Arrayed grating beam combining control method and system for fiber lasers

Abstract

The application provides an array grating beam combination control method and system of a fiber laser, relates to the technical field of fiber lasers, and acquires a grating array structure, takes collimation-beam combination-shaping as control logic, takes grating parameters and arrangement modes as coupling conditions, supervises and trains a coupling wave module, and the coupling wave module is in communication connection with the grating array and an optical modulator; receives laser conditions, wherein the laser conditions are beam combination standards; according to the laser conditions, the coupling wave module executes decoupling decision, responds to the grating array and the optical modulator, and executes beam combination control driving. The application solves the technical problem that, due to the lack of multistage coupling decision and dynamic temperature drift compensation, the beam combination control precision and flexibility are insufficient in the prior art, achieves the technical effects of improving the beam combination control precision, enhancing the beam combination field consistency of the fiber laser, and enhancing long-term operation stability.

Description

Technical Field

[0001] This invention relates to the field of fiber laser technology, and specifically to a method and system for controlling the beam combining of an array grating in a fiber laser. Background Technology

[0002] Fiber lasers, due to their high efficiency, compact design, and excellent beam quality, are widely used in industrial processing, lidar, and optical communication. To achieve high-power output, fiber lasers typically employ beam combining using arrayed grating structures. Existing fiber laser arrayed grating beam combining control methods are mostly based on single-layer coupling control and static beam combining strategies. These rely on preset grating parameters and arrangements for fixed coupling, lacking flexible adjustment capabilities under different laser conditions. They cannot accurately decouple the grating array and control the beam combining precisely, resulting in relatively low beam combining accuracy. Furthermore, existing technologies generally lack dynamic compensation methods for thermally induced wavelength drift caused by temperature changes. This can easily lead to a decrease in the matching degree of the combined optical field during high-power or multi-channel beam combining, thus affecting the accuracy and stability of beam combining control. Especially under complex laser conditions, the inability to achieve flexible and adaptive beam combining control affects the long-term stable operation and performance of fiber lasers. Summary of the Invention

[0003] This invention provides a method and system for controlling the beam combining of an array grating in a fiber laser. It solves the technical problem that the existing technology lacks multi-level coupling decision-making and dynamic temperature drift compensation, resulting in insufficient beam combining control accuracy and flexibility. It achieves the technical effect of improving beam combining control accuracy and enhancing the consistency of the beam combining optical field and the long-term operational stability of the fiber laser.

[0004] In view of the above problems, on the one hand, the present invention provides a method for beam combining control of an array grating in a fiber laser. The method includes: acquiring the grating array structure; using collimation-beam combining-shaping as the control logic and grating parameters and arrangement as coupling conditions; supervising and training a coupling wave module, wherein the coupling wave module establishes a communication connection with the grating array and the optical modulator; receiving laser conditions, wherein the laser conditions are beam combining criteria; and, based on the laser conditions, the coupling wave module performs decoupling decisions and, in response to the grating array and the optical modulator, performs beam combining control drive.

[0005] Preferably, the supervised training of the coupled wave module includes: performing first-order decision training based on optical coupling and decoupling according to the grating array structure to determine the first beam combining unit; performing second-order logic training with collimation-beam combining-shaping as the control logic and coupling conditions as the reference to determine the second beam combining unit; and cascading the first beam combining unit and the second beam combining unit to determine the coupled wave module.

[0006] Preferably, according to the laser conditions, the coupling wave module performs decoupling decisions, including: receiving the laser conditions, importing them into the first beam combining unit, performing decoupling decisions based on the grating array structure, and determining a first parameter set, wherein the first parameter set includes grating parameters and arrangement based on a grating subarray, and the grating subarray is the part of the array grating that participates in beam combining; importing the first parameter set into the second beam combining unit, performing logical reorganization of control drive, and determining a beam combining strategy, wherein the collimation and shaping stages are selectively triggered.

[0007] Preferably, the logical restructuring of the control drive includes: introducing timestamp constraints and position code constraints, wherein the timestamp executes the time synchronization and asynchronous constraints of the array grating, and the position code executes the position constraints of the driving component; and performing logical integration of the beam combining control based on the timestamp and the position code.

[0008] Preferably, in response to the grating array and the optical modulator, the method includes: splitting the beam combining strategy according to the response target to determine a sub-strategy; and applying a timestamp constraint to the sub-strategy in response to the grating array and the optical modulator, wherein the timestamp includes a synchronous timestamp and an asynchronous timestamp.

[0009] Preferably, the sub-strategy is subject to position code constraints in response to the grating array and the optical modulator, wherein each component in the grating array and the optical modulator is identified by a unique code.

[0010] Preferably, the execution of beam combining control drive includes: setting a step control condition, wherein the step control condition is a single amplitude modulation constraint of the fiber laser component adjustment; determining whether the step control condition is met by switching the laser condition and starting / stopping the fiber laser; if not, performing control linearization processing.

[0011] Preferably, the beam combining control drive includes: performing multi-channel temperature monitoring, evaluating thermally induced wavelength drift, and determining the drift coefficient, wherein the evaluation is based on the thermo-optical properties of the grating array material, and the multi-channel refers to the portion of the array grating that participates in beam combining; and performing gradient temperature control compensation based on the drift coefficient.

[0012] Preferably, after executing the beam combining control drive, the process includes: establishing a temporary database, wherein the temporary database is used to store beam combining operation records; mapping the beam combining operation records to laser conditions and storing them in the temporary database; according to a preset period, mining the non-consistent features between the beam combining effect and the laser conditions, performing drive tracing, and locating the beam combining drift point, wherein a preset frequency is used as the mining constraint; and making targeted adjustments to the hardware components and coupling wave module of the fiber laser based on the beam combining drift point.

[0013] On the other hand, the present invention also provides an array grating beam combining control system for a fiber laser, the system comprising: a coupled-wave module training unit for acquiring the grating array structure, using collimation-beam combining-shaping as control logic, and using grating parameters and arrangement as coupling conditions to supervise and train the coupled-wave module, wherein the coupled-wave module establishes a communication connection with the grating array and the optical modulator; a laser condition receiving unit for receiving laser conditions, wherein the laser conditions are beam combining criteria; and a beam combining control driving unit for executing decoupling decisions by the coupled-wave module according to the laser conditions, and executing beam combining control driving in response to the grating array and the optical modulator.

