An acousto-optic modulation component auxiliary measurement calibration system and response curve calibration method

Abstract

The application discloses an acousto-optic modulation component auxiliary measurement calibration system and a response curve calibration method. The system comprises a first signal chain connected by a digital I / O module, a direct digital frequency synthesis module, a first power amplifier, an acoustic deflector, a first photodetector and a first oscilloscope in sequence. The frequency drive word and the amplitude drive word of the acoustic deflector are double-dimensionally traversed and calibrated to generate a response curve mapping table. The second signal chain is connected by an arbitrary waveform generator, a second power amplifier, an acoustic modulator, a second photodetector and a second oscilloscope in sequence. The amplitude sequence scanning is performed on each channel of the acoustic modulator to generate a channel dose distribution curve. The upper computer control module is in communication connection with the two signal chains. The timing control and data acquisition are coordinated through a synchronous trigger acquisition mechanism. The two types of calibration results are associated and calculated to generate a joint calibration data set for the whole machine. The application is suitable for the whole machine level collaborative calibration of acousto-optic modulation devices in precision optical control equipment such as laser processing and photoetching.

Description

Technical Field

[0001] This invention relates to the field of testing and calibration technology for acousto-optic modulation devices, and in particular to a test and calibration system for acousto-optic modulation components and a method for calibrating response curves. Background Technology

[0002] In laser processing, photolithography, and precision optical control equipment, acoustic deflectors (AOD) and acoustic modulators (AOM) are core components for achieving beam deflection and optical power modulation. To ensure the overall optical power control accuracy, the response relationship between the driving parameters of these components and the diffracted optical power needs to be calibrated before installation.

[0003] However, existing calibration schemes for acousto-optic modulators typically only test a single device or a single driving dimension (such as only the scanning frequency dimension), failing to cover the full range of response characteristics across the driving parameter space, resulting in calibration blind spots in practical applications. Furthermore, the calibration of each device is independent, lacking the ability to coordinate the calibration of acoustic deflectors and modulators at the system-wide level, making it difficult to meet the requirements for precise optical power control at the system-wide level. In addition, existing schemes rely on manual operation, lack a systematic testing process, and do not possess self-calibration and fault location functions during service, resulting in high maintenance costs. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration system and response curve calibration method for acousto-optic modulation components, in order to solve the following technical problems existing in the prior art: existing acousto-optic modulation device calibration schemes can only test a single device or a single driving dimension, and cannot cover the full range of response characteristics of the driving parameter space, resulting in calibration blind spots; the calibration work of each device is independent of each other, and there is a lack of ability to coordinate the calibration of acoustic deflectors and acoustic modulators at the whole machine level; and existing schemes rely on manual operation, do not have in-service self-calibration and fault location functions, and have high maintenance costs.

[0005] To achieve the above objectives, the first technical solution of the present invention is: A calibration system for an acousto-optic modulation component includes: Digital I / O modules are used to output multi-channel drive word signals; A direct digital frequency synthesis module, signal-connected to the digital I / O module, is used to generate a corresponding radio frequency signal based on the received drive word signal; A first power amplifier, connected to the direct digital frequency synthesis module, is used to amplify the radio frequency signal and drive the acoustic deflector. An acoustic deflector, connected to the signal of the first power amplifier, is used to perform acousto-optic deflection of the incident light beam according to the radio frequency signal, and output diffracted light; An arbitrary waveform generator is used to output radio frequency drive signals with a preset amplitude sequence. The second power amplifier, connected to the arbitrary waveform generator, is used to amplify the radio frequency drive signal and drive the acoustic modulator. An acoustic modulator, connected to the second power amplifier, is used to perform acousto-optic modulation on the incident beam according to the radio frequency drive signal, and output diffracted light from each channel. The photoelectric detection module is used to collect the diffracted light power output by the acoustic deflector and the acoustic modulator, and generate an optical power electrical signal; An oscilloscope module, connected to the photoelectric detection module, is used to acquire waveform data of the optical power electrical signal; The host computer control module is communicatively connected to the digital I / O module, the arbitrary waveform generator, and the oscilloscope module, respectively. It is used to control the digital I / O module to perform a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector, control the arbitrary waveform generator to output radio frequency drive signals to each channel of the acoustic modulator in sequence, and generate an acoustic deflector response curve mapping table, an acoustic modulator channel dose distribution curve, and a joint calibration dataset based on the waveform data collected by the oscilloscope module.

