A multi-dispersed laser system and method of controlling the same

Abstract

The application relates to the technical field of laser data transmission, and provides a multi-dispersion laser system and a control method thereof. The control method of the multi-dispersion laser system comprises the following steps: establishing a first model and a second model; in an initial state, adjusting a pumping power of a pumping light source, combining a first attenuation coefficient, a second attenuation coefficient and the first model to determine a first target pulse interval and a first target power; combining the second attenuation coefficient being zero and the second model to determine a second target power, a second target pulse interval and a target attenuation coefficient; controlling the real-time pumping power to be the first target power, the first real-time attenuation coefficient to be zero, the second real-time attenuation coefficient to be zero, the first laser to be in a first state and the second laser to be in a third state; the third state comprises a dissipative soliton state; controlling the real-time pumping power to be the second target power, the first real-time attenuation coefficient to be the target attenuation coefficient, the second real-time attenuation coefficient to be zero, the first laser to be in the first state and the second laser to be in a second state.

Description

Technical Field

[0001] This application relates to the field of laser data transmission technology, and in particular to a multi-dispersion laser system and its control method. Background Technology

[0002] In the field of optical communication technology, data can be transmitted efficiently in the form of optical signals. This process can generally be divided into two main scenarios based on the transmission distance: short-distance transmission and long-distance transmission. Short-distance transmission is commonly used within data centers or for interconnection between devices, while long-distance transmission is widely used in fiber optic backbone networks spanning cities, oceans, and even globally. Together, they constitute the communication cornerstone of the modern information society.

[0003] To adapt to the modern development of data transmission, short-distance and long-distance transmission can be integrated into a single system to achieve synchronous transmission over multiple distances. In existing solutions, integrating short-distance and long-distance transmission typically involves using two lasers outputting two vertically polarized beams to meet the communication needs at different distances. This requires additional servo control of the polarization direction. Furthermore, changes in temperature can cause the polarization direction of the transmitted pulses to shift, necessitating constant monitoring of the two polarization directions and adjustments to the servo control to ensure they are perpendicular. This results in a more complex system structure and a significant increase in cost and power consumption. Summary of the Invention

[0004] This application provides a multidispersive laser system and its control method. The multidispersive pulsed laser system has a simple structure and can effectively reduce cost and power consumption.

[0005] This application provides a method for controlling a multidispersive laser system, comprising: constructing a first model and a second model; the first model characterizing the evolution of a first laser under a first dispersion condition, and the second model characterizing the evolution of a second laser under a second dispersion condition, wherein the first dispersion condition and the second dispersion condition are different; in an initial state, adjusting the pump power of a pump source according to a set of source power, and determining a first target pulse spacing and a first target power by combining a first attenuation coefficient, a second attenuation coefficient, and the first model; the set of source power is a set of multiple pump powers formed with the initial power as the initial value; the first attenuation coefficient is the attenuation coefficient of the first laser, and the second attenuation coefficient is the attenuation coefficient of the second laser; in the initial state, both the first attenuation coefficient and the second attenuation coefficient are zero; the first target power is the pump power corresponding to the first laser outputting in a first state, and the first target pulse is the first laser in the first state. Pulse spacing; the first state includes the traditional soliton molecule state; combined with the second attenuation coefficient being zero and the second model, the second target power, the second target pulse spacing, and the target attenuation coefficient are determined; the second target power is the pump power corresponding to the second laser outputting in the second state, and the second target pulse spacing is the pulse spacing of the second laser in the second state; the target attenuation coefficient is the attenuation coefficient of the first laser at the second target power; the second target power is greater than the first target power; the second state includes the dissipative soliton molecule state; controlling the real-time pump power to the first target power, the first real-time attenuation coefficient being zero, and the second real-time attenuation coefficient being zero, the first laser outputs in the first state, and the second laser outputs in the third state; the third state includes the dissipative soliton state; controlling the real-time pump power to the second target power, the first real-time attenuation coefficient being the target attenuation coefficient, and the second real-time attenuation coefficient being zero, the first laser outputs in the first state, and the second laser outputs in the second state.

[0006] In some feasible implementations, in the initial state, the pump power of the pump source is adjusted according to the power set of the light source, and the first target pulse spacing and the first target power are determined by combining the first attenuation coefficient, the second attenuation coefficient, and the first model. This includes: controlling the first attenuation coefficient and the second attenuation coefficient to be zero, adjusting the pump power of the pump source according to the power set of the light source; and in response to the first model determining that the first laser is output in the first state, obtaining the first target pulse spacing and the first target power.

[0007] In some feasible implementations, the second target power, the second target pulse spacing, and the target attenuation coefficient are determined by combining the second attenuation coefficient being zero and the second model. This includes: controlling the second attenuation coefficient to be zero, adjusting the pump power of the pump source according to the power set of the light source and controlling the first attenuation coefficient to increase; and obtaining the second target power, the second target pulse spacing, and the target attenuation coefficient in response to the second model determining that the second laser is output in the second state.

[0008] In some feasible implementations, the first and second lasers propagate through the same fiber segment; the first dispersion condition is negative dispersion, and the second dispersion condition is positive dispersion.

[0009] The control method for a multidispersive laser system provided in the first aspect of this application, by adjusting the pump power, the size of the S-polarization attenuator, and the size of the P-polarization attenuator, enables the realization of femtosecond pulse-width conventional soliton molecule channels and picosecond pulse-width dissipative soliton molecule channels within the same multidispersive laser system, achieving co-origin dual-pulse sequence output. This allows for graded optical signal transmission to meet different transmission distance requirements without affecting data consistency.

[0010] The multidispersive laser system provided in the second aspect of this application includes: a pump source configured to generate a pump laser; an adjustment module, a beam splitting control component, and a first polarizer arranged sequentially along the optical path of the pump laser; the adjustment module, the beam splitting control component, and the first polarizer forming a first circulating cavity; the input end of the adjustment module is connected to the pump source and configured to adjust the dispersion value; the beam splitting control component is connected to the adjustment module and configured to split the pump laser into a first laser and a second laser; the first polarizer is configured to polarize the first laser in a first direction, and the first laser is in the first circulating cavity. The second laser circulates within the second circulating cavity and is output through the output end of the first circulating cavity; a second polarizer and a polarization-maintaining dispersion compensation fiber are included; an adjustment module, a beam splitting control component, the second polarizer, and the polarization-maintaining dispersion compensation fiber form the second circulating cavity; the second polarizer is configured to polarize the second laser in a second direction, and the polarization-maintaining dispersion compensation fiber is configured to compensate for the dispersion value of the second laser. The second laser circulates within the second circulating cavity and is output through the output end of the second circulating cavity; wherein the polarization directions of the first and second directions are orthogonal, and the net dispersion values ​​of the first and second circulating cavities are different.

[0011] In some feasible implementations, the beam splitting control component includes: a polarization beam splitter cube, a first collimator, a first adjustable attenuator, a second collimator, and a second adjustable attenuator; the polarization beam splitter cube, the first collimator, and the first adjustable attenuator are arranged sequentially along a first direction; the polarization beam splitter cube is configured to split the pump laser into a first laser and a second laser, the first collimator is configured to collimate the first laser, and the first adjustable attenuator is configured to adjust the attenuation coefficient of the first laser; the polarization beam splitter cube, the second collimator, and the second adjustable attenuator are arranged sequentially along a second direction; the second collimator is configured to collimate the second laser, and the second adjustable attenuator is configured to adjust the attenuation coefficient of the second laser.

[0012] In some feasible implementations, the beam splitting control component further includes: a first polarization-independent beam splitter, a first optical power meter, a second polarization-independent beam splitter, and a second optical power meter; the first polarization-independent beam splitter is disposed between the polarization beam splitter cube and the first collimator, and the first optical power meter is opposite to the first polarization-independent beam splitter; the first polarization-independent beam splitter is configured to split the first laser beam to the first optical power meter; the first optical power meter is configured to detect the output power of the first laser; the second polarization-independent beam splitter is disposed between the polarization beam splitter cube and the second collimator, and the second optical power meter is opposite to the second polarization-independent beam splitter; the second polarization-independent beam splitter is configured to split the second laser beam to the second optical power meter; the second optical power meter is configured to detect the output power of the second laser.