[0014] One or more technical solutions provided in this invention have at least the following beneficial effects:

[0015] By acquiring the physical structure data and key parameters of the grating array and combining them with supervised training, an intelligent coupled-wave module is established. This coupled-wave module communicates with the grating array and optical modulator to achieve dynamic interaction, providing intelligent decision support for subsequent beam combining control operations. Upon receiving laser conditions, the module clarifies the specific goals and requirements for beam combining, i.e., the beam combining criteria, providing a basis and direction for subsequent decoupling decisions and beam combining control. This allows the entire control process to flexibly adjust the beam combining strategy according to different laser conditions. After receiving the laser conditions, the coupled-wave module executes decisions in stages: the first stage performs decoupling decisions based on the parameters of the grating subarray, forming the first parameter set; the second stage logically reorganizes the beam combining strategy, flexibly switching collimation, beam combining, and shaping operations to generate a precise beam combining strategy. Subsequently, the beam combining strategy is decomposed and synchronous and asynchronous timestamps are introduced to ensure that the grating array and optical modulator can respond according to precise time and sequence, improving the timing accuracy and dynamic adaptability of beam combining control. By setting step control conditions, a smooth transition is ensured during laser condition switching or start-stop processes, avoiding beam combining instability caused by sudden condition changes. By using multi-channel real-time temperature monitoring and compensating for the thermo-optical properties of materials, the beam-combining stability under complex operating conditions is significantly improved. Finally, by establishing a temporary database and tracing beam-combining operation records, historical records and periodic mining of the beam-combining process are achieved. This allows for the location of drift points and reverse optimization of hardware components and coupling wave modules, forming a closed-loop optimization that improves the beam-combining consistency and long-term operational reliability of fiber lasers.

[0016] In summary, this invention achieves high-precision, high-stability, and high-flexibility control of fiber laser array grating beam combining through multi-level decision-making, dynamic response, temperature monitoring compensation, and process monitoring optimization. Under different laser conditions, it can quickly and accurately make decoupling decisions and execute beam combining operations, while effectively responding to interference from external factors such as temperature changes, ensuring the continuous stability of the beam combining effect. By establishing a temporary database and a drive traceability mechanism, the beam combining process can be continuously optimized and improved, enhancing beam combining stability and adapting to diverse laser conditions, thus meeting the needs of fiber lasers in high-precision, high-performance applications.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a fiber laser array grating beam combining control method provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of an array grating beam combining control system for a fiber laser provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: Coupled wave module training unit 10, laser conditional receiver unit 20, beam combining control drive unit 30. Detailed Implementation

[0021] This invention provides a method and system for controlling the beam combining of an array grating in a fiber laser. This solves the technical problem of insufficient beam combining control accuracy and flexibility in the prior art due to the lack of multi-level coupling decision-making and dynamic temperature drift compensation. It achieves the technical effect of improving beam combining control accuracy and enhancing the consistency of the beam combining optical field and the long-term operational stability of the fiber laser.

[0022] Example 1, as Figure 1 As shown, this embodiment of the invention provides a method for controlling the beam combining of an array grating in a fiber laser, the method comprising:

[0023] Step S100: Obtain the grating array structure, use collimation-beam combining-shaping as the control logic, and use grating parameters and arrangement as coupling conditions to supervise the training of the coupled wave module, wherein the coupled wave module establishes a communication connection with the grating array and the optical modulator.

[0024] Specifically, a grating array structure refers to an array of optical devices composed of multiple gratings (such as fiber Bragg gratings, phase gratings, etc.) arranged in a specific geometric configuration and optical path configuration. The arrangement and grating parameters directly affect the beam combining effect. The collimation-beam combining-shaping control logic refers to the three-stage control process of parallelizing (collimating), combining (beam combining), and optimizing the shape (shaping) of the incident beam. Grating parameters include grating period, length, reflection spectral width, coupling coefficient, etc., used to describe the optical performance of a single grating. The arrangement refers to the relative spatial relationship of the gratings in the array, such as linear, two-dimensional matrix, coaxial superposition, etc. The coupled wave module refers to a software module trained using supervised machine learning algorithms, used to handle the coupling and decoupling of optical signals between the grating array and the optical modulator, achieving dynamic adaptation.

[0025] First, the physical structure information of the grating array is acquired through sensors or a design database, including the grating parameters of each grating and its spatial arrangement in the array. This information, collected as coupling conditions, is then imported into a coupled-wave module trained using a supervised machine learning algorithm. This coupled-wave module establishes a bidirectional communication connection with the grating array and the optical modulator, enabling real-time issuance of subsequent coupling control commands and reception of feedback data. Using a three-stage control logic framework of collimation-beam combining-shaping, the coupled-wave module comprehensively considers the structural information of the grating array during training, performing multiple coupling simulations and error feedback to achieve adaptive identification and updating of the coupling mode, thereby providing dynamic decision support for subsequent beam combining control.

[0026] This step, through supervised training of the coupled wave module, significantly improves the flexibility and real-time adaptability of beam combining control, providing data support and an intelligent control foundation for beam combining under diverse laser conditions.

[0027] Step S200: Receive laser conditions, wherein the laser conditions are beam combining criteria.

[0028] Specifically, laser conditions refer to the technical requirements and process parameters for beam combining in different application scenarios, i.e., beam combining specifications, such as output power, beam quality (M² value), divergence angle, brightness, and polarization state. External laser conditions are received through a human-machine interface (HMI) or automated control interface, serving as the driving basis for subsequent control logic. Laser conditions include multi-dimensional parameter requirements for the final combined beam, such as power, spot diameter, uniformity, and polarization matching. After receiving these conditions, the coupling wave module uses them as target values ​​for beam combining control, updating the output strategy of the internal coupling model in real time to ensure that subsequent control actions can specifically meet the beam combining standards under different application scenarios. This not only enables standardized beam combining but also flexibly addresses customized needs in various fields. For example, in laser cutting scenarios, laser conditions require the combined beam power to reach 1000W, an M² value less than 1.2, and a spot diameter not exceeding 200μm; while in optical communication, polarization stability is required to be better than -20dB. These conditions can be received in real time from an industrial computer via Ethernet communication or RS485 serial port and transmitted to the coupling wave module in JSON or Modbus protocol format.

