JP2014038985A - Optical signal amplification device, optical signal amplification method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical signal amplification device, an optical signal amplification method and a program capable of preventing the increase of costs to be spent on the output terminal release detection of an optical amplifier to be used for a route selection section accompanied by the increase of the number of routes.SOLUTION: An optical signal amplifier 1 includes: an amplification section 10 for amplifying a first optical signal; an output section 20 for outputting a first output signal obtained by amplifying a first optical signal; an amplification section 30 for amplifying a second optical signal; an output section 40 for outputting a second output signal obtained by amplifying a second optical signal; a reflected light detection section 50 for detecting whether or not reflected light with respect to the first or second output signal has been generated in at least one of the output sections 20 and 40; and a control section 60 for controlling the amplification factor of the optical signal in the amplification section 10 or 30 in accordance with the detection result of the reflected light in the reflected light detection section 50.

Description

  The present invention relates to an optical signal amplification device, an optical signal amplification method, and a program, and more particularly, to an optical signal amplification device having a plurality of paths, and an optical signal amplification method and program in the optical signal amplification device.

  In recent years, techniques such as OADM (Optical Add Drop Multiplexing) have been applied to wavelength division multiplexing systems (WDM systems). OADM is an indispensable technology especially for metro access networks that connect user-side and backbone networks. This is because by adding / dropping an arbitrary wavelength from the wavelength-multiplexed optical signal, the communication capacity can be changed according to the user, and a flexible network can be configured.

  For such optical signal relay / amplification, optical amplifiers such as rare earth natural optical fiber amplifiers such as EDFA (Erbium-doped Fiber Amplifier), semiconductor optical amplifiers, and Raman amplifiers using stimulated Raman scattering that is a nonlinear optical effect. Is used.

  When these optical amplifiers are used to amplify and output the output of the optical transmitter, high output light of several tens to several hundreds mW is emitted from the optical amplifier output. If such high-power light enters the eye by mistake, there is a risk of damaging the eye, so some protection is required. For example, Patent Document 1 discloses a method of detecting the release of the output connector and shutting off the optical amplifier.

  Here, the configuration of a general optical amplifier with a reflected light detection function will be described with reference to FIG. The shut-off mechanism when the output connector 102 is released is as follows. The signal light is input via the input connector 101. The input signal light is output to the optical amplifying medium 351 through the optical coupler 301. Further, the signal light is detected by the signal light detector 201, and the detection result is output to the control circuit 501.

  The optical coupler 303 is installed at the output end of the optical amplifier 100. The optical coupler 303 branches a part of the output light output to the transmission line and the reflected light input from the output connector 102 and outputs them to the output light detector 203 and the reflected light detector 202, respectively. These signals are photoelectrically converted and input to the control circuit 501. When the ratio of the reflected light intensity to the output light intensity exceeds a certain level, the control circuit 501 determines that the output terminal has been released. When the control circuit 501 detects that the output end has been released, the pumping light supplied from the pumping light source 251 via the optical coupler 302 to the optical amplifying medium 351 is reduced or blocked, and the gain of the optical amplifier is reduced. .

Japanese Patent Application Laid-Open No. 07-190887

  By the way, current optical amplifiers are increasingly handling eight paths and 80 waves or more. In such a case, an optical amplification path is required according to the number of input wavelengths and the number of corresponding paths, and a concentrated optical amplifier in which a plurality of optical amplification paths are combined has been studied. In this case, a mechanism for detecting the release of the output end of the optical amplifier is also required for the optical amplification path to be used. Therefore, when the optical amplifier 100 shown in FIG. 7 is used, the mechanism for detecting the release of the output end increases with the increase in the number of paths and the number of wavelengths, which increases the circuit area and the device cost. There is.

  In order to solve such a problem, the present invention provides an optical signal amplifying device capable of preventing an increase in cost for detecting an output end release of an optical amplifier used in a route selection portion as the number of routes increases, An object is to provide an optical signal amplification method and program.

