JP2002353939A - Optical transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the need for manual control of ASE dummy optical power, when a signal wavelength is added. SOLUTION: Signal light output devices 12-1 to 12-4 respectively output signal beams of mutually different wavelength to optical amplifiers 14-1 to 14-4. Each of optical amplifiers 14-1 to 14-4 amplifies the input signal light, so that the optical power becomes a fixed value. An ASE light source 16 outputs ASE dummy light of wavelengths λa and λb lying outside the signal wavelength band. An optical multiplexer 20 multiplexes the output beams of the ASE light sources 16 and 18, and an optical amplifier 22 amplifies the output light of the optical multiplexer 20 with a gain corresponding to a control signal from a control circuit 32. An optical multiplexer 24 multiplexes the output light of the optical amplifiers 14-1 to 14-4 and 22, and a demultiplexer 26 supplies almost all of the output light of the optical multiplexer 24 to an optical amplifier 28 and supplies the remaining light to a photodetector 30. The photodetector 30 converts the light signal from the demultiplexer 26 into an electrical signal. In accordance with the output of the photodetector 30, the control circuit 32 controls the gain of the optical amplifier 22, the total optical power of the optical multiplexer 24 becomes equal to the total optical power when the entire wavelength band is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmitter, and more particularly, to an optical transmitter capable of easily changing the number of wavelengths used in a WDM transmission system.

[0002]

2. Description of the Related Art A high-density wavelength division multiplexing (DWDM) optical transmission system initially operates using a small number of wavelengths,
The number of wavelengths used is increased in accordance with an increase in demand. At the stage where the number of wavelengths used is small, the ASE light is multiplexed on the signal light as dummy light. This is because if no dummy light is present, the input power of the optical amplifier on the optical transmission path becomes smaller than a predetermined value, and as a result, the SNR of the output of the optical amplifier deteriorates. Then, the total power of the light (the signal light and the ASE dummy light) output from the optical transmission device to the optical transmission path becomes the optical power assumed when all the predetermined signal wavelengths are used.
The power of the ASE dummy light is adjusted in advance.

When the number of signal wavelengths is small, the central part of the signal wavelength band is used, and ASE dummy light is arranged on both sides thereof. FIG. 7 shows an example of the spectrum distribution of light output from the optical transmission device to the optical transmission line. In FIG. 7, four signal lights having wavelengths λ1, λ2, λ3, and λ4 are present at the center, and ASE dummy lights having wavelengths λa and λb having a wide spectral width are present on both sides thereof. λa <λ1 <λ2 <λ3 <λ4 <λ
b. In an optical transmission system designed on the premise of multiple wavelengths exceeding 100 wavelengths, ASEs on both sides
Each of the dummy lights needs to carry an optical power equivalent to about 50 wavelengths. Therefore, according to the number of wavelengths to be covered,
The optical power increases.

[0004] Irrespective of the number of wavelengths used, the optical power of each wavelength is preferably constant, and the total power of light output from the optical transmitter to the optical transmission line is preferably constant. Therefore, in the conventional example, as described above, the power of each signal light and each ASE dummy light is adjusted by the AGC optical amplifier before the multiplexing thereof.

[0005]

SUMMARY OF THE INVENTION Each signal light and each ASE
In the conventional method of individually adjusting the optical power of the dummy light, for example, when the number of signal wavelengths increases, the optical power of the ASE dummy light must be readjusted. That is, the A
The target value of the AFC optical amplifier for adjusting the optical power of the SE dummy light must be readjusted. Also, for example, when one light source of signal light fails, the optical power of the ASE dummy light must be readjusted to compensate for the failure. Such work requires quickness, but requires manual labor, and it is difficult to respond quickly. Also, AS
It is not easy to readjust the optical power of the E dummy light to an appropriate amount.

According to the present invention, such troubles can be avoided.
An object of the present invention is to provide an optical transmission device that realizes automation of power control of SE dummy light.