[0029] This step enables flexible updates to the beam-combining control target by dynamically receiving laser conditions, allowing fiber lasers to adapt to the refined needs of different application scenarios.

[0030] Step S300: Based on the laser conditions, the coupled wave module performs a decoupling decision and, in response to the grating array and the optical modulator, performs beam combining control drive.

[0031] Specifically, after receiving the laser conditions, the coupled-wave module first uses its pre-trained model library to perform a first-stage decoupling decision, extracting the optimal combination of optical parameters for the grating subarray, such as specific grating spacing, arrangement, and phase delay, forming the first parameter set. Next, the coupled-wave module imports the first parameter set into the second-stage beam-combining logic control, strategically reshaping the alignment, beam-combining, and shaping processes, and dynamically and selectively triggering optical shaping or spatial filtering operations when necessary. Throughout the process, the coupled-wave module establishes a bidirectional data link with the grating array and the optical modulator, receiving real-time sensor data such as temperature, phase, and power, and adjusting output commands within milliseconds to ensure a high degree of consistency between the physical process and the theoretical model, achieving precise beam combining.

[0032] This step achieves efficient interaction and precise control between the grating array and the optical modulator through phased decoupling decisions based on laser conditions, improving the flexibility and accuracy of beam combining control and significantly enhancing the beam quality and stability of fiber lasers in various scenarios.

[0033] Furthermore, step S100 includes:

[0034] Step S110: Based on the grating array structure, perform first-order decision training based on optical coupling and decoupling to determine the first beam combining unit.

[0035] Step S120: Using collimation-bundling-shaping as the control logic and coupling conditions as the benchmark, perform second-order logic training to determine the second bundle unit.

[0036] Step S130: Cascade the first beam combiner unit and the second beam combiner unit to determine the coupled wave module.

[0037] Specifically, optical coupling refers to the effective superposition of different light beams or light fields in space and phase; optical decoupling refers to the separation or interference elimination of light beams or light fields. First-order decision training refers to preliminary training and model fitting based on a single feature or basic coupling relationship in the coupled-wave module, used to quickly screen and identify potential beam combining modes. First, grating array structure data is imported, including the physical characteristics of each grating and the geometric arrangement information of the array. The coupled-wave module performs first-order decision training on this input data using supervised learning algorithms (such as convolutional neural networks or support vector machines). The main goal is to explore the most basic optical coupling relationships and decoupling states between gratings, thereby quickly identifying which grating combinations can achieve efficient light energy combining. This training process includes data preprocessing, feature extraction, and model fine-tuning, ultimately forming the first beam combining unit. The first beam combining unit is a preliminary, coarse-grained beam combining model formed based on the first-order decision training results, which can be further superimposed or optimized in subsequent processes.

[0038] Second-order logic training refers to the training and optimization of a higher-order, more refined model based on the first beam combiner unit, taking into account multiple dimensions (optical path collimation, beam combining efficiency, shaping requirements, etc.). The grating subarray combination of the first beam combiner unit is used as input, and second-order logic training is performed using more complex collimation-beam combining-shaping optical path control logic. The training focuses on phase matching, intensity equalization, and spatial shaping of the multiple beams, ensuring that the combined beam can still achieve stable, high-quality output under different laser conditions and variable environments. The module uses a deeper neural network model or ensemble decision tree model, integrating optical characteristics, mechanical control factors (such as optical stage attitude), and environmental variables such as dynamic thermal drift, to refine the output of the second beam combiner unit. The second beam combiner unit is a further refined and improved beam combining model after second-order logic training, possessing higher robustness and adaptability, and capable of achieving higher beam quality and stability under different coupling conditions.

[0039] The control logic, optical parameters, and coupling characteristics of the first and second beam combining units are systematically integrated and cascaded through a neural network coupling layer or a self-attention mechanism layer within the module to form a unified beam combining control module, namely the coupled wave module. This coupled wave module can not only dynamically switch the combination mode of the first and second beam combining units, but also flexibly adjust the beam combining mode according to actual laser conditions and the state of the fiber laser. The coupled wave module establishes a real-time communication channel with the grating array and optical modulator, possessing self-learning, self-correction, and dynamic adaptation capabilities, achieving efficient beam combining drive.

[0040] Taking a neural network as an example, the training process of the coupled-wave module is as follows: First, grating array structure data is collected as input features, including basic parameters such as the center wavelength, reflectivity, fiber length, and arrangement position of each grating. Simultaneously, beam combining performance indicators (such as beam coherence, beam combining efficiency, and spot shape) are acquired as label data. The neural network first performs first-order decision training in the first stage, mainly identifying the basic coupling relationships between the grating subarrays in the grating array. The network structure can be designed as several convolutional layers plus pooling layers for automatically extracting coupling feature maps. For example, the coupled-wave module neural network uses 3 convolutional layers (each with a 3×3 kernel size and 64 channels), 2 pooling layers, and 3 fully connected layers at the back end (128, 64, and 10 neurons respectively). The input data is a 10-dimensional parameter vector of the grating array, and the output is the label category of the beam combining mode (the number of the grating combination and its beam combining efficiency). After completing the first stage, the model introduces second-order logic training in the second stage. The network structure, after feature extraction from convolutional layers, incorporates multiple fully connected layers, combining the laser's collimation-beam combining-shaping control logic with additional coupling conditions (such as phase matching and beam shaping parameters) for higher-order mode optimization. To ensure model generalization and robustness, the training dataset can be generated through experimental measurements or simulated optical modeling (e.g., BPM simulation of array response using the beam propagation method). Model training employs a supervised learning cross-entropy loss function (or a mean squared error loss function for regression tasks), and introduces L2 regularization to suppress overfitting. Finally, the neural network can adaptively output the configuration of the first and second beam combining units based on the input grating array and optical conditions, and dynamically switch between modules through soft switching or self-attention mechanisms.

