CN113300771B - Optical amplifier, optical transmission system and optical signal processing method - Google Patents
Optical amplifier, optical transmission system and optical signal processing method Download PDFInfo
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- CN113300771B CN113300771B CN202010753713.0A CN202010753713A CN113300771B CN 113300771 B CN113300771 B CN 113300771B CN 202010753713 A CN202010753713 A CN 202010753713A CN 113300771 B CN113300771 B CN 113300771B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/29—Repeaters
- H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
- H04B10/2912—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form characterised by the medium used for amplification or processing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/29—Repeaters
- H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
- H04B10/293—Signal power control
- H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
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Abstract
The embodiment of the application provides an optical amplifier, an optical transmission system and a processing method of an optical signal, wherein the method comprises the following steps: a wavelength selective switch; and a gain unit connected to the wavelength selective switch; the wavelength selective switch carries out attenuation treatment on the optical signals of the transmission channel according to attenuation parameters corresponding to the transmission channel. According to the embodiment of the application, the gain flattening requirement can be realized in a wide frequency range, namely, the frequency range with the flattened gain can be improved.
Description
Technical Field
The present disclosure relates to the field of optical fiber communication technologies, and in particular, to an optical amplifier, an optical transmission system, and a method for processing an optical signal.
Background
Optical amplifiers (OA, optical amplifier) are one of the key devices in fiber optic communication systems. The function of OA includes amplifying the gain of the optical signal so that the power at the receiving end is within the sensitivity range of the receiver. In a transmission link of an optical fiber communication system, the different optical channels are easily subjected to different attenuation/gain due to the factors such as unevenness of OA gain, wavelength dependent loss (WDL, wavelength dependent loss) in an optical cable, and energy transfer between the optical channels caused by stimulated Raman scattering (SRS, stimulated Raman scattering), so that it is difficult to keep balance between power and performance of the different optical channels at a receiving end.
Currently, a gain flattening filter (GFF, gain flatness filter) is arranged in the OA, and a test method is adopted to determine the spectrum shape of the GFF, so that the spectrum shape of the GFF is matched with the gain spectrum of the OA, and further, the requirement of gain flattening can be met.
The inventors have found in practicing embodiments of the present application that current OA generally achieves gain flattening requirements over a narrower frequency range. More and more fiber optic communication systems operate over a wide frequency range, and thus the current OA application range is narrower.
Disclosure of Invention
The technical problem to be solved in the embodiments of the present application is to provide an optical amplifier capable of realizing a gain flattening requirement in a wide frequency range, that is, improving a frequency range with flattened gain.
Correspondingly, the embodiment of the application also provides an optical transmission system and an optical signal processing method, which are used for ensuring the realization and the application of the optical amplifier.
To solve the above-mentioned problems, an embodiment of the present application discloses an optical amplifier, including:
a wavelength selective switch; and
a gain unit connected to the wavelength selective switch;
the wavelength selective switch carries out attenuation treatment on the optical signals of the transmission channel according to attenuation parameters corresponding to the transmission channel.
In another aspect, an embodiment of the present application discloses an optical transmission system, including: the aforementioned optical amplifier.
In still another aspect, an embodiment of the present application further discloses a method for processing an optical signal, including:
determining attenuation parameters corresponding to the transmission channels;
controlling a wavelength selection switch in the optical amplifier, and carrying out attenuation treatment on the optical signal of the transmission channel according to the attenuation parameter;
the optical amplifier further includes: and a gain unit connected with the wavelength selective switch.
In yet another aspect, an embodiment of the present application further discloses an apparatus, including:
one or more processors; and
one or more machine-readable media having instructions stored thereon, which when executed by the one or more processors, cause the apparatus to perform one or more of the methods described previously.
In yet another aspect, embodiments of the present application disclose one or more machine-readable media having instructions stored thereon that, when executed by one or more processors, cause an apparatus to perform one or more of the methods described previously.
Embodiments of the present application include the following advantages:
according to the wavelength selective switch, according to the attenuation parameters corresponding to the transmission channels, the attenuation corresponding to the transmission channels is realized, the attenuation can be matched with the gain realized by the gain unit, and further the gain flattening requirement among different transmission channels is realized.
Because the embodiment of the application can support dynamic configuration of the attenuation parameters corresponding to the transmission channels, and different transmission channels can correspond to different wavelengths or frequencies, the embodiment of the application can realize the gain flattening requirement in a wide frequency range based on the dynamic configuration of the attenuation parameters corresponding to the transmission channels, namely the frequency range with flattened gain can be improved.
In addition, the wavelength selective switch and the gain unit are combined, so that the gain flattening requirement in a wide frequency range is realized. Since the requirements can be realized with fewer components and a simple structure, the cost of the optical amplifier can be reduced.
Drawings
Fig. 1, fig. 2, fig. 3, fig. 4, fig. 5, fig. 6 are schematic structural diagrams of an optical amplifier according to an embodiment of the present application;
FIG. 7 is an illustration of a mapping relationship between attenuation and frequency in accordance with an embodiment of the present application;
fig. 8, 9, 10 and 11 are schematic structural diagrams of an optical amplifier according to an embodiment of the present application; and
fig. 12, 13 and 14 are flowcharts of steps of an embodiment of a method for processing an optical signal according to the present application.