[0007]

An optical transmitter according to the present invention comprises: a signal light output device for outputting a plurality of signal lights having different wavelengths from each other; an ASE dummy light generating device for generating an ASE dummy light; Output light of light generating device and AS
An optical multiplexing device for multiplexing the output light of the E dummy light generating device, an optical power detecting device for detecting the output light power of the optical multiplexing device, and the ASE dummy light generating device according to the detection result of the optical power detecting device. A control device for controlling the optical power level of the ASE dummy light output from the device.

With such a configuration, the optical power of the ASE dummy light is feedback-controlled so that the output optical power of the optical multiplexer becomes constant. That is, even if the signal light increases or decreases, the optical power of the ASE dummy light is automatically adjusted accordingly. Thereby, when the signal wavelength is added, the transmission characteristics of the signal wavelength, for example, S per use wavelength
NR can be kept constant. In other words, the addition of signal wavelengths while providing communication services, so-called in-service
Upgrade is possible. Further, even if one of the signal light sources fails, the transmission characteristics of the remaining signal light can be maintained in a good state.

Preferably, the ASE dummy light generator includes an ASE light source for generating ASE dummy light and the ASE light source.
An optical power level adjusting device for adjusting the optical power level of the output light from the E light source, the optical power level adjusting device being controlled by the control device for the optical power level adjustment amount. The optical power level adjusting device includes, for example, an optical amplifier whose gain can be changed freely. With this configuration, the optical power level of the ASE dummy light can be easily controlled to an appropriate value.

[0010] Preferably, the ASE dummy light generator includes an excitation light source for generating excitation light, a variable attenuator for attenuating the output light of the excitation light source with an attenuation controlled by the control device, and a variable attenuator. And an ASE light source that is excited by the output light of the device and generates the ASE dummy light.
Also with this configuration, the optical power level of the ASE dummy light can be easily controlled to an appropriate value.

Preferably, the ASE light source comprises an output AS
At least one of the center wavelength and the bandwidth of the E dummy light can be changed.

Preferably, the ASE dummy light generator generates ASE dummy light having a wavelength on both sides of the wavelengths of the plurality of signal lights.

Preferably, the signal light output device includes a plurality of signal light generation devices for generating signal lights having different wavelengths, and amplifies each signal light output from the plurality of signal light generation devices to a predetermined light power level. And a plurality of optical amplifiers. Thereby, the optical power of each signal light can be controlled to a desired value.

Preferably, the signal light output device includes a plurality of signal light generators (40) for generating signal lights having different wavelengths from each other, and each signal light output from the plurality of signal light generators is grouped into groups. And a plurality of optical amplifiers (4) that amplify output lights of the plurality of second optical multiplexers to a predetermined optical power level.
4). Thus, the optical power of each signal light can be controlled to a desired value with a small number of optical amplifiers.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention. Reference numeral 10 denotes an optical transmission device according to the present embodiment. 1
2 (12-1, 12-2, 12-3, 12-4) are signal light output devices for outputting signal lights of mutually different wavelengths λ1, λ2, λ3, λ4. Here, λ1 <
It is assumed that λ2 <λ3 <λ4. 14 (14-1, 14)
−2, 14-3, 14-4) are the signal light output devices 12 (12-1, 12-2, 12-3, 12-4), respectively.
Gain control (AG) to amplify the signal light output from the
C) An optical amplifier. The AGC optical amplifier is an optical amplifier that monitors the amplified output and performs feedback control so that the gain becomes constant. Since the AGC optical amplifier can maintain a constant gain irrespective of the number of input channels (signal wavelengths), the output optical power of each channel can be kept constant even if the number of input channels increases or decreases.

