CN111865427B - Wavelength alignment method, device, transmitter and optical network system - Google Patents
Wavelength alignment method, device, transmitter and optical network system Download PDFInfo
- Publication number
- CN111865427B CN111865427B CN202010702013.9A CN202010702013A CN111865427B CN 111865427 B CN111865427 B CN 111865427B CN 202010702013 A CN202010702013 A CN 202010702013A CN 111865427 B CN111865427 B CN 111865427B
- Authority
- CN
- China
- Prior art keywords
- laser
- filter
- output
- locking
- optical power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
- H04B10/50—Transmitters
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
-
- 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
- H04B10/40—Transceivers
-
- 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
- H04B10/50—Transmitters
- H04B10/564—Power control
-
- 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
- H04B10/50—Transmitters
- H04B10/572—Wavelength control
Abstract
The embodiment of the application provides a method and a device for wavelength alignment, which are applied to a chirp management laser comprising a laser and a filter, wherein the method comprises the following steps: determining a locking initial value according to the magnitude and the linearity of the output optical power of the filter, wherein the locking initial value is used for representing a target ratio of the optical power output by the filter to the optical power output by the laser; and determining and adjusting the temperature of the laser according to the initial locking value so as to realize the wavelength alignment of the laser and the filter. Some embodiments of the present application provide an embodiment for determining a locking initial value, and compared with the related art, the embodiment of the present application may determine the locking initial value of a chirp management laser without using a test system such as an eye-pattern analyzer, and when the temperature of the laser is adjusted according to the locking initial value, the output optical power of 1bits and 0bits signals output by the laser is ensured, thereby improving the automatic locking process of the chirp management laser.
Description
Technical Field
The present application relates to the field of optical communications, and in particular, to a wavelength alignment method, apparatus, transmitter, and optical network system.
Background
An existing Direct Modulated Laser (DML) cannot perform long-distance transmission due to Chirp influence, and a Chirp Management Laser (CML) is added with an Optical Spectrum modulator (OSR) on the basis of the DML, and the OSR filters a Spectrum output by the DML to filter a part of Chirp effects, where the filtered Chirp effects mainly refer to adiabatic Chirp generated when the DML modulates a bit signal and a zero bit signal respectively, and outputs different Optical wavelengths respectively, and the spectral shaper filters the zero bit signal to remove the adiabatic Chirp and improve an extinction ratio.
However, since the magnitude of the adiabatic chirp is influenced by the input bias current and the driving modulation current of the directly modulated laser, different adiabatic chirps are generated, so that the output effect of the chirp management laser is directly influenced by adjusting the corresponding relationship between the laser spectrum and the filtering spectrum of the spectrum shaping element, that is, the spectrum of zero bits is filtered as much as possible, and the spectrum of one bit is reserved, so that the chirp management laser achieves the optimal output performance.
Therefore, how to improve the alignment effect of the filter and directly adjust the laser to retain the optical power of the one-bit signal output by the laser and filter the zero-bit signal output by the laser as much as possible is a technical problem to be solved urgently.
Disclosure of Invention
Some embodiments of the present application may complete initialization calibration of a directly modulated laser without an additional test system (e.g., an eye pattern analyzer, etc.), and other embodiments of the present application may lock output optical powers of 0bits and 1bit in a temperature adjustment change process, so that a locking effect of a chirp management laser CML may achieve a better state.
In a first aspect, some embodiments of the present application provide a method of wavelength alignment for a chirp management laser including a laser and a filter, the method comprising: determining a locking initial value according to the magnitude and the linearity of the output optical power of the filter, wherein the locking initial value is used for representing a target ratio of the optical power output by the filter to the optical power output by the laser; and determining and adjusting the temperature of the laser according to the initial locking value so as to realize the wavelength alignment of the laser and the filter.
Some embodiments of the present application provide an embodiment for determining an initial locking value, and compared with the related art, the embodiment of the present application may determine the initial locking value of the chirp management laser without using a test system such as an eye-pattern analyzer, thereby improving an automatic locking process of the chirp management laser and improving an alignment effect of the laser and a filter.
In some embodiments, the initial lock value comprises a point on an alignment interval, wherein the alignment interval is on a low frequency side of a point where the filter outputs a maximum optical power.
Some embodiments of the present application set the initial locking value of the chirp management laser in the linear region on the left of the maximum output optical power point of the filter, that is, some embodiments of the present application provide a method for determining the range of the initial locking value according to the purpose of shaping the output optical signal of the laser by the filter, thereby improving the accuracy and the reasonableness of obtaining the initial locking value.
In some embodiments, the alignment region is a linear region.