[0013] In some feasible implementations, the adjustment module includes a wavelength division multiplexer, a polarization-maintaining rare-earth ion-doped gain fiber, a polarization-maintaining filter, a polarization-maintaining circulator, and a polarization-maintaining fiber Bragg grating arranged sequentially. The wavelength division multiplexer is connected to the input of the pump source and is configured to introduce the pump laser into the first circulation cavity. The polarization-maintaining rare-earth ion-doped gain fiber is configured to generate gain. The polarization-maintaining filter is configured to generate soliton molecules. The first port of the polarization-maintaining circulator is connected to the polarization-maintaining filter, the second port of the polarization-maintaining circulator is connected to the polarization-maintaining fiber Bragg grating, and the third port of the polarization-maintaining circulator is connected to the beam splitting control component. The polarization-maintaining fiber Bragg grating is configured to provide dispersion.

[0014] In some feasible implementations, the multidispersive laser system also includes a microcontroller connected to a pump source, a first optical power meter, a second optical power meter, a first adjustable attenuator, and a second adjustable attenuator; the microcontroller is also configured to adjust the pump power of the pump source, the first attenuation coefficient, and the second attenuation coefficient to control the output state of the first laser and the second laser.

[0015] In some feasible implementations, the multidispersion laser system further includes a first polarization-maintaining coupler, a second polarization-maintaining coupler, a saturable absorber, and a polarization-maintaining polarization combiner. The first polarization-maintaining coupler is located at the output end of the first circulating cavity and includes a first output optical path and a second output optical path. The first output optical path is configured to output a first laser beam, and the second output optical path is configured to transmit the first laser beam to a microcontroller. The second polarization-maintaining coupler is located at the output end of the second circulating cavity and includes a third output optical path and a fourth output optical path. The third output optical path is configured to output a second laser beam, and the fourth output optical path is configured to transmit the second laser beam to the microcontroller. The first input end of the polarization-maintaining polarization combiner is connected to a first polarizer, the output end of the polarization-maintaining polarization combiner is connected to the saturable absorber, and the second input end of the polarization-maintaining polarization combiner is connected to a polarization-maintaining dispersion compensation fiber. The saturable absorber is configured to mode-lock the first and second laser beams.

[0016] The multi-dispersive laser system provided in the second aspect of this application constructs femtosecond pulse width conventional soliton molecular channels and picosecond dissipative soliton molecular channels respectively, and generates two types of pulse signals carrying the same data information simultaneously in the same signal generator to realize homologous dual-pulse sequences. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a multidispersive laser system provided in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of a spectral control component provided in an embodiment of this application;

[0020] Figure 3 This is a flowchart illustrating a control method for a multidispersive laser system provided in an embodiment of this application;

[0021] Figure 4 This is a schematic diagram of different output states in a multidispersive laser system provided in an embodiment of this application;

[0022] Figure 5 This is a flowchart illustrating a control method for a multidispersive laser system in a specific implementation provided in this application embodiment.

[0023] Illustration markings:

[0024] 1. Pump light source;

[0025] 2. Adjustment module; 21. Wavelength division multiplexer; 22. Polarization-maintaining rare-earth ion-doped gain fiber; 23. Polarization-maintaining filter; 24. Polarization-maintaining circulator; 25. Polarization-maintaining fiber Bragg grating;

[0026] 3. Beam splitting control assembly; 30. Incident collimator; 31. Polarization beam splitter cube; 32. First collimator; 33. First adjustable attenuator; 34. Second collimator; 35. Second adjustable attenuator; 36. First polarization-independent beam splitter; 37. First optical power meter; 38. Second polarization-independent beam splitter; 39. Second optical power meter;

[0027] 4. First polarizer; 5. Second polarizer; 6. Polarization-maintaining dispersion compensation fiber; 7. Microcontroller; 8. First polarization-maintaining coupler; 9. Second polarization-maintaining coupler; 10. Saturable absorber; 11. Polarization-maintaining polarization combiner; 12. First polarization-maintaining output coupler; 13. Second polarization-maintaining output coupler. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0029] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0030] Furthermore, in this application, directional terms such as "upper," "lower," "inner," and "outer" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0031] In the field of optical communication technology, data can be transmitted via optical signals, and this transmission can include short-distance and long-distance transmission. Short-distance optical communication typically refers to fiber optic links with a transmission distance of less than 100km, while long-distance optical communication typically refers to fiber optic links with a transmission distance of more than 100km. Short-distance transmission usually uses modulated optical pulse sequences as the information carrier, achieving high-capacity and high-speed transmission by adding more optical fibers. Because the overall signal loss in short-distance optical communication is relatively low, these links are mainly used for interconnection within data centers or between devices. Long-distance transmission, on the other hand, is widely used in fiber optic backbone networks spanning cities, oceans, and even globally. Together, they constitute the communication cornerstone of modern information society.

[0032] To adapt to the modern development of data transmission, short-distance and long-distance transmission can be integrated into a single system to achieve synchronous transmission over multiple distances. Current solutions typically employ two lasers outputting two polarized beams: one for short-distance transmission and the other for long-distance transmission. However, the difference in polarization direction between each laser output can easily lead to interference between the two signals, causing transmission errors. This necessitates additional servo control of the polarization direction. Furthermore, temperature changes can alter the polarization direction of the transmitted pulses, requiring constant monitoring and adjustment of the servo control to ensure perpendicularity. This necessitates complex receiving structures and digital signal processing to improve transmission distance and system stability, resulting in a more complex system structure and significantly increased cost and power consumption.

[0033] To address the aforementioned problems, this invention provides a multidispersive pulsed laser system and its control method. A polarization-splitting cubic beam is placed within a ring cavity, splitting the signal light into two mutually orthogonal polarization directions. Long-distance and short-distance data transmission are achieved within a single signal generator. Both types of signal transmission can be implemented within a single optical fiber without interference between them. This multidispersive pulsed laser system has a simple structure, effectively reducing cost and power consumption. One polarization direction outputs narrow-pulse conventional soliton molecules, while the other polarization direction outputs high-energy dissipative soliton molecules. The data transmitted in both polarization directions is identical. The narrow-pulse conventional soliton molecules have a fast signal propagation speed, suitable for reception at a short distance; the high-energy dissipative soliton molecules are received by a long-distance receiver, enabling transmission of optical signals at different distances.

[0034] Figure 1 This is a schematic diagram of the structure of a multidispersive laser system provided in an embodiment of this application.

[0035] See Figure 1 As shown, the multi-dispersion laser system provided in this application embodiment includes a pump source 1, an adjustment module 2, a beam splitting control component 3, a first polarizer 4, a second polarizer 5, and a polarization-maintaining dispersion compensation fiber 6.

[0036] Pump source 1 is used to generate pump laser; pump source 1 can output 980nm polarization-maintaining butterfly pump light. The polarization-maintaining pump light ensures the coupling stability between the pump light and the erbium-doped fiber and reduces polarization-dependent coupling fluctuations.

[0037] The adjustment module 2, the beam splitting control component 3, and the first polarizer 4 are arranged sequentially along the optical path of the pump laser.

[0038] The adjustment module 2, the beam splitting control component 3, and the first polarizer 4 form the first circulation cavity; the input end of the adjustment module 2 is connected to the pump light source 1 and is used to adjust the dispersion value.

[0039] The beam splitting control component 3 is connected to the adjustment module 2 and is used to split the pump laser into a first laser and a second laser. The first laser is polarized along a first direction and circulates in a first circulation cavity. The second laser is polarized along a second direction, and the first and second directions are orthogonal. The first polarizer 4 is used to polarize the first laser in the first direction and output it through the output end of the first circulation cavity.

[0040] The adjustment module 2, the beam splitting control component 3, the first polarizer 4, the second polarizer 5, and the polarization-maintaining dispersion compensation fiber 6 form a second circulating cavity. The second laser circulates in the second circulating cavity, and the dispersion values ​​of the first circulating cavity and the second circulating cavity are different.

[0041] The second polarizer 5 is used to polarize the second laser in the second direction. The polarization-maintaining dispersion compensation fiber 6 is used to compensate for the dispersion value of the second laser. The second laser circulates in the second circulation cavity and is output through the output end of the second circulation cavity.