Reference numeral 16 denotes an ASE light source for generating ASE light having a wavelength λa shorter than λ1, and reference numeral 18 denotes a wavelength λ longer than λ4.
b is an ASE light source that generates the ASE light. The ASE light sources 16 and 18 are internally controlled so that their output powers become constant. Reference numeral 20 denotes an optical multiplexing device that multiplexes the output lights of the ASE light sources 16 and 18, and reference numeral 22 denotes an automatic level control (ALC) optical amplifier that amplifies the output light of the optical multiplexing device 20. The ALC optical amplifier is an optical amplifier that monitors the amplified output and performs feedback control so that the output optical power becomes constant. The ALC optical amplifier responds to changes in the input level.
It has the feature that output level fluctuation is small. In this embodiment, the output level of the ALC optical amplifier 22 can be externally controlled.

Reference numeral 24 denotes optical amplifiers 14-1 to 14-4, 22
An optical multiplexing device for multiplexing the output light of the optical multiplexing device; 26, a demultiplexer that divides the multiplexed output light of the optical multiplexing device 24 into two at a predetermined division ratio; Is an automatic power control (APC) optical amplifier that amplifies the light, 30 is a light receiving element that converts the other output light of the demultiplexer 26 into electricity, and 32 is an output light of the optical multiplexer 24 according to the output of the light receiving element 30. This is a control circuit that feedback-controls the gain of the optical amplifier 22 so that the total optical power becomes a predetermined value (total optical power when all the designed wavelengths are used).

The APC optical amplifier is an optical amplifier that monitors the excitation light power and performs feedback control so that the excitation light power becomes constant. The APC optical amplifier has a feature that, when the input level changes, the output level changes so as to compress the change amount of the input level by a gain compression effect.
That is, in the APC optical amplifier, the gain is large when the input level is low, and the gain is low when the input level is high.

The signal wavelengths λ1 to λ4 and the ASE light wavelength λa,
The relationship of λb is the same as the relationship shown in FIG.

The operation of this embodiment will be described. The signal light output devices 12-1, 12-2, 12-3, and 12-4 respectively output the signal lights of different wavelengths λ1, λ2, λ3, and λ4 to the optical amplifiers 14-1, 14-2, and 14-3. , 14-4
Output to Optical amplifiers 14-1, 14-2, 14-3,
14-4 amplify the input signal light so that its optical power becomes a constant value. Thereby, each wavelength λ1 to λ
4 is controlled to the same constant value. The signal lights of the wavelengths λ1 to λ4 controlled to the same constant optical power are input to the optical multiplexer 24.

The ASE light source 16 outputs ASE dummy light of λa, and the ASE light source 18 outputs ASE dummy light of wavelength λb. ASE output from ASE light sources 16 and 18
The power of the dummy light is controlled to the same constant value. The optical multiplexing device 20 multiplexes the output light of the ASE light sources 16 and 18, and the optical amplifier 22 converts the output light of the optical multiplexing device 20 into
The signal is amplified so as to have an output level corresponding to the control signal from the control circuit 32. The output light of the optical amplifier 22 is applied to the optical multiplexing device 24.

The optical multiplexing device 24 includes optical amplifiers 14-1 to 14-1.
The output lights of 14-4 and 22 are multiplexed, and the demultiplexer 26 supplies most of the output light of the optical multiplexing device 24 to the optical amplifier 28 and the rest to the light receiving element 30. The optical amplifier 28 amplifies the light from the demultiplexer 26 and outputs the amplified light to the optical transmission line. The light receiving element 30 converts the light from the duplexer 26 into electricity. The electric output of the light receiving element 30 indicates the input light power, that is, the total power of the output light of the optical multiplexing device 24. The control circuit 32 controls the optical multiplexing device 24 according to the output of the light receiving element 30.
The feedback control of the gain of the optical amplifier 22 is performed so that the total optical power of the output light is equal to a predetermined value (total optical power when all the designed wavelengths are used).

In this embodiment, the optical power of each channel is controlled to be constant by the optical amplifier 14, and the total optical power of the signal light and the ASE dummy light is controlled to be constant by the optical amplifier 22. In such a situation, since the optical amplifier 28 is an APC optical amplifier, the total optical power at the output of the optical amplifier 28 and the optical power for each channel are constant regardless of the increase or decrease in the number of signal wavelengths.