Detailed Description
In order that the above-recited objects, features and advantages of the present application will become more readily apparent, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings.
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application are within the scope of the protection of the present application.
The concepts of the present application are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the concepts of the present application to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives.
Reference in the specification to "one embodiment," "an embodiment," "one particular embodiment," etc., means that a particular feature, structure, or characteristic may be included in the described embodiments, but every embodiment may or may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, where a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments whether or not explicitly described. In addition, it should be understood that the items in the list included in this form of "at least one of A, B and C" may include the following possible items: (A); (B); (C); (A and B); (A and C); (B and C); or (A, B and C). Likewise, an item listed in this form of "at least one of A, B or C" may mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B and C).
In some cases, the disclosed embodiments may be implemented as hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried on or stored on one or more transitory or non-transitory machine-readable (e.g., computer-readable) storage media, which may be executed by one or more processors. A machine-readable storage medium may be implemented as a storage device, mechanism, or other physical structure (e.g., volatile or non-volatile memory, a media disc, or other media other physical structure device) for storing or transmitting information in a form readable by a machine.
In the drawings, some structural or methodological features may be shown in a particular arrangement and/or ordering. Preferably, however, such specific arrangement and/or ordering is not necessary. Rather, in some embodiments, such features may be arranged in a different manner and/or order than as shown in the drawings. Furthermore, inclusion of a feature in a particular figure that is not necessarily meant to imply that such feature is required in all embodiments and that, in some embodiments, may not be included or may be combined with other features.
The embodiment of the application can be applied to an optical fiber communication scene. The optical fiber communication converts the transmitted information (such as call signals) into electric signals at a transmitting end, then modulates the electric signals onto a laser beam emitted by a laser, changes the intensity of the optical signals along with the amplitude (frequency) change of the electric signals, and transmits the electric signals through an optical fiber; at the receiving end, the detector receives the optical signal and converts the optical signal into an electric signal, and the electric signal is demodulated to recover the original information.
The application field of optical fiber communication is relatively wide. For example, the optical fiber scenario may be used in the areas of local trunks, long-haul trunk communications, global communications networks, national public telecommunications networks, high quality color television transmissions, industrial production site monitoring and scheduling, traffic monitoring control command, town cable television networks, shared antennas, fiber optic local area networks, and the like.
The embodiment of the application can be applied to a wavelength division multiplexing (WDM, wavelength division multiplexing) system in an optical fiber communication scene. Wavelength division multiplexing combines optical signals of a plurality of different wavelengths together at a transmitting end through a Multiplexer (also called a Multiplexer) and is coupled to the same optical fiber of an optical line for transmission. At the receiving end, the optical signals of the multiple wavelengths are separated by a Demultiplexer (also called a Demultiplexer) and then further processed by an optical receiver to recover the original signal. This technique of transmitting two optical signals of different wavelengths simultaneously in the same optical fiber is called wavelength division multiplexing.
Optical amplifiers are one of the key devices in fiber optic communication systems. In order to solve the technical problem of realizing the gain flattening requirement in a narrower frequency range in the current optical amplifier, the embodiment of the application provides an optical amplifier, which specifically comprises:
wavelength selective switches (WSS, wavelength selectable switch); and
a gain unit connected to the wavelength selective switch;
the wavelength selective switch carries out attenuation treatment on the optical signals of the transmission channel according to the attenuation parameters corresponding to the transmission channel.
The wavelength selective switch has the characteristics of wide frequency band and low dispersion, supports independence of ports and wavelengths, and can realize attenuation of any wavelength or any wavelength combination at any port. And the attenuation parameter of the wavelength selective switch has dynamic adjustability.
According to the wavelength selective switch, according to the attenuation parameters corresponding to the transmission channels, the attenuation corresponding to the transmission channels is realized, the attenuation can be matched with the gain realized by the gain unit, and further the gain flattening requirement among different transmission channels is realized.
Because the embodiment of the application can support dynamic configuration of the attenuation parameters corresponding to the transmission channels, and different transmission channels can correspond to different wavelengths or frequencies, the embodiment of the application can realize the gain flattening requirement in a wide frequency range based on the dynamic configuration of the attenuation parameters corresponding to the transmission channels, namely the frequency range with flattened gain can be improved.
In addition, the wavelength selective switch and the gain unit are combined, so that the gain flattening requirement in a wide frequency range is realized. Since the requirements can be realized with fewer components and a simple structure, the cost of the optical amplifier can be reduced.
Example 1
The wavelength selective switch of the embodiment of the application specifically includes: at least one input port and at least one output port;
the gain unit specifically comprises at least one of the following gain units:
a first gain unit connected to at least a portion of the input ports; and
and a second gain unit connected to at least part of the output ports.
Referring to fig. 1, 2 and 3, schematic structural diagrams of an optical amplifier according to an embodiment of the present application are shown, respectively.
The optical amplifier in fig. 1 specifically includes: a first gain unit and a wavelength selective switch. The optical amplifier in fig. 2 includes in particular: a wavelength selective switch and a second gain unit. The optical amplifier in fig. 3 specifically includes: a first gain unit, a wavelength selective switch and a second gain unit.
