JP2013026295A - Optical amplifier and controlling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption of an optical amplifier.SOLUTION: The optical amplifier includes: an amplification section that amplifies an inputted signal light; a temperature detection section that outputs a temperature of a heating/cooling section for heating or cooling the amplification section and a temperature of the amplification section; a wavelength information detection section that outputs wavelength information that is information of a wavelength multiplexed in a signal light; a temperature characteristic storage section that stores a relationship between the temperature of the amplifier section and a wavelength characteristic; a temperature calculation section that outputs a target temperature so that the amplifier section has a predetermined gain characteristic on the basis of the wavelength information and information stored in the temperature characteristic storage section; and a control section that controls the heating/cooling section on the basis of the temperature indicated by the output of the temperature detection section and a target value.

Description

  The present invention relates to an optical amplifier and an optical amplifier control method, and more particularly to an optical amplifier used in a wavelength division multiplexing optical transmission system and an optical amplifier control method.

  An optical amplifier used in a wavelength division multiplexing optical transmission system is required to have a variation in amplification characteristics for each wavelength within a range allowed by the system. Specifically, the optical amplifier is required to have a small wavelength dependency of gain, that is, good gain flatness.

  In an optical fiber amplifier widely used as an optical amplifier, the gain wavelength characteristic of a rare earth-doped fiber as an amplification medium is not flat. For this reason, an optical amplifier configured to obtain a flat gain characteristic in a wide band by inserting a filter having a characteristic to cancel the wavelength characteristic of the rare earth-doped fiber into the transmission line is used.

  However, in the optical fiber amplifier, the wavelength characteristic of the gain changes depending on the temperature due to the temperature characteristic of the rare earth-doped fiber that is an amplification medium. Therefore, it is necessary to control the temperature of the amplification medium of the optical amplifier so that the influence of the temperature characteristics of the amplification medium is reduced and the gain of the entire band of the optical signal transmitted through the optical amplifier becomes flat.

  Moreover, there are the following Patent Documents 1 to 6 as documents describing techniques related to optical level control in an optical transmission system.

  Patent Document 1 describes a configuration in which a light level for each wavelength is detected and a light attenuating unit is controlled so that the light level becomes a predetermined value in a wavelength division multiplexing transmission system.

  Patent Document 2 describes a configuration in which a pumping light source and an optical attenuator are controlled so that an output signal of an optical amplifier has a desired power and spectrum in a wavelength division multiplexing transmission system.

  Patent Document 3 describes a configuration in which the number of wavelengths of an input signal to an optical amplifier is obtained and the gain of the optical amplifier is controlled based on the obtained number of wavelengths in an optical transmission system.

  Patent Document 4 describes an optical amplifying apparatus that detects the number of wavelengths of light input to an optical amplifier and a light reception level, and outputs an alarm when the optical SN ratio at the output of the optical amplifier deviates from a reference range.

  Patent Document 5 describes an optical transmitter that adjusts a wavelength control current of a wavelength light source and a set value of a bias or temperature of an electroabsorption modulator according to wavelength information.

  Patent Document 6 describes a configuration in which, in an optical amplifier including a plurality of pump light source elements, the drive current or temperature of the pump light source element in which deterioration has occurred is controlled to suppress the progress of the deterioration of the pump light source element. .

JP 2006-101470 A JP 2006-286918 A JP 2006-295113 A JP 2007-258929 A JP 2009-081512 A JP 2010-183104 A

  In an optical amplifier used in a wavelength division multiplexing optical transmission system, the temperature of the amplification medium is set so that the gain of the entire band of the optical amplifier becomes flat so that signal light of all wavelengths that can pass through the optical amplifier can be amplified. Control is performed.

  However, there are cases where the number of wavelengths in operation in the wavelength division multiplexing optical transmission system is small and only a part of the amplification band of the optical amplifier is used. In such a case, if the temperature of the amplification medium is controlled so that the gain of the entire band of the optical amplifier becomes flat, the power consumption of the optical amplifier may be increased more than necessary. That is, an optical amplifier that controls the temperature of the amplification medium may increase power consumption by performing temperature control so that the gain of the entire band of the optical amplifier is flat regardless of the number of input wavelengths. There was a problem.