[0006] Preferably, the direct digital frequency synthesis module is configured to generate radio frequency signals with corresponding center frequency and amplitude based on the combination of frequency drive word and amplitude drive word, wherein the value range of the frequency drive word covers the full operating frequency range of the acoustic deflector.

[0007] Preferably, the host computer control module is further configured to control the arbitrary waveform generator to sequentially switch the output of the radio frequency drive signals corresponding to each channel according to a preset channel sequence, so as to perform sequential calibration on each channel of the acoustic modulator.

[0008] Preferably, the host computer control module is further configured to delay a preset stabilization waiting time after sending a drive word switching command to the digital I / O module or the arbitrary waveform generator, and then send a trigger acquisition command to the oscilloscope module; the preset stabilization waiting time is determined according to the response time constant of the acoustic deflector or the acoustic modulator.

[0009] Preferably, the host computer control module is further configured to execute a maintenance self-calibration working mode: call a pre-stored benchmark calibration dataset, execute a simplified calibration process, compare the deviation between the real-time measurement results and the corresponding data in the benchmark calibration dataset, and output the working status judgment results of each module based on the deviation comparison results.

[0010] Preferably, the deviation comparison includes: independently testing the acoustic deflector signal chain and the acoustic modulator signal chain respectively, and locating the fault to a specific hardware module by comparing the signal injection at each stage with the optical power, and generating a fault location report.

[0011] Preferably, the joint calibration dataset includes a three-dimensional mapping table between the frequency drive word, amplitude drive word and diffraction power of the acoustic deflector, and a two-dimensional curve between the radio frequency drive amplitude and diffraction power of each channel of the acoustic modulator. The three-dimensional mapping table and the two-dimensional curve are associated and indexed through a unified drive parameter coordinate system.

[0012] To achieve the above objectives, the second technical solution of the present invention is: A method for calibrating the response curve of an acousto-optic modulation component includes: Step S1: The control digital I / O module performs a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector, and drives the acoustic deflector sequentially through the direct digital frequency synthesis module and the first power amplifier. The diffraction power under each combination of drive words is synchronously collected by the photoelectric detection module and the oscilloscope module to generate an acoustic deflector response curve mapping table; Step S2: Control the arbitrary waveform generator to sequentially output a preset amplitude sequence of radio frequency drive signals to each channel of the acoustic modulator, drive the acoustic modulator through the second power amplifier, and synchronously acquire the diffraction power of each channel through the photoelectric detection module and the oscilloscope module to generate the channel dose distribution curve of the acoustic modulator; Step S3: Perform correlation calculation between the acoustic deflector response curve mapping table and the acoustic modulator channel dose distribution curve to generate a joint calibration dataset for the whole machine.

[0013] Preferably, the method further includes step S4: In the maintenance self-calibration mode, a fast calibration is performed on the preset key driving byte points, the calibration results are compared with the historical data of the corresponding nodes in the benchmark dataset, the deviation rate is calculated, and the fault location process is triggered when the deviation rate exceeds the preset threshold.

[0014] The main technical effects of this invention are reflected in the following aspects: 1. By controlling the digital I / O module through the host computer control module to perform a two-dimensional nested traversal of the frequency drive word and amplitude drive word of the acoustic deflector, and combining it with the direct digital frequency synthesis module to generate the corresponding radio frequency signal in real time, a complete two-dimensional coverage of the acoustic deflector drive parameter space is achieved. This completely eliminates the calibration blind zone caused by calibrating only a single drive dimension in the existing technology. The response characteristics of the acoustic deflector are fully characterized, and the overall optical power control accuracy is effectively improved.

[0015] 2. By associating the acoustic deflector response curve mapping table with the acoustic modulator channel dose distribution curve, a joint calibration dataset for the whole machine is generated. The dataset is then indexed using a unified driving parameter coordinate system, enabling collaborative calibration of the acoustic deflector and acoustic modulator at the whole machine level. This overcomes the shortcomings of existing technologies where the calibration of each device is independent and cannot meet the requirements for precise optical power control at the whole machine level. It provides a complete driving parameter mapping relationship that can be directly called for the whole machine control system.

[0016] 3. By delaying the preset stabilization waiting time after the upper computer control module issues the driver word switching command before triggering the oscilloscope module to collect data, the synchronous triggering mechanism ensures that the sound field is fully established and stabilized before optical power is collected in each driver word state. This eliminates the impact of switching transients on data validity and ensures the accuracy and repeatability of calibration data. Compared with the existing test process that relies on manual operation, this significantly improves the degree of calibration automation and data consistency.