In practical applications, the first gain unit or the second gain unit may be used to implement the gain amount. The corresponding components thereof may include: gain media, pumps, couplers, isolators, etc. Wherein the gain medium may include: erbium-doped optical fibers, ytterbium-doped optical fibers, or the like. It can be appreciated that the embodiments of the present application do not limit specific components corresponding to the first gain unit or the second gain unit.
The wavelength selection switch can be used for providing corresponding attenuation quantity according to corresponding attenuation parameters aiming at the transmission channel, and further can realize the gain flattening requirement based on the coordination of the attenuation quantity and the gain quantity.
In one embodiment of the present application, the working principle of the wavelength selective switch is: the free space optical stage based on the diffraction grating outputs light energy of a corresponding wavelength from a designated port partially (or entirely) by a selection mechanism by changing the angle or position of the optical path of the designated transmission channel. The corresponding technology of the selection mechanism specifically comprises the following steps: micromechanical System (MEMS) technology, liquid Crystal on silicon (LCoS, liquid Crystal on Silicon) and Liquid Crystal (LC) technology, etc.
In practical applications, the ports of the wavelength selective switch may be: n x M ports, wherein N, M may be a natural number. For example, a wavelength selective switch of 1*N may be employed and commonly used ports and sub-ports therein used.
In another embodiment of the present application, the wavelength selective switch may employ a programmable filter of 1*1. It can be appreciated that any structure capable of providing a corresponding attenuation amount for the transmission channel is within the protection scope of the structure of the wavelength selective switch according to the embodiment of the present application, and the specific structure of the wavelength selective switch is not limited in the embodiment of the present application.
In an optional embodiment of the present application, the optical amplifier may further include: the storage unit is used for storing the mapping relation between the environment parameters and the attenuation parameters; the environmental parameters specifically include: and a transmission channel.
The storage unit may be disposed inside or outside the wavelength selective switch, and configured to store the mapping relationship, and then the wavelength selective switch may determine, according to the actual environment parameter and the mapping relationship, a target attenuation parameter corresponding to the actual environment parameter, so as to use the target attenuation parameter in the actual environment.
For example, the environmental parameters include: the transmission channel may then use the corresponding attenuation parameters for the particular transmission channel.
As another example, the above environmental parameters may further include: temperature parameters and/or gain parameters.
Some components of the wavelength selective switch are sensitive to temperature changes, so that the embodiment of the application can provide different attenuation parameters for different temperature parameters.
The gain parameter may characterize an amount of gain realized by the optical amplifier, e.g., an amount of gain realized by the first gain element and/or the second gain element. To achieve gain flattening requirements, different attenuation parameters may be provided for different gain parameters.
In an alternative embodiment of the present application, the mapping relationship described above may be determined in a scaled manner. Scaling may be used to determine the criteria of the wavelength selective switch to improve its accuracy. Alternatively, the voltage or power values may be scaled according to the dimensions of the environmental parameters, the port and the decay parameters.
For example, the corresponding voltage values may be calibrated for a particular wavelength switch to a particular port and a particular attenuation parameter. In the embodiment of the present application, the optical signal with the specific wavelength is transmitted in the specific transmission channel, so that the wavelength and the transmission channel have a corresponding relationship. Thus, the scaling for wavelengths of embodiments of the present application may be equivalent to the scaling for transmission channels. In addition, the wavelength is inversely proportional to the frequency, and thus, different wavelengths may have corresponding frequency ranges.
In the embodiment of the present application, the scaling principle may be: the gain flatness between different transmission channels meets preset conditions.
Gain flatness may refer to the values of "sharp increase" and "rapid decrease" in gain over a frequency range, measured in decibels (dB). The preset conditions may be: the deviation between the upper limit and the lower limit of the gain flatness between different transmission channels is smaller than a preset deviation, for example, the preset deviation may be 0-6 dB, etc., it is understood that the embodiment of the present application does not limit the specific preset deviation.
In summary, the embodiment of the application can perform calibration under the condition of environmental parameters to obtain attenuation parameters corresponding to a plurality of environmental parameters, and store the mapping relation between the environmental parameters and the attenuation parameters. Therefore, the requirement of realizing gain flatness for different environmental parameters can be satisfied.
In an optional embodiment of the present application, the optical amplifier may further include: and the processing unit is used for determining the attenuation parameters corresponding to the transmission channels according to the slope parameters set by the user for the transmission channels. The embodiment of the application can support the transmission channel focused by a user, set the corresponding slope parameter, convert the slope parameter into the corresponding attenuation parameter and apply the corresponding attenuation parameter to the processing process of the optical signal.
The processing unit of the embodiments of the present application may be disposed inside or outside the wavelength selective switch, and may communicate with the wavelength selective switch to provide real-time or static attenuation parameters to the wavelength selective switch. The processing units may be implemented based on a single chip microcomputer or digital signal processing (DSP, digital Signal Processing) technology, and it is to be understood that the embodiments of the present application are not limited to specific implementation forms of the processing units.