  Patent Documents 1 to 6 described above describe a technique relating to optical level adjustment in a wavelength division multiplexing optical transmission system or a technique relating to temperature control of an excitation light source in an optical amplifier. However, Patent Documents 1 to 6 do not describe a technique related to reduction of power consumption in temperature control of an amplification medium of an optical amplifier.

[Object of invention]
An object of the present invention is to provide a technique for solving the problem of reducing the power consumption of an optical amplifier.

  The optical amplifier according to the present invention includes an amplification unit that amplifies input signal light, a heating / cooling unit that heats or cools the amplification unit, a temperature detection unit that outputs the temperature of the amplification unit, and wavelength-multiplexed with the signal light. Based on the wavelength information detection unit that outputs wavelength information that is wavelength information, the temperature characteristic storage unit that stores the relationship between the temperature and the wavelength characteristic of the amplification unit, and the information stored in the wavelength information and the temperature characteristic storage unit A temperature calculation unit that outputs a target temperature at which the amplification unit has a predetermined gain characteristic; and a control unit that controls the heating and cooling unit based on the temperature and the target value indicated by the output of the temperature detection unit.

  The optical amplifier control method according to the present invention amplifies the input signal light by the amplifying unit, outputs the temperature of the amplifying unit, outputs the wavelength information that is the wavelength information wavelength-multiplexed with the signal light, and amplifies it The relationship between the temperature of the unit and the wavelength characteristic of the amplification unit is stored, and based on the relationship between the wavelength information and the temperature of the amplification unit and the wavelength characteristic of the amplification unit, a target temperature at which the amplification unit has a predetermined gain characteristic is output, The amplification unit is heated or cooled based on the temperature of the amplification unit and the target value.

  The present invention has an effect of reducing the power consumption of the optical amplifier.

It is a figure which shows the structure of the optical amplifier of the 1st Embodiment of this invention. It is a figure which shows the structure of the optical amplifier of the 2nd Embodiment of this invention. It is a figure which shows the specific structure of a monitoring module as the 3rd Embodiment of this invention. It is a figure which shows the other structure of the monitoring module as the 4th Embodiment of this invention. It is a figure which shows the structure of the optical amplifier of the 5th Embodiment of this invention. It is a figure which shows the structure of the optical amplifier of the 6th Embodiment of this invention. It is the figure which showed an example of the relationship between the temperature of an amplification medium, and a gain characteristic as a graph.

(First embodiment)
The configuration of the optical amplifier according to the first embodiment of the present invention is shown in FIG. The optical amplifier 100 includes an input unit 101, an output unit 105, a multiplexer 102, a pumping light source 103, and an amplification medium 104. The optical amplifier 100 further includes a duplexer 106, an SV unit 107, a temperature detection unit 108, a control unit 109, a heating / cooling unit 110, a temperature calculation unit 201, and a temperature characteristic storage unit 202.

  The optical amplifier 100 amplifies the light input from the input unit 101 by the amplification medium 104 and outputs it from the output unit 105. The optical amplifier 100 is typically an erbium-doped fiber amplifier (EDF amplifier, EDFA) using an erbium-doped fiber (EDF) as the amplification medium 104.

  The excitation light source 103 is a semiconductor laser diode, for example, and generates excitation light for exciting the amplification medium 104.

  Wavelength multiplexed signal light (wavelength multiplexed light) input from the input unit 101 and excitation light generated by the excitation light source 103 are combined by the multiplexer 102 and input to the amplification medium 104. The power of the excitation light injected into the amplification medium 104 may be controlled so that the wavelength multiplexed light input from the input unit 101 has a predetermined output power at the output unit 105. The optical amplifier 100 is not limited to an EDFA, and may be an optical amplifier using an optical fiber to which other rare earth elements such as thulium are added, a Raman optical amplifier, or the like.