[0042] In this way, by adjusting the dispersion value of the pump laser through module 2, the beam splitting control component 3 separates the pump laser into two orthogonally polarized first and second lasers. The two lasers are independently transmitted in the first and second circulating cavities, respectively. Since the net dispersion values ​​of the two circulating cavities are different, multi-dispersive laser outputs with different dispersion characteristics are generated in the same multi-dispersive laser system, which effectively improves the flexibility and applicability of the multi-dispersive laser system.

[0043] In some feasible implementations, the first polarizer 4 has its slow axis cut off through the fast axis, outputting S-polarized light with its direction aligned with the slow axis of the polarizer, thus realizing the function of an S-polarization polarizer. This first polarizer 4 not only ensures that the signal light in the optical path is S-polarized but also acts as an analyzer, working together with the polarization beam splitter 31 to ensure the polarization direction of the optical path. The second polarizer 5 has its slow axis cut off through the fast axis, outputting P-polarized light with its direction aligned with the slow axis of the polarizer, thus realizing the function of a P-polarization polarizer. Similar to the first polarizer 4, the second polarizer 5 not only ensures that the signal light in the optical path is P-polarized but also acts as an analyzer, ensuring the polarization direction of the optical path.

[0044] It should be emphasized that in the above implementation, the first direction is the S-polarization direction and the second direction is the P-polarization direction. This is just an example. In other implementations, the first and second directions can also be other directions that are orthogonal to each other.

[0045] In some feasible implementations, the polarization-maintaining dispersion-compensating fiber 6 can be PM2000D, with a second-order dispersion of approximately 70.2 ps at 1550 nm. 2 The fiber diameter is 2.1 μm, which is smaller than that of polarization-maintaining single-mode fiber PM1550 and polarization-maintaining erbium-doped gain fiber. The smaller core diameter results in a higher nonlinear coefficient, which is beneficial for achieving dissipative soliton generation in this polarization direction at lower pump power. Thus, the dissipative solitons obtained through dispersion management can maintain controllable propagation at higher energies, while the optical power is sufficiently high to maintain noise and loss resistance over long distances, ensuring a high signal-to-noise ratio at the receiver.

[0046] In other implementations, the polarization-maintaining dispersion-compensating fiber 6 can also be of other types.

[0047] In multidispersion laser systems, fiber optic devices can be connected via polarization-maintaining passive fibers. The polarization-maintaining passive fiber is PM1550, used to connect various fiber optic devices as well as active and dispersion-compensating fibers. Its second-order dispersion at 1550 nm is approximately -20.5 ps. 2 / km.

[0048] Figure 2 This is a schematic diagram of the structure of a spectral control component provided in an embodiment of this application.

[0049] See Figure 2 As shown, in a specific implementation, the beam splitting control component 3 includes: a polarization beam splitting cube 31, a first collimator 32, a first adjustable attenuator 33, a second collimator 34, and a second adjustable attenuator 35.

[0050] A polarization beam splitter 31, a first collimator 32, and a first adjustable attenuator 33 are sequentially arranged along a first direction. The polarization beam splitter 31 splits the pump laser into a first laser and a second laser. The first collimator 32 receives and collimates the first laser, and the first adjustable attenuator 33 adjusts the attenuation coefficient of the first laser. A polarization beam splitter 31, a second collimator 34, and a second adjustable attenuator 35 are sequentially arranged along a second direction. The second collimator 34 receives and collimates the second laser, and the second adjustable attenuator 35 adjusts the attenuation coefficient of the second laser. The first collimator 32 can be an S-polarized light incident collimator, and the second collimator 34 can be a P-polarized light incident collimator. The first adjustable attenuator 33 can be an S-polarized light adjustable attenuator, and the second adjustable attenuator 35 can be a P-polarized light adjustable attenuator.

[0051] Specifically, the beam splitting control component 3 splits the input signal light into two directions: S-polarized light and P-polarized light. These are then received by the first collimator 32 and the second collimator 34 in these two directions and enter the corresponding optical paths to output different types of soliton molecules. Since the intracavity polarization beam splitter 31 directly splits the signal light into two perpendicular directions, and the polarization-maintaining fiber within the cavity ensures that the two polarization directions do not interfere with each other, it can be used for signal transmission over various distances. The two orthogonal polarization directions of the signal light are generated using the same polarization beam splitter 31, resulting in two naturally orthogonal output signal lights that can be transmitted in the same fiber without interference. This eliminates the need for additional servo control to adjust the output polarization direction, effectively reducing the number of components used, simplifying the structure, and meeting the requirements for miniaturization. Within the operating center wavelength range of 1550nm, the polarization beam splitter 31 has an extinction ratio of no less than 34.7dB, an S-polarized light reflectivity >98%, and a P-polarized light transmittance >99%.

[0052] In a specific implementation, see [link to relevant documentation]. Figure 2 As shown, the beam splitting control assembly 3 may further include an incident collimator 30, used to collimate the signal light incident on the polarization beam splitter 31, ensuring that it couples into the polarization beam splitter 31 in the optimal mode. The incident collimator 30, the first collimator 32, and the second collimator 34 can all be polarization-maintaining fiber collimators with the same focal length, operating on the slow axis and cut off on the fast axis. The collimator's operating wavelength matches the signal band, and a low-reflection anti-reflection coating is used to suppress intracavity parasitic feedback. Simultaneously, a slow-axis alignment structure ensures that the incident polarization state is consistent with the working axis of the polarization beam splitter, thereby maintaining high extinction ratio separation of the dual polarization channels. One side of the incident collimator 30 is connected to the polarization-maintaining circulator 24, and the other side is aligned with the polarization beam splitter 31.

[0053] In one specific implementation, the first adjustable attenuator 33 and the second adjustable attenuator 35 can both be polarization-maintaining fiber couplers, using variable optical attenuators (VOAs) controlled by voltage. The attenuation coefficient of the corresponding voltage can be calculated by microprocessor calibration, thereby ensuring the attenuation value of the target size in the P-polarization and S-polarization directions.

[0054] In a specific implementation, see [link to relevant documentation]. Figure 2 As shown, the beam splitting control component 3 also includes: a first polarization-independent beam splitter 36, a first optical power meter 37, a second polarization-independent beam splitter 38, and a second optical power meter 39.

[0055] A first polarization-independent beam splitter 36 is disposed between a polarization beam splitter cube 31 and a first collimator 32, and a first optical power meter 37 is opposite to the first polarization-independent beam splitter 36. The first polarization-independent beam splitter 36 is used to split the first laser beam to the first optical power meter 37. The first optical power meter 37 is used to detect the average power of the first laser in the first circulating cavity. A second polarization-independent beam splitter 38 is disposed between a polarization beam splitter cube 31 and a second collimator 34, and a second optical power meter 39 is opposite to the second polarization-independent beam splitter 38. The second polarization-independent beam splitter 38 is used to split the second laser beam to the second optical power meter 39. The second optical power meter 39 is used to detect the average power of the second laser in the second circulating cavity.

[0056] Specifically, the first polarization-independent beam splitter 36 can be an S-polarization direction-independent beam splitter, and the second polarization-independent beam splitter 38 can be a P-polarization direction-independent beam splitter. Both can be installed at their nominal operating incident angles, such as 45°. Before the signal light from the two polarization directions enters the corresponding collimators, a non-polarization-independent beam splitter extracts a small amount of spatial light signal, reflecting the cavity power G to an optical power meter (G=1-5%). This power is then used to estimate the average power in the two polarization direction loops, and precise power control is achieved by adjusting the adjustable attenuator. The polarization-independent beam splitter uses a low polarization-dependent loss structure to avoid affecting the dual polarization ratio.

[0057] The first optical power meter 37 can be an S-polarization direction optical power meter, and the second optical power meter 39 can be a P-polarization direction optical power meter. The first optical power meter 37 and the second optical power meter 39 can transmit the measured average power signal to the data processing module (not shown in the figure) of the microcontroller 7. The microcontroller 7 calculates the actual average power in the corresponding polarization direction loop according to the pre-calibrated beam splitting ratio, compares it with the set target power, and then controls the adjustable optical attenuator of the corresponding channel to realize independent closed-loop adjustment of the power of the dual polarization channels.

[0058] In this way, real-time closed-loop feedback adjustment of dual-channel power balance can be achieved, so that the power ratio of P and S polarized light is stabilized within the preset tolerance range.