The slope parameter may be used to characterize a linear parameter in a corresponding linear relationship between the input and output of the optical amplifier.
Alternatively, the slope parameter may be converted into a corresponding attenuation parameter according to the attenuation parameter corresponding to the start point, the end point and the middle point of the frequency range, respectively, and the linear relationship. Assuming that the slope parameter is between [ -a, a ], the attenuation parameter corresponding to the start point is-a, the attenuation parameter corresponding to the midpoint is 0, the attenuation parameter corresponding to the end point is a, etc. The frequency range may correspond to the entire frequency band of the optical fiber communication system, or may correspond to a part of the frequency band of the optical fiber communication system.
In one embodiment of the present application, assuming that the slope parameter is T, the unit of the attenuation parameter is dB, and the frequency range of the optical amplifier is [ LowFreq, highFreq ], the attenuation parameter atttlit corresponding to the transmission channel with frequency of frequency may be determined according to the frequency, the slope parameter, and the frequency range corresponding to the transmission channel.
Alternatively, a first difference between frequency and the mean of the frequency range may be determined first; determining half of the difference between HighFreq and LowFreq as a second difference; determining a ratio of the first difference to the second difference, and determining a product of the ratio and T/2; and fusing the opposite number of the product with T/2 to obtain an attenuation parameter AttTilt.
In summary, the embodiment of the application can meet the requirements of users on the concerned transmission channel and the realization of gain flatness.
In an optional embodiment of the present application, the optical amplifier may further include: and the processing unit is used for determining the attenuation parameters corresponding to the transmission channels according to the mapping relation between the environment parameters and the attenuation parameters obtained through calibration and the slope parameters set by the user for the transmission channels.
In this embodiment of the present application, assuming that an attenuation parameter obtained according to scaling is a first attenuation parameter and an attenuation parameter obtained according to a slope parameter set by a user is a second attenuation parameter, the first attenuation parameter and the second attenuation parameter may be fused, and the first fusion parameter obtained by fusion may be used for transmission of an optical signal.
In summary, according to the optical amplifier of the embodiment of the present application, the wavelength selective switch implements the attenuation amount corresponding to the transmission channel according to the attenuation parameter corresponding to the transmission channel, where the attenuation amount can be matched with the gain amount implemented by the first gain unit and/or the second gain unit, so as to implement the gain flattening requirement between different transmission channels.
Because the embodiment of the application can support dynamic configuration of the attenuation parameters corresponding to the transmission channels, and different transmission channels can correspond to different wavelengths or frequencies, the embodiment of the application can realize the gain flattening requirement in a wide frequency range based on the dynamic configuration of the attenuation parameters corresponding to the transmission channels, namely the frequency range with flattened gain can be improved.
In addition, the wavelength selective switch is combined with the first gain unit and/or the second gain unit, so that the gain flattening requirement in a wide frequency range is realized. Since the requirements can be realized with fewer components and a simple structure, the cost of the optical amplifier can be reduced.
Example two
With respect to the first embodiment, the optical amplifier of the present embodiment may further include:
an optical channel monitoring unit (OCM, optical channel monitor) connected between the input port and the output port of the optical amplifier, for monitoring the performance parameter corresponding to the transmission channel;
and the processing unit is used for determining attenuation parameters corresponding to the transmission channels according to the performance parameters.
The OCM of the embodiments of the present application may be two independent devices, or may be a combination of one device and one 1*2 optical switch; the purpose of monitoring the performance parameters of the transmission channel of the optical amplifier can be achieved through polling.
The performance parameters can reflect the actual performance of the optical amplifier, and the embodiment of the application can update the attenuation parameters corresponding to the wavelength selective switch according to the difference between the performance parameters and the set performance parameters and apply the updated attenuation parameters to the processing process of the optical signals, so that the performance parameters can be matched with the set performance parameters, and further the optical amplifier can realize the performance corresponding to the set performance parameters.
Referring to fig. 4, a schematic structural diagram of an optical amplifier according to an embodiment of the present application is shown, where an OCM is added on the basis of fig. 1. Referring to fig. 5, a schematic diagram of an optical amplifier according to an embodiment of the present application is shown, where OCM is added on the basis of fig. 2. Referring to fig. 6, a schematic diagram of an optical amplifier according to an embodiment of the present application is shown, where OCM is added on the basis of fig. 3.
The processing unit is not shown in fig. 4 to 6, and may be provided as a unit of an optical amplifier in practice, or may be provided inside the wavelength selection unit or the OCM. And, the processing unit may communicate with the OCM, e.g., the OCM sends the monitored performance parameter to the processing unit to cause the processing unit to derive the attenuation parameter based on the performance parameter.
The optical amplifiers shown in fig. 4 to 6 can utilize the performance parameters to perform negative feedback adjustment on the attenuation parameters corresponding to the wavelength selective switch, so that the performance parameters conform to the set performance parameters, and meanwhile, the requirements of gain flatness can be met.
According to one embodiment, the performance parameters specifically include: the actual gain parameters of the transmission channel; the processing unit is configured to determine an attenuation parameter corresponding to the transmission channel according to deviation information between the actual gain parameter and the set gain parameter. According to the embodiment of the application, the actual gain parameter can be enabled to accord with the set gain parameter set by the user, and meanwhile the requirement of gain flatness can be met.