  An optical signal amplifying device according to a first aspect of the present invention includes a first optical signal amplifying unit that amplifies a first optical signal, and a first output signal that amplifies the first optical signal. 1 output unit, a second optical signal amplification unit that amplifies a second optical signal, a second output unit that outputs a second output signal obtained by amplifying the second optical signal, and the first And a reflected light detection unit for detecting whether reflected light for the first or second output signal is generated in at least one of the second output unit, and a detection result of the reflected light in the reflected light detection unit. And an optical signal amplification control unit that controls the amplification factor of the optical signal in the first or second optical signal amplification unit.

  In the optical signal amplification method according to the second aspect of the present invention, the reflected light for obtaining the reflected light for the first output signal obtained by amplifying the first optical signal and the second output signal obtained by amplifying the second optical signal. In the detection unit, it is detected whether or not the reflected light is generated in at least one of the first output signal and the second output signal, and the first or second is determined according to a detection result of the reflected light. The gain of the optical signal is controlled.

  A program according to a third aspect of the present invention is a reflected light detection unit that acquires reflected light for a first output signal obtained by amplifying a first optical signal and a second output signal obtained by amplifying a second optical signal. Detecting whether the reflected light is generated in at least one of the first output signal and the second output signal; and depending on a detection result of the reflected light, the first or the second The step of controlling the amplification factor of the optical signal is executed by a computer of the optical signal amplification device.

  The present invention provides an optical signal amplifying apparatus, an optical signal amplifying method, and a program capable of preventing an increase in cost for detecting an output end release of an optical amplifier used in a path selection portion as the number of paths increases. be able to.

1 is a configuration diagram of an optical amplifier according to a first embodiment; FIG. 3 is a configuration diagram of an optical amplifier according to a second embodiment. FIG. 4 is a configuration diagram of a control circuit according to a second embodiment. FIG. 10 is a diagram showing a flow of processing for generating a reflected light monitoring target port list according to the second exemplary embodiment; 6 is a flow of reflected light monitoring processing according to the second embodiment; FIG. 6 is a configuration diagram of an optical amplifier according to a third embodiment. It is a block diagram of a general optical amplifier.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. A configuration example of the optical amplifier 1 according to the first embodiment of the present invention will be described with reference to FIG. The optical amplifier 1 includes an amplification unit 10, an output unit 20, an amplification unit 30, an output unit 40, a reflected light detection unit 50, and a control unit 60. The amplification unit 10 and the output unit 20 constitute one optical amplification path. Furthermore, the amplification unit 30 and the output unit 40 also constitute one optical amplification path. The optical amplification path is determined according to the number of wavelengths and the number of paths of the optical signal input to the optical amplifier 1. For example, the optical amplification path configured by the amplification unit 10 and the output unit 20 and the optical amplification path configured by the amplification unit 30 and the output unit 40 amplify the intensity of the optical output signal output to different paths. Alternatively, the optical amplification path configured by the amplification unit 10 and the output unit 20 and the optical amplification path configured by the amplification unit 30 and the output unit 40 amplify the intensities of optical signals having different wavelengths.

  The amplifying unit 10 amplifies the intensity of the input optical signal. The amplification factor of the intensity of the optical signal is controlled using the control unit 60. The amplifying unit 10 outputs the amplified optical signal to the output unit 20. The output unit 20 outputs the input optical signal to an optical fiber or the like connected to the optical amplifier 1. Here, the output unit 20 outputs the reflected light to the reflected light detection unit 50 when the output end is released and the reflected light is generated due to unconnected optical fiber or the like when outputting the optical signal.

  The amplifying unit 30 amplifies the intensity of the input optical signal. The amplification factor of the intensity of the optical signal is controlled using the control unit 60. The amplifying unit 30 outputs the amplified optical signal to the output unit 40. The output unit 40 outputs the input optical signal to an optical fiber or the like connected to the optical amplifier 1. Here, the output unit 40 outputs the reflected light to the reflected light detection unit 50 when the output end is released and the reflected light is generated due to unconnected optical fiber or the like when outputting the optical signal.

  The reflected light detection unit 50 detects the occurrence of reflected light at the output unit 20 or the output unit 40. The reflected light detection unit 50 may detect reflected light generated in one of the output units 20 and 40 or may detect reflected light generated in the output units 20 and 40. The reflected light detection unit 50 detects the reflected light depending on whether the reflected light is output from the output unit 20 or 40. The reflected light detection unit 50 outputs the output result of the reflected light to the control unit 60.