[0017] 4. By setting a self-calibration working mode for maintenance, the system can periodically call the pre-stored benchmark calibration dataset to perform a simplified calibration process during the service life of the whole machine. By injecting signals step by step and comparing optical power, the fault can be located to a specific hardware module. This solves the defects of existing technologies that do not have in-service self-calibration and fault location functions, greatly reduces the maintenance cost of precision optical control equipment, and improves the reliability of the whole machine. Attached Figure Description

[0018] Figure 1 This is a block diagram illustrating the overall structural principle of the acoustic-optic modulation component testing and calibration system in this embodiment. Figure 2 This is a schematic diagram showing the peak-to-peak values ​​at different frequencies when the grayscale value of the acoustic deflector is 200 in the embodiment. Figure 3 This is a schematic diagram showing the peak-to-peak values ​​corresponding to different amplitude values ​​when the acoustic deflector is fixed at a frequency of 200MHz in the embodiment. Figure 4 This is a schematic diagram of the dose of each channel under the condition of fixed acoustic deflector frequency and gray value in the embodiment; Figure 5 This is a schematic diagram showing the amplitude and peak-to-peak value of the acoustic deflector at different acoustic deflector frequencies in the embodiment.

[0019] Reference numerals: 10, Digital I / O module; 20, Direct digital frequency synthesis module; 30, First power amplifier; 40, Acoustic deflector; 51, First photodetector; 52, Second photodetector; 61, First oscilloscope; 62, Second oscilloscope; 70, Host computer control module; 80, Arbitrary waveform generator; 90, Second power amplifier; 100, Acoustic modulator. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so that the technical solution of the present invention can be more easily understood and mastered. Example 1

[0021] Reference Figure 1 The system's overall structural principle block diagram shown illustrates the acoustic-optical modulation component testing and calibration system, which includes a digital I / O module 10, a direct digital frequency synthesis module 20, a first power amplifier 30, an acoustic deflector 40, an arbitrary waveform generator 80, a second power amplifier 90, an acoustic modulator 100, a photoelectric detection module, an oscilloscope module, and a host computer control module 70. These modules form two parallel signal chains, used respectively for calibrating the response characteristics of the acoustic deflector 40 and the acoustic modulator 100. The photoelectric detection module includes a first photodetector 51 and a second photodetector 52, and the oscilloscope module includes a first oscilloscope 61 and a second oscilloscope 62.

[0022] The first signal chain is dedicated to calibrating the two-dimensional response characteristics of the acoustic deflector 40. The digital I / O module 10 has multi-channel parallel output capability. Its multi-channel parallel output terminal is connected to the drive word input terminal of the direct digital frequency synthesis module 20, used to write combinations of frequency drive words and amplitude drive words to the direct digital frequency synthesis module 20. Based on the received drive word combinations, the direct digital frequency synthesis module 20 synthesizes radio frequency signals corresponding to the center frequency and amplitude in real time. Its radio frequency output terminal is connected to the transducer input terminal of the acoustic deflector 40 via the first power amplifier 30. The first power amplifier 30 amplifies the radio frequency signal output by the direct digital frequency synthesis module 20 to achieve the power level required to drive the transducer of the acoustic deflector 40. The transducer of the acoustic deflector 40 receives the amplified radio frequency signal, excites sound waves in the acousto-optic medium, and generates an acousto-optic deflection effect on the incident light beam, forming diffracted light output. The diffracted light output end of the acoustic deflector 40 is aligned with the photosensitive surface of the first photodetector 51. The first photodetector 51 converts the received diffracted light power into an optical power electrical signal and transmits the electrical signal to the first oscilloscope 61. The first oscilloscope 61 acquires the waveform data of the optical power electrical signal and transmits the acquisition result to the host computer control module 70 through the communication interface.