According to another embodiment, the performance parameters specifically include: the actual power parameters of the transmission channel; the processing unit is configured to determine an attenuation parameter corresponding to the transmission channel according to deviation information between the actual power parameter and the set power parameter. According to the embodiment of the application, the actual power parameter can be enabled to meet the set power parameter set by a user, and meanwhile the requirement of gain flatness can be met.
In this embodiment of the present application, the OCM may first determine a transmission channel or frequency corresponding to the optical signal, and then determine a performance parameter corresponding to the optical signal according to the transmission channel or frequency corresponding to the optical signal.
In practical application, a channel recognition algorithm built in the OCM can be utilized to determine a transmission channel or frequency corresponding to the optical signal. Alternatively, the transmission channel or frequency corresponding to the optical signal may be determined according to the configuration of the user, for example, the transmission channel or frequency corresponding to the optical signal may be determined according to the transmission channel corresponding to the port.
In this embodiment of the present application, optionally, the OCM may monitor the corresponding performance parameter for a set transmission channel or a set frequency set by a user. If the frequencies corresponding to the optical signals or the set frequencies are not matched, the corresponding performance parameters may not be monitored. In this way, a customisation of the performance parameter tuning of the transmission channel or frequency can be achieved.
In the embodiment of the application, it is assumed that an attenuation parameter obtained according to calibration is a first attenuation parameter, an attenuation parameter obtained according to a slope parameter set by a user is a second attenuation parameter, and an attenuation parameter obtained according to frequency monitoring feedback set by the user is a third attenuation parameter; any one of the first, second and third attenuation parameters may be used or at least two of the first, second and third attenuation parameters may be used in combination.
For example, the first attenuation parameter, the second attenuation parameter, and the third attenuation parameter may be fused, and the fused second fusion parameter may be used for transmission of the optical signal.
Referring to fig. 7, a schematic representation of a mapping relationship between attenuation and frequency is shown in an embodiment of the present application, wherein the horizontal axis represents frequency and the vertical axis represents attenuation.
The first region 701 characterizes a region corresponding to the first attenuation parameter, which may correspond to a gain of 6dB, for achieving gain flattening requirements at different frequencies in the range of 6 dB.
The second region 702 characterizes a region corresponding to the second attenuation parameter, which may correspond to a gain of 3dB for achieving a slope of the gain in the range of 3 dB. It is understood that the second region 702 corresponds to the entire frequency range as an alternative embodiment only, and may actually correspond to a portion of the frequency range.
The third region 703 characterizes a region corresponding to a third attenuation parameter, which may correspond to a gain of 6 dB. The third area 703 may be opened to the user to allow the user to adjust the performance parameters corresponding to the transmission channel of interest. For example, a user may set a set power or a set gain corresponding to a certain frequency, and in this embodiment of the present application, the attenuation parameter may be updated according to the set power or the set gain, so that the actual power of the optical amplifier matches with the set power.
Example III
In contrast to the first embodiment, the second gain unit of this embodiment specifically includes: at least two second gain units;
the optical amplifier may further include:
and the optical switch is connected between the output ends of the at least two second gain units and the output port of the optical amplifier.
According to the embodiment of the application, the at least two second gain units can correspond to different gain amounts, the output of the at least two second gain units is connected with the output port of the optical amplifier through the optical switch, and the requirements of different users on the different gain amounts can be met.
And, the embodiment of the application cooperates the wavelength selective switch with at least two second gain units to provide different gain amounts. This can reduce the processing cost of the optical signal relative to a plurality of optical amplifiers using different amounts of gain.
By applying the embodiment of the application, under the condition that the gain amount is required to be switched, the input signal of the wavelength selective switch can be switched to the target gain unit, and the optical switch is connected with the target gain unit.
Referring to fig. 8, a schematic structural diagram of an optical amplifier according to an embodiment of the present application is shown, where on the basis of fig. 1, the second gain unit specifically includes: a second gain unit a and a second gain unit B. And an optical switch is additionally arranged and is connected between the output ends of the second gain unit A and the second gain unit B and the output port of the optical amplifier so as to switch the gain amounts corresponding to the second gain unit A and the second gain unit B.
Example IV
With respect to the first embodiment, the optical amplifier of the present embodiment may further include:
a noise generating unit connected to at least part of the input ports;
the second input port corresponding to the noise generating unit corresponds to the first input port corresponding to the optical signal and different transmission channels.
The noise generation unit may be configured to generate noise corresponding to the second transmission channel and the optical signal corresponding to the first transmission channel. The first transmission channel is complementary with the second transmission channel, so that the stability of optical signal transmission can be improved.
In practical applications, the noise generating unit is a source of spontaneous emission noise (ASE, amplifier spontaneous emission).
ASE and optical signals respectively enter sub-ports of the wavelength selective switch, and the combined signals are output from a common port of the wavelength selective switch. The ASE source may be built in the optical amplifier, or may be externally input to a port reserved in an equipment panel of the optical amplifier.