  When notified from the reflected light detection unit 50 that reflected light is generated in at least one of the output unit 20 and the output unit 40, the control unit 60 reduces the amplification factor of the intensity of the optical signal in the amplification units 10 and 30. To control. Thereby, the intensity | strength of the reflected light which generate | occur | produces in at least one of the output part 20 and the output part 40 can be reduced.

  When the control unit 60 detects the generation of reflected light in either one of the output units 20 and 40 from the reflected light detection unit 50, the control unit 60 reduces the amplification factors in the amplification unit 10 and the amplification unit 30 as described above. Alternatively, when the control unit 60 can specify that the reflected light is generated in any of the output units 20 and 40, the control unit 60 sets the amplification factor in the amplification unit that outputs the optical signal to the output unit in which the reflected light is generated. Reduce. The case where the control unit 60 can specify that the reflected light is generated in any one of the output units 20 and 40 is, for example, that the reflected light is transmitted from any one of the output unit 20 or the output unit 40 from the reflected light detection unit 50. When the information regarding whether it was output is output to the control part 60, the control part 60 can specify the output part from which reflected light generate | occur | produced.

  Further, reducing the amplification factor includes setting the amplification factor in the amplification unit 10 or the amplification unit 30 to zero. Alternatively, the control unit 60 may stop the output of the optical signal from the amplification unit 10 to the output unit 20.

  As described above, when there are two optical amplification paths, the optical amplifier 1 according to the first embodiment of the present invention is used not for each optical amplification path but for two optical amplification paths. The reflected light detection unit 50 and the control unit 60 are provided. Therefore, even when the number of optical amplification paths is increased, it is possible to suppress an increase in the reflected light detection unit 50 and the control unit 60. Further, although FIG. 1 shows an example in which there are two optical amplification paths, the present invention can be similarly applied to the case where there are three or more optical amplification paths.

(Embodiment 2)
Then, the detailed structural example of the optical amplifier 1 concerning Embodiment 2 of this invention is demonstrated using FIG. The optical amplifier 1 includes an input optical connector 11, an optical coupler 12, an optical amplification medium 13, a PD 14, an optical coupler 21, an output optical connector 22, an input optical connector 31, an optical coupler 32, an optical amplification medium 33, a PD 34, an optical coupler 41, The optical output connector 42, the PD 51, the optical selection switch 52, the PD 53, the PD 54, the optical coupler 61, the LD 62, the LD 63, the optical coupler 64, and the control circuit 65 are provided. Further, the optical amplifier 1 receives a plurality of WDM signal lights demultiplexed by the demultiplexer 70. In this figure, an example of receiving two WDM signal lights will be described. The duplexer 70 demultiplexes, for example, WDM signal light output to different paths, and outputs the demultiplexed WDM signal light to the input optical connector 11 and the input optical connector 31.

  The input optical connector 11 outputs the WDM signal light output from the duplexer 70 to the optical coupler 12. The optical coupler 12 outputs the WDM signal light output from the input optical connector 11 to the optical amplification medium 13. Further, the optical coupler 12 branches a part of the WDM signal light output from the input optical connector 11 and outputs the branched WDM optical signal to a PD (Photo Diode) 14. The optical coupler 12 outputs the WDM signal light to the optical amplification medium 13 and the PD 14 based on a predetermined branching ratio.

  The PD 14 receives the WDM signal light output from the optical coupler 12 and measures the intensity or power of the WDM signal light. The PD 14 measures the intensity of the WDM signal light by photoelectrically converting the WDM signal light. The PD 14 outputs information on the measured intensity of the WDM signal light to the control circuit 65.

  The optical amplifying medium 13 amplifies the intensity of the WDM signal light output from the optical coupler 12 and outputs the output light OL to the optical coupler 61. The optical amplifying medium 13 amplifies the intensity of the WDM signal light passing through the optical amplifying medium 13 by injecting signal light having a specific wavelength from an LD (excitation light source) 62. As a result, the intensity of the signal light output from the optical amplifier 1 can be controlled to be constant.