[0059] See also the following for some feasible implementation methods. Figure 1 As shown, the multi-dispersion laser system also includes a microcontroller 7, which is connected to the pump source 1, the first optical power meter 37, the second optical power meter 39, the first adjustable attenuator 33, and the second adjustable attenuator 35, respectively. The microcontroller 7 is also used to adjust the pump power, the first attenuation coefficient, and the second attenuation coefficient of the pump source 1 to control the output state of the first laser and the second laser.

[0060] In this way, microcontroller 7 can construct a multi-parameter collaborative control strategy based on real-time power monitoring data of the dual polarization channels. Specifically, when the output power in a certain polarization direction deviates from the target value, microcontroller 7 first determines the source of the deviation: if both channels simultaneously experience power drift in the same direction, the driving current of pump source 1 is adjusted first to change the total pump power; if only a single channel has abnormal power, local correction is performed by adjusting the attenuation coefficient of the corresponding adjustable attenuator. This hierarchical control mechanism avoids the impact of frequent pump power fluctuations on the operational stability of the multidispersive laser system, while ensuring rapid convergence of the dual polarization power ratio.

[0061] See also the following for some feasible implementation methods. Figure 2 As shown, the first adjustable attenuator 33, the second adjustable attenuator 35, the first optical power meter 37 and the second optical power meter 39 are all electrically connected to the microcontroller 7 via wires, forming a complete closed-loop control circuit.

[0062] See also the following for some feasible implementation methods. Figure 1 As shown, the adjustment module 2 includes a wavelength division multiplexer 21, a polarization-maintaining rare-earth ion-doped gain fiber 22, a polarization-maintaining filter 23, a polarization-maintaining circulator 24, and a polarization-maintaining fiber Bragg grating 25 arranged sequentially.

[0063] The wavelength division multiplexer 21 is connected to the input terminal of the pump light source 1, and the wavelength division multiplexer 21 is used to introduce the pump laser into the first circulating cavity.

[0064] Specifically, wavelength division multiplexer 21 can be a 980 / 1550nm polarization-maintaining wavelength division multiplexer, used to couple the 980nm pump light source 1 into the circulating cavity while ensuring that the polarization direction of the pump laser remains unchanged.

[0065] The polarization-maintaining rare-earth ion-doped gain fiber 22 is used to generate gain. The polarization-maintaining rare-earth ion-doped gain fiber 22 can be an erbium-doped polarization-maintaining gain fiber.

[0066] Specifically, the polarization-maintaining rare-earth ion-doped gain fiber 22 is positioned after the wavelength division multiplexer 21 and can be a PM-EDF (Er80-4 / 125-HD-PM), with a second-order dispersion of approximately 28.04 ps at 1550 nm. 2 / km, ensuring sufficient gain within the circulation cavity to generate soliton molecules in two polarization directions. In this implementation, the rare earth ion is erbium. In other implementations, the rare earth ion can also be ytterbium, thulium, praseodymium, neodymium, holmium, europium, etc. For example, when the rare earth ion is ytterbium, the polarization-maintaining rare earth ion-doped gain fiber 22 is a polarization-maintaining ytterbium-doped gain fiber.

[0067] When the rare earth ions in the polarization-maintaining rare earth ion-doped gain fiber 22 are different, the operating wavelengths of the pump light source and other devices are synchronously adjusted to adapt to different types of rare earth ions.

[0068] The polarization-maintaining filter 23 is placed after the polarization-maintaining rare-earth ion-doped gain fiber 22, with a bandwidth of 10nm. The narrow bandwidth is beneficial for generating multi-pulse soliton molecules, ensuring stability and reliability. At the same time, the narrow bandwidth polarization-maintaining filter 23 can be used to shield noise signals in multi-dispersion laser systems.

[0069] Specifically, the pump laser generated by the pump source 1 passes through the polarization-maintaining rare-earth ion-doped gain fiber 22, where it is absorbed and output as signal light. The remaining pump laser is absorbed by a polarization-maintaining filter 23 placed in the optical path.

[0070] The first port of the polarization-maintaining circulator 24 is connected to the polarization-maintaining filter 23, the second port of the polarization-maintaining circulator 24 is connected to the polarization-maintaining fiber Bragg grating 25, and the third port of the polarization-maintaining circulator 24 is connected to the beam splitting control component 3; the polarization-maintaining fiber Bragg grating 25 is used to provide dispersion.

[0071] Specifically, the signal light is output from the polarization-maintaining rare-earth ion-doped gain fiber 22 and enters the first port of the polarization-maintaining circulator 24. After exiting from the second port, it passes through the polarization-maintaining fiber Bragg grating 25, is reflected back to the second port of the polarization-maintaining circulator 24, and finally outputs from the third port of the polarization-maintaining circulator 24 to the beam splitting control component 3. The polarization-maintaining circulator 24 operates at a wavelength of 1550±30nm and has an isolation degree >40dB, acting as an isolator to effectively isolate residual pump laser light.

[0072] The polarization-maintaining fiber Bragg grating 25 is placed after the second port of the polarization-maintaining circulator 24, and its net dispersion is approximately 0.0064 ps. 2 While maintaining the polarization state within the circulating cavity, it increases the net dispersion within the cavity, achieving a reflectivity >99%. This is used to control the net dispersion of the optical path composed of wavelength division multiplexer 21, polarization-maintaining rare-earth ion-doped gain fiber 22, polarization-maintaining filter 23, polarization-maintaining circulator 24, polarization-maintaining fiber Bragg grating 25, and beam splitting control component 3 to zero. This facilitates the management of net dispersion in subsequent optical paths, enabling the realization of both traditional soliton molecules and dissipative soliton molecules.

[0073] See also the following for some feasible implementation methods. Figure 1 As shown, the multi-dispersion laser system also includes a first polarization-maintaining output coupler 12, a second polarization-maintaining output coupler 13, a first polarization-maintaining coupler 8, a second polarization-maintaining coupler 9, a saturable absorber 10, and a polarization-maintaining polarization combiner 11.

[0074] The first polarization-maintaining output coupler 12 and the polarization-maintaining polarization combiner 11 are sequentially arranged in the output optical path of the first polarizer 4. The first polarization-maintaining coupler 8 is connected to the output end of the first polarization-maintaining output coupler 12 and is arranged in the output end of the first circulating cavity. The first polarization-maintaining coupler 8 includes a first output optical path and a second output optical path. The first output optical path is used to output the first laser; the second output optical path is used to transmit the first laser to the microcontroller 7.

[0075] Specifically, the first polarization-maintaining output coupler 12 is located at the output end of the first polarizer 4, and is used to output the first laser power in the first circulating cavity according to a ratio of 7:3, 8:2, or 9:1, where 70%, 80%, or 90% circulates within the first circulating cavity to ensure stable pulse operation, and 30%, 20%, or 10% is used for output. The first polarization-maintaining coupler 8 is located after the first polarization-maintaining output coupler 12, and is used to split the output laser power according to a ratio of 9:1, 8:2, or 7:3, using most of the laser for output, and converting a small portion of the laser into a corresponding voltage signal through a photoelectric converter, which is received by the data processing module of the microcontroller 7. The data processing module calculates the incident light time-domain waveform detected by the photoelectric converter based on the received voltage signal through analog-to-digital conversion, and obtains the peak power and pulse spacing of the current multi-dispersion laser system output pulse through calibration calculation.

[0076] The second polarization-maintaining coupler 9 is located at the output end of the second circulating cavity. The second polarization-maintaining coupler 9 includes a third output optical path and a fourth output optical path. The third output optical path is used to output the second laser; the fourth output optical path is used to transmit the second laser to the microcontroller 7.

[0077] Specifically, the second polarization-maintaining output coupler 13 is located at the output end of the second polarizer 5. It is used to output the second laser power in the second circulating cavity according to a ratio of 7:3, 8:2, or 9:1, where 70%, 80%, or 90% circulates within the second circulating cavity to ensure stable pulse operation, and 30%, 20%, or 10% is output to the second polarization-maintaining coupler 9. The second polarization-maintaining coupler 9 is located after the second polarization-maintaining output coupler 13 in the cavity. It is used to split the output laser power according to a ratio of 9:1, 8:2, or 7:3, consistent with the first polarization-maintaining coupler 8. Most of the laser is used for output, and a small portion of the laser is converted into a corresponding voltage signal by a photoelectric converter and received by the data processing module of the microcontroller 7. The data processing module calculates the incident light time-domain waveform detected by the photoelectric converter based on the received voltage signal through analog-to-digital conversion. Through calibration calculation, the peak power and pulse spacing of the current multi-dispersion laser system output pulse can be obtained.