To avoid the influence of ASE on the optical signal, different transmission channels may be configured for the first input port and the second input port. For example, channel sets {1,2,3} are configured for the first input port, channel sets {4,5,6} are configured for the second input port, and so on. Since the transmission channels corresponding to the noise are generated from the inside of the optical amplifier, the user only declares the power of the noise, and then the attenuation parameters are adjusted by the OCM negative feedback to the wavelength selective switch. The OCM may filter out the performance parameters of the noise from the monitored performance parameters of the output to filter out the effects of the noise.
Referring to fig. 9, a schematic structural diagram of an optical amplifier according to an embodiment of the present application is shown, where ASE is added on the basis of fig. 1, and the ASE may be connected to an input port of a wavelength selective switch.
Referring to fig. 10, a schematic diagram of an optical amplifier according to an embodiment of the present application is shown, where ASE is added to the optical amplifier of fig. 2, and the ASE may be connected to an input port of a wavelength selective switch.
Referring to fig. 11, a schematic structural diagram of an optical amplifier according to an embodiment of the present application is shown, where ASE is added on the basis of fig. 3, and the ASE may be connected to an input port of a wavelength selective switch.
It will be appreciated that the embodiments of the present application may be used in combination with the first to fourth embodiments, for example, ASE may be increased on the basis of the second embodiment, or the second embodiment may be combined with the third embodiment, or the like.
In summary, the optical amplifier of the embodiment of the present application, in which the wavelength selective switch is embedded in the optical amplifier, can achieve gain flatness and more ideal gain slope in a larger frequency range by adjusting the attenuation parameter of the wavelength selective switch.
In addition, the embodiment of the application can support the user to set the corresponding set power or set gain for the concerned transmission channel, and the embodiment of the application can update the attenuation parameter according to the set power or set gain so as to enable the actual power of the optical amplifier to be matched with the set power, thereby realizing the function of locking the power.
In addition, ASE is introduced into the optical amplifier, and the corresponding transmission channel can be occupied by self-made noise, so that the stability of transmission can be improved.
The embodiment of the application also provides an optical transmission system, which may include: the aforementioned optical amplifier.
In one embodiment of the present application, an optical transmission system may include: optical transmitter, optical fiber transmission line, and optical amplifier.
The optical transmitter outputs an optical signal within a preset frequency range. The wavelength interval of the optical signal output from the optical transmitter may be 10nm (nanometers) or more. The optical signal may be modulated. Specifically, these optical signals may be directly modulated, or may be externally modulated by an external modulator.
The optical fiber transmission line transmits the multiplexed signal output from the optical transmitter 110 to the optical amplifier. The optical fiber transmission line may include, but is not limited to: single mode fiber (SMF, single-Mode OpticalFiber); a Non-zero dispersion shifted fiber (NZDSF, non-Zero Dispersion Shifted Optical Fiber); dispersion shifted fiber (DSF: dispersion Shifted OpticalFiber); pure silica core optical fibers, and the like.
The optical amplifier receives the optical signal transmitted from the optical fiber transmission line 120, amplifies the optical signal, and can meet the requirement of gain flattening.
Method embodiment
Referring to fig. 12, a flowchart illustrating steps of a first embodiment of a method for processing an optical signal according to the present application may specifically include the following steps:
1202, controlling a wavelength selective switch in an optical amplifier, and performing attenuation processing on the optical signal of the transmission channel according to the attenuation parameter;
wherein, the optical amplifier may further comprise: and a gain unit connected with the wavelength selective switch.
Optionally, the wavelength selective switch specifically includes: at least one input port and at least one output port;
the gain unit may specifically include:
a first gain unit connected to at least part of the input ports, and/or
And a second gain unit connected to at least part of the output ports.
According to the embodiment of the application, the wavelength selection switch in the optical amplifier can be controlled according to the attenuation parameters, and the optical signals of the transmission channels are attenuated according to the attenuation parameters so as to realize dynamic adjustment of the attenuation parameters.
In practical applications, the processing unit may determine an attenuation parameter corresponding to the transmission channel, and send the attenuation parameter to the wavelength selective switch, so that the wavelength selective switch works according to the attenuation parameter.
According to one embodiment, the determining the attenuation parameter corresponding to the transmission channel specifically includes: reading a mapping relation between the environment parameter and the attenuation parameter from a storage unit of the optical amplifier, and determining the attenuation parameter corresponding to the transmission channel according to the mapping relation; the above environmental parameters include: and a transmission channel.
Optionally, the above environmental parameters further include: temperature parameters and/or gain parameters.
According to another embodiment, the determining the attenuation parameter corresponding to the transmission channel specifically includes: and determining attenuation parameters corresponding to the transmission channels according to slope parameters set by a user for the transmission channels.
According to still another embodiment, the determining the attenuation parameter corresponding to the transmission channel specifically includes: and determining the attenuation parameters corresponding to the transmission channels according to the mapping relation between the environment parameters and the attenuation parameters obtained through calibration and the slope parameters set by the user for the transmission channels.
According to yet another embodiment, the optical amplifier may further include:
the optical channel monitoring unit is connected between the input port and the output port of the optical amplifier and is used for monitoring the corresponding performance parameters of the transmission channel;
The determining the attenuation parameter corresponding to the transmission channel may specifically include: and determining attenuation parameters corresponding to the transmission channels according to the performance parameters.