  The optical coupler 61 outputs signal light having a specific wavelength (hereinafter, pumping light EL) output from the LD 62 to the optical amplification medium 13. Further, the optical coupler 61 outputs the output light OL output from the optical amplification medium 13 to the optical coupler 21. The optical coupler 21 outputs the output light OL output from the optical coupler 61 to the output optical connector 22. The output optical connector 22 outputs the output light OL received from the optical coupler 21 to a connected optical fiber or the like.

  Further, the optical coupler 21 branches a part of the output light OL output from the optical coupler 61 and outputs the branched output light OL to the PD 51. The optical coupler 21 outputs the output light OL to the output optical connector 22 and the PD 51 based on a predetermined branching ratio. The branching ratio may be changed by a user operation.

  Furthermore, the optical coupler 21 outputs the reflected light RL to the optical selection switch 52 when the reflected light RL for the output light OL output to the output optical connector 22 is output from the output optical connector 22. When an optical fiber is not connected to the output optical connector 22, Fresnel reflection occurs at the interface between the optical fiber and air. In that case, the output light OL is reflected by the output optical connector 22, and the reflected light RL is generated.

  The PD 51 receives the output light OL output from the optical coupler 21 and measures the intensity or power of the output light OL. The PD 51 measures the intensity of the output light OL by photoelectrically converting the output light OL. The PD 51 outputs information related to the intensity of the measured output light OL to the control circuit 65.

  Here, the input optical connector 31, the optical coupler 32, the optical amplification medium 33, the PD 34, the LD 63, the optical coupler 64, the optical coupler 41, the output optical connector 42, and the PD 53 are the input optical connector 11, the optical coupler 12, and the optical amplification medium 13. , PD 14, optical coupler 61, LD 62, optical coupler 21, output optical connector 22, and PD 51 have the same functions and operations, and detailed description thereof is omitted. Alternatively, the path between the input optical connector 11 and the output optical connector 22 may be a first optical amplification path, and the path between the input optical connector 31 and the output optical connector 42 may be a second optical amplification path. That is, the optical amplifier 1 has two optical amplification paths.

  The optical selection switch 52 receives the reflected light RL from either the optical coupler 21 or the optical coupler 41. The light selection switch 52 outputs one of the reflected lights RL among the reflected lights RL output from the optical coupler 21 and the optical coupler 41 to the PD 54. For example, the optical selection switch 52 controls the control circuit 65 to turn off the port to which the optical coupler 41 is connected while the port to which the optical coupler 21 is connected is turned on. While the connected port is turned off, the port to which the optical coupler 41 is connected is turned on. In this way, the optical selection switch 52 sequentially receives the reflected light RL output from the optical coupler 21 or the optical coupler 41. The control content of the light selection switch 52 in the control circuit 65 will be described in detail later.

  The PD 54 measures the intensity of the reflected light RL by photoelectrically converting the reflected light RL output from the light selection switch 52. The PD 54 outputs information related to the intensity of the reflected light RL to the control circuit 65.

  Subsequently, in order to explain the control of the excitation light EL output from the LD 62 and the LD 63 and the selection control of the reflected light RL of the light selection switch 52 in the control circuit 65, a configuration example of the control circuit 65 will be described with reference to FIG. explain.

  The control circuit 65 includes an input light intensity monitoring unit 81, an excitation light source control unit 82, an output light intensity monitoring unit 83, a timer unit 84, a reflected light intensity monitoring unit 85, a light selection switch control unit 86, a ROM 87, a RAM 88, and a CPU 89. doing.

  The input light intensity monitoring unit 81 monitors whether or not the WDM signal light is input to the optical amplifier 1 based on the information regarding the intensity of the WDM signal light output from the PD 14 and PD 34 to the control circuit 65. For example, when it is notified from the PD 14 that the intensity of the WDM signal light is greater than a predetermined value, the input light intensity monitoring unit 81 determines that the WDM signal light is input to the input optical connector 11. To do. Similarly, when it is notified from the PD 34 that the intensity of the WDM signal light is greater than a predetermined value, the input light intensity monitoring unit 81 indicates that the WDM signal light is input to the input optical connector 31. judge.