  The duplexer 106 splits SV (supervision, transmission monitoring control) light from the signal light input to the input unit 101 and inputs the branched light to the SV unit 107. The SV unit 107 extracts monitoring control information from the received SV light. The monitoring control information is information generated by a device upstream of the transmission path, and includes information on the wavelength of the signal light being operated.

  As described above, in order to use the optical amplifier 100 in the wavelength division multiplexing optical transmission system, it is desirable that the gain is flat over the wavelength band to be used. However, the gain wavelength characteristic of the amplification medium 104 changes depending on the temperature. In order to prevent the intensity of the signal light output from the optical amplifier 100 from being affected by the temperature characteristic, the heating / cooling unit 110 controls the temperature of the amplification medium 104 under the control of the control unit 109.

  The temperature characteristic storage unit 202 stores a relational expression between the temperature of the amplification medium 104 and the gain characteristic or a table indicating the relation. The temperature calculation unit 201 determines a target value for temperature control of the amplification medium 104 based on the monitoring control information extracted by the SV unit 107 and the relationship between the temperature and gain characteristic of the amplification medium 104 stored in the temperature characteristic storage unit 202. Output to the control unit 109.

  The heating / cooling unit 110 heats or cools the amplification medium 104 under the control of the control unit 109. The temperature detection unit 108 is a temperature sensor that detects the temperature of the amplification medium 104, and outputs the temperature of the amplification medium 104 to the control unit 109. The heating / cooling unit 110 is, for example, a Peltier element. When heating only the amplification medium 104, a heater may be used as the heating / cooling unit 110.

  The control unit 109 controls the heating / cooling unit 110 based on the target temperature value of the amplification medium 104 input from the temperature calculation unit 201 and the temperature of the amplification medium input from the temperature detection unit 108. For example, the control unit 109 controls the heating / cooling unit 109 so that the temperature of the amplification medium input from the temperature detection unit 108 matches the target temperature.

  FIG. 7 is a graph showing an example of the relationship between the temperature of the amplification medium 104 stored in the temperature characteristic storage unit 202 and the gain characteristic. FIG. 7 shows the temperature characteristic of the wavelength characteristic of the gain of the amplification medium 104 as a change with respect to normal temperature (for example, 25 ° C.). FIG. 7 shows characteristics at a high temperature (for example, + 65 ° C.) and characteristics at a low temperature (for example, −20 ° C.). The temperature characteristics other than these may be held in the temperature characteristic storage unit 202 as data by actual measurement, or may be obtained whenever necessary by interpolation. The temperature characteristics of the amplifying medium 104 in FIG. 7 schematically show an example, and the temperature characteristics change depending on the components and length of the amplifying medium 104 or the excitation conditions.

  FIG. 7 shows that even if the wavelength characteristic of the optical amplifier 100 is adjusted to be substantially flat at room temperature, the gain of the amplification medium 104 increases at the center of the band when the temperature rises, and the center of the band when the temperature decreases. This shows that the gain of the amplification medium 104 decreases.

  When the wavelength in operation extends over a wide range of the band of the optical amplifier 100 (example is indicated by arrow A in the figure), the gain difference between both ends and the center of the band is large. Therefore, in order to reduce the influence of the wavelength characteristic of the gain of the amplification medium 104, it is necessary to control the temperature of the amplification medium 104 to be close to room temperature.

  However, when the wavelength in operation is, for example, only near the center of the band shown in FIG. 7 (for example, indicated by an arrow B in the figure), the wavelength does not fall within that band even if the temperature of the amplification medium 104 is away from the normal temperature. The gain difference between them is small. Therefore, in this case, in order to reduce the influence of the wavelength characteristic of the amplification medium 104, it is not necessary to set the target temperature of the amplification medium 104 near normal temperature. That is, if the gain difference between the wavelengths of the signal light in operation is relatively small, the control unit 109 is operating even if the target temperature of the amplification medium 104 is set to a temperature closer to the current temperature than the normal temperature. The gain difference between the signal lights can be kept within the range of values required by the system.