For example, the performance parameters described above include: the actual gain parameters of the transmission channel; determining attenuation parameters corresponding to the transmission channel according to the performance parameters specifically includes: and determining attenuation parameters corresponding to the transmission channels according to deviation information between the actual gain parameters and the set gain parameters.
As another example, the performance parameters described above include: the actual power parameters of the transmission channel; determining attenuation parameters corresponding to the transmission channel according to the performance parameters specifically includes: and determining attenuation parameters corresponding to the transmission channels according to the deviation information between the actual power parameters and the set power parameters.
In an optional embodiment of the present application, the second gain unit includes: at least two second gain units;
the optical amplifier may further include: an optical switch connected between the output ends of the at least two second gain units and the output port of the optical amplifier;
the method may further include: and determining a target gain unit from the at least two second gain units, and controlling the optical switch to be connected with the target gain unit. For example, the target gain unit may be determined in accordance with a user instruction.
Optionally, the method may further include: and updating attenuation parameters corresponding to the transmission channels according to the target gain unit, controlling a wavelength selection switch in the optical amplifier, and carrying out attenuation processing on the optical signals of the transmission channels according to the updated attenuation parameters.
In case the target gain unit to which the optical switch is connected is changed, the gain amount of the optical amplifier will be changed. Because different gain amounts can correspond to different attenuations, the embodiment of the application can update the attenuation parameters corresponding to the transmission channel according to the mapping relation between the environment parameters and the attenuation parameters, and the updated attenuation parameters are used in the processing process of the optical signals.
In another alternative embodiment of the present application, the optical amplifier may further include: a noise generating unit connected to at least part of the input ports; the input port corresponding to the noise generating unit corresponds to different transmission channels with the input port corresponding to the optical signal.
In summary, the optical signal processing method according to the embodiment of the present application may control the wavelength selection switch to work according to the dynamic attenuation parameter during the optical signal processing process, so as to achieve the gain flattening requirement in a larger frequency range.
Referring to fig. 13, a flowchart illustrating steps of a second embodiment of a method for processing an optical signal according to the present application may specifically include the following steps:
The embodiment of the application can be applied to an optical amplifier with an input port connected with a first gain unit of a wavelength selective switch, wherein the first gain unit performs first gain processing on an optical signal, and the wavelength selective switch performs attenuation processing on the first optical signal after the first gain processing according to attenuation parameters corresponding to a transmission channel. Wherein the attenuation parameters may be dynamically adjustable, thus enabling a gain flattening requirement over a larger frequency range.
Referring to fig. 14, a flowchart illustrating steps of a third embodiment of a method for processing an optical signal according to the present application may specifically include the following steps:
The embodiment of the application can be applied to an optical amplifier with an output port connected with a second gain unit of a wavelength selective switch, wherein the wavelength selective switch carries out attenuation processing on an optical signal according to attenuation parameters corresponding to a transmission channel, and the second gain unit carries out second gain processing on the second optical signal after the attenuation processing. Wherein the attenuation parameters may be dynamically adjustable, thus enabling a gain flattening requirement over a larger frequency range.
In other embodiments of the present application, the first gain unit performs a first gain process on the optical signal, the wavelength selective switch performs an attenuation process on the first optical signal after the first gain process according to an attenuation parameter corresponding to the transmission channel, and the second gain unit performs a second gain process on the second optical signal after the attenuation process, so as to obtain and output a third optical signal.
It should be noted that, for simplicity of description, the method embodiments are shown as a series of acts, but it should be understood by those skilled in the art that the embodiments are not limited by the order of acts described, as some steps may occur in other orders or concurrently in accordance with the embodiments. Further, those skilled in the art will appreciate that the embodiments described in the specification are all preferred embodiments and that the acts referred to are not necessarily required by the embodiments of the present application.
In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.
Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable object recognition device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable processing 13 apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present embodiments have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the present application.
Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The foregoing has described in detail an optical amplifier, an optical transmission system, and a method for processing an optical signal, to which specific examples are applied to illustrate the principles and embodiments of the present application, the above examples being provided only to assist in understanding the method and core idea of the present application; meanwhile, as those skilled in the art will have modifications in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.
Claims (22)
1. An optical amplifier, comprising:
a wavelength selective switch; and
a gain unit connected to the wavelength selective switch;
the wavelength selection switch carries out attenuation treatment on the optical signals of the transmission channel according to attenuation parameters corresponding to the transmission channel;
the optical amplifier further includes:
a noise generating unit connected to at least part of the input ports;
the input port corresponding to the noise generating unit corresponds to different transmission channels with the input port corresponding to the optical signal.
2. The optical amplifier of claim 1, wherein the optical amplifier further comprises:
the storage unit is used for storing the mapping relation between the environment parameters and the attenuation parameters; the environmental parameters include: and a transmission channel.
3. The optical amplifier of claim 2, wherein the environmental parameters further comprise: temperature parameters and/or gain parameters.
4. The optical amplifier of claim 1, wherein the optical amplifier further comprises:
and the processing unit is used for determining attenuation parameters corresponding to the transmission channel according to slope parameters set by a user for the transmission channel.