[0023] The second signal chain is dedicated to calibrating the dose distribution curves of each channel of the acoustic modulator 100. The arbitrary waveform generator 80 outputs radio frequency (RF) drive signals according to a preset amplitude sequence. Its RF output terminal is connected to the transducer input terminals of each channel of the acoustic modulator 100 via the second power amplifier 90. The second power amplifier 90 amplifies the RF drive signals output by the arbitrary waveform generator 80, driving the transducers of the corresponding channels of the acoustic modulator 100. The acoustic modulator 100 performs acousto-optic modulation on the incident beam according to the RF drive signals, and each channel outputs corresponding diffracted light. The diffracted light output terminals of each channel of the acoustic modulator 100 are aligned with the photosensitive surface of the second photodetector 52. The second photodetector 52 collects the diffracted light power of each channel and converts it into an optical power electrical signal, which is then acquired by the second oscilloscope 62 and transmitted to the host computer control module 70.

[0024] The host computer control module 70 establishes communication connections with the digital I / O module 10, the arbitrary waveform generator 80, and the oscilloscope module, respectively, undertaking the unified timing control and data acquisition coordination functions of the two signal chains. The host computer control module 70 runs the control software and executes the following core control flow: First, it controls the digital I / O module 10 to perform a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector 40, using the frequency drive word as the outer loop variable and the amplitude drive word as the inner loop variable for nested traversal. The value range of the frequency drive word covers the entire operating frequency range of the acoustic deflector 40, and the value range of the amplitude drive word covers the entire amplitude control range of the acoustic deflector 40. For each drive word combination, after the host computer control module 70 issues a drive word switching command to the digital I / O module 10, it delays for a preset stable waiting time. After the sound field in the transducer of the acoustic deflector 40 has been fully established and stabilized, a trigger acquisition command is sent to the first oscilloscope 61. After being triggered, the first oscilloscope 61 acquires the waveform data of the optical power electrical signal output by the first photodetector 51. The host computer control module 70 reads the waveform data acquired by the first oscilloscope 61 and records the diffraction optical power value under the corresponding drive word combination. After traversing all drive word combinations, an acoustic deflector response curve mapping table is generated. This mapping table uses the frequency drive word and amplitude drive word as two-dimensional indexes and the diffraction optical power as the value, which fully characterizes the response characteristics of the acoustic deflector 40 in the full drive parameter space.

[0025] After the acoustic deflector 40 is calibrated, the host computer control module 70 controls the arbitrary waveform generator 80 to sequentially switch the output of the RF drive signal corresponding to each channel according to the preset channel sequence, and performs sequential calibration on each channel of the acoustic modulator 100 to avoid optical power crosstalk that may be caused by simultaneous excitation of multiple channels. For each channel of the acoustic modulator 100, the arbitrary waveform generator 80 outputs RF drive signals of different amplitudes according to the preset amplitude sequence; after each amplitude switch, the host computer control module 70 also delays the preset stabilization waiting time before triggering the second oscilloscope 62 to collect and record the diffraction optical power value of the channel under each drive amplitude, and completes the acquisition of the dose distribution curve of the channel; after all channels are calibrated, the dose distribution curve of the acoustic modulator channel is generated. This curve reflects the power modulation characteristics of each channel with the RF drive amplitude of each channel as the horizontal axis and the diffraction optical power as the vertical axis.

[0026] The aforementioned preset stabilization waiting time is determined based on the response time constant of the acoustic deflector 40 or the acoustic modulator 100, and is specifically no less than the setup time required for the transducer to switch from the previous driving state to the current driving state. This ensures that the sound field is sufficiently stable before the acquisition trigger, eliminating interference from the switching transient process on the validity of the acquired data. The acquisition time window of the first oscilloscope 61 and the second oscilloscope 62 covers no less than three complete RF signal cycles, ensuring that the acquired data contains sufficient valid signal samples and improving the statistical reliability of optical power measurement. Through the above synchronous trigger acquisition mechanism, the optical power acquisition data in each driving word state has high accuracy and repeatability, significantly improving the degree of calibration automation and data consistency compared to the test process that relies on manual operation.

[0027] In some implementations, a monotonically increasing scan from the minimum drive amplitude to the maximum drive amplitude and a monotonically decreasing scan from the maximum drive amplitude to the minimum drive amplitude are performed on each channel of the acoustic modulator 100, and the average of the two scan results is taken as the dose distribution curve for that channel. Performing increasing and decreasing scans on each channel separately and taking the average can effectively eliminate the influence of the hysteresis effect of the acoustic modulator 100 transducer on the calibration accuracy and obtain a more accurate channel dose distribution curve.

[0028] In one implementation, after acquiring the acoustic deflector response curve mapping table and the acoustic modulator channel dose distribution curve, the host computer control module 70 performs correlation calculations on the two types of calibration results to generate a joint calibration dataset for the whole machine.