  When the input light intensity monitoring unit 81 detects that the WDM signal light is input to the input optical connector 11, the excitation light source control unit 82 supplies the excitation light EL predetermined for the LD 62 to the optical amplification medium 13. Control to output. Similarly, when the input light intensity monitoring unit 81 detects that the WDM signal light is input to the input optical connector 31, the excitation light source control unit 82 optically amplifies the excitation light EL that is predetermined for the LD 63. Control to output to the medium 33. Here, when the input light intensity monitoring unit 81 does not detect the input of the WDM signal light, the excitation light source control unit 82 applies the light amplification medium 13 or 33 of the optical amplification path in which the input of the WDM signal light is not detected. On the other hand, control is performed so as not to output the excitation light EL.

  In this way, the signal intensity amplification process in the optical amplifying medium 13 or 33 can be operated only when the WDM signal light is input. Thereby, a reduction in power consumption can be realized as compared with the case where the amplification process is always operated.

  The output light intensity monitoring unit 83 selects a port of the light selection switch 52 to which the optical coupler to be monitored is connected based on information on the intensity of the output light OL output from the PD 51 and PD 53 to the control circuit 65. In the optical selection switch 52, the optical coupler 21 and the optical coupler 41 are connected to different ports, respectively. Therefore, when the reflected light RL output from the optical coupler 21 is to be monitored, the output light intensity monitoring unit 83 sets the port to which the optical coupler 21 is connected as the monitoring target port. When the reflected light RL output from the optical coupler 41 is to be monitored, the output light intensity monitoring unit 83 sets the port to which the optical coupler 41 is connected as the monitoring target port.

  When the intensity of the output light OL detected by the PD 51 is equal to or greater than a predetermined threshold, the output light intensity monitoring unit 83 determines whether the optical selection switch 52 connected to the reflected light monitoring target port list has the optical coupler 21 connected thereto. Add a port as a monitored port. The reflected light monitoring target port list may be stored in the RAM 88, for example. When the intensity of the output light OL detected by the PD 53 is greater than or equal to a predetermined threshold value, the output light intensity monitoring unit 83 is connected to the reflected light monitoring target port list of the light selection switch 52 connected to the optical coupler 41. Add a port as a monitored port. As the predetermined threshold value related to the intensity of the output light OL, for example, a value of the intensity of the output light OL that may be affected by the human body may be used. By doing so, the reflected light RL is monitored for the high intensity output light OL that affects the human body, and the reflected light RL is monitored for the weak intensity output light OL that does not affect the human body. You can not.

  The light selection switch controller 86 switches the port of the light selection switch 52 registered in the reflected light monitoring target port list and monitors whether or not reflected light is generated in the optical coupler 21 or 41. That is, the light selection switch control unit 86 controls the light selection switch 52 so as to turn on the port of the light selection switch 52 to be monitored. The light selection switch control unit 86 may control the port switching timing as follows. For example, even if the monitoring time of a port to which an optical coupler having a high intensity of detected output light OL is connected is increased and the monitoring time of a port to which an optical coupler having a low intensity of output light OL is connected is shortened. Good. As the time for monitoring the port, a count value incremented in the timer unit 84 may be used.

  The timer unit 84 may be reset each time the monitoring target port is switched by the light selection switch control unit 86 and may increment the count value.

  The reflected light intensity monitoring unit 85 monitors whether or not the reflected light RL is generated in the optical coupler 21 or the optical coupler 41 according to the information regarding the intensity of the reflected light RL output from the PD 54. For example, when it is determined that the reflected light RL is generated in the optical coupler 21, the reflected light intensity monitoring unit 85 stops the output of the excitation light EL from the LD 62 to the optical amplification medium 13. By doing so, it is possible to prevent the output light OL from being amplified in the optical amplifying medium 13, and thus it is possible to prevent the intensity of the reflected light EL from increasing.

  When the output of the excitation light EL from the LD 62 is stopped and the reflected light RL is not generated in the optical coupler 21, the reflected light intensity monitoring unit 85 outputs the excitation light to the optical amplification medium 13 from the LD 62. Let it resume.