Some embodiments of the present application determine a locking initial value in a linear region of optical power output by the optical wave shaping unit, so as to improve a filtering effect of a filter (or called as an optical wave shaping unit) on a zero-bit signal, improve a retaining effect on a one-bit signal, and further improve a shaping purpose of the filter.
In some embodiments, the determining a locking initial value according to the magnitude and linearity of the output optical power of the filter includes: adjusting the output frequency of the laser, and recording the output optical power of the filter corresponding to the frequency; obtaining output optical power values of the filter at a plurality of the frequencies; determining the linearity of the output light power value of the filter at a low-frequency side position of the maximum value of the output light power of the filter; and acquiring the ratio of the output light power of the laser to the output light power of the filter as an initial locking value according to the linearity.
In some embodiments of the present application, the output optical power of the OSR at multiple frequencies can be scanned to fix the correspondence between the laser spectrum and the spectrum shaping device filtering spectrum without passing through the test system, i.e. to fix the ratio of the first detection amount obtained by splitting the output of the laser and the second detection amount obtained by splitting the reflected or transmitted light of the OSR.
In some embodiments, the obtaining, according to the linearity, a ratio of output optical power of the laser to output optical power of the filter as an initial locking value includes: and obtaining the initial locking value when the linearity is determined to meet a judgment condition.
Some embodiments of the present application control the laser to continue to shift left after obtaining the maximum output optical power of the optical spectrum shaping device OSR, so that the output optical power of the OSR enters a linear region of change, and the linear region is the optimal alignment region of the laser and the OSR. And selecting a point in the optimal alignment interval, recording the ratio of the laser power and the OSR output power at the moment, and taking the ratio as an automatic locking target of the CML, so that the initial locking value of the chirp management laser can be obtained under the condition that a test system such as an eye pattern instrument is not needed.
In some embodiments, said determining to adjust the temperature of said laser according to said initial lock value to achieve wavelength alignment of said laser and said filter comprises: and locking the output optical power of the zero bit signal and the one bit signal output by the laser under the adjusted first temperature condition so as to realize the wavelength alignment of the laser and the filter.
Some embodiments of the application realize the alignment of the output spectrum of the laser and the filtering spectrum shape of the OSR by only adjusting the temperature of the laser, and simultaneously lock the output optical power of 0bits and 1bit under different temperature conditions, so that the locking effect of the CML reaches a better state.
In some embodiments, the output optical powers of the zero and one bit signals are locked by locking the output optical power and the extinction ratio of the laser.
Some embodiments of the present application may employ the output optical power and the extinction ratio of a locked laser in order to achieve locking of the output optical powers of 0bits and 1bits under different temperature conditions.
In some embodiments, said locking the output optical power of said zero and one bit signals by locking the output optical power and the extinction ratio of said laser comprises: locking the average power of the laser to a target power by power control; and adjusting the driving current of the laser to control the extinction ratio to be kept unchanged.
In some embodiments, the drive current of the laser is adjusted by a temperature fit curve or a look-up table.
In a second aspect, some embodiments of the present application provide a wavelength alignment device, the device comprising: a laser backlight detection unit configured to detect an output optical power of the laser; a filter backlight detection unit configured to detect an output optical power of the filter; the control unit is configured to determine a locking initial value according to the output optical power of the filter and linearity, store the locking initial value, determine to adjust the temperature of the laser according to the locking initial value when the temperature changes, and lock the output optical powers of a zero bit signal and a one bit signal output by the laser in the temperature adjustment process, wherein the locking initial value comprises a target ratio of the optical powers of the filter and the laser; a temperature adjustment unit configured to adjust the laser die temperature.
In a third aspect, some embodiments of the present application provide a transmitter comprising a directly modulated laser, a filter, and the wavelength alignment device of the second aspect.
In a fourth aspect, some embodiments of the present application provide a transceiver comprising a directly modulated laser, a filter, a detector, and the wavelength alignment device of the second aspect.
In a fifth aspect, some of the facts of the present application provide an optical network system, which includes an optical line terminal and an optical network unit, where the optical line terminal and/or the optical network unit includes at least the transmitter of the third aspect.