As described above, in this embodiment, the feedback control of the optical power of the ASE dummy light for supplementing the shortage of the signal wavelength is performed so that the total optical power after multiplexing all the wavelengths becomes constant. The total optical power on the optical transmission line can be automatically controlled to a constant value in any state from the initial state where the used wavelength is small to the full mounting state where all signal wavelengths are used.
That is, irrespective of a change in the number of signal wavelengths, stable transmission characteristics can be obtained, and maintenance management becomes easy.

For example, when a signal light of a new wavelength is added, in the conventional example, the optical power of the ASE dummy light on both sides has to be manually adjusted according to the optical power of the added signal light. However, in the present embodiment, the optical power of the ASE dummy light is automatically adjusted to an appropriate amount, and it is not necessary to arrange personnel for the adjustment operation. When one or a plurality of signal light output devices 12 fail, A
Since the optical power of the SE dummy light increases by an appropriate amount,
The transmission characteristics of the surviving signal light are maintained in a good state.
This feature according to the present embodiment also enables an in-service upgrade to freely increase or decrease the signal wavelength while providing communication services.

In the embodiment shown in FIG. 1, an AGC optical amplifier is arranged for each signal light for easy understanding. However, after a plurality of signal lights are multiplexed, the optical power is increased by one AGC optical amplifier. The present invention can also be applied to a configuration for adjusting. An example of such a modified configuration is shown in FIG. The same components as those in FIG. 1 are denoted by the same reference numerals.

Numeral 40 (40-1 to 40-n) is a signal light output device for outputting signal light having wavelengths λ1 to λn different from each other. The signal light output devices 40-1 to 40-n are divided into k groups, and each signal light output device 40-1
To 40-n are multiplexed by the optical multiplexing device 42 (42-1 to 42-k) for each group and applied to the AGC optical amplifier 44 (44-1 to 44-k). Is done. The AGC optical amplifiers 44-1 to 44-k amplify the output light of the corresponding optical multiplexing devices 42-1 to 42-n to a constant optical power for each channel and apply the same to the optical multiplexing device 24. . As described above, the AGC optical amplifier is feedback-controlled so as to maintain a constant gain regardless of the number of input channels (signal wavelengths). Power can be kept constant. This means that it is not necessary to readjust the optical amplifier 44 even if signal light is added or deleted in units of the optical multiplexing devices 42-1 to 42-k.

The subsequent operation is the same as that of the embodiment shown in FIG. 1, and a detailed description thereof will be omitted.

In the optical transmitting apparatus 10a of the embodiment shown in FIG. 2, when the number of signal wavelengths is increased or decreased in the unit of the optical amplifier 44 or the optical multiplexing apparatus 42, the operation of adjusting the optical amplifier 44 during the operation is unnecessary. Become. The embodiment shown in FIG. 2 has an advantage that the number of optical amplifiers 44 can be reduced as compared with the number of signal wavelengths. In a WDM transmission system exceeding 100 wavelengths, the cost of the optical transmission device is reduced.

The ASE light can be generated by not inputting the signal light to the optical amplifier. The ASE light source having such a configuration requires pump light for pumping an optical amplification medium (for example, an erbium-doped optical fiber), like a normal optical amplifier. The ASE light power can also be adjusted by adjusting. FIG.
Shows a schematic block diagram of such an embodiment.

Reference numeral 50 denotes an optical transmitter of the present embodiment. 52
(52-1 to 52-n) are signal light output devices that output signal light having wavelengths λ1 to λn different from each other.
The signal light output devices 52-1 to 52-n are divided into two groups, and the signal light output from each of the signal light output devices 52-1 to 52-n is divided into an optical multiplexing device 54 (54-1, 54-1) for each group.
54-2) and multiplexed by the AGC optical amplifier 56.
(56-1, 56-2).