[0029] The joint calibration dataset includes a three-dimensional mapping table between the frequency drive word and amplitude drive word of the acoustic deflector 40 and the diffracted optical power, and two-dimensional curves between the RF drive amplitude and diffracted optical power of each channel of the acoustic modulator 100. The three-dimensional mapping table and the two-dimensional curves are linked and indexed through a unified drive parameter coordinate system. The joint calibration dataset is stored in the form of a lookup table. During operation, the whole system control system determines the corresponding combination of drive words for the acoustic deflector 40 and the drive amplitude of the acoustic modulator 100 channels by looking up the table in reverse according to the target optical power value, thereby realizing closed-loop control of optical power. The whole system control system does not need to perform complex interpolation calculations in real time during operation. It can quickly obtain the optimal combination of drive parameters by directly looking up the table, supporting real-time closed-loop control of the whole system's optical power. By linking and indexing the three-dimensional mapping table of the acoustic deflector 40 and the two-dimensional curves of each channel of the acoustic modulator 100 through a unified drive parameter coordinate system, collaborative calibration of the acoustic deflector 40 and the acoustic modulator 100 at the whole system level is realized, overcoming the shortcomings of existing technologies where the calibration of each device is independent and cannot meet the requirements of precise optical power control at the whole system level.

[0030] Specifically, the construction method of the unified driving parameter coordinate system is as follows: the acoustic deflector 40 forms a two-dimensional plane with the frequency driving word as the first axis and the amplitude driving word as the second axis, and the acoustic modulator 100 uses the radio frequency driving amplitude as an independent axis; the alignment method of the two types of curves is as follows: the driving amplitude axis of the acoustic modulator 100 and the amplitude driving word axis of the acoustic deflector 40 are aligned with the same normalized dimensions.

[0031] In addition, the host computer control module 70 is also configured to perform a maintenance self-calibration mode. In this mode, the host computer control module 70 calls a pre-stored benchmark calibration dataset to perform a simplified calibration process, specifically including: performing rapid calibration only on preset key driver byte points, instead of performing a complete traversal of all driver word combinations. For each key driver byte point, the host computer control module 70 controls the digital I / O module 10 or the arbitrary waveform generator 80 to output the corresponding drive signal according to the same synchronous trigger acquisition mechanism as the complete calibration process. After a preset stabilization waiting time, it triggers the first oscilloscope 61 and the second oscilloscope 62 to acquire and read the real-time optical power measurement value.

[0032] The host computer control module 70 compares the real-time measurement results with the historical data of the corresponding nodes in the benchmark calibration dataset to calculate the deviation rate, and outputs the working status judgment results of each module based on the deviation comparison results. The deviation rate calculation formula is: Deviation rate = |real-time measurement value - benchmark value| / benchmark value × 100%.

[0033] When the deviation rate exceeds a preset threshold, a fault location process is triggered: The signal chains of the acoustic deflector 40 and the acoustic modulator 100 are tested independently. By comparing the signal injection at each stage with the optical power, the fault range is gradually narrowed down from the system level to the specific hardware module, generating a fault location report. The threshold is determined primarily based on the optical power stability index (e.g., 5%) specified in the device datasheet. If the datasheet does not specify this, it is determined by engineers based on historical calibration data. The thresholds for the two signal chains can be set independently.

[0034] The specific method of step-by-step signal injection is as follows: known signals are injected sequentially at the input terminals of each stage of the signal chain, and the optical power or electrical signal at the output terminals of each stage is compared to see if they meet expectations (the expected values ​​are derived from the baseline data of signal parameters recorded during the initial complete calibration). This determines the stage at which the fault occurs and thus pinpoints the specific hardware module. For example, if the output deviation of a certain stage exceeds a threshold while the preceding stage is normal, it is determined that the corresponding module at that stage is faulty.

[0035] The parameters of the known injected signal are selected as follows: the radio frequency signal corresponding to the device's nominal center frequency and rated drive power is selected; The injection sequence and injection point location of the known signal include: injecting from the first stage (output of digital I / O module 10 or output of arbitrary waveform generator 80) to the next stage, and comparing at the DDS output, power amplifier output, and diffraction output stage.

[0036] The self-calibration mode of maintenance does not require the execution of a complete calibration process. It can be performed periodically during the service life of the machine, enabling early detection of system performance degradation and quickly locating the fault to a specific module. This provides maintenance personnel with accurate fault location information and reduces troubleshooting time.