  As described above, in the first embodiment, when the number of operating wavelengths is small and the band of signal light is limited to a part of the band of the optical amplifier 100, the target temperature of the amplification medium 104 is set to a room temperature. Can also be set to a temperature close to the current temperature. This is because in the optical amplifier 100, it is sufficient that the gain of the optical amplifier 100 is flat with respect to the signal light of the wavelength being used. Therefore, in the optical amplifier according to the first embodiment, the target temperature of the amplification medium after temperature control is requested by setting the target temperature of the amplification medium according to the wavelength information of the signal light in operation. Is alleviated.

  That is, the optical amplifier according to the first embodiment has an effect that the power consumption of the optical amplifier can be suppressed.

In FIG. 1, it is assumed that the duplexer 106 is between the input unit 101 and the multiplexer 102. However, the duplexer 106 can be placed at any position between the input unit 101 and the output unit 105 as long as the SV unit 107 can detect SV light.
(Second Embodiment)
In the first embodiment, the configuration for notifying the temperature calculation unit 201 of the wavelength information of the operating signal light included in the SV light has been described as a method for obtaining the wavelength information of the operating signal light.
In the following second to fifth embodiments, a configuration will be described in which information on the wavelength of signal light in operation within the optical amplifier is monitored and the information is notified to the temperature calculation unit 201.

  FIG. 2 is a diagram showing the configuration of the optical amplifier according to the second embodiment of the present invention. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  In the optical amplifier 200 shown in FIG. 2, the duplexer 106 and the SV unit 107 are omitted as compared with the optical amplifier 100 shown in FIG. On the other hand, the optical amplifier 200 includes a branching device 111 and a monitoring module (OCM: Optical Channel Monitor) 301.

  The branching device 111 branches a part of the wavelength multiplexed signal light amplified by the amplification medium 104. The monitoring module 301 receives the wavelength-division multiplexed signal light branched by the branching device 111 and notifies the temperature calculation unit 201 of information on the wavelength in operation. The specific configuration of the monitoring module 301 will be described in the third and fourth embodiments.

  From the relational expression or relation table between the information on the wavelength of the signal light in operation notified from the monitoring module 301 and the temperature and gain of the amplification medium 104 stored in the temperature characteristic storage unit 202, the temperature calculation unit 201 A target value of the temperature of the amplification medium 104 is calculated. As described with reference to FIG. 7 of the first embodiment, the target value is set so that the gain difference of the amplification medium 104 with respect to the signal light having the wavelength in operation is within the allowable range in the system. .

  Thus, also in the optical amplifier 200, the target value of the temperature of the amplification medium 104 is calculated based on the wavelength of the signal light in operation. Therefore, in the optical amplifier 200, as with the optical amplifier 100 of the first embodiment, the demand for the flatness of the wavelength characteristics is relaxed according to the wavelength information of the signal light in operation. As a result, the optical amplifier according to the second embodiment also has an effect that the power consumption of the optical amplifier can be suppressed.

  Furthermore, by using the monitoring module 301, the optical amplifier 200 can obtain information on the wavelength of signal light in operation without using SV light. Accordingly, the optical amplifier 200 according to the second embodiment does not require a function of superimposing SV light on a device upstream of the optical amplifier 200. Therefore, the device constituting the wavelength division multiplexing optical transmission system can be reduced in size and cost. There is also an effect that is possible.

  In FIG. 2, the branching device 111 is located between the amplification medium 104 and the output unit 105, but the branching device 111 can be disposed at any position between the input unit 101 and the output unit 105. .