In a sixth aspect, some embodiments of the present application provide an optical network system, which includes an optical line terminal and an optical network unit, wherein the optical line terminal and/or the optical network unit at least includes the transceiver of the fourth aspect.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
Fig. 1 is a flowchart of a method for wavelength alignment according to an embodiment of the present disclosure;
fig. 2 is a first state in the process of searching for the initial locking value for adjusting the laser frequency according to the embodiment of the present application;
fig. 3 is a second state in the process of searching for the initial locking value for adjusting the laser frequency according to the embodiment of the present application;
fig. 4 is a third state in the process of searching for the initial locking value for adjusting the laser frequency according to the embodiment of the present application;
fig. 5 is a block diagram of a first apparatus for chirp management of a laser according to an embodiment of the present disclosure;
fig. 6 is a block diagram illustrating a second apparatus for chirp management of a laser according to an embodiment of the present disclosure;
FIG. 7 is a schematic diagram of the relationship between the laser driving current and the output optical power of the laser according to the embodiment of the present application;
FIG. 8 is a diagram illustrating a process for locking a chirp management laser according to an initial value of a lock according to an embodiment of the present disclosure;
fig. 9 is a block diagram of a transceiver according to an embodiment of the present disclosure;
fig. 10 is a first block diagram of an optical network system according to an embodiment of the present application;
fig. 11 is a block diagram of a second optical network system according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.
CML: chirp management laser
OSR: filters or so-called spectral shaping units
The problems associated with the related alignment techniques are discussed below in conjunction.
There are automatic closed-loop control and open-loop control for the wavelength locking method in chirp managed lasers.
The open-loop control method controls the temperature of the laser and the OSR of the filter respectively, determines whether the optimal point is modulated (namely, determines the initial locking value) by testing the eye pattern and the dispersion cost, and saves the current control state of the laser and the OSR of the filter after the optimal point is confirmed. However, the open-loop control method requires an additional test system to calibrate the initial parameters of the laser, and the production efficiency is low.
The automatic closed-loop control mainly splits the output of the laser as the detection amount 1 of the laser backlight detection unit, and splits the reflected or transmitted light of the filter OSR as the detection amount 2 of the filter backlight detection unit. The aim of fixing the corresponding relation between the laser spectrum and the spectrum shaping component filtering spectrum is achieved by controlling the ratio of the detection quantity 1 and the detection quantity 2 to be a fixed value (namely determining a locking initial value) in a closed loop mode. Some of the methods adopt the temperature control on the laser and the filter OSR simultaneously, which results in complicated structure and increased cost, and some methods adopt the temperature control on the laser only, but the temperature compensation on the filter OSR does not result in the change of the spectral correspondence between the laser and the filter OSR, and the optimal state cannot be maintained. The above closed-loop control method does not explicitly describe how to determine the ratio of the detected quantity 1 to the detected quantity 2, so that an additional test system is still required for initial calibration, and the efficiency is low.
Therefore, the embodiments of the present application can at least provide a technical solution for automatically determining the initial lock value (i.e. the initial lock value). Specifically, after the maximum output optical power of the filter OSR is obtained, the spectrum of the laser is controlled to continue to shift left, the output optical power of the filter OSR enters a linear region of change, and the linear region is the optimal alignment region of the laser and the filter OSR. And selecting a point in the optimal alignment interval, recording the ratio of the laser power and the OSR output power at the moment, and taking the ratio as an automatic locking target (namely obtaining an initial locking value) of the CML.
Referring to fig. 1, fig. 1 is a wavelength alignment method provided in an embodiment of the present application, the method including: s101, determining a locking initial value according to the output light power of the filter and the linearity, wherein the locking initial value is used for representing a target ratio of the output light power of the filter to the output light power of the laser; and S102, determining and adjusting the temperature of the laser according to the initial locking value so as to realize the wavelength alignment of the laser and the filter.
It should be noted that the target ratio determined in S101 may be used as an automatic locking target of the CML, that is, the chirp management laser may determine whether to start an automatic locking process of the laser and the filter according to the target ratio and determine whether to end the process of adjusting the temperature of the laser according to the target ratio.
The specific process of S101 is exemplarily set forth below in conjunction with fig. 2-6.
In order to improve the accuracy of the obtained locking initial value, i.e. to better suppress the power of the zero-bit signal, in some embodiments, the locking initial value S101 includes a point on an alignment interval, wherein the alignment interval is on the low frequency side of the point where the filter outputs the maximum optical power.
In order to further enhance the alignment effect of the laser and the light wave shaping unit, in some embodiments, the alignment region is a linear region.
In some embodiments, the determining a locking initial value according to the magnitude and linearity of the output optical power of the filter includes: adjusting the output frequency of the laser, and recording the output optical power of the filter corresponding to the frequency; obtaining output optical power values of the filter at a plurality of the frequencies; determining the linearity of the output light power value of the filter at a low-frequency side position of the maximum value of the output light power of the filter; and acquiring the ratio of the output light power of the laser to the output light power of the filter as an initial locking value according to the linearity.