[0037] It is worth noting that the hardware modules in the above-mentioned test and calibration system can be replaced with alternative solutions to achieve the same calibration function. The digital I / O module 10 can be replaced with an analog output module based on PXI or PXIe architecture, coupled with an analog-to-digital converter. The analog output module outputs the control voltage of the corresponding drive word, which is then converted by the analog-to-digital converter to drive the direct digital frequency synthesis module 20. The oscilloscope module can be replaced with a high-speed data acquisition card, which directly samples the optical power signal output by the photoelectric detection module at high speed, replacing the waveform acquisition function of the oscilloscope module. The arbitrary waveform generator 80 can be replaced with a combination of a phase-locked loop frequency synthesizer and an adjustable attenuator. The phase-locked loop frequency synthesizer generates the radio frequency signal with the required center frequency, and the adjustable attenuator precisely adjusts the amplitude of the radio frequency signal to achieve the output of the radio frequency drive signal with a preset amplitude sequence. The host computer control software can be replaced with a control program based on Python and PyVISA, or a control program based on C++ and the corresponding instrument driver library, which communicates and controls with each hardware module through a standard instrument communication interface. The above alternative solutions, without changing the core technical mechanisms such as dual-dimensional driving word traversal calibration, synchronous trigger acquisition, and joint calibration dataset generation, are suitable for application scenarios that require higher integration, stricter electromagnetic compatibility requirements, or deep integration with existing factory automation systems. Example 2

[0038] Based on the system framework in Embodiment 1, this embodiment also provides a response curve calibration method, which includes the following steps: Step S1 The host computer control module 70 controls the digital I / O module 10 to perform a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector 40 (see reference). Figure 3 The loop iterates through the frequency-driven word as the outer loop variable and the amplitude-driven word as the inner loop variable.

[0039] Digital I / O module 10 writes each driver word combination into direct digital frequency synthesis module 20 through multi-channel parallel output terminal.

[0040] The direct digital frequency synthesis module 20 synthesizes radio frequency signals corresponding to the center frequency and amplitude in real time according to the combination of frequency drive word and amplitude drive word, and drives the transducer of acoustic deflector 40 after being amplified by the first power amplifier 30.

[0041] The acoustic deflector 40 generates acousto-optic deflection of the incident light beam and outputs diffracted light; the photoelectric detection module collects the power of the diffracted light and converts it into an optical power electrical signal.

[0042] After each driver word switch, the host computer control module 70 delays for a preset stabilization time before triggering the oscilloscope module to acquire waveform data of the optical power electrical signal. The host computer control module 70 reads the waveform data acquired by the oscilloscope module and records the diffraction optical power value under the corresponding driver word combination. After iterating through all driver word combinations, it generates a mapping table of acoustic deflector response curves (see reference). Figure 2 ).

[0043] By adopting a nested traversal order with the frequency-driven word as the outer loop and the amplitude-driven word as the inner loop, the full amplitude range is continuously scanned after each frequency switch, which reduces the number of frequency switches and helps to reduce the thermal effects caused by the frequent frequency switching of the acoustic deflector 40 transducer.

[0044] Step S2 The host computer control module 70 controls the arbitrary waveform generator 80 to switch the output of the radio frequency drive signal corresponding to each channel in sequence according to the preset channel sequence, and performs sequential calibration on each channel of the acoustic modulator 100 in sequence.

[0045] For each channel of the acoustic modulator 100, the arbitrary waveform generator 80 outputs a radio frequency drive signal with a preset amplitude sequence, which is amplified by the second power amplifier 90 and then drives the transducer of the corresponding channel of the acoustic modulator 100.

[0046] The acoustic modulator 100 performs acousto-optic modulation on the incident beam and outputs the diffracted light of the channel; the photoelectric detection module collects the diffracted light power, and the host computer control module 70 delays the preset stabilization time after each amplitude switch before triggering the oscilloscope module to collect and record the diffracted light power value of the channel under each driving amplitude.

[0047] For each channel, perform monotonically increasing scans from minimum to maximum drive amplitude and monotonically decreasing scans from maximum to minimum drive amplitude. The average of the two scans is taken as the dose distribution curve for that channel (see reference). Figure 4 After all channels are calibrated, the dose distribution curves of the acoustic modulator channels are generated.