[0041] Furthermore, in step S300, based on the laser conditions, the coupled wave module performs a decoupling decision, including:

[0042] Step S310: Receive the laser conditions, import them into the first beam combining unit, perform decoupling decision based on the grating array structure, and determine the first parameter group, wherein the first parameter group includes grating parameters and arrangement based on the grating subarray, and the grating subarray is the part of the array grating that participates in beam combining.

[0043] Step S320: Import the first parameter group into the second beam combining unit, perform logical reshaping of the control drive, and determine the beam combining strategy, wherein the collimation and shaping stages are selectively triggered.

[0044] Specifically, after receiving the laser conditions, the coupling wave module inputs them into the first beam combining unit. The first beam combining unit then makes decoupling decisions based on the grating array structure information, determining which grating subarrays (i.e., combinations of partial gratings) are more suitable for beam combining, ensuring the coherence and matching of the beam during coupling. The first beam combining unit quickly outputs a first set of parameters through a pre-trained neural network or decision model. This first set of parameters specifically determines the grating subarrays (e.g., gratings 1, 3, and 5) participating in beam combining within the arrayed grating, their arrangement (e.g., centrosymmetric or compact arrangement), and specific optical parameters (e.g., 80% reflectivity, 20° phase retardation, etc.). The grating subarray is the part of the arrayed grating that actually participates in beam combining; it can be a subset or a specific region of the entire grating array.

[0045] Next, the coupled wave module imports the first parameter set into the second beam combining unit. Based on this, the second beam combining unit performs more complex control-driven logic reshaping. Depending on different operating conditions and beam requirements, it dynamically determines whether to initiate beam collimation (correcting beam angular deviation) and shaping (compensating for uneven energy distribution and optimizing spot quality) stages during the beam combining process. If the laser conditions indicate the need for high power or high coherence operation, the second beam combining unit can trigger the collimation and shaping stages to achieve higher beam combining consistency. During the collimation stage, the second beam combining unit further adjusts the parameters of the grating subarray (such as fine-tuning the blaze angle and duty cycle of the grating) and the phase modulation state of the optical modulator based on information such as the beam divergence angle and direction, making the beam more parallel and directional. During the shaping stage, based on the beam intensity distribution, it optimizes the beam shape and intensity distribution by adjusting the arrangement of the grating subarray and the amplitude modulation of the optical modulator. Throughout the logical reshaping process, the second beam combining unit monitors beam quality indicators (such as beam quality factor and intensity uniformity) in real time and continuously optimizes the beam combining strategy based on the monitoring results until the combined beam meets all performance requirements specified by the laser conditions. Finally, a complete beam combining strategy is determined to guide the actual control operations of the grating array and optical modulator, achieving high-quality beam combining. The beam combining strategy is a set of overall control instructions generated by the second beam combining unit, containing the operational steps for driving the grating array, optical modulator, collimation module, and shaping module to achieve beam combining. All of these steps are executed synchronously through the real-time communication interface between the optical modulator and the grating array, ensuring precise matching of beam combining control actions.

[0046] Furthermore, a logical restructuring of the control-driven processes is performed, including:

[0047] Step S321: Introduce timestamp constraints and position code constraints, wherein the timestamp executes the time synchronization and asynchronous constraints of the array grating, and the position code executes the position constraints of the driving component;

[0048] Step S322: Logically integrate the bundle control based on the timestamp and the location code.

[0049] In this embodiment, timestamp constraints and position code constraints are first introduced as key synchronization and positioning parameters in the beam combining control process to ensure coordinated execution of all participating components in the array grating in both time and space dimensions. The timestamp constraint manages the activation sequence of each unit in the array grating; the timestamp information records and identifies the start-up time of each grating unit, thereby achieving time synchronization control and asynchronous triggering scheduling of the optical signal. For example, when multiple grating units need to be activated in a specific time sequence to form an interference beam combining effect, the start-up delay of each unit can be controlled by precisely set timestamps, thus preventing phase misalignment or signal interference between the laser outputs of multiple units.

[0050] Meanwhile, position code constraints are introduced to address the physical distribution characteristics of the driving components within the grating array structure. The position code is a unique spatial identifier parameter, assigning corresponding spatial position encoding information to each execution component in the grating array and optical modulator. This position code is used not only for component identification but also to constrain the spatial mapping between the transmission path of the driving signal and the target response, ensuring that control commands can accurately match the target component. For example, in a grating subarray, if it is necessary to selectively activate grating elements located in a specific region, directional driving can be performed based on pre-calibrated component position codes, thereby avoiding accidental triggering in non-target areas.

[0051] Furthermore, based on the synergistic effect of the timestamps and position codes mentioned above, a logical integration operation for beam combining control is further executed. This integration process essentially involves a logic controller uniformly parsing the constraint parameters in both the temporal and spatial dimensions to generate an executable beam combining activation logic sequence. For example, based on the target beam combining scheme, the control system extracts a time-position mapping matrix from the database that conforms to the target power distribution or beam shape requirements. Through logical integration, this matrix is ​​converted into a set of specific control signals used to schedule the individual light-emitting units in the array grating. In this way, both the spatiotemporal consistency of dynamic coordination during laser beam combining is achieved, and the response capability of the array grating to complex beam combining strategies is improved, enhancing the stability and flexibility of the system in multi-channel laser integrated applications.

[0052] Furthermore, in step S300, in response to the grating array and the optical modulator, the following is included:

[0053] Step S330: Based on the response objective, the bundle strategy is split to determine sub-strategies.

[0054] Step S340: Apply timestamp constraints to the sub-strategy in response to the grating array and the optical modulator, wherein the timestamp includes a synchronous timestamp and an asynchronous timestamp.