In some embodiments, the obtaining, according to the linearity, a ratio of output optical power of the laser to output optical power of the filter as an initial locking value includes: and obtaining the initial locking value when the linearity is determined to meet a judgment condition.
Some embodiments of the present application control the laser to continue to shift left after obtaining the maximum output optical power of the optical spectrum shaping device OSR, so that the output optical power of the OSR enters a linear region of change, and the linear region is the optimal alignment region of the laser and the OSR. And selecting a point in the optimal alignment interval, recording the ratio of the laser power and the OSR output power at the moment, and taking the ratio as an automatic locking target of the CML, so that the initial locking value of the chirp management laser can be obtained under the condition that a test system such as an eye pattern instrument is not needed.
The principle and process of acquiring the initial value of the lock in the embodiment of the present application are described below with reference to fig. 2 to 5.
Some embodiments of the present application move the output wavelength of the laser by temperature control while keeping the OSR temperature constant, making an alignment scan of the laser output wavelength and the OSR spectrum. That is, the output optical power of the OSR at the corresponding time is recorded while the output wavelength of the laser is adjusted. After the corresponding relation between the wavelength of the laser and the output optical power of the OSR is obtained through scanning, whether the laser and the OSR are in the optimal alignment interval can be determined through the size of the output optical power of the OSR and the changing linearity. The optimal interval is on the low frequency side of the corresponding laser wavelength at the point of maximum optical power output by the OSR.
As shown in fig. 2, the OSR filter spectrum shape is obtained through the scanning process, the maximum output optical power (i.e. the maximum value of the ordinate in fig. 2) can be obtained from the OSR filter spectrum shape, and the 1bits and 0bits signals output by the laser in fig. 2 are on the high frequency side of the maximum output optical power, so that the states shown in fig. 3 and fig. 4 can be obtained by shifting the laser frequency in the low frequency direction (i.e. the adjusted laser frequency marked in fig. 2 is shifted in one direction) as shown by the arrow in fig. 2 in order to obtain the initial locking value. Fig. 3 is a diagram showing a relationship between a laser and an OSR spectrum corresponding to the maximum OSR output optical power, and fig. 4 is a diagram showing a relationship between a laser and an OSR spectrum corresponding to a linear region (i.e., a linear region where the locking initial value is located) after the maximum OSR output optical power is exceeded. That is, some embodiments of the present application control the laser spectrum to continue to shift left after obtaining the maximum output optical power of the OSR, and the output optical power of the OSR enters a varying linear region, and the linear region is the optimal alignment region between the laser and the OSR. And selecting a point in the optimal alignment interval, recording the ratio of the laser power and the OSR output power at the moment, and taking the ratio as an automatic locking target (namely obtaining an initial locking value) of the CML.
S101 is further illustrated below in conjunction with fig. 5.
The chirp management laser shown in fig. 5 includes a laser driving unit 600, a direct modulation laser DML300, a light wave shaping unit OSR400, a control unit 200, a first lens 310 and an isolator 320 between the laser 300 and the light wave shaping unit 400, a first detection unit 330 (i.e., PD1 of fig. 5) for detecting the split light of the laser 300, a second detection unit 430 (i.e., PD2 of fig. 5) for detecting the reflected or transmitted light of the light wave shaping unit OSR, a first thermistor 800 for detecting the temperature of the laser tube core, and a temperature driving unit 520 (i.e., TEC of fig. 5), a third analog-to-digital conversion unit 700 for converting the analog signal detected by the first detection unit 330 into a digital signal, a first analog-to-digital conversion unit 700 for converting the temperature value collected by the first thermistor 800 into a digital signal, a second analog-to-digital conversion unit 700 for converting the analog signal collected by the second detection unit 430 into a digital signal, A temperature driving unit 510 connected with the control unit 200 and the temperature driving unit TEC, a further isolator disposed after the OSR, and a second lens 410.
The wavelength alignment method is briefly described below in connection with the apparatus of fig. 5.
After the laser driving unit 600 is started and set, the control unit 200 of the CML first controls the temperature driving unit (TEC) to change the die temperature of the DML, continuously adjusts the output frequency f1 of the DML, and records the detection value of the first detection unit PD1 and the detection value of the second detection unit PD2 once every adjustment; the first detection unit PD1 detects the backlight size of the DML to obtain the output light power P1 of the laser; the second detection unit PD2 detects the spectral optical power output by the OSR to obtain the output optical power P2 of the OSR; r1 was obtained from P2/P1 as the normalized optical power of the OSR output.