(Third embodiment)
FIG. 3 shows a specific configuration of the monitoring module as the third embodiment of the present invention. A monitoring module 400 illustrated in FIG. 3 is an example of a configuration of the monitoring module 301 included in the optical amplifier 200 described in FIG. In FIG. 3, the monitoring module 400 includes an arrayed waveguiding grating (AWG) 401, a photodiode 402, an I / V converter 403, and a wavelength monitoring unit 404. The AWG 401 demultiplexes the wavelength multiplexed signal light input from the branching device 111 for each wavelength, and outputs it to the photodiode 402 provided corresponding to each wavelength. Each photodiode 402 converts the input light into a photocurrent and outputs it to the I / V conversion unit 403. An I / V conversion unit 403 is provided for each photodiode 402, converts the photocurrent input from the photodiode 402 into a voltage, and outputs the voltage to the wavelength monitoring unit 404.

  The wavelength monitoring unit 404 determines the presence / absence of signal light for each wavelength from the voltage value for each wavelength output from the I / V conversion unit 403, and wavelength information indicating the presence / absence of signal light for each wavelength is calculated by the temperature calculation unit 201. Notify Here, if the voltage value for each wavelength output from a certain I / V conversion unit 403 is equal to or greater than a predetermined value, the wavelength monitoring unit 404 is connected to the AWG 401 connected upstream of the I / V converter 403. It may be determined that a signal with an output wavelength exists (that is, is operating in the system).

  By using the monitoring module 400 having such a configuration, the optical amplifier 200 can obtain wavelength information during operation without using SV light. Therefore, the optical amplifier 200 using the monitoring module 400 can reduce the power consumption of the optical amplifier and reduce the size and the size of the apparatus constituting the wavelength division multiplexing optical transmission system, as in the second embodiment. There is an effect of enabling price.

(Fourth embodiment)
FIG. 4 shows another configuration of the monitoring module as the fourth embodiment of the present invention. The monitoring module 420 shown in FIG. 4 includes an optical wavelength variable bandpass filter 410, a photodiode 402, an I / V converter 403, and a wavelength monitoring unit 414. The functions of the photodiode 402 and the I / V converter 403 are the same as those described in the third embodiment. The wavelength monitoring unit 414 determines the presence / absence of signal light for each wavelength from the voltage value for each wavelength output from the I / V conversion unit 403, and wavelength information indicating the presence / absence of the signal light for each wavelength to the temperature calculation unit 201. Notice. Further, the wavelength monitoring unit 414 has a function of controlling the transmission wavelength of the optical wavelength variable bandpass filter 410.

  A monitoring module 420 shown in FIG. 4 includes an optical wavelength variable bandpass filter 410 instead of the AWG 401, as compared with the monitoring module 400 described in FIG. In the monitoring module 420, at least one photodiode 402 and one I / V converter 403 may be provided. The optical wavelength tunable bandpass filter 410 transmits only the signal light of the wavelength designated from the outside among the signal light used in the wavelength division multiplexing optical transmission system.

  The monitoring module 420 switches the wavelength of light transmitted through the optical wavelength variable bandpass filter 410 according to an instruction from the wavelength monitoring unit 414. The photodiode 402 generates a photocurrent and outputs it to the I / V converter 403 only when there is signal light having a wavelength that is transmitted through the optical wavelength variable bandpass filter 410. The wavelength monitoring unit 414 monitors the output voltage from the I / V converter 403 for each wavelength while changing the wavelength transmitted by the optical wavelength variable bandpass filter 410. Then, the wavelength monitoring unit 414 detects the wavelength of the light input to the monitoring module based on the output voltage from the I / V converter 403 for each set wavelength.

  Here, if the voltage value for each wavelength output from the I / V conversion unit 403 is equal to or greater than a predetermined value, the wavelength monitoring unit 414 receives a signal having a wavelength that is transmitted through the optical wavelength variable bandpass filter 410 at that time. It may be determined that it exists (that is, is operating in the system). By changing the wavelength of light transmitted through the optical wavelength tunable bandpass filter 410 over the entire band of the wavelength division multiplexing optical transmission system, the wavelength monitoring unit 414 can obtain information on the wavelength of the signal light in operation.