[0055] Specifically, the response objective refers to the specific response actions or requirements that need to be achieved during the beam combining process. These may include specific response behaviors such as power adjustment of different fiber channels, beam spot shape correction, and suppression of thermal drift. First, the ultimate goal (i.e., the response objective) to be achieved by the beam combining strategy is clearly defined, such as obtaining a high-quality combined beam that meets laser conditions. Then, the various stages and steps required to achieve this ultimate goal are analyzed, such as the initial beam focusing stage, the collimation adjustment stage, and the shaping optimization stage. For each stage, its corresponding response objective is determined. For example, in the initial focusing stage, the response objective is to converge multiple beams into a general area; in the collimation adjustment stage, the response objective is to adjust the converged beam into a parallel beam, etc. Based on these response objectives, the beam combining strategy is broken down into multiple sub-strategies. Each sub-strategy contains specific control parameters and operation steps for the corresponding stage, such as the adjustment parameters of the grating array and the modulation state of the optical modulator, to guide the control operations of the grating array and optical modulator at different stages. For example, sub-strategy one includes adjusting the period and duty cycle of the grating subarray to achieve initial beam convergence; sub-strategy two includes adjusting the blaze angle of the grating and the phase modulation of the optical modulator to achieve beam collimation, etc.

[0056] Timestamp constraints refer to the time limits set for the execution of sub-strategies, ensuring that each sub-strategy is completed within the specified time, thereby guaranteeing the timing and coordination of the entire beam combining control process. Timestamps include synchronous and asynchronous timestamps, used to distinguish the execution timing and order of different sub-strategies. Synchronous timestamps are used to identify that multiple sub-strategies or multiple control operations need to be executed synchronously at the same time point or within the same time period, ensuring the coordination and consistency between these operations and ensuring that the joint control of the grating array and optical modulator can be carried out in an orderly manner. Asynchronous timestamps are used to identify that sub-strategies or control operations can be executed at different time points or within different time periods. They are suitable for some relatively independent control tasks, allowing for flexible arrangement of the execution order and time according to actual conditions, improving the flexibility and efficiency of beam combining control.

[0057] Based on the timing requirements of the beam combining control process and the dependencies between different sub-strategies, a synchronous or asynchronous timestamp is assigned to each sub-strategy. For sub-strategies that need to be executed synchronously, such as the adjustment of the grating array and the phase modulation of the optical modulator, the same synchronous timestamp is assigned to ensure that they are executed at the same time point or within the same time period, thus achieving coordinated work between the two. For sub-strategies that can be executed asynchronously, such as the initial adjustment of the grating array and subsequent fine adjustment, different asynchronous timestamps are assigned to allow them to be executed at different time points, flexibly arranging the execution order according to the actual operating conditions. During execution, the execution timing of each sub-strategy is precisely controlled according to the timestamp indication, ensuring that the grating array and the optical modulator respond in a predetermined time sequence. For example, at one moment, according to the synchronous timestamp indication, control signals for adjusting the period and duty cycle are simultaneously sent to the grating array, and control signals for phase modulation are sent to the optical modulator, so that the two execute the corresponding sub-strategies synchronously; at another moment, according to the asynchronous timestamp indication, control signals for adjusting the arrangement spacing are first sent to the grating array, and after its execution is completed, control signals for amplitude modulation are sent to the optical modulator, achieving asynchronous execution.

[0058] By refining the beam combining strategy into controllable sub-strategies and adding flexible timestamp constraints, the coordinated adjustment of the grating array and the optical modulator is realized, improving the flexibility and stability of beam combining control and meeting the high-precision beam combining output requirements of diverse laser application scenarios.

[0059] The sub-strategy is constrained by a position code in response to the grating array and the optical modulator, wherein each component in the grating array and the optical modulator is identified by a unique code.

[0060] In this embodiment, position code constraints are introduced for the decomposed sub-strategies to achieve spatial positioning control of each execution component in the grating array and optical modulator. Each sub-strategy is a specific control sequence derived from the overall beam combining strategy, and each sub-strategy corresponds to a specific optical path or beam combining control target for a sub-array unit. To ensure that each sub-strategy can accurately act on its target component, position codes are used as constraint identifiers and embedded into the scheduling logic of the sub-strategy.

[0061] The position code is a unique coded identifier assigned to each component in the array grating and optical modulator, used to describe the specific location of the component in the entire spatial structure. By pre-establishing a mapping relationship between position codes and component physical addresses, the control system can achieve precise response to target components based on position code information when executing sub-strategies. For example, when a sub-strategy requires adjusting the grating element in the m-th row and n-th column of the array to change its emission angle or phase, the unique position code of the component is first identified, and then the control signal is directionally sent to the drive unit corresponding to that code to complete targeted activation.

[0062] Furthermore, location code constraints are not only used for component identification and target locking, but also for interference isolation and priority determination in multi-component collaborative control processes. In the case of concurrent execution of multiple sub-policies, the target domain corresponding to each policy can be quickly distinguished based on the location code, avoiding cross-interference of control signals and ensuring that the physical objects controlled by each sub-policy do not overlap, thereby improving the overall system stability and scheduling efficiency.

[0063] In summary, the introduction of position code constraints enables the sub-strategy to establish a strict one-to-one correspondence between the grating array and the optical modulator, realizing an efficient mapping of the beam combining control strategy from the logic level to the execution level. This helps to improve the accuracy, reliability, and modular scalability of the multi-dimensional beam control system.

[0064] Furthermore, step S300 executes the beam-combining control drive, including:

[0065] Step S350: Set step control conditions, wherein the step control conditions are single amplitude modulation constraints of the fiber laser component adjustment.

[0066] Step S360: Based on the switching of the laser conditions and the start / stop of the fiber laser, determine whether the step control condition is met. If not, perform control linearization processing.

[0067] Specifically, step control conditions refer to the upper limit of the single adjustment amplitude of hardware components (such as grating arrays and optical modulators) during the beam combining process of a fiber laser. This is used to prevent instability or shortened device lifespan caused by sudden large-amplitude adjustments. First, step control conditions are set for each key component of the fiber laser (such as grating arrays and optical modulators), clarifying the maximum allowable adjustment amplitude for each component during a single adjustment, i.e., single-amplitude constraints. Examples include the maximum offset range for phase adjustment and the safe range for light intensity adjustment. These single-amplitude constraints are determined based on the physical characteristics and reliability standards of the fiber laser.

