveform-shaped spontaneous emission light; an optical branching means for branching the waveform-shaped spontaneous emission light into a plurality of branched lights propagating through a plurality of optical transmission paths; a first connection means configured to introduce the plurality of branched lights into a plurality of interface devices provided for each of the plurality of optical transmission paths; and a second connection means configured to introduce the waveform-shaped spontaneous emission light into an operational interface device included in the plurality of interface devices; The operational interface device is connected to an optical transmission line corresponding to an operational optical transmission line through which a main signal light propagates among the plurality of optical transmission lines. Light source device.

2. The optical control means controls a band and a power of the amplified spontaneous emission light in accordance with characteristics of the operational optical transmission line.

2. The light source device according to claim 1.

3. The light generating means includes an optical waveguide having a rare earth element in its core, and a pumping laser that generates pumping light for exciting the rare earth element.

3. A light source device according to claim 1 or 2.

4. The optical control means comprises a wavelength selective switch.

4. A light source device according to claim 1.

5. A light generating means for generating amplified spontaneous emission light; an optical control means for controlling a band and a power of the amplified spontaneous emission light to generate a waveform-shaped spontaneous emission light; an optical branching means for branching the waveform-shaped spontaneous emission light into a plurality of branched lights propagating through a plurality of optical transmission paths; a first connection means configured to introduce the plurality of branched lights into a plurality of interface devices provided for each of the plurality of optical transmission paths; The plurality of interface devices, Each of the plurality of interface devices includes an optical multiplexing means for multiplexing one of the plurality of branched lights with a supervisory optical signal. light device.

6. The optical control means controls a band and a power of the amplified spontaneous emission light in accordance with the number of the plurality of interface devices.

6. An optical device according to claim 5.

7. Further comprising a second connection means configured to introduce the waveform-shaped spontaneous emission light into an operational interface device included in the plurality of interface devices; The operational interface device is connected to an optical transmission line corresponding to an operational optical transmission line through which a main signal light propagates among the plurality of optical transmission lines.

6. An optical device according to claim 5.

8. The optical control means controls a band and a power of the amplified spontaneous emission light in accordance with characteristics of the operational optical transmission line.

8. An optical device according to claim 7.

9. generating amplified spontaneous emission light; generating waveform-shaped amplified spontaneous emission light by controlling a band and a power of the amplified spontaneous emission light; branching the waveform-shaped spontaneous emission light into a plurality of branch lights propagating through a plurality of optical transmission paths; Introducing the plurality of branched lights into a plurality of interface devices provided for each of the plurality of optical transmission paths, respectively; The waveform-shaped spontaneous emission light is introduced into an operational interface device included in the plurality of interface devices. A control light generating method, comprising: The operational interface device is connected to an optical transmission line corresponding to the operational optical transmission line through which the main signal light propagates among the plurality of optical transmission lines. Control light generation method.

10. The band and power of the amplified spontaneous emission light are controlled in accordance with the characteristics of the operational optical transmission line.

10. A method for generating control light according to claim 9.

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