After scanning out the complete correspondence of R1 and f1, find the maximum value of R1, and then for calculating the linearity of the OSR output optical power of the maximum value at the position on the low frequency side of the laser 300, when the linearity is less than the decision value, i.e., it is considered that the best lock point (i.e., the frequency point at which the initial lock value is located) is found, the control unit 200 records the current parameter state and the current R1 value as the lock target (the lock target, i.e., the initial lock value, may be represented as K, as in fig. 8).
Because the change of the environmental temperature and the device per se causes the change of the R1 value, for example, the R1 value becomes smaller, the TEC needs to be controlled to adjust the laser to high frequency; when the value of R1 becomes larger, the TEC needs to be controlled to adjust the laser to the low frequency.
It should be noted that some embodiments of the present application may also use the apparatus of fig. 6 for wavelength alignment. The difference between fig. 6 and fig. 5 is that the second detection unit PD2 of fig. 6 and the laser DML are placed together on the same side of the OSR, the OSR reflects a part of the output light of the laser 300 back by being inclined at an angle, and the reflected light path does not coincide with the output light path of the laser 300, and the second detection unit PD2 receives and detects the reflected light of the OSR.
It can be understood that some embodiments of the present application may automatically calibrate the initial lock value by scanning the correspondence between the output frequency of the laser and the OSR output power, thereby improving the production efficiency; some embodiments of the application can also automatically feed back and lock without a lookup table or extra temperature calibration; some embodiments of the present application also do not require OSR temperature control.
The specific process of S102 is exemplarily set forth below in conjunction with fig. 7-8.
In some embodiments, S102 comprises: and locking the output optical power of zero bit and one bit output by the laser under the adjusted first temperature condition so as to realize the wavelength alignment of the laser and the filter. Some embodiments of the application realize the alignment of the output spectrum of the laser and the filtering spectrum shape of the OSR by only adjusting the temperature of the laser, and simultaneously lock the output optical power of 0bits and 1bit under different temperature conditions, so that the locking effect of the CML reaches a better state. For example, the zero and one bit output optical powers are locked by locking the output optical power and the extinction ratio of the laser. For example, the extinction ratio is locked by testing in advance different AC output swings (i.e., mod current of the laser) of the laser required for maintaining the same extinction ratio at different temperatures, determining the relationship between the temperature and the AC output amplitude, and writing the relationship into the control unit 200 of the CML, so that the control unit 200 of the CML can adjust the different AC output swings according to the different temperatures, thereby realizing the constant extinction ratio output by the laser, and further locking the output optical powers of the 1bits signal and the 0bits signal output by the laser at different temperatures.
In some embodiments, said locking the output optical power of said zero and one bit signals by locking the output optical power and the extinction ratio of said laser comprises: locking the average power of the laser to a target power by power control; and adjusting the driving current of the laser to control the extinction ratio to be kept unchanged. The drive temperature of the laser is adjusted, for example, by a temperature fit curve or a look-up table. It should be noted that the laser has two currents, one is a DC bias current, which belongs to a DC signal and is also a bias current, and the other is a driving swing current, which belongs to a mod current (or called as a driving current) of an AC signal; adjusting the Bias current through power control, and locking the average output light power of the laser to a target value; by adjusting the mod current, the extinction ratio is controlled to be constant. When the average output power of the laser is not changed and the extinction ratio is also not changed, it means that the output optical powers of the zero bit signal and the one bit signal are locked.
An exemplary explanation of S102 is provided below in conjunction with fig. 5, 6 and the principle.
In the related technology, only the direct modulation laser is subjected to temperature control, and the feedback proportional relation between the first detection unit PD1 and the second detection unit PD2 is fixed by adjusting the TEC, so that the aim of locking the CML is achieved, but the laser is subjected to temperature control, so that not only can the wavelength of the laser be adjusted, but also the output optical power and ER of the laser are changed, so that the adiabatic chirp of 1bit and 0bit output of the laser is changed, and finally, an OSR filtered signal is also changed. Therefore, it is necessary to lock the laser output power and ER while adjusting the laser temperature to keep the output performance of the CML unchanged.
As can be seen from the above description, the temperature of the laser needs to be adjusted to lock the R1 value at the lock initial value (or within a certain range near the lock initial value) because the lock initial value R1 changes due to the change of the environment and the device itself. For example, if the value of R1 becomes smaller, the TEC needs to be controlled to adjust the laser to high frequency; when the value of R1 becomes larger, the TEC needs to be controlled to adjust the laser to the low frequency. Since it is necessary to align the output spectrum of the laser with the filtered spectral shape of the OSR by adjusting the laser temperature, changes in the laser temperature also change the response curve of the laser to the drive current, as shown in fig. 7. In fig. 7, 0bits and 1bit of the driving current are respectively maintained at a and B at 50 ℃, when the temperature of the laser is adjusted to 20 ℃, if the driving current of the laser is not adjusted, the output optical power of the laser at 0bits and 1bit is changed, and the corresponding adiabatic chirp of the laser at 0bits and 1bit is changed. Therefore, the adiabatic chirp size of the 0bits and the 1bits of the locked laser is not changed by locking the 0bits and the 1bits of the laser at C and D at 20 ℃.