  As described above, also by using the monitoring module 420 having such a configuration, the optical amplifier 200 can obtain wavelength information during operation without using SV light. Accordingly, even by using the monitoring module described in the fourth embodiment, the optical amplifier 200 can reduce the power consumption of the optical amplifier and reduce the size of the apparatus constituting the wavelength division multiplexing optical transmission system. In addition, there is an effect that the price can be reduced.

(Fifth embodiment)
FIG. 5 is a diagram showing the configuration of the optical amplifier according to the fifth embodiment of the present invention. An optical amplifier 500 illustrated in FIG. 5 includes an optical amplification unit 501 and a wavelength monitoring unit 502. The optical amplification unit 501 and the wavelength monitoring unit 502 are configured as independent units, and wavelength information during operation monitored by the wavelength monitoring unit 502 is notified from the wavelength monitoring unit 502 to the optical amplification unit 501 by inter-unit communication.

  The optical amplification unit 501 includes the multiplexer 102, the excitation light source 103, and the amplification medium 104 described with reference to FIG. The optical amplification unit 501 further includes a temperature detection unit 108, a control unit 109, a heating / cooling unit 110, a temperature calculation unit 201, and a temperature characteristic storage unit 202.

  The wavelength monitoring unit 502 includes a branching unit 111 and a monitoring module 301. The monitoring module 301 receives the wavelength-division multiplexed signal light branched by the branching device 111 and notifies the temperature calculation unit 201 of the optical amplification unit 501 of information on the wavelength in operation by inter-unit communication. As the monitoring module 301, the monitoring module having the configuration described in the third and fourth embodiments may be used.

  In the fifth embodiment, the optical amplification unit 501 and the wavelength monitoring unit 502 are configured as different units. For this reason, when a part of the optical amplifier 500 needs to be replaced due to failure or functional improvement, only the corresponding unit needs to be replaced. As a result, the optical amplifier 500 of the fifth embodiment reduces the power consumption of the optical amplifier, and further enables maintenance and functions in addition to the effects of enabling downsizing and cost reduction of the devices constituting the optical transmission system. There is also an effect that the cost required for improvement can be reduced.

  In the first embodiment, the configuration in which the information on the wavelength of the signal light in operation is acquired from the received SV light has been described. In the second to fifth embodiments, the configuration in which the information on the wavelength of the signal light in operation is acquired based on the result of detecting the signal light has been described. However, the optical amplifier may acquire information on the wavelength of the signal light in operation without using SV light or signal light. For example, the optical amplifier may include a storage unit that stores in advance information on the wavelength of the signal light being operated, and the storage unit may output the information to the temperature calculation unit 201 as necessary.

(Sixth embodiment)
FIG. 6 is a diagram showing the configuration of the optical amplifier according to the sixth embodiment of the present invention. An optical amplifier 600 illustrated in FIG. 6 includes an amplification unit 601, a heating / cooling unit 602, and a temperature detection unit 603. The optical amplifier 600 further includes a wavelength information output unit 604, a temperature characteristic storage unit 605, a temperature calculation unit 606, and a control unit 607.

  In FIG. 6, an amplifying unit 601 amplifies input signal light. The heating / cooling unit 602 heats or cools the amplification unit 601, and the temperature detection unit 603 outputs the temperature of the amplification unit. The wavelength information output unit 604 outputs wavelength information that is information on the wavelength of the signal light.

  The temperature characteristic storage unit 605 stores the relationship between the temperature of the amplification unit 601 and the wavelength characteristic. Based on the wavelength information output from the wavelength information output unit 604 and the information stored in the temperature characteristic storage unit 605, the temperature calculation unit 606 controls the target value of the temperature at which the amplification unit 601 has a predetermined gain characteristic. To 607. The control unit 607 controls the heating / cooling unit 602 based on the target value output by the temperature calculation unit 606 and the temperature indicated by the output of the temperature detection unit 603.