  The CPU 89 controls the operation of each component of the control circuit 65. The ROM 87 stores various control program data executed by the CPU 89. The ROM 87 temporarily stores information related to the intensity of the received signal light. Input light intensity monitoring unit 81, excitation light source control unit 82, output light intensity monitoring unit 83, timer unit 84, reflected light intensity monitoring unit 85, light selection switch control unit 86, ROM 87, RAM 88 and CPU 89 are connected via a bus. Has been.

  Next, the flow of processing for generating a reflected light monitoring target port list according to the second exemplary embodiment of the present invention will be described with reference to FIG. FIG. 4 shows processing in the optical amplification path between the input optical connector 11 and the output optical connector 22. In the case of having a plurality of optical amplification paths, the processing shown in FIG. 4 may be executed for each optical amplification path in order or in parallel.

  First, the input light intensity monitoring unit 81 determines whether WDM signal light is input to the input optical connector 11 (S11). When the input light intensity monitoring unit 81 determines that the WDM signal light is input to the input optical connector 11, the excitation light source control unit 82 injects the excitation light EL into the optical amplification medium 13 (S12). Next, the output light intensity monitoring unit 83 determines whether or not the intensity of the output light OL output from the optical amplification medium 13 is equal to or greater than a predetermined threshold (S13).

  When the output light intensity monitoring unit 83 determines that the intensity of the output light OL output from the optical amplification medium 13 is greater than or equal to the threshold value, the port of the light selection switch 52 to which the optical coupler 21 is connected is the reflected light monitoring target. It is determined whether it is registered in the port list (S14). The output light intensity monitoring unit 83 can acquire the reflected light monitoring target port list stored in the RAM 88 and check the registered content of the reflected light monitoring target port list.

  When the output light intensity monitoring unit 83 determines that the port of the optical selection switch 52 to which the optical coupler 21 is connected is not registered in the reflected light monitoring target port list, the port is added to the reflected light monitoring target port list. (S15). When the output light intensity monitoring unit 83 determines that the port is registered in the reflected light monitoring target port list, the process ends.

  In step S 11, if the input light intensity monitoring unit 81 determines that the WDM signal light is not input to the input optical connector 11, is the excitation light source control unit 82 injecting the excitation light EL into the optical amplification medium 13? It is determined whether or not (S16). When determining that the excitation light EL is being injected, the excitation light source control unit 82 stops the injection of the excitation light EL (S17). When it is determined that the excitation light EL is not injected, the excitation light source controller 82 executes the process of step S18.

  Next, the output light intensity monitoring unit 83 determines whether or not the port of the optical selection switch 52 to which the optical coupler 21 is connected is registered in the reflected light monitoring target port list (S18). When the output light intensity monitoring unit 83 determines that the port of the optical selection switch 52 to which the optical coupler 21 is connected is registered in the reflected light monitoring target port list, the port is deleted from the reflected light monitoring target port list. (S19). When the output light intensity monitoring unit 83 determines that the port of the light selection switch 52 to which the optical coupler 21 is connected is not registered in the reflected light monitoring target port list, the process ends.

  In step S13, when the output light intensity monitoring unit 83 determines that the intensity of the output light OL does not exceed a predetermined threshold, the process after step S18 is executed.

  Subsequently, the flow of the monitoring process of the reflected light RL according to the second embodiment of the present invention will be described with reference to FIG. “N” used in the description of FIG. 5 indicates the registration order of the ports registered in the reflected light monitoring target port list. In the reflected light monitoring target port list, ports are registered in order from n = 0.

  First, the optical selection switch controller 86 sets a port registered as n = 0 as a monitoring target (S21), and turns on a port of the optical selection switch 52 registered as n = 0 (S22). At this time, the light selection switch controller 86 turns off the other ports. Further, the light selection switch control unit 86 switches the port to be monitored, and starts the counting by the timer unit 84. This count is used to measure the monitoring time of the reflected light RL for one port. The monitoring time may be set by the user. For example, when the intensity of the output light OL is high, the monitoring time is set to be long, and when the intensity of the output light OL is low, the monitoring time is set to be short so that weighting is set to the monitoring time. May be.