[0068] Control linearization refers to the process of switching to a smooth, continuous, small-amplitude gradual adjustment strategy when the conditions for a step adjustment are not met, thus avoiding the negative impact of large jumps. When a change in the laser's operating conditions is detected (e.g., laser power switching from 5W to 10W) ​​or a laser start-up / shutdown action (e.g., restarting from a powered-off state), real-time detection data is used to determine whether the current hardware components will exhibit an excessively rapid instantaneous response. If the adjustment amplitude exceeds a preset safety threshold, control linearization is triggered, dynamically adjusting the control command to avoid sudden large jumps. Specifically, the parameter change originally planned for a single adjustment is decomposed into multiple continuous, small-amplitude adjustment steps, forming a smooth, approximately linear change curve. This ensures the final parameter attainment while avoiding optical instability or hardware losses caused by excessively rapid adjustments. This process can be achieved through hardware and software collaboration; for example, using a digital signal processor (DSP) to dynamically generate multiple small-amplitude control command sequences, or using a closed-loop feedback control module (e.g., a PID controller) to dynamically correct the command amplitude, achieving safe and smooth beam-combining control.

[0069] By introducing step control conditions and linearization processing based on real-time detection, the beam combining process is made smooth, controllable, and highly reliable, thus improving the overall safety of the fiber laser array grating beam combining process.

[0070] Furthermore, the execution of bundle control drive also includes:

[0071] Step S370: Perform multi-channel temperature monitoring, evaluate thermally induced wavelength drift, and determine the drift coefficient. The evaluation is based on the thermo-optical properties of the grating array material, and the multi-channel refers to the part of the array grating that participates in the light beam combination.

[0072] Step S380: Perform gradient temperature control compensation based on the drift coefficient.

[0073] Specifically, multi-channel temperature monitoring refers to the real-time acquisition and monitoring of the temperature of multiple sub-units within the array grating during the beam combining process of a fiber laser array grating, ensuring that the temperature state of each channel is captured independently and accurately. Thermally induced wavelength drift refers to the center wavelength shift caused by the thermo-optical properties of the grating material (such as changes in thermal expansion coefficient and thermo-optical refractive index). The drift coefficient is the ratio or response coefficient between thermally induced wavelength drift and temperature change, usually expressed as the ratio of thermally induced wavelength drift to temperature change (unit: nm / K).

[0074] In the beam combining process of fiber laser array gratings, temperature variation is a crucial factor affecting the beam combining quality and stability, especially when multiple grating units participate in beam combining simultaneously. Local temperature differences can lead to thermally induced wavelength drift, disrupting beam combining coherence. First, high-precision temperature sensors (such as NTC thermistors, integrated temperature chips, etc.) are deployed on each sub-array unit participating in beam combining within the array grating, forming a multi-channel temperature monitoring network to collect temperature data from each channel in real time. Next, based on the thermo-optical properties of the grating array material, combined with historical experimental data or dynamic calibration models, the temperature-wavelength response of each channel is modeled, and the thermally induced drift coefficient of each sub-array is calculated, forming the drift coefficient for each channel. Using these drift coefficients, customized temperature compensation is applied to each channel of the array grating through a temperature control module (such as thermoelectric coolers, microheaters, etc.). The compensation strategy employs a gradient approach, prioritizing adjustment for the channel with the highest temperature or most severe drift, while also considering the temperature balance between adjacent channels, forming a gradient temperature control field to gradually offset the wavelength drift of each channel and restore beam combining consistency. The entire process is executed in a closed loop by a temperature feedback controller (such as a PID temperature control unit) to achieve a fast and dynamic temperature control response.

[0075] By employing multi-channel temperature monitoring, quantitative evaluation of drift coefficients, and gradient temperature control compensation, the coherence, stability, and long-term reliability of the beam combining process are significantly improved, providing strong support for high-quality beam combining of fiber lasers in complex application scenarios.

[0076] Furthermore, after executing the bundle control drive, the following steps are included:

[0077] Step S410: Establish a temporary database, wherein the temporary database is used to store bundle merging operation records.

[0078] Step S420: Map the beam combining operation record - laser conditions and store them in the temporary database.

[0079] Step S430: According to the preset period, the non-consistent features between the beam combining effect and the laser conditions are explored, the driving source is traced, and the beam combining drift point is located, wherein the preset frequency is used as the exploration constraint condition.

[0080] Step S440: Based on the beam-combining drift point, make targeted adjustments to the hardware components and coupling wave module of the fiber laser.

[0081] Specifically, a temporary database refers to a database specifically used in fiber laser array grating beam combining control systems for short-term or phased storage of various operational data, control parameters, and detection results during the beam combining process. It features fast writing, real-time response, and periodic cleaning. Beam combining operation records refer to a complete record of the specific operational steps, control parameters, and execution status generated during the beam combining process. Inconsistent characteristics refer to deviations or abnormal states between the beam combining effect and laser conditions, such as power shifts and decreased coherence. Beam combining drift points refer to the core control parameters or hardware components that cause changes in the beam combining effect, as determined after drive tracing analysis.

[0082] In the beam combining control of arrayed gratings in fiber lasers, beam combining stability and long-term consistency are crucial indicators. To achieve full-cycle monitoring and traceability of the beam combining process, a temporary database is first established to store multi-dimensional data generated during beam combining in real time, including beam combining operation parameters, coupling wave module status, temperature control parameters, and other beam combining operation records. Next, the beam combining operation records are mapped to the real-time received laser conditions, establishing a correlation table or mapping model to ensure complete data support for subsequent traceability analysis.