  In the optical amplifier 600 having such a configuration, the amplification unit 601 has a predetermined gain characteristic based on the wavelength information output from the wavelength information output unit 604 and the information stored in the temperature characteristic storage unit 605. Its temperature is controlled. That is, the temperature of the amplifying unit 601 is controlled so as to have a predetermined gain characteristic based on information on the wavelength that is wavelength-multiplexed with the signal light. Therefore, since the temperature control of the amplifying unit 601 is performed only for the wavelength in operation, the optical amplifier of the sixth embodiment also has an effect that the power consumption of the optical amplifier can be suppressed.

  The present invention has been described above with reference to the first to sixth embodiments. However, the form to which the present invention can be applied is not limited to the above-described embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and detailed description of the present invention within the scope of the present invention.

100, 200, 500, 600 Optical amplifier 101 Input unit 102 Multiplexer 103 Excitation light source 104 Amplifying medium 105 Output unit 106 Demultiplexer 107 SV unit 108, 603 Temperature detection unit 109, 607 Control unit 110, 602 Heating / cooling unit 111 Branch unit 201, 606 Temperature calculation unit 202, 605 Temperature characteristic storage unit 301, 400, 420 Monitoring module 401 AWG
402 Photodiode 403 I / V conversion unit 404, 414 Wavelength monitoring unit 501 Optical amplification unit 502 Wavelength monitoring unit 601 Amplification unit 604 Wavelength information output unit

Claims (10)

An amplifier for amplifying the input signal light;
A heating / cooling unit for heating or cooling the amplification unit, and a temperature detection unit for outputting the temperature of the amplification unit,
A wavelength information detector that outputs wavelength information that is information on the wavelength of the signal light;
A temperature characteristic storage unit for storing the relationship between the temperature of the amplification unit and the wavelength characteristic;
Based on the wavelength information and the information stored in the temperature characteristic storage unit, a temperature calculation unit that outputs a target value of a temperature at which the amplification unit has a predetermined gain characteristic;
A control unit that controls the heating and cooling unit based on the temperature indicated by the output of the temperature detection unit and the target value;
An optical amplifier comprising: The wavelength information detection unit includes a branching unit that branches a part of the signal light, and outputs the wavelength information based on a transmission line monitoring signal included in the branched signal light. Optical amplifier. 2. The optical amplifier according to claim 1, wherein the wavelength information detection unit detects the intensity of each wavelength of light wavelength-multiplexed with the signal light and outputs the wavelength information. The wavelength information detection unit is a demultiplexing unit that demultiplexes and outputs the signal light branched by the branching unit for each wavelength, and a light receiving unit that converts the light output from the demultiplexing unit into an electrical signal. The optical amplifier according to claim 3, further comprising: The optical amplifier according to claim 4, wherein the demultiplexing unit is configured by an arrayed waveguide grating (AWG). The wavelength information detection unit is a wavelength tunable filter unit capable of controlling a wavelength for transmitting the signal light branched by the branch unit, and a light receiving unit that converts the signal light output from the wavelength tunable filter unit into an electrical signal. And an optical amplifier according to claim 3. The optical amplifier according to claim 2, wherein the branching unit is disposed on an input side of the amplifying unit. The optical amplifier according to claim 2, wherein the branching unit is disposed on an output side of the amplifying unit. An optical amplification unit comprising the amplification unit, the heating / cooling unit, the temperature detection unit, the temperature characteristic storage unit, and the temperature control unit;
A wavelength monitoring unit comprising the wavelength information detection unit and outputting the wavelength information to the optical amplification unit;
An optical amplifier according to any one of claims 1 to 8. The input signal light is amplified by the amplifier,
Output the temperature of the amplification unit,
Outputs wavelength information that is information on the wavelength of the signal light,
Storing the relationship between the temperature of the amplifier and the wavelength characteristic of the amplifier;
Based on the wavelength information and the relationship between the temperature of the amplification unit and the wavelength characteristic of the amplification unit, the target value of the temperature at which the amplification unit has a predetermined gain characteristic is output,
Heating or cooling the amplification unit based on the temperature of the amplification unit and the target value;
Control method of optical amplifier.

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