[0078] The first input terminal of the polarization-maintaining polarization combiner 11 is connected to the first polarizer 4 through the first polarization-maintaining output coupler 12, the output terminal of the polarization-maintaining polarization combiner 11 is connected to the saturable absorber 10, and the second input terminal of the polarization-maintaining polarization combiner 11 is connected to the polarization-maintaining dispersion compensation fiber 6.

[0079] Specifically, the polarization-maintaining beam combiner 11 is placed after the first polarization-maintaining output coupler 12 to couple S-polarized light and P-polarized light into a polarization-maintaining fiber, so that the two perpendicular signal lights can achieve mode-locking through the tapered saturable absorber 10, and then obtain gain through the polarization-maintaining rare earth ion doped gain fiber 22.

[0080] The saturable absorber 10 is used to mode-lock the first laser and the second laser.

[0081] Specifically, the saturable absorber 10 can be a tapered saturable absorber. The tapered saturable absorber 10 is placed after the polarization-maintaining combiner 11 and can be fabricated using a tapered single-mode polarization-maintaining fiber. Cr2S3 powder is uniformly sprinkled onto this fiber, giving it isotropic characteristics. For signal light with different polarization directions, it has the same adjustment depth, unsaturated loss, and saturated power parameters. Signal light with S-polarization and P-polarization directions is combined into a single fiber by the polarization-maintaining combiner 11 and then input into the tapered saturable absorber 10. Because the saturable absorber 10 has consistent characteristics in all polarization directions, it can realize conventional soliton molecules and dissipative soliton molecules in the S-polarization and P-polarization directions, respectively.

[0082] The polarization-maintaining fiber Bragg grating 25 provides dispersion such that the dispersion value of the common portion of the first and second circulating cavities is zero. This common portion comprises the polarization-maintaining polarization combiner 11, the saturable absorber 10, the wavelength division multiplexer 21, the polarization-maintaining rare-earth ion-doped gain fiber 22, the polarization-maintaining filter 23, the polarization-maintaining circulator 24, and the beam splitting control assembly 3.

[0083] The multi-dispersion laser system provided in this application uses dual-dispersion management and polarization multiplexing technology to simultaneously generate S-polarized conventional soliton molecules and P-polarized dissipative soliton molecules in a single resonant cavity. The two have independently adjustable pulse widths, repetition frequencies, and peak powers, and are combined with microcontroller 7 for real-time closed-loop feedback control of the two output pulses.

[0084] See also Figure 1As shown, the operating sequence of the first laser is as follows: pump source 1, wavelength division multiplexer 21, polarization-maintaining rare-earth ion-doped gain fiber 22, polarization-maintaining filter 23, polarization-maintaining circulator 24, polarization-maintaining fiber Bragg grating 25, beam splitting control component 3, first polarizer 4, first polarization-maintaining output coupler 12, polarization-maintaining polarization combiner 11, and saturable absorber 10. This circuit operates in an environment with net dispersion less than zero, generating soliton molecules. The operating sequence of the second laser is as follows: pump source 1, wavelength division multiplexer 21, polarization-maintaining rare-earth ion-doped gain fiber 22, polarization-maintaining filter 23, polarization-maintaining circulator 24, polarization-maintaining fiber Bragg grating 25, beam splitting control component 3, second polarizer 5, second polarization-maintaining output coupler 13, polarization-maintaining dispersion compensation fiber 6, polarization-maintaining polarization combiner 11, and saturable absorber 10. This circuit operates in an environment with net dispersion greater than zero, generating dissipative soliton molecules.

[0085] The multi-dispersion laser system provided in this application can construct femtosecond pulse-width conventional soliton molecule channels and picosecond dissipative soliton molecule channels respectively. Two types of pulse signals carrying the same data information are simultaneously generated within the same signal generator, realizing a homogeneous dual-pulse sequence. The femtosecond pulsed conventional soliton molecules can be used for high-speed, short-distance transmission, while the picosecond pulse-width dissipative soliton molecules can be used for long-distance transmission. Narrow-pulse-width conventional soliton molecule pulses and high-energy dissipative soliton molecule pulses are obtained separately in a single laser. These two types of pulses are orthogonally polarized in the same optical fiber, serving as two independent data streams. This solves the problem of high system complexity in existing optical fiber data transmission systems, which typically rely on multiple signal sources or multi-channel structures for different transmission distances.

[0086] Corresponding to the aforementioned embodiments of multidispersive laser systems, this application also provides embodiments of a control method for multidispersive laser systems. This control method for multidispersive laser systems realizes conventional soliton molecules and dissipative soliton molecules in two orthogonal polarization directions within the cavity, thereby transmitting data. This allows the same data to be transmitted over different distances. The conventional soliton molecules in the S-polarization direction transmit faster, enabling high-speed data transmission over short distances, while the dissipative soliton molecules in the P-polarization direction have higher pulse energy, enabling long-distance data transmission.

[0087] Figure 3 This is a flowchart illustrating a control method for a multidispersive laser system provided in an embodiment of this application.

[0088] See Figure 3 As shown, the control method of the multi-dispersion laser system may include steps S1 to S5.

[0089] Step S1: Construct a first model and a second model; the first model is used to characterize the evolution of the first laser under the first dispersion condition, and the second model is used to characterize the evolution of the second laser under the second dispersion condition. The first dispersion condition is different from the second dispersion condition. Specifically, the first dispersion condition is negative dispersion, and the second dispersion condition is positive dispersion.

[0090] Specifically, in this step, firstly, based on the multidispersive laser system mentioned in the above embodiments, a corresponding mode-locked fiber laser model is established. A lumped iterative mapping model is adopted, and the intracavity components act sequentially according to their actual physical orientation. A dual-polarization pulse simulation unit is established to numerically calculate the pulse evolution process in two orthogonal polarization directions. Within the same fiber (PM1550 and PM-EDF) sharing the same polarization directions, the pulse evolution is represented by the propagation model of two coupled beams as follows:

[0091] ;

[0092] in, The normalized envelope of the optical field along the S-polarization direction, This is the normalized envelope of the optical field along the P-polarization direction. For complex units, The wavenumber difference between modes These are the coordinates of the pulse's propagation distance within the optical fiber. This represents the saturable gain coefficient of a high-gain fiber. , It is the small-signal gain coefficient, and its relationship with the pump power is as follows: , For efficiency parameters, For pump power, The saturation light intensity is the gain medium. To achieve saturation energy, in a passive optical fiber, a setting is made... . For gain bandwidth, This is the gain detuning parameter. To propagate the angular frequency of light, The angular frequency at the peak position of the fiber gain. These are the time delay coordinates in the group velocity reference frame, used to describe the temporal structure evolution of a pulse. They exist when light with two polarization directions propagates in the same optical fiber. The effective second-order dispersion coefficient in the S-polarization direction is... The effective second-order dispersion coefficient in the P-polarization direction is... This represents the nonlinear coefficient of the optical fiber. Indicates the center frequency of the pulse. It is a nonlinear refractive index. At the speed of light, This represents the effective mode field area of ​​the optical fiber.

[0093] After splitting the polarization-polarized cubic pair of pulses, a first model for pulse propagation in the S-polarization direction is established. This first model is used to characterize the evolution of the first laser under the first dispersion condition:

[0094] ;

[0095] A second model for pulse propagation in the P-polarization direction is established. This second model is used to characterize the evolution of the second laser under the second dispersion condition:

[0096] ;

[0097] Where α is the inherent loss, and the attenuation transfer function for each polarization direction is expressed as: Where rho is the attenuation coefficient. The transfer function of the cone-shaped saturable absorber is: , Incident light intensity, The saturation power of a saturable absorber. The modulation depth of the saturable absorber. The unsaturated loss of the saturable absorber is represented by this modeling method, which better encapsulates the dynamic characteristics introduced by each component. A time-stepped numerical integration method is used to solve the numerical model describing the propagation of dual-polarized pulses within the cavity. The numerical model is constructed segmentally according to the intracavity devices, establishing transmission operators for the gain fiber, fiber segments with different dispersions, the saturable absorber, and the polarizing device, which are then applied sequentially to the pulse envelope in each round-trip cycle. Different net dispersion and filtering parameters are set for the two orthogonal polarization channels. By performing multi-parameter scans of the pump power and polarization channel attenuation coefficients, the formation thresholds and stable operating regions of conventional and dissipative solitons are systematically analyzed, providing theoretical guidance for the rapid realization of S-polarized conventional solitons and P-polarized dissipative solitons.