Reference numeral 58 denotes an ASE light source that generates ASE dummy light having a wavelength λa shorter than λ1, and reference numeral 60 denotes an ASE light source that generates ASE dummy light having a wavelength λb longer than λn. Both of the ASE light sources 58 and 60 are supplied with pumping light from the outside, and the ASE light sources 58 and 60 have a power of AS according to the pumping light power.
Outputs E light. Reference numeral 62 denotes an excitation light source that generates excitation light to be supplied to the ASE light sources 58 and 60. Reference numeral 64 denotes an excitation light output from the excitation light source 62, which is attenuated at an externally controlled attenuation rate. , 60 are supplied to the optical variable attenuator.

Reference numeral 66 denotes an optical multiplexing device for multiplexing the output lights of the optical amplifiers 56-1, 56-2 and the ASE light sources 58, 60, and 68 denotes a multiplexed output light of the optical multiplexing device 66 at a predetermined division ratio. A splitter 70; an automatic power control (APC) optical amplifier 70 for amplifying one output light of the splitter 68; and a light receiving device 72 for converting the other output light of the splitter 68 into electricity. The element 74 is provided with an attenuator 64 such that the total optical power of the output light of the optical multiplexing device 66 becomes a predetermined value (total optical power when all the designed wavelengths are used) in accordance with the output of the light receiving element 72. ASE light sources 58, 6
This is a control circuit for feedback-controlling the output power of 0.

The operation of the embodiment shown in FIG. 3 will be described. In this embodiment, the signal light output devices 52-1 to 52-n are divided into two groups, and the optical multiplexer 54-1
The signal light output from the signal light output device 52 of the group is multiplexed, and the optical multiplexing device 54-2 multiplexes the signal light output from the signal light output device 52 of the second group.
The optical amplifiers 56-1 and 56-2 amplify the output light of the optical multiplexing devices 54-1 and 54-2 to a predetermined constant optical power, respectively, and apply the amplified light to the optical multiplexing device 66.

The excitation light source 62 generates excitation light for the ASE light sources 58 and 60 and applies it to the variable attenuator 64. The variable attenuator 64 attenuates the excitation light from the excitation light source 62 at an attenuation rate controlled by the control circuit 74, equally divides the light,
It is applied to the E light sources 58 and 60. The ASE light sources 58 and 60 follow the pump light from the variable attenuator 64, and the A of the wavelengths λa and λb of the optical power corresponding to the optical power of the pump light.
An SE light is generated and output to the optical multiplexer 66.

The optical multiplexing device 66 includes optical amplifiers 56-1,
The output light of the ASE light sources 58 and 760 is multiplexed, and the splitter 68 supplies most of the output light of the optical multiplexer 66 to the optical amplifier 70 and the rest to the light receiving element 72.
The optical amplifier 70 amplifies the light from the splitter 68 so as to have a constant optical power and outputs the amplified light to the optical transmission line. Light receiving element 7
2 converts the light from the duplexer 68 into electricity. Light receiving element 7
The electrical output 2 indicates the input optical power, that is, the total power of the output light of the optical multiplexing device 66. Control circuit 74
Is set so that the total optical power of the output light of the optical multiplexing device 66 becomes equal to a predetermined value (total optical power when all the designed wavelengths are used) in accordance with the output of the light receiving element 72.
The attenuation rate of the variable attenuator 64 is feedback-controlled.

As a result of the control of the attenuation factor of the variable attenuator 64 by the control circuit 74, the output power of the ASE light sources 58 and 60 is determined by the total optical power of the output light of the optical multiplexing device 66. Feedback control is performed so as to be equal to the total optical power when all wavelengths are used. As in the embodiment shown in FIGS. 1 and 2, the output power of the ASE light sources 58 and 60 is automatically controlled to an appropriate amount according to the increase and decrease of the number of signal wavelengths. Even if the number of signal wavelengths increases or decreases, ASE
There is no need to manually adjust the output power of the light sources 58, 60, which facilitates maintenance and management.