Some embodiments of the application realize the alignment of the output spectrum of the laser and the filtering spectrum shape of the OSR by only adjusting the temperature of the laser, and simultaneously lock the output optical power of 0bits and 1bit under different temperature conditions, so that the locking effect of the CML reaches a better state. For example, locking the output optical power of 0bits and 1bit can be achieved by locking the output optical power of the laser to ER.
S102 is exemplarily set forth below in conjunction with fig. 5.
For the specific structure of the apparatus in fig. 5, please refer to the above description, which will not be described herein.
Some embodiments of the present application only control the temperature of the laser 300, saving TEC for OSR. When the ambient temperature changes, the output wavelength of the laser 300 and the filter spectrum of the OSR both shift in frequency, and the proportional relationship between the output powers of the laser and the filter changes (i.e., the ratio between the current output power of the laser and the output power of the filter determined in S101 is not equal to the initial locking value), at this time, the temperature of the laser 300 needs to be adjusted to realign the output wavelength of the laser 300 and the filter spectrum of the OSR, and the realignment flag is the proportional relationship between the output powers of the laser and the filter (or referred to as a light wave shaping unit) to return to the value before the temperature change. That is, as shown in fig. 8, by detecting the ratio R between the output light Power of the laser 300 and the output light Power of the filter in real time or periodically, the ratio R changes due to temperature changes such as environment, when the ratio R does not coincide with the locking target value K (or is referred to as a locking initial value) or exceeds a certain range, the temperature of the laser 300 starts to be adjusted, after the temperature of the laser is adjusted, the automatic Power control apc (automatic Power control) is performed by the first detection unit PD1 for backlight detection of the laser 300, the average Power of the laser 300 is locked, then the driving current (or is referred to as mod current) of the laser starts to be adjusted, so that after the temperature changes, the output light powers of 0bits and 1bits of the laser are not changed, and after the locking of the light powers and the output powers of 0bits and 1bits is completed, whether R and K are consistent or return to a certain range is checked, if not, the adjustment is continued until the requirements are met. Where the adjustment of mod can be accomplished by a temperature fit curve or a look-up table. The extinction ratio er (extinction ratio) is locked by adjusting the mod current of the laser in a manner that different mod currents are adjusted at different temperatures, and the adjusted value is obtained by calibration in advance in the manner described above.
That is, some embodiments of the present application further reduce CML output signal degradation introduced in wavelength locking; the CML laser automatically finishes wavelength alignment control and improves the production efficiency; and OSR and TEC are not needed, so that the cost is reduced.
As shown in fig. 9, some embodiments of the present application provide a transceiver 900, the transceiver 900 comprising a directly modulated laser, a filter, a detector 902 and a wavelength alignment device as described in the second aspect. Wherein the directly modulated laser and the filter comprise the chirp management laser 901 of figure 8.
As shown in fig. 10, some facts of the present application provide an optical network system including an optical line terminal 1001 and an optical network unit 1002, where the optical line terminal 1100 and/or the optical network unit 1101 includes at least a transmitter 1003.
As shown in fig. 11, some embodiments of the present application provide an optical network system including an optical line terminal 1100 and an optical network unit 1101, wherein the optical line terminal and/or the optical network unit at least includes a transceiver 1103.
It should be noted that the transmitter 1003 and the transceiver 1103 in fig. 10 or 11 include the wavelength alignment apparatus shown in fig. 5 or 6, and the transmitter 1003 and the transceiver 1103 may be configured to perform the wavelength alignment method in fig. 1 or 8. To avoid repetition, it is not described herein in any greater detail.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus embodiments described above are merely illustrative, and for example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
In addition, functional modules in the embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
It is noted that, herein, relational terms such as first and second, and the like may be 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. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Claims (13)
1. A method of wavelength alignment for a chirp management laser comprising a laser and a filter, the method comprising:
determining a locking initial value according to the magnitude and the linearity of the output optical power of the filter, wherein the locking initial value is used for representing a target ratio of the optical power output by the filter to the optical power output by the laser;
determining and adjusting the temperature of the laser according to the initial locking value so as to realize the wavelength alignment of the laser and the filter;
wherein the content of the first and second substances,
the determining a locking initial value according to the magnitude and the linearity of the output optical power of the filter includes:
adjusting the output frequency of the laser, and recording the output optical power of the filter corresponding to the frequency;
obtaining output optical power values of the filter at a plurality of the frequencies;
determining the linearity of the output light power value of the filter at a low-frequency side position of the maximum value of the output light power of the filter;
and acquiring the ratio of the output light power of the laser to the output light power of the filter as an initial locking value according to the linearity.