  Next, the reflected light intensity monitoring unit 85 determines whether or not the intensity of the reflected light RL output from the PD 54 is equal to or greater than a predetermined threshold (S23). When the reflected light intensity monitoring unit 85 determines that the intensity of the reflected light RL output from the PD 54 is equal to or greater than a predetermined threshold, the excitation light source control unit 82 uses the light of the optical amplification path having the corresponding port. The output of the excitation light EL to the amplification medium is stopped (S24). Next, the light selection switch control unit 86 determines whether or not the port to be monitored is the last port registered in the reflected light monitoring target port list (S25). If the light selection switch control unit 86 determines that the port is the last registered port, the process of step S21 is repeated. If the light selection switch control unit 86 determines that the port is not the last registered port, the light selection switch control unit 86 adds 1 to the value of n and sets the next registered port in the reflected light monitoring target port list as the monitoring target port. As above, the processing from step S22 is repeated.

  As described above, by using the optical amplifier 1 according to the second embodiment of the present invention, a single control circuit 65 is used for the intensity change processing and reflected light detection processing of the output light OL in a plurality of optical amplification paths. Can be realized. Specifically, by using the optical selection switch 52, the control circuit 65 can sequentially switch the optical amplification path to be monitored and monitor the generation of the reflected light EL in the plurality of optical amplification paths. Thus, it is not necessary to provide a control circuit for each optical amplification path, and one control circuit can monitor the generation of reflected light EL from a plurality of optical amplification paths.

(Embodiment 3)
Next, a configuration example of the optical amplifier 2 according to the third embodiment of the present invention will be described with reference to FIG. In the optical amplifier 2 of FIG. 6, the optical selection switch 52 in the optical amplifier 1 of FIG. Other configurations are the same as those of the optical amplifier 1 of FIG.

  When the optical coupler 55 is used instead of the optical selection switch 52, the optical coupler 55 may simultaneously receive the reflected light RL output from the optical coupler 21 and the optical coupler 41. You may receive the reflected light RL output from either. The optical coupler 55 outputs the reflected light RL to the PD 54 when receiving the reflected light RL from at least one of the optical coupler 21 and the optical coupler 41.

  The PD 54 measures the intensity of the received reflected light RL and notifies the control circuit 65 of the measurement result. That is, the control circuit 65 does not monitor the reflected light RL by switching the optical amplification path to be monitored as described in the second embodiment, but collectively monitors the reflected light RL generated in all the optical amplification paths. . In this case, when the reflected light RL is detected in one of the optical coupler 21 and the optical coupler 41, the optical amplification medium 13 and the optical amplification medium 33 are not affected regardless of which optical coupler the reflected light RL is detected. Stop the excitation light output. Further, the control circuit 65 of the optical amplifier 2 does not require a reflected light monitoring target port list.

  Further, the control circuit 65 restarts the output of the excitation light to the optical amplification medium 13 and the optical amplification medium 33 when all the reflected light RL is not detected.

  As described above, by using the optical amplifier 2 according to the third embodiment of the present invention, when the reflected light RL is generated in any of the optical amplification paths, the output of the excitation light EL to all the optical amplification media Therefore, as compared with the second embodiment, it is not necessary to specify the optical amplification path that is the generation source of the reflected light RL. Therefore, the optical amplifier 2 according to the third embodiment can prevent an increase in the intensity of reflected light while reducing the processing load as compared with the optical amplifier 1 according to the second embodiment.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

  In the above-described embodiment, the hardware configuration has been described. However, the present invention is not limited to this, and the control circuit can be realized by causing a CPU (Central Processing Unit) to execute a computer program. is there. In this case, the computer program can be stored using various types of non-transitory computer readable media and supplied to the computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W and semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