[0083] The process automatically initiates a non-consistency feature mining workflow according to a set analysis cycle (e.g., 10 minutes, 1 hour, etc.), using data mining algorithms (e.g., clustering, association analysis, anomaly detection, etc.) to find deviations between the beam combining effect (e.g., beam combining efficiency, output power stability) and laser conditions (e.g., input power, wavelength). For example, if a temperature change causes abnormal fluctuations in output power, this data is automatically marked as a beam combining drift point. Finally, based on these drift points, targeted fine-tuning or parameter correction is performed on the fiber laser's hardware components (e.g., the thermal control unit of the grating array, the driver components of the optical modulator) and the coupling wave module (e.g., the weight parameters of the neural network model, etc.) to restore the consistency and efficiency of the beam combining output. For example, in a typical beam combining task, a temporary database is written with information such as beam combining power, grating temperature, and drive current every second. After one hour of operation, the temporary database records non-consistency features such as a surge in grating array temperature and a decrease in beam combining power. Through data mining algorithms, the temperature drift point caused by the temperature control response delay of channel 5 is located. The temperature control PID parameters of channel 5 are then automatically adjusted, the heating power is finely tuned, and the grating phase compensation parameters in the coupled wave module are updated, ultimately restoring the combined power to the nominal value.

[0084] By establishing a temporary database, mapping operation records and laser conditions after beam combining control is driven, and discovering beam combining drift points based on periodic mining, targeted optimization and adjustment of hardware components and coupling wave modules are finally achieved, significantly improving the beam combining consistency and long-term stability of fiber lasers.

[0085] In summary, the array grating beam combining control method for fiber lasers provided by the embodiments of the present invention has the following beneficial effects:

[0086] By acquiring the physical structure data and key parameters of the grating array and combining them with supervised training, an intelligent coupled-wave module is established. This coupled-wave module communicates with the grating array and optical modulator to achieve dynamic interaction, providing intelligent decision support for subsequent beam combining control operations. Upon receiving laser conditions, the module clarifies the specific goals and requirements for beam combining, i.e., the beam combining criteria, providing a basis and direction for subsequent decoupling decisions and beam combining control. This allows the entire control process to flexibly adjust the beam combining strategy according to different laser conditions. After receiving the laser conditions, the coupled-wave module executes decisions in stages: the first stage performs decoupling decisions based on the parameters of the grating subarray, forming the first parameter set; the second stage logically reorganizes the beam combining strategy, flexibly switching collimation, beam combining, and shaping operations to generate a precise beam combining strategy. Subsequently, the beam combining strategy is decomposed and synchronous and asynchronous timestamps are introduced to ensure that the grating array and optical modulator can respond according to precise time and sequence, improving the timing accuracy and dynamic adaptability of beam combining control. By setting step control conditions, a smooth transition is ensured during laser condition switching or start-stop processes, avoiding beam combining instability caused by sudden condition changes. By using multi-channel real-time temperature monitoring and compensating for the thermo-optical properties of materials, the beam-combining stability under complex operating conditions is significantly improved. Finally, by establishing a temporary database and tracing beam-combining operation records, historical records and periodic mining of the beam-combining process are achieved. This allows for the location of drift points and reverse optimization of hardware components and coupling wave modules, forming a closed-loop optimization that improves the beam-combining consistency and long-term operational reliability of fiber lasers.

[0087] Overall, the embodiments of this invention achieve high-precision, high-stability, and high-flexibility control of fiber laser array grating beam combining through multi-level decision-making, dynamic response, temperature monitoring compensation, and process monitoring optimization. Under different laser conditions, it can quickly and accurately make decoupling decisions and execute beam combining operations, while effectively responding to interference from external factors such as temperature changes, ensuring the continuous stability of the beam combining effect. By establishing a temporary database and a drive traceability mechanism, the beam combining process can be continuously optimized and improved, enhancing beam combining stability and adapting to diverse laser conditions, thus meeting the needs of fiber lasers in high-precision, high-performance applications.

[0088] Example 2, as Figure 2 As shown, based on the same inventive concept as in Embodiment 1 above, this embodiment of the invention provides an array grating beam combining control system for a fiber laser, the system comprising:

[0089] The coupled wave module training unit 10 is used to acquire the grating array structure, using collimation-beam combining-shaping as the control logic and grating parameters and arrangement as the coupling conditions to supervise the training of the coupled wave module. The coupled wave module establishes a communication connection with the grating array and the optical modulator.

[0090] Laser condition receiving unit 20 is used to receive laser conditions, wherein the laser conditions are beam combining standards.

[0091] The beam combining control drive unit 30 is used to perform decoupling decisions by the coupled wave module according to the laser conditions, and to perform beam combining control drive in response to the grating array and the optical modulator.

[0092] Furthermore, in this embodiment of the invention, the coupled wave module training unit 10 is also used to perform the following steps:

[0093] Based on the grating array structure, first-order decision training based on optical coupling and decoupling is performed to determine the first beam combining unit; second-order logic training is performed with collimation-beam combining-shaping as the control logic and coupling conditions as the reference to determine the second beam combining unit; the first beam combining unit and the second beam combining unit are cascaded to determine the coupled wave module.

[0094] Furthermore, in this embodiment of the invention, the beam-combining control drive unit 30 is also used to perform the following steps:

[0095] The laser conditions are received and imported into the first beam combining unit. Decoupling decisions are made based on the grating array structure to determine a first parameter set, wherein the first parameter set includes grating parameters and arrangement based on the grating subarray, and the grating subarray is the part of the array grating that participates in beam combining. The first parameter set is imported into the second beam combining unit for logical reorganization of control drive to determine the beam combining strategy, wherein the collimation and shaping stages are selectively triggered.

[0096] Furthermore, in this embodiment of the invention, the beam-combining control drive unit 30 is also used to perform the following steps:

[0097] Timestamp constraints and position code constraints are introduced, wherein the timestamp executes the time synchronization and asynchronous constraints of the array grating, and the position code executes the position constraints of the driving component; based on the timestamp and the position code, the logical integration of beam combining control is performed.

[0098] Furthermore, in this embodiment of the invention, the beam-combining control drive unit 30 is also used to perform the following steps:

[0099] Based on the response objective, the beam combining strategy is split to determine sub-strategies; the sub-strategies are time-stamped in response to the grating array and the optical modulator, wherein the timestamps include synchronous timestamps and asynchronous timestamps.

[0100] Furthermore, in this embodiment of the invention, the beam combining control drive unit 30 is also used to perform the following steps: applying position code constraints to the sub-strategy in response to the grating array and the optical modulator, wherein each component in the grating array and the optical modulator is identified by a unique code.