[0048] Step S3 The host computer control module 70 performs correlation calculations between the acoustic deflector response curve mapping table generated in step S1 and the acoustic modulator channel dose distribution curve generated in step S2, and constructs a three-dimensional mapping table using the frequency drive word, amplitude drive word, and diffracted light power of the acoustic deflector 40 (see reference). Figure 5 The two-dimensional curves are constructed using the RF drive amplitude and diffraction power of each channel of the acoustic modulator 100. The three-dimensional mapping table and the two-dimensional curves are associated and indexed through a unified drive parameter coordinate system to generate a joint calibration dataset for the whole machine.

[0049] The joint calibration dataset is stored in the form of a lookup table. The overall control system reversely looks up the corresponding combination of the 40 driving words of the acoustic deflector and the driving amplitude of the 100 channels of the acoustic modulator based on the target optical power value, thereby realizing closed-loop control of the optical power. The specific implementation of the reverse lookup is: nearest neighbor matching or linear interpolation. Nearest neighbor is used when the sampling density is sufficient, and bilinear interpolation is used in high-precision scenarios.

[0050] Step S4 In maintenance self-calibration mode, the host computer control module 70 calls the pre-stored benchmark calibration dataset, performs rapid calibration only on preset key drive byte points, compares the real-time calibration results of each key node with the historical data of the corresponding node in the benchmark dataset, and calculates the deviation rate; When the deviation rate exceeds the preset threshold, the fault location process is triggered, and the signal chains of the acoustic deflector 40 and the acoustic modulator 100 are tested independently. By injecting signals step by step and comparing optical power, the fault is located to the specific hardware module, and a fault location report is generated. When the deviation rate of each key node does not exceed the preset threshold, the judgment result of the normal working status of each module is output.

[0051] In particular, step S4 only performs rapid calibration on preset key driver byte points, which significantly shortens the maintenance and inspection time compared to the complete calibration process, and the deviation rate threshold judgment mechanism realizes automatic early warning of system performance degradation.

[0052] It is understandable that the photoelectric detection module is not limited to a single-point photoelectric detector, but can also adopt a combination scheme of integrating sphere and power meter to reduce the impact of beam position drift on the acquisition accuracy; the loop order of the two-dimensional traversal is not limited to the nesting method of frequency-driven outer layer and amplitude-driven inner layer, but can also adopt the nesting method of amplitude-driven outer layer and frequency-driven inner layer according to specific calibration requirements; the synchronous triggering mechanism is not limited to the software timing trigger command issued by the host computer control software, but can also send hardware trigger signal directly to the oscilloscope module through the dedicated trigger output port of digital I / O module 10 to further reduce the timing jitter introduced by software scheduling; the test calibration system and response curve calibration method of this application are not limited to laser processing machine, but can also be applied to lithography system, lidar system or other precision optical control equipment using acousto-optic modulation devices.

[0053] In summary, the two embodiments described above aim to address the problems in existing acousto-optic modulator calibration schemes, such as the lack of system-wide joint calibration capabilities, reliance on manual operation, and the absence of in-service self-calibration and fault location functions. By constructing two parallel signal chains and having the host computer control module uniformly coordinate timing control and data acquisition, the system achieves complete two-dimensional traversal calibration of the acoustic deflector driving parameter space, calibration of the multi-channel dose distribution curve of the acoustic modulator, and correlation calculation of the two types of calibration results, generating a joint calibration dataset for the entire system.

[0054] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A calibration system for an acousto-optic modulation component, characterized in that, include: Digital I / O module (10) is used to output multi-channel drive word signals; A direct digital frequency synthesis module (20) is signal-connected to the digital I / O module (10) and is used to generate a corresponding radio frequency signal based on the received drive word signal; The first power amplifier (30) is signal-connected to the direct digital frequency synthesis module (20) and is used to amplify the radio frequency signal to drive the acoustic deflector (40). An acoustic deflector (40) is connected to the first power amplifier (30) for acousto-optic deflection of the incident beam according to the radio frequency signal, and outputs diffracted light; An arbitrary waveform generator (80) is used to output a radio frequency drive signal with a preset amplitude sequence; The second power amplifier (90) is connected to the arbitrary waveform generator (80) and is used to amplify the radio frequency drive signal to drive the acoustic modulator (100). An acoustic modulator (100), signal-connected to the second power amplifier (90), is used to perform acousto-optic modulation on the incident beam according to the radio frequency drive signal and output diffracted light from each channel; The photoelectric detection module is used to collect the diffracted light power output by the acoustic deflector (40) and the acoustic modulator (100) and generate an optical power electrical signal; An oscilloscope module, connected to the photoelectric detection module, is used to acquire waveform data of the optical power electrical signal; The host computer control module (70) is communicatively connected to the digital I / O module (10), the arbitrary waveform generator (80), and the oscilloscope module, respectively. It is used to control the digital I / O module (10) to perform a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector (40), control the arbitrary waveform generator (80) to output radio frequency drive signals to each channel of the acoustic modulator (100) in sequence, and generate an acoustic deflector response curve mapping table, an acoustic modulator channel dose distribution curve, and a joint calibration dataset based on the waveform data collected by the oscilloscope module.