In a situation where the signal wavelength is increased, it may be necessary to change the center wavelength or the bandwidth of the ASE light. FIG. 4 shows an example of changing the spectrum distribution of the ASE dummy light with an increase in the number of signal wavelengths. FIG. 4A shows an example of the spectrum distribution before the addition of the signal wavelengths λ1 and λ6 outside the existing wavelengths λ2 to λ5, and FIGS. 4B and 4C show the spectrum distribution after the addition of the signal wavelengths λ1 and λ6, respectively. 3 shows an example of the spectrum distribution. 4B and 4C, the signal wavelengths λ1, λ6
The spectrum distribution of the ASE dummy light before insertion is indicated by a broken line, and the spectrum distribution of the ASE dummy light after insertion is indicated by a solid line.

In FIG. 4B, as the signal wavelengths λ1 and λ6 increase, the center wavelengths of the ASE dummy lights on both sides are changed to λa and λ.
The band width is narrowed while keeping b. In FIG. 4C, as the signal wavelengths λ1 and λ6 increase, the center wavelength of the ASE dummy light on the short wavelength side is changed from λa to λ
The center wavelength of the ASE dummy light on the long wavelength side is shifted from λb to longer λb ′.

An example of the configuration of the ASE light source that can cope with such a change in the center wavelength or the bandwidth of the ASE dummy light will be described below. FIG. 5 is a schematic block diagram of an example of an ASE light source whose center wavelength and / or bandwidth can be changed.

An optical amplifier 80 has an input terminal opened. A variable optical filter circuit 82 capable of selecting a center wavelength and / or a bandwidth is connected to the output side of the optical amplifier 80.
In FIG. 5, the variable optical filter circuit 82 has a center wavelength and / or
Alternatively, one of the plurality of optical filters 84 having different bandwidths is
The optical filter 84 is configured to be selected by optical switches 86 and 88 arranged on the input side and the output side. One of the optical switches 86 and 88 may be omitted. Of course, other configurations in which the center wavelength and / or the bandwidth can be selected may be used.

FIG. 6 shows an example of the configuration of an ASE light source that can change the spectral distribution or gain profile of the ASE light more flexibly. A wavelength separation element (AW) is connected to the output of the optical amplifier 90.
G) Connect 92. The wavelength separating element 92 is an optical amplifier 90
Is separated into a plurality of wavelength components. Variable attenuator 94
Can individually attenuate each wavelength component output from the wavelength separation element 92 by a desired attenuation amount. The wavelength multiplexing element (AWG) 96 multiplexes the output light of each variable attenuator 94 again. The optical amplifier 98 amplifies the output light of the wavelength multiplexing element 96. The optical coupler 100 outputs most of the output light of the optical amplifier 98 to the optical multiplexing device 20 and returns the rest to the input of the optical amplifier 90. The gain of the optical amplifiers 90 and 98 is controlled to a small amount such that laser oscillation does not occur.
The spectral distribution of the ASE light output to the optical multiplexing device 20 can be flexibly changed according to the attenuation of the variable attenuator 94 for each wavelength component and the gains and gain profiles of the optical amplifiers 90 and 92.

[0044]

As can be easily understood from the above description, according to the present invention, the total optical power input to the optical transmission line can be kept constant even when the number of signal wavelengths increases or decreases. Thereby, when the signal wavelength is added, the transmission characteristics of the signal wavelength, for example, the SNR per used wavelength can be kept constant. That is, it is possible to add a signal wavelength while providing a communication service, so-called in-service upgrade. Also, if any signal light source fails,
The transmission characteristics of the remaining signal light can be maintained in a good state.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a first embodiment of the present invention.

FIG. 2 is a schematic configuration block diagram of a second embodiment of the present invention.

FIG. 3 is a schematic configuration block diagram of a third embodiment of the present invention.

FIG. 4 is an example of a change in the center wavelength and the bandwidth of the ASE dummy light with the addition of the signal wavelength.

FIG. 5 is a first configuration example of an ASE light source 16;

FIG. 6 is a second configuration example of the ASE light source 16;

FIG. 7 is an arrangement example of ASE dummy light.