5. The optical amplifier of claim 1, wherein the optical amplifier further comprises:
And the processing unit is used for determining the attenuation parameters corresponding to the transmission channel according to the mapping relation between the environment parameters and the attenuation parameters obtained through calibration and the slope parameters set by the user for the transmission channel.
6. The optical amplifier of claim 1, wherein the optical amplifier further comprises:
the optical channel monitoring unit is connected between the input port and the output port of the optical amplifier and is used for monitoring the corresponding performance parameters of the transmission channel;
and the processing unit is used for determining attenuation parameters corresponding to the transmission channels according to the performance parameters.
7. The optical amplifier of claim 6, wherein the performance parameters comprise: the actual gain parameter of the transmission channel;
the processing unit is configured to determine an attenuation parameter corresponding to the transmission channel according to deviation information between the actual gain parameter and the set gain parameter.
8. The optical amplifier of claim 6, wherein the performance parameters comprise: the actual power parameter of the transmission channel;
the processing unit is configured to determine an attenuation parameter corresponding to the transmission channel according to deviation information between the actual power parameter and the set power parameter.
9. An optical amplifier according to any one of claims 1 to 8, wherein the wavelength selective switch comprises: at least one input port and at least one output port;
the gain unit includes at least one of the following gain units:
a first gain unit connected to at least a portion of the input ports; and
and a second gain unit connected to at least part of the output ports.
10. The optical amplifier of claim 9, wherein the second gain unit comprises: at least two second gain units;
the optical amplifier further includes:
and the optical switch is connected between the output ends of the at least two second gain units and the output port of the optical amplifier.
11. An optical transmission system, comprising: the optical amplifier of any one of claims 1 to 10.
12. A method of processing an optical signal, the method comprising:
determining attenuation parameters corresponding to the transmission channels;
controlling a wavelength selection switch in the optical amplifier, and carrying out attenuation treatment on the optical signal of the transmission channel according to the attenuation parameter;
the optical amplifier further includes: a gain unit connected to the wavelength selective switch;
The optical amplifier further includes: a noise generating unit connected to at least part of the input ports;
the input port corresponding to the noise generating unit corresponds to different transmission channels with the input port corresponding to the optical signal.
13. The processing method according to claim 12, wherein determining the attenuation parameter corresponding to the transmission channel comprises:
reading a mapping relation between the environment parameter and the attenuation parameter from a storage unit of the optical amplifier, and determining the attenuation parameter corresponding to the transmission channel according to the mapping relation; the environmental parameters include: and a transmission channel.
14. The method of claim 13, wherein the environmental parameters further comprise: temperature parameters and/or gain parameters.
15. The method of claim 12, wherein determining the attenuation parameter corresponding to the transmission channel comprises:
and determining attenuation parameters corresponding to the transmission channel according to slope parameters set by a user for the transmission channel.
16. The method of claim 12, wherein determining the attenuation parameter corresponding to the transmission channel comprises:
and determining the attenuation parameters corresponding to the transmission channel according to the mapping relation between the environment parameters and the attenuation parameters obtained through calibration and the slope parameters set by a user for the transmission channel.
17. The method of claim 12, wherein the optical amplifier further comprises:
the optical channel monitoring unit is connected between the input port and the output port of the optical amplifier and is used for monitoring the corresponding performance parameters of the transmission channel;
the determining the attenuation parameter corresponding to the transmission channel comprises the following steps:
and determining attenuation parameters corresponding to the transmission channels according to the performance parameters.
18. The method of claim 17, wherein the performance parameters comprise: the actual gain parameter of the transmission channel;
determining the attenuation parameter corresponding to the transmission channel according to the performance parameter includes:
and determining attenuation parameters corresponding to the transmission channels according to deviation information between the actual gain parameters and the set gain parameters.
19. The method of claim 17, wherein the performance parameters comprise: the actual power parameter of the transmission channel;
determining the attenuation parameter corresponding to the transmission channel according to the performance parameter includes:
and determining attenuation parameters corresponding to the transmission channels according to deviation information between the actual power parameters and the set power parameters.
20. The method according to any one of claims 12 to 19, wherein the wavelength selective switch comprises: at least one input port and at least one output port;
the gain unit includes at least one of the following gain units:
a first gain unit connected to at least a portion of the input ports; and
and a second gain unit connected to at least part of the output ports.
21. The method of claim 20, wherein the second gain unit comprises: at least two second gain units;
the optical amplifier further includes: the optical switch is connected between the output ends of the at least two second gain units and the output port of the optical amplifier;
the method further comprises the steps of:
and determining a target gain unit from the at least two second gain units, and controlling the optical switch to be connected with the target gain unit.
22. The method of claim 21, wherein the method further comprises:
updating attenuation parameters corresponding to the transmission channel according to the target gain unit, controlling a wavelength selection switch in the optical amplifier, and carrying out attenuation processing on the optical signal of the transmission channel according to the updated attenuation parameters.
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| EP1280288A1 (en) * | 2001-07-27 | 2003-01-29 | Alcatel | Method and system for automatic gain equalization in an optical transmission system using WDM technique |
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