2. The acousto-optic modulation component testing and calibration system according to claim 1, characterized in that, The direct digital frequency synthesis module (20) is configured to generate radio frequency signals with corresponding center frequency and amplitude based on the combination of frequency driving word and amplitude driving word, wherein the value range of the frequency driving word covers the full operating frequency range of the acoustic deflector (40).

3. The acousto-optic modulation component testing and calibration system according to claim 1, characterized in that, The host computer control module (70) is also configured to control the arbitrary waveform generator (80) to sequentially switch the output of the radio frequency drive signals corresponding to each channel according to the preset channel sequence, so as to perform sequential calibration on each channel of the acoustic modulator (100).

4. The acousto-optic modulation component testing and calibration system according to claim 1, characterized in that, The host computer control module (70) is further configured to delay a preset stabilization waiting time after sending a drive word switching command to the digital I / O module (10) or the arbitrary waveform generator (80), and then send a trigger acquisition command to the oscilloscope module; the preset stabilization waiting time is determined according to the response time constant of the acoustic deflector (40) or the acoustic modulator (100).

5. The acousto-optic modulation component testing and calibration system according to claim 1, characterized in that, The host computer control module (70) is also configured to perform maintenance self-calibration working mode: call the pre-stored benchmark calibration dataset, perform simplified calibration process, compare the deviation between the real-time measurement results and the corresponding data in the benchmark calibration dataset, and output the working status judgment results of each module according to the deviation comparison results.

6. The acousto-optic modulation component testing and calibration system according to claim 5, characterized in that, The deviation comparison includes: independently testing the signal chain of the acoustic deflector (40) and the signal chain of the acoustic modulator (100), respectively, and locating the fault to a specific hardware module by comparing the signal injection at each level with the optical power, and generating a fault location report.

7. The acousto-optic modulation component testing and calibration system according to claim 1, characterized in that, The joint calibration dataset includes a three-dimensional mapping table between the frequency drive word, amplitude drive word and diffraction power of the acoustic deflector (40), and a two-dimensional curve between the radio frequency drive amplitude and diffraction power of each channel of the acoustic modulator (100). The three-dimensional mapping table and the two-dimensional curve are associated and indexed through a unified drive parameter coordinate system.

8. A method for calibrating the response curve of an acousto-optic modulation component, characterized in that, include: Step S1: Control the digital I / O module (10) to perform a two-dimensional traversal of the frequency drive word and amplitude drive word of the acoustic deflector (40), and drive the acoustic deflector (40) in sequence through the direct digital frequency synthesis module (20) and the first power amplifier (30). Simultaneously collect the diffraction light power under each drive word combination through the photoelectric detection module and the oscilloscope module to generate an acoustic deflector response curve mapping table; Step S2: Control the arbitrary waveform generator (80) to output radio frequency drive signals with preset amplitude sequences to each channel of the acoustic modulator (100) in sequence, drive the acoustic modulator (100) through the second power amplifier (90), and synchronously collect the diffracted light power of each channel through the photoelectric detection module and the oscilloscope module to generate the acoustic modulator channel dose distribution curve; Step S3: Perform correlation calculation between the acoustic deflector response curve mapping table and the acoustic modulator channel dose distribution curve to generate a joint calibration dataset for the whole machine.

9. The method for calibrating the response curve of an acousto-optic modulation component according to claim 8, characterized in that, It also includes step S4: In the maintenance self-calibration mode, a fast calibration is performed on the preset key driving byte points, the calibration results are compared with the historical data of the corresponding nodes in the benchmark dataset, the deviation rate is calculated, and the fault location process is triggered when the deviation rate exceeds the preset threshold.

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