[Explanation of symbols]

10, 10a: optical transmission device 12 (12-1 to 12-4): signal light output device 14 (14-1 to 14-4): automatic gain control (AGC)
Optical amplifiers 16 and 18: ASE light source 20: Optical multiplexer 22: Automatic level control (ALC) optical amplifier 24: Optical multiplexer 26: Demultiplexer 28: Automatic power control (APC) optical amplifier 30: Light receiving element 32 : Control circuit 40 (40-1 to 40-n): signal light output device 42 (42-1 to 42-k): optical multiplexer 44 (44-1 to 44-k): AGC optical amplifier 50: light Transmitting device 52 (52-1 to 52-n): signal light output device 54 (54-1, 54-2): optical multiplexing device 56 (56-1, 56-2): AGC optical amplifier 58, 60: ASE light source 62: excitation light source 64: variable optical attenuator 66: optical multiplexer 68: duplexer 70: automatic power control (APC) optical amplifier 72: light receiving element 74: control circuit 80: optical amplifier 82: variable optical filter Circuit 84: Optical Fill 86, 88: 90: optical amplifier 92: wavelength demultiplexing element (AWG) 94: variable attenuator 96: wavelength multiplexing element (AWG) 98: optical amplifier 100: light coupler

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/14 H04J 14/02 F term (Reference) 2H079 AA08 AA13 BA01 CA09 CA24 DA14 EA05 EA09 FA01 HA07 KA11 KA18 KA19 5F072 AB09 AK06 HH02 HH05 HH06 RR01 YY17 YY20 5K002 AA01 CA08 CA13 DA02 FA01

Claims (8)

[Claims] 1. A signal light output device for outputting a plurality of signal lights having different wavelengths from each other (12, 14; 40, 42, 44).
And an ASE dummy light generator (1) for generating ASE dummy light.
6, 18, 58, 60) and an optical multiplexer (24, 66) for multiplexing the output light of the signal light generator and the output light of the ASE dummy light generator.
An optical power detection device (30, 72) for detecting the output optical power of the optical multiplexing device; and an optical power of the ASE dummy light output from the ASE dummy light generation device according to the detection result of the optical power detection device. An optical transmission device, comprising: a control device (32, 74) for controlling a level. 2. The ASE dummy light generator according to claim 1, wherein
An ASE light source (16, 18) for generating a dummy light, and an optical power level adjusting device (22) for adjusting an optical power level of output light of the ASE light source, wherein the control device controls an optical power level adjustment amount. The optical transmission device according to claim 1, further comprising an optical power level adjustment device. 3. The optical transmitter according to claim 2, wherein said optical power level adjusting device comprises an optical amplifier whose gain can be changed. 4. An ASE dummy light generator, comprising: an excitation light source (62) for generating excitation light; and a variable attenuator (64) for attenuating output light of the excitation light source by an attenuation controlled by the controller. And an ASE light source (5) that is excited by the output light of the variable attenuator and generates the ASE dummy light.
8. The optical transmitter according to claim 1, comprising: (8, 60). 5. The optical transmission device according to claim 2, wherein the ASE light source is capable of changing at least one of a center wavelength and a bandwidth of the output ASE dummy light. 6. The optical transmitter according to claim 1, wherein the ASE dummy light generator generates ASE dummy lights having wavelengths on both sides of the wavelengths of the plurality of signal lights. 7. A plurality of signal light generating devices for generating signal lights having different wavelengths from each other.
The optical transmission device according to claim 1, comprising: a plurality of optical amplifiers (14) for amplifying each signal light output from the plurality of signal light generation devices to a predetermined optical power level. 8. A plurality of signal light generators (40) for generating signal lights having different wavelengths from each other.
And each signal light output from the plurality of signal light generation devices,
A plurality of second optical multiplexing devices (4
2. The optical transmission device according to claim 1, comprising: 2) and a plurality of optical amplifiers (44) for amplifying output lights of the plurality of second optical multiplexing devices to a predetermined optical power level.