Modular laser controller

Abstract

This invention discloses a modular laser controller, belonging to the field of precision laser control technology. It includes a main control module that acquires the frequency difference signal output by the laser and performs closed-loop control based on the frequency difference signal to achieve frequency locking and stabilization of the laser; a laser drive module that adopts a switch-linear coupling architecture, simultaneously providing response ripple and transient components corresponding to load changes, as well as a steady-state DC component, to provide operating current for the laser; a temperature control module that acquires the temperature signal during laser operation and achieves temperature control through a digital PID algorithm; a piezoelectric ceramic drive module that performs pre-distortion processing based on a simplified curve fitting dynamic model to eliminate the inherent hysteresis of the piezoelectric ceramic; and a power supply module that supplies power to the main control module, laser drive module, temperature control module, and piezoelectric ceramic drive module.

Description

Technical Field

[0001] This invention belongs to the field of precision laser control technology, and in particular relates to a modular laser controller. Background Technology

[0002] In fields such as precision optical systems, laser processing, optical communication, and scientific research experiments, the stable operation of lasers relies on the coordinated work of multiple control subsystems: the laser driver circuit provides constant current or modulation current to the laser diode; the temperature controller, such as the TEC, maintains a constant laser operating temperature to ensure wavelength and power stability; the piezoelectric ceramic driver is used to precisely adjust the resonant cavity length; and the acousto-optic modulator driver module is used to drive the acousto-optic modulator to achieve functions such as rapid modulation of laser intensity, optical switching, and frequency shifting. In existing technologies, the above three functions are usually implemented by discrete devices, which has the following drawbacks: low system integration, large size, and high cost. Traditional constant current driving schemes for lasers mainly include two types: switching constant current driving and linear constant current driving. Switching constant current driving has advantages such as high efficiency, low heat generation, and suitability for high current output, which can meet the power requirements of high-power lasers. However, due to the periodic on and off of power switching devices, this type of driving method inevitably introduces switching ripple and high-frequency noise into the output current, resulting in increased noise level and linewidth broadening of the laser output optical signal, and even affecting the long-term stability of the system. Linear constant-current driven power transistors operate in the linear region, where all voltage difference is converted into heat loss. This results in extremely low efficiency and significant heat generation under high current conditions. Furthermore, piezoelectric ceramic actuators lack automatic calibration and compensation mechanisms, making them prone to displacement drift during long-term operation.

[0003] Based on the above situation, there is an urgent need to provide a modular laser controller that adopts a switch-linear coupling architecture to achieve both high efficiency and low noise laser driving, improves the shortcomings of single switch-type driving and linear driving, and can also realize the compensation function of piezoelectric ceramic driver to improve the stability of laser frequency. Summary of the Invention

[0004] In view of this, the present invention proposes a laser driving method that combines the efficiency and low noise of switching constant current drive and linear constant current drive, and a modular laser controller with compensation function of piezoelectric ceramic driver.

[0005] This invention provides a modular laser controller, comprising: The main control module acquires the frequency difference signal output by the laser and performs closed-loop control based on the frequency difference signal to achieve frequency locking and frequency stabilization of the laser. The laser driver module adopts a switch-linear coupling architecture, which simultaneously provides the response ripple and transient components corresponding to load changes, as well as the steady-state DC component, to provide the operating current for the laser. The temperature control module is used to acquire the temperature signal when the laser is working and to achieve temperature control through a digital PID algorithm. The piezoelectric ceramic drive module eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing based on a simplified curve fitting dynamic model. The power supply module is used to supply power to the main control module, laser driver module, temperature control module and piezoelectric ceramic driver module.

[0006] Based on the above technical solutions, preferably, the main control module includes a SOC, several transimpedance amplifier circuits, several first temperature measurement circuits, and a comparator circuit; the several transimpedance amplifier circuits are used to acquire the current signal output by the laser and convert it into a voltage signal before sending it into the SOC. The transimpedance amplifier circuits also acquire the beat frequency feedback signal and send it into the comparator circuit. The comparator circuit shapes the beat frequency feedback signal into a square wave pulse signal and sends it into the SOC. The SOC measures the frequency of the square wave signal and compares it with a set frequency difference signal to output a frequency difference feedback quantity, thereby performing frequency control in a closed-loop manner; the several first temperature measurement circuits are used to acquire the voltage signal corresponding to the ambient temperature and send it into the SOC.