2. The method of claim 1, wherein the initial lock value comprises a point on an alignment interval, wherein the alignment interval is on a low frequency side of a point where the filter outputs a maximum optical power.
3. The method of claim 2, wherein the alignment interval is a linear region.
4. The method as claimed in claim 1, wherein said obtaining a ratio between an output optical power of the laser and an output optical power of the filter as initial locking values according to the linearity comprises: and obtaining the initial locking value when the linearity is determined to meet a judgment condition.
5. The method of claim 1, wherein said determining from said initial lock value to adjust the temperature of said laser to achieve wavelength alignment of said laser and said filter comprises: and locking the output optical power of the zero bit signal and the one bit signal output by the laser under the adjusted first temperature condition so as to realize the wavelength alignment of the laser and the filter.
6. A method as claimed in claim 5, wherein the output optical powers of the zero and one bit signals are locked by locking the output optical power and the extinction ratio of the laser.
7. The method of claim 6, wherein said locking the output optical power of the zero-bit signal and the one-bit signal by locking the output optical power and the extinction ratio of the laser comprises:
locking the average power of the laser to a target power by power control;
and adjusting the driving current of the laser to control the extinction ratio to be kept unchanged.
8. The method of claim 7, wherein the drive current of the laser is adjusted by temperature fitting a curve or a look-up table.
9. A wavelength alignment device, the device comprising:
a laser backlight detection unit configured to detect an output optical power of the laser;
a filter backlight detection unit configured to detect an output optical power of the filter;
the control unit is configured to determine a locking initial value according to the output optical power of the filter and linearity, store the locking initial value, determine to adjust the temperature of the laser according to the locking initial value when the temperature changes, and lock the output optical powers of a zero bit signal and a one bit signal output by the laser in the temperature adjustment process, wherein the locking initial value comprises a target ratio of the optical powers of the filter and the laser;
a temperature adjustment unit configured to adjust the laser die temperature;
wherein the control unit is further configured to:
adjusting the output frequency of the laser, and recording the output optical power of the filter corresponding to the frequency;
obtaining output optical power values of the filter at a plurality of the frequencies;
determining the linearity of the output light power value of the filter at a low-frequency side position of the maximum value of the output light power of the filter;
and acquiring the ratio of the output light power of the laser to the output light power of the filter as an initial locking value according to the linearity.
10. A transmitter, characterized in that it comprises a directly modulated laser, a filter and a wavelength alignment device according to claim 9.
11. A transceiver comprising a directly modulated laser, a filter, a detector and a wavelength alignment device according to claim 9.
12. An optical network system, characterized in that the optical network system comprises an optical line terminal and an optical network unit, wherein the optical line terminal and/or the optical network unit comprises at least a transmitter according to claim 10.