[0101] Furthermore, in this embodiment of the invention, the beam-combining control drive unit 30 is also used to perform the following steps:

[0102] A step control condition is set, wherein the step control condition is a single amplitude modulation constraint of the fiber laser component adjustment; the switching of the laser condition and the start and stop of the fiber laser are used to determine whether the step control condition is met. If it is not met, control linearization processing is performed.

[0103] Furthermore, in this embodiment of the invention, the beam-combining control drive unit 30 is also used to perform the following steps:

[0104] Multi-channel temperature monitoring is performed to evaluate thermally induced wavelength drift and determine the drift coefficient. The evaluation is based on the thermo-optical properties of the grating array material, and the multi-channel refers to the part of the array grating that participates in the light-combining beam. Gradient temperature control compensation is performed based on the drift coefficient.

[0105] Furthermore, the system described in this embodiment of the invention is also used to perform the following steps:

[0106] A temporary database is established to store beam combining operation records. The beam combining operation records are mapped to laser conditions and stored in the temporary database. According to a preset period, the non-consistent features between the beam combining effect and the laser conditions are mined, and the source of the driving is traced to locate the beam combining drift point, wherein a preset frequency is used as the mining constraint. Based on the beam combining drift point, the hardware components and coupling wave module of the fiber laser are adjusted accordingly.

[0107] Through the foregoing detailed description of an array grating beam combining control method for a fiber laser, those skilled in the art can clearly understand that the array grating beam combining control system for a fiber laser in this embodiment corresponds to the system disclosed in Embodiment 2, as it has corresponding functional units and beneficial effects as it corresponds to the method disclosed in Embodiment 1. For relevant details, please refer to the method section.

[0108] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the beam combining of an array grating in a fiber laser, characterized in that, The method includes: The structure of the grating array is obtained, and the collimation-beam combining-shaping is used as the control logic, and the grating parameters and arrangement are used as the coupling conditions to supervise the training of the coupled wave module. The coupled wave module establishes a communication connection with the grating array and the optical modulator. Laser receiving conditions, wherein the laser conditions are beam combining criteria; Based on the laser conditions, the coupled wave module performs a decoupling decision and, in response to the grating array and the optical modulator, performs beam combining control drive. The supervised training coupled-wave module includes: Based on the grating array structure, a first-order decision training based on optical coupling and decoupling is performed to determine the first beam combining unit; Using collimation-beam combining-shaping as the control logic and coupling conditions as the benchmark, second-order logic training is performed to determine the second beam combining unit; The first beam combiner unit and the second beam combiner unit are cascaded to determine the coupled wave module.

2. The array grating beam combining control method for a fiber laser as described in claim 1, characterized in that, Based on the laser conditions, the coupled wave module performs a decoupling decision, including: The laser conditions are received and imported into the first beam combining unit. Decoupling decisions are made based on the grating array structure to determine the first parameter group. The first parameter group includes grating parameters and arrangement based on the grating subarray. The grating subarray is the part of the array grating that participates in beam combining. The first parameter set is imported into the second beam combining unit for logical reshaping of the control drive to determine the beam combining strategy, wherein the collimation and shaping stages are selectively triggered.

3. The method as described in claim 2, characterized in that, Perform logical restructuring of control-driven processes, including: The system introduces timestamp constraints and position code constraints, wherein the timestamp executes the time synchronization and asynchronous constraints of the array grating, and the position code executes the position constraints of the driving component. Logical integration of bundle control is performed based on the timestamp and the location code.

4. The array grating beam combining control method for a fiber laser as described in claim 3, characterized in that, Responsive to the grating array and the optical modulator, including: Based on the response objective, the bundle combination strategy is broken down to determine sub-strategies; The sub-strategy is time-stamped in response to the grating array and the optical modulator, wherein the timestamps include synchronous timestamps and asynchronous timestamps.

5. The method as described in claim 4, characterized in that, The sub-strategy is subject to position code constraints in response to the grating array and the optical modulator, wherein each component in the grating array and the optical modulator is identified by a unique code.

6. The array grating beam combining control method for a fiber laser as described in claim 1, characterized in that, Execute bundle control drive, including: Set a step control condition, wherein the step control condition is a single amplitude modulation constraint of the fiber laser component adjustment; The switching of laser conditions and the start / stop of the fiber laser are used to determine whether the step control conditions are met. If not, control linearization is performed.

7. The array grating beam combining control method for a fiber laser as described in claim 1, characterized in that, Execute bundle control drive, including: Multi-channel temperature monitoring was performed to evaluate thermally induced wavelength drift and determine the drift coefficient. The evaluation was based on the thermo-optical properties of the grating array material, and the multi-channel refers to the part of the array grating that participates in the light-combining beam. Gradient temperature control compensation is performed based on the drift coefficient.

8. The array grating beam combining control method for a fiber laser as described in claim 1, characterized in that, After executing the bundle-combining control drive, the following is included: A temporary database is established, wherein the temporary database is used to store bundle merging operation records; The laser conditions of the beam combining operation are mapped and stored in the temporary database; According to the preset cycle, the non-consistent features between the beam combining effect and the laser conditions are explored, and the driving source is traced to locate the beam combining drift point. The preset frequency is used as the exploration constraint. Based on the beam-combining drift point, the hardware components and coupling wave module of the fiber laser are adjusted accordingly.

9. A fiber laser array grating beam combining control system, characterized in that, The system is used to execute the array grating beam combining control method for a fiber laser according to any one of claims 1-8, comprising: The coupled-wave module training unit is used to acquire the grating array structure, using collimation-beam combining-shaping as the control logic and grating parameters and arrangement as the coupling conditions to supervise the training of the coupled-wave module. The coupled-wave module establishes a communication connection with the grating array and the optical modulator. A laser condition receiving unit is used to receive laser conditions, wherein the laser conditions are beam combining criteria; A beam combining control drive unit is used to perform decoupling decisions by the coupled wave module according to the laser conditions, and to perform beam combining control drive in response to the grating array and the optical modulator.

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