[0098] In a specific implementation, combined with Figure 1 and Figure 2 As shown, in the initial state, the fiber attenuators in the two polarization directions of the multidispersive laser system have no attenuation. Based on the cavity length and fiber type, the net dispersion in the first cyclic cavity of the net negative dispersion optical path in the S-polarization direction can be calculated to be <-0.0047 ps. 2 The single-pulse repetition frequency is 210.6 MHz. In the net positive dispersion optical path in the P-polarization direction, the net dispersion within the second cyclic cavity is >0.0115 ps. 2 The single-pulse repetition frequency is 157.4MHz.

[0099] During the process of controlling the pump power in the microcontroller's data processing module, the output of the pump laser is split into 9:1 beams. 10% of the light is received by a photodetector with a response wavelength of 980nm. This photodetector contains a small, fast-response, and high-quantum-efficiency photodiode. When the laser light is incident on the photodiode, photogenerated carriers are generated. The diffusion of these carriers produces a photocurrent. and incident light power P L The ratio is: , Determined by the inherent performance of the photodiode, the photocurrent is then output as a voltage signal to the microcontroller's data processing module via a transimpedance amplifier. ,in The microcontroller's data processing module determines the value of the feedback resistor based on the received data. The incident light power detected by photoelectric detection is obtained through analog-to-digital conversion, and the current output power value of the pump source can be obtained through calibration calculation. If the actual output power of the pump source deviates significantly from the set power, the microcontroller's data processing module calculates the power output value according to the PID control algorithm and converts it into the actual driving current value to achieve the desired control effect.

[0100] For a polarization-maintaining coupler with two polarization directions in a multidispersive laser system, the S-polarization direction uses a 7:3 beam splitting output, with 70% of the light used for output and 30% received by a photodetector with a response band of 1550 nm. The P-polarization direction uses a 9:1 beam splitting output, with 90% of the light used for output and 10% received by a photodetector with a response band of 1550 nm. This photodetector internally contains a small, fast-response, high-quantum-efficiency photodiode. When laser light is incident on the photodiode, photogenerated carriers are generated. These carriers diffuse to produce a photocurrent, which... I ) and incident light power ( P L1 The ratio is: , Determined by the inherent performance of the photodiode, the photocurrent is then output as a voltage signal to the microcontroller's data processing module via a transimpedance amplifier. ,in The microcontroller's data processing module determines the value of the feedback resistor based on the received data. The time-domain state of the output pulse is obtained by analog-to-digital conversion, and the peak power of the pulse and the interval between the two peak powers are recorded.

[0101] Step S2: In the initial state, adjust the pump power of the pump source according to the source power set, and determine the first target pulse spacing and the first target power by combining the first attenuation coefficient, the second attenuation coefficient, and the first model; the source power set is a set of multiple pump powers formed with the initial power as the initial value; the first attenuation coefficient is the attenuation coefficient of the first laser, and the second attenuation coefficient is the attenuation coefficient of the second laser; in the initial state, both the first attenuation coefficient and the second attenuation coefficient are zero; the first target power is the pump power corresponding to the first laser output in the first state, and the first target pulse is the pulse spacing of the first laser in the first state; the first state includes the traditional soliton molecule state.

[0102] It is worth noting that after the pump laser is started according to the power set of the light source, the second laser is output in the state of dissipative soliton molecules.

[0103] The microcontroller data processing module increases the pump power according to the light source power set P{P1, P2, P3, ...}, and at the same time, the microcontroller data processing module will record the output pulse status received by the two orthogonal polarization direction photodetectors in real time.

[0104] Specifically, after the model is established, the mode-locked pulse is obtained. When the pump power of the pump source is adjusted according to the source power set P, the pulse power set in the S polarization direction is P1{P 11 P 12 P 13 ...}, the peak power interval is the first interval M s The corresponding repetition frequency can be 210.6MHz, and the pulse interval is 4.63ns. The pulse power set in the P-polarization direction is P2{P 21 P 22 P 23 ...}, the peak power interval is the second interval M p The corresponding repetition frequency is 157.4MHz and the pulse interval is 6.35ns.

[0105] Subsequently, by establishing a simulation model of the experiment, the pulse evolution in two orthogonal polarization directions was numerically predicted using two coupled beam propagation models.

[0106] Specifically, step S2 may include steps S21 and S22.

[0107] Step S21: Control the first attenuation coefficient rhos and the second attenuation coefficient rhop to both be zero, and adjust the pump power of the pump light source according to the light source power set.

[0108] Based on two orthogonally polarized pulse propagation models, a time-stepped numerical integration method is used to systematically solve the propagation equations describing the propagation characteristics of optical pulses within the cavity, obtaining the optical pulse characteristics in the S-polarization and P-polarization directions of the corresponding multidispersive laser system. A multi-parameter control combination, including pump power P, the first attenuation coefficient rhos in the S-polarization direction, and the second attenuation coefficient rhop in the P-polarization direction, is constructed to regulate the pulse evolution in the two orthogonally polarized directions within the cavity. In the first control parameter combination {P... t Under rhos1, rhop1}, the output of traditional soliton molecules in the S-polarization direction is achieved, with the pulse spacing between the two pulses being the first target pulse spacing ΔL < M. s The pulse spacing refers to the distance between two pulses within one cycle. Here, rhos1 represents the case where the first attenuation coefficient rhos is zero, and rhop1 represents the case where the second attenuation coefficient rhop is zero. The first target pulse spacing ΔL < 4ps, and the P polarization direction is a dissipative soliton.

[0109] Step S22: In response to the first model determining that the first laser is outputting in a first state, the first target pulse spacing and the first target power are obtained.

[0110] Under the control of the first combination of control parameters, the first laser is output in the first state, corresponding to the first target pulse spacing ΔL and the first target power P. t .

[0111] Step S3: Combine the fact that the second attenuation coefficient is zero and the second model to determine the second target power, the second target pulse spacing, and the target attenuation coefficient; the second target power is the pump power corresponding to the second laser output in the second state, the second target pulse spacing is the pulse spacing of the second laser in the second state; the target attenuation coefficient is the attenuation coefficient of the first laser under the second target power; the second target power is greater than the first target power; the second state includes the dissipative soliton molecule state.

[0112] Specifically, step S3 may include steps S31 and S32.

[0113] Step S31: Control the second attenuation coefficient to zero, adjust the pump power of the pump light source according to the light source power set, and control the first attenuation coefficient to increase.

[0114] Further increase pump power to P n Simultaneously, the first attenuation coefficient in the S-polarization direction is adjusted to keep the power in the S-polarization direction constant, maintaining the traditional soliton molecule state, in the second control parameter combination {P n Under the conditions rhos2, rhop1, where rhos2 is the target attenuation coefficient and rhop1 remains zero, the dissipative soliton molecules are realized in the P polarization direction, and the second target pulse spacing M p '<Mp The average output power in the P polarization direction is P', where P' ranges from 24 to 40 mW, and the S polarization direction remains in the traditional soliton molecule state.

[0115] Step S32: In response to the second model determining that the second laser is outputting in the second state, obtain the second target power, the second target pulse spacing, and the target attenuation coefficient.

[0116] Under the control of the first combination of control parameters, the first laser outputs in a first state, and the second laser outputs in a second state, corresponding to the second target pulse spacing M. p '、Second target power P n And the target attenuation coefficient. The target attenuation coefficient is obtained by continuously increasing the first attenuation coefficient from zero.

[0117] Specifically, the first target power can be the critical value for the first laser to output in a first state, and the second target power can be the critical value for the second laser to output in a second state. In this way, the output states of the first laser and the second laser can be switched through the first target power and the second target power.

[0118] Step S4: Control the real-time pump power to the first target power, the first real-time attenuation coefficient to zero, the second real-time attenuation coefficient to zero, the first laser to be output in the first state, and the second laser to be output in the third state; the third state includes the dissipative soliton state.