13. An optical network system, characterized in that the optical network system comprises an optical line terminal and an optical network unit, wherein the optical line terminal and/or the optical network unit comprises at least a transceiver according to claim 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010702013.9A CN111865427B (en) | 2020-07-20 | 2020-07-20 | Wavelength alignment method, device, transmitter and optical network system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010702013.9A CN111865427B (en) | 2020-07-20 | 2020-07-20 | Wavelength alignment method, device, transmitter and optical network system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111865427A CN111865427A (en) | 2020-10-30 |
| CN111865427B true CN111865427B (en) | 2022-03-11 |
Family
ID=73001221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010702013.9A Active CN111865427B (en) | 2020-07-20 | 2020-07-20 | Wavelength alignment method, device, transmitter and optical network system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111865427B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113741590B (en) * | 2021-09-09 | 2023-03-28 | 江苏奥雷光电有限公司 | Silicon optical micro-ring wavelength calibration and locking control method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6785308B2 (en) * | 2002-03-28 | 2004-08-31 | Nortel Networks Limited | Spectral conditioning system and method |
| CN101124752A (en) * | 2004-09-02 | 2008-02-13 | 阿兹纳有限责任公司 | Optical transmitter of thermal chirp management of a direct modulation |
| CN101465515A (en) * | 2008-12-26 | 2009-06-24 | 中兴通讯股份有限公司 | Debugging apparatus and method based on chirp management laser |
| CN102742099A (en) * | 2011-12-20 | 2012-10-17 | 华为技术有限公司 | Laser, passive optical network system and apparatus, and control method of laser |
| CN103703700A (en) * | 2013-07-15 | 2014-04-02 | 华为技术有限公司 | Method, apparatus and optical network system for wavelength aligning |
| CN105634614A (en) * | 2014-10-30 | 2016-06-01 | 华为技术有限公司 | Light emitter, wavelength alignment method, and passive optical network system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7212555B2 (en) * | 2002-11-01 | 2007-05-01 | Finisar Corporation | Methods and devices for monitoring the wavelength and power of a laser |
| CN101282179A (en) * | 2008-05-27 | 2008-10-08 | 中兴通讯股份有限公司 | Method and system for locking light transmitter output wavelength |
-
2020
- 2020-07-20 CN CN202010702013.9A patent/CN111865427B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6785308B2 (en) * | 2002-03-28 | 2004-08-31 | Nortel Networks Limited | Spectral conditioning system and method |
| CN101124752A (en) * | 2004-09-02 | 2008-02-13 | 阿兹纳有限责任公司 | Optical transmitter of thermal chirp management of a direct modulation |
| CN101465515A (en) * | 2008-12-26 | 2009-06-24 | 中兴通讯股份有限公司 | Debugging apparatus and method based on chirp management laser |
| CN102742099A (en) * | 2011-12-20 | 2012-10-17 | 华为技术有限公司 | Laser, passive optical network system and apparatus, and control method of laser |
| CN103703700A (en) * | 2013-07-15 | 2014-04-02 | 华为技术有限公司 | Method, apparatus and optical network system for wavelength aligning |
| CN105634614A (en) * | 2014-10-30 | 2016-06-01 | 华为技术有限公司 | Light emitter, wavelength alignment method, and passive optical network system |
Non-Patent Citations (1)
| Title |
|---|
| 10G PON系统中L波段直调分布反馈激光器传输性能研究;李佳;《中国优秀硕士学位论文全文数据库 信息科技辑》;20171115;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111865427A (en) | 2020-10-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7324713B2 (en) | Apparatus for and method of controlling optical interferometer | |
| EP0574816B1 (en) | Laser bias and modulation circuit | |
| US5311005A (en) | Optical transmitters | |
| US7106486B1 (en) | Optical modulator control system | |
| JPH10123471A (en) | Light transmitter | |
| CN102210072A (en) | Optical signal generating device and method for adjusting same | |
| CN111865427B (en) | Wavelength alignment method, device, transmitter and optical network system | |
| JPH10228041A (en) | Wavelength converter for binary optical signal | |
| JPH0591047A (en) | Optical balanced transmitter | |
| US20060072927A1 (en) | Optical receiver for receiving differential phase and frequency shift-keyed optical signals | |
| US7023534B2 (en) | Optical modulating apparatus having bias controller and bias control method | |
| US20030002141A1 (en) | Semiconductor optical amplifiers using wavelength locked loop tuning and equalization | |
| EP1841101B1 (en) | Optical transmission system | |
| US20100142956A1 (en) | Method and Apparatus for Reshaping a Channel Signal | |
| JP2014158263A (en) | System and method for filtering optical signal in order to optimize linearity by avoiding fading | |
| US6697388B1 (en) | Control system for use with DBR lasers | |
| US6697397B2 (en) | Wavelength compensated ALC loop | |
| NL8006952A (en) | DATA TRANSMISSION WITH DC COUPLING. | |
| US7075694B2 (en) | Apparatus and method for automatically correcting bias voltage for carrier suppressed pulse generating modulator | |
| JP2005203536A (en) | Optical transmitter | |
| KR102004918B1 (en) | Appratus and method for implementation of laser source with narrow linewidth by phase noise compensation | |
| JP2022139531A (en) | Optical transmitter and control method of tunable optical filter | |
| US6266179B1 (en) | Optical transmission apparatus, optical repetition apparatus and optical transmission method | |
| CN111865426B (en) | Spectrum alignment method and device, transmitter and optical network system | |
| KR101190863B1 (en) | Optical transmitter for optimizing input dc bias voltage of optical modulator with duo-binary modulation and method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: A wavelength alignment method, device, transmitter and optical network system Effective date of registration: 20230104 Granted publication date: 20220311 Pledgee: Chengdu SME financing Company Limited by Guarantee Pledgor: Chengdu youbochuang Communication Technology Co.,Ltd. Registration number: Y2023990000005 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right |