DESCRIPTION OF SYMBOLS 1 Optical amplifier 2 Optical amplifier 10 Amplification part 11 Input optical connector 12 Optical coupler 13 Optical amplification medium 14 PD
DESCRIPTION OF SYMBOLS 20 Output part 21 Optical coupler 22 Output optical connector 30 Amplification part 31 Input optical connector 32 Optical coupler 33 Optical amplification medium 34 PD
40 Output Unit 41 Optical Coupler 42 Output Optical Connector 50 Reflected Light Detection Unit 51 PD
52 Light selection switch 53 PD
54 PD
55 Optical Coupler 60 Control Unit 61 Optical Coupler 62 LD
63 LD
64 Optical coupler 65 Control circuit 70 Demultiplexer 81 Input light intensity monitoring unit 82 Excitation light source control unit 83 Output light intensity monitoring unit 84 Timer unit 85 Reflected light intensity monitoring unit 86 Light selection switch control unit 87 ROM
88 RAM
89 CPU

Claims (9)

A first optical signal amplifier for amplifying the first optical signal;
A first output unit for outputting a first output signal obtained by amplifying the first optical signal;
A second optical signal amplifier for amplifying the second optical signal;
A second output unit for outputting a second output signal obtained by amplifying the second optical signal;
A reflected light detector that detects whether or not reflected light for the first or second output signal is generated in at least one of the first and second output units;
An optical signal amplification apparatus comprising: an optical signal amplification control unit that controls an amplification factor of an optical signal in the first or second optical signal amplification unit according to a detection result of the reflected light in the reflected light detection unit. A switch unit that switches and acquires the first reflected light with respect to the first output signal and the second reflected light with respect to the second output signal;
The optical signal amplifying apparatus according to claim 1, further comprising: a switch control unit that controls timing for acquiring the first reflected light and the second reflected light. A monitoring unit for monitoring the intensity of the first output signal and the intensity of the second output signal;
The switch control unit
3. The light according to claim 2, wherein timing for acquiring the first reflected light and the second reflected light is controlled based on an intensity of the first output signal and an intensity of the second output signal. Signal amplification device. The reflected light detector is
When the monitoring unit determines that the intensity of the first output signal has an intensity greater than a predetermined value, it monitors whether or not the first reflected light is generated, and the second The optical signal amplifying apparatus according to claim 3, wherein when it is determined that the intensity of the output signal has an intensity greater than a predetermined value, it is monitored whether or not the second reflected light is generated. The reflected light detector is
A reflected light intensity detector for detecting the intensity of the first and second reflected lights;
The optical signal amplification controller is
When the reflected light intensity detection unit determines that the intensity of the reflected light with respect to the first output signal exceeds a predetermined value, the amplification factor of the optical signal in the first optical signal amplification unit is determined. 5. The optical signal amplification factor of the second optical signal amplification unit is decreased when it is determined that the intensity of the second reflected light exceeds a predetermined value. The optical signal amplifying device according to any one of the above. A first pumping light source that outputs pumping light to the first optical signal amplifier;
A second pumping light source that outputs pumping light to the second optical signal amplifier, and
When the reflected light intensity detection unit determines that the intensity of the first reflected light exceeds a predetermined value, the optical signal amplification control unit receives the first excitation light source from the first excitation light source. When the output of the excitation light to the optical signal amplification unit is stopped and it is determined that the intensity of the second reflected light exceeds a predetermined value, the second excitation light source causes the second The optical signal amplification device according to claim 5, wherein output of the excitation light to the optical signal amplification unit is stopped. The optical signal amplification controller is
When the reflected light detection unit detects that at least one of the first reflected light with respect to the first output signal and the second reflected light with respect to the second output signal has occurred, the first and first The optical signal amplification device according to claim 1, wherein the amplification factor of the optical signal in the second optical signal amplification unit is reduced. In a reflected light detection unit that acquires reflected light for a first output signal obtained by amplifying the first optical signal and a second output signal obtained by amplifying the second optical signal, the first output signal and the second output signal are obtained. Detecting whether or not the reflected light is generated in at least one of the output signals;
An optical signal amplification method for controlling an amplification factor of the first or second optical signal according to a detection result of the reflected light. In a reflected light detection unit that acquires reflected light for a first output signal obtained by amplifying the first optical signal and a second output signal obtained by amplifying the second optical signal, the first output signal and the second output signal are obtained. Detecting whether the reflected light is generated in at least one of the output signals;
A program for causing a computer of the optical signal amplifying apparatus to execute the step of controlling the amplification factor of the first or second optical signal according to the detection result of the reflected light.

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