[0119] Thus, in the actual operation of a multidispersive laser system, the real-time pump power can be adjusted to the first target power P using a microcontroller. t The first and second real-time attenuation coefficients are simultaneously reduced to zero, enabling independent control of the output states of the first and second lasers in the multidispersive laser system. At this point, the first laser, driven by the first target power, maintains its conventional soliton molecule state, with its power characteristics in the S-polarization direction remaining stable and the pulse spacing maintained at the first target pulse spacing ΔL. Meanwhile, the second laser, not modulated by the second attenuation coefficient, undergoes a transformation in its dissipative soliton molecule state in the P-polarization direction, entering the third state, the dissipative soliton state.

[0120] Combination Figure 2 As shown, the polarization-independent beam splitter can reflect 5% of the cavity power to the optical power meter. The optical power meter has a working center wavelength of 1550nm, a resolution of 0.01dB, and an accuracy of ±0.2dB / ±1nW. It can accurately measure the optical power of the polarization-independent beam splitter. The microcontroller's data processing module will then transfer the pump power P... t The power reflected by the polarization-independent beam splitter is calculated based on the pre-calibrated beam splitting ratio, and the actual average power P in the corresponding polarization direction loop is then calculated. aThis is taken as the target value. Subsequently, the microcontroller's data processing module follows the pump power set P. t Increasing the intracavity pump power will cause the microcontroller's data processing module to adjust the voltage of the S-polarization direction adjustable optical attenuator, maintaining the intracavity power in the S-polarization direction at the target value P. a .

[0121] Step S5: Control the real-time pump power to the second target power, the first real-time attenuation coefficient to the target attenuation coefficient, the second real-time attenuation coefficient to zero, the first laser to be output in the first state, and the second laser to be output in the second state.

[0122] In this way, by increasing the real-time pump power to the second target power P n The first real-time attenuation coefficient is set to the target attenuation coefficient, while the second real-time attenuation coefficient is kept at zero, thus achieving independent control of the output states of the first and second lasers again. At this time, driven by the second target power, the first laser, due to the modulation effect of the first attenuation coefficient, maintains its conventional soliton molecular state in the S-polarization direction, and the pulse spacing remains at the first target pulse spacing ΔL, maintaining stable output power characteristics. Simultaneously, driven by the second target power, the second laser, not being modulated by the second attenuation coefficient, changes its P-polarization direction from the third state (dissipative soliton state) and re-enters the second state (dissipative soliton molecular state), with the pulse spacing returning to the second target pulse spacing M. p The average power of the output pulse is P. The advantage of this control method is that it enables flexible switching between two laser output states with different dispersion characteristics by combining a single pump power parameter with two independent attenuation coefficients.

[0123] By adjusting the pump power, the magnitude of the first attenuation coefficient output by the first adjustable attenuator, and the magnitude of the second attenuation coefficient output by the second adjustable attenuator, a femtosecond pulse-width conventional soliton molecule channel and a picosecond pulse-width dissipative soliton molecule channel are realized within the same multidispersive laser system, achieving co-origin dual-pulse sequence output. The femtosecond pulse-width conventional soliton molecule is used for high-speed, short-distance transmission, while the picosecond pulse-width dissipative soliton molecule is used for long-distance, stable transmission.

[0124] Narrow-pulse-width conventional soliton molecular pulses have the characteristics of narrow pulse width, high time-domain resolution, and low single-pulse energy, making them suitable for short-distance high-speed transmission; high-energy dissipation soliton molecular pulses have the characteristics of high energy and strong anti-attenuation ability, making them suitable for long-distance receiver detection. In other words, the control method of the multi-dispersive laser system provided in this application embodiment can realize graded optical signal transmission for different transmission distance requirements without affecting the consistency of data information.

[0125] Figure 4This is a schematic diagram of different output states in a multidispersive laser system provided in an embodiment of this application; wherein, Figure 4 Figure (a) shows a schematic diagram of the first laser outputting in the first state. Figure 4 Figure (b) shows a schematic diagram of the second laser outputting in the third state. Figure 4 Figure (c) shows a schematic diagram of the second laser outputting in the second state. The horizontal axis represents the number of intracavity cycles, and the vertical axis represents time, in picoseconds.

[0126] With a gain factor of 1.8, corresponding to a pump power of 5.11W, Figure 4 In (a), the molecule is a traditional soliton with polarization in the S direction. Figure 4 In diagram (b), the dissipative soliton corresponds to the P-polarization direction. The output S-polarization direction represents a stable soliton molecule with a pulse repetition rate of M1. Figure 4 From the time-domain evolution diagram in (a), we can see that the pulse interval is 1.612 ps and the single pulse width is 284 fs. From... Figure 4 In (b), it was found that the pulse width of the dissipative soliton corresponding to the P polarization direction was 8.8 ps.

[0127] When the gain factor is 2.8, corresponding to a pump power of 8.96W, Figure 4 In (a), the molecule is a traditional soliton with polarization in the S direction. Figure 4 In diagram (c), the dissipative soliton molecule corresponds to the P-polarization direction. The S-polarization direction still represents the traditional soliton molecule with a pulse spacing of ΔL, where the pulse spacing is 1.613 ps, the single pulse width is 282 fs, the peak power is 73.89 W, and the corresponding average pulse output power is 3.65 mW. The P-polarization direction generates a stable dissipative soliton molecule, with a pulse spacing of 28.86 ps, a peak power of 15.39 W, and a corresponding average pulse output power of 33 mW.

[0128] Figure 5 This is a flowchart illustrating a control method for a multidispersive laser system in a specific implementation provided in this application embodiment.

[0129] See Figure 5 As shown, in a specific implementation, the control method of the multi-dispersion laser system may include steps S51 to S56.

[0130] Step S51: In the initial state, the attenuation coefficients in the two orthogonal polarization directions are zero, and the fundamental frequency pulse interval M between the S-polarization and P-polarization directions is... s With M p The microcontroller's data processing module increases the pump power according to the power set P{P1, P2, P3, ...}, and receives and records the pulse spacing, pulse width, and peak power for each of the two polarization directions within the cavity.

[0131] Step S52: Establish a dual-polarization pulse simulation model and perform numerical calculations on the pulse evolution process in two orthogonal polarization directions.

[0132] In this step, the simulation model for the dual-polarization pulse is as follows:

[0133] .

[0134] Step S53: Based on two orthogonal polarization pulse propagation models, obtain the optical pulse characteristics in the S-polarization direction and the P-polarization direction. Adjust the pump power P, the attenuation coefficient rhos in the S-polarization direction, and the attenuation coefficient rhop in the P-polarization direction, in the first set of control parameter combinations {P t rhos1, rhop1}, to achieve a pulse spacing of ΔL < M in the S-polarization direction. s Traditional solitary molecules.

[0135] Steps S51 to S53 can refer to steps S1 and S2 provided in the foregoing embodiments.

[0136] Step S54: Increase pump power, in the second set of control parameter combinations {P n In the S-polarization direction, the spacing between conventional soliton molecules remains unchanged, while in the P-polarization direction, two pulses are formed with a spacing of M. p '<M p The dissipative soliton molecule, while the average output power in the P polarization direction is P'.

[0137] This step can refer to step S3 provided in the foregoing embodiments.

[0138] Step S55: The microcontroller's data processing module gradually increases the pump power according to the light source power set until the traditional soliton molecule generation threshold P in the S polarization direction is reached. n The polarization direction of S is when the pulse spacing ΔL < M. s The traditional soliton molecular state, where the polarization direction of P is the pulse spacing M p Dissipative solitons. P n Power P in the lower S polarization direction a As the target value, the first attenuator is controlled to ensure that the power in the S-polarization direction remains unchanged.

[0139] This step can refer to step S4 provided in the foregoing embodiments.

[0140] Step S56: The microcontroller's data processing module continues to increase the pump power while ensuring that the power in the S-polarization direction is at the target value. When the pump power increases to P... n When the S polarization direction is rhos2, the P polarization direction achieves a pulse spacing of M. pThe dissipative soliton molecule, where the polarization direction of S is such that the pulse spacing ΔL < M. s Traditional soliton molecules. A dual-channel multiplexed light source with both high-speed short-distance transmission and high-stability long-distance transmission capabilities was obtained.

[0141] This step can refer to step S5 provided in the foregoing embodiment.

[0142] It should be noted that, upon considering the specification and practicing the application disclosed herein, those skilled in the art will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0143] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The true scope is indicated by this application.

Claims

1. A control method for a multi-dispersion laser system, characterized in that, include: A first model and a second model are constructed; the first model is used to characterize the evolution of the first laser under the first dispersion condition, and the second model is used to characterize the evolution of the second laser under the second dispersion condition, wherein the first dispersion condition and the second dispersion condition are different. In the initial state, the pump power of the pump source is adjusted according to the light source power set, and the first target pulse spacing and the first target power are determined by combining the first attenuation coefficient, the second attenuation coefficient, and the first model; the light source power set is a set of multiple pump powers formed with the initial power as the initial value; the first attenuation coefficient is the attenuation coefficient of the first laser, and the second attenuation coefficient is the attenuation coefficient of the second laser; in the initial state, both the first attenuation coefficient and the second attenuation coefficient are zero; the first target power is the pump power corresponding to the first laser output in the first state, and the first target pulse is the pulse spacing of the first laser in the first state; The first state includes the traditional soliton molecule state; The second target power, the second target pulse spacing, and the target attenuation coefficient are determined by combining the second attenuation coefficient being zero and the second model; the second target power is the pump power corresponding to the second laser outputting in the second state; the second target pulse spacing is the pulse spacing of the second laser in the second state; the target attenuation coefficient is the attenuation coefficient of the first laser at the second target power; the second target power is greater than the first target power; the second state includes the dissipative soliton molecule state; The real-time pump power is controlled to the first target power, the first real-time attenuation coefficient is zero, and the second real-time attenuation coefficient is zero. The first laser is output in the first state, and the second laser is output in the third state; the third state includes the dissipative soliton state. The real-time pump power is controlled to the second target power, the first real-time attenuation coefficient is the target attenuation coefficient, the second real-time attenuation coefficient is zero, the first laser is output in the first state, and the second laser is output in the second state.

2. The control method for a multi-dispersion laser system according to claim 1, characterized in that, In the initial state, the pump power of the pump source is adjusted according to the power set of the light sources. The first target pulse spacing and the first target power are determined by combining the first attenuation coefficient, the second attenuation coefficient, and the first model, including: Controlling both the first attenuation coefficient and the second attenuation coefficient to zero, the pump power of the pump light source is adjusted according to the light source power set; In response to the first model determining that the first laser is outputting in the first state, the first target pulse spacing and the first target power are obtained.

3. The control method for a multi-dispersion laser system according to claim 2, characterized in that, Combining the fact that the second attenuation coefficient is zero and the second model, the second target power, the second target pulse spacing, and the target attenuation coefficient are determined, including: The second attenuation coefficient is controlled to be zero, and the pump power of the pump light source is adjusted according to the light source power set while the first attenuation coefficient is controlled to increase. In response to the second model determining that the second laser is outputting in the second state, the second target power, the second target pulse spacing, and the target attenuation coefficient are obtained.

4. The control method for a multi-dispersion laser system according to claim 1, characterized in that, The first laser and the second laser travel through the same fiber segment during propagation; The first dispersion condition is negative dispersion, and the second dispersion condition is positive dispersion.

5. A multi-dispersion laser system, characterized in that, include: The control method for a multidispersive laser system as described in any one of claims 1-4, wherein the multidispersive laser system comprises: A pump source is configured to generate a pump laser; An adjustment module, a beam splitting control component, and a first polarizer are sequentially arranged along the optical path of the pump laser; The adjustment module, the beam splitting control component, and the first polarizer form a first circulating cavity; the input end of the adjustment module is connected to the pump light source and is configured to adjust the dispersion value; the beam splitting control component is connected to the adjustment module and is configured to split the pump laser into a first laser and a second laser; the first polarizer is configured to polarize the first laser in a first direction, the first laser circulates within the first circulating cavity, and is output through the output end of the first circulating cavity; Second polarizer and polarization-maintaining dispersion compensation fiber; The adjustment module, the beam splitting control component, the second polarizer, and the polarization-maintaining dispersion compensation fiber form a second circulating cavity; the second polarizer is configured to polarize the second laser in a second direction, the polarization-maintaining dispersion compensation fiber is configured to compensate for the dispersion value of the second laser, the second laser circulates within the second circulating cavity, and is output through the output end of the second circulating cavity; The polarization directions of the first direction and the second direction are orthogonal, and the net dispersion values ​​of the first circulating cavity and the second circulating cavity are different.

6. The multidispersive laser system according to claim 5, characterized in that, The beam splitting control assembly includes: a polarization beam splitter cube, a first collimator, a first adjustable attenuator, a second collimator, and a second adjustable attenuator; The polarization beam splitter, the first collimator, and the first adjustable attenuator are arranged sequentially along the first direction; the polarization beam splitter is configured to split the pump laser into the first laser and the second laser, the first collimator is configured to collimate the first laser, and the first adjustable attenuator is configured to adjust the attenuation coefficient of the first laser. The polarization beam splitter, the second collimator, and the second adjustable attenuator are arranged sequentially along the second direction; the second collimator is configured to collimate the second laser, and the second adjustable attenuator is configured to adjust the attenuation coefficient of the second laser.

7. The multidispersive laser system according to claim 6, characterized in that, The beam splitting control assembly further includes: a first polarization-independent beam splitter, a first optical power meter, a second polarization-independent beam splitter, and a second optical power meter; The first polarization-independent beam splitter is disposed between the polarization beam splitter cube and the first collimator, and the first optical power meter is opposite to the first polarization-independent beam splitter. The first polarization-independent beam splitter is configured to split the first laser beam to the first optical power meter; the first optical power meter is configured to detect the output power of the first laser. The second polarization-independent beam splitter is disposed between the polarization beam splitter cube and the second collimator, and the second optical power meter is opposite to the second polarization-independent beam splitter. The second polarization-independent beam splitter is configured to split the second laser beam to the second optical power meter; the second optical power meter is configured to detect the output power of the second laser.

8. The multidispersive laser system according to claim 7, characterized in that, The adjustment module includes a wavelength division multiplexer, a polarization-maintaining rare-earth ion-doped gain fiber, a polarization-maintaining filter, a polarization-maintaining circulator, and a polarization-maintaining fiber Bragg grating arranged in sequence. The wavelength division multiplexer is connected to the input of the pump light source, and the wavelength division multiplexer is configured to introduce the pump laser into the first circulation cavity; The polarization-maintaining rare-earth ion-doped gain fiber is configured to generate gain. The polarization-maintaining filter is configured to generate soliton molecules; The first port of the polarization-maintaining circulator is connected to the polarization-maintaining filter, the second port of the polarization-maintaining circulator is connected to the polarization-maintaining fiber Bragg grating, and the third port of the polarization-maintaining circulator is connected to the beam splitting control component. The polarization-maintaining fiber Bragg grating is configured to provide dispersion.

9. The multidispersive laser system according to claim 8, characterized in that, The multi-dispersion laser system also includes a microcontroller, which is connected to the pump source, the first optical power meter, the second optical power meter, the first adjustable attenuator, and the second adjustable attenuator, respectively. The microcontroller is also configured to adjust the pump power, the first attenuation coefficient, and the second attenuation coefficient of the pump source to control the output state of the first laser and the second laser.

10. The multidispersive laser system according to claim 9, characterized in that, The multidispersive laser system also includes a first polarization-maintaining coupler, a second polarization-maintaining coupler, a saturable absorber, and a polarization-maintaining beam combiner; The first polarization-maintaining coupler is disposed at the output end of the first circulating cavity. The first polarization-maintaining coupler includes a first output optical path and a second output optical path. The first output optical path is configured to output the first laser; the second output optical path is configured to transmit the first laser to the microcontroller. The second polarization-maintaining coupler is disposed at the output end of the second circulating cavity. The second polarization-maintaining coupler includes a third output optical path and a fourth output optical path. The third output optical path is configured to output the second laser; the fourth output optical path is configured to transmit the second laser to the microcontroller. The first input terminal of the polarization-maintaining polarization combiner is connected to the first polarizer, the output terminal of the polarization-maintaining polarization combiner is connected to the saturable absorber, and the second input terminal of the polarization-maintaining polarization combiner is connected to the polarization-maintaining dispersion compensation fiber. The saturable absorber is configured to mode-lock the first laser and the second laser.

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