[0007] Preferably, each of the plurality of transimpedance amplifier circuits includes a feedback resistor R and a first operational amplifier. The inverting input terminal of the first operational amplifier is electrically connected to the output terminal of the laser, and the non-inverting input terminal of the first operational amplifier is grounded. The two ends of the feedback resistor R are electrically connected to the output terminal and the inverting input terminal of the first operational amplifier, respectively. The output terminal of the first operational amplifier is electrically connected to the analog-to-digital conversion channel of the SOC, or the output terminal of the first operational amplifier is electrically connected to the input terminal of the comparator circuit, and the output terminal of the comparator circuit is electrically connected to the SOC; the comparator circuit is a hysteresis comparator.

[0008] Preferably, the laser driving module includes a switch driving unit, a linear driving unit, a current tuning unit, and a coupling control and monitoring unit; the laser driving current includes a switch driving current, a linear driving current, and a tuning current; the coupling control and monitoring unit is electrically connected to the enable terminal and the current setting terminal of the switch driving unit, respectively, and is electrically connected to the enable terminal and the current setting terminal of the linear driving unit; the coupling control and monitoring unit also acquires the current monitoring signals of the switch driving unit and the linear driving unit, and also provides a tuning voltage to the current tuning unit, which provides a tuning current to the laser according to the input tuning voltage; the switch driving unit and the linear driving unit provide the switch driving current and the linear driving current to the laser, respectively.

[0009] More preferably, the coupling control and monitoring unit includes a first MCU, a first ADC module, and a first DAC module; both the first ADC module and the first DAC module are electrically connected to the first MCU, and the first MCU is also connected to the SOC via a communication port; The switching drive unit includes a PWM controller, a gate drive circuit, a first MOSFET device, an inductor L1, a first sampling resistor, a differential amplifier circuit, and a low-pass filter circuit. The coupling control and monitoring unit directly provides an enable signal to the PWM controller. The coupling control and monitoring unit also provides a first set current signal to the PWM controller through a first DAC module. The output terminal of the PWM controller is electrically connected to the gate drive circuit for power amplification of the PWM controller's output signal. The output terminal of the gate drive circuit is electrically connected to the gate of the first MOSFET device. The drain of the first MOSFET device is electrically connected to the cathode of the laser through inductor L1, and the anode of the laser is electrically connected to the power supply Vdrive. The source of the first MOSFET device is electrically connected to one end of the first sampling resistor. The other end of the first sampling resistor is grounded; one end of the first sampling resistor is electrically connected to one input terminal of the differential amplifier circuit, the other end of the differential amplifier circuit receives a reference voltage, the output terminal of the differential amplifier circuit is electrically connected to the input terminal of the low-pass filter circuit, and the output terminal of the low-pass filter circuit is electrically connected to one input terminal of the first ADC module and the feedback terminal of the PWM controller; the first MOSFET device operates in the linear region, the first sampling resistor performs current-to-voltage conversion, compares the voltage on the first sampling resistor with the reference voltage in the differential amplifier circuit, and adjusts the gate drive signal of the first MOSFET device according to the comparison result; the inductor L1 is an energy storage inductor used to suppress current surges when the first MOSFET device is turned on and off; when the load changes, the switching drive unit takes over the steady-state DC component; The linear drive unit includes a fourth operational amplifier, a fifth operational amplifier, a second MOSFET device, and a third MOSFET device; the coupling control and monitoring unit inputs a second set current signal to the linear drive unit through the first DAC module; the fourth operational amplifier, the second MOSFET device, the fifth operational amplifier, and the second sampling resistor RS form a current closed loop, and the third MOSFET device forms an enable circuit; when the load changes, the linear drive unit responds to ripple and transient components. The current tuning unit acquires the tuning voltage signal provided by the first DAC module, converts the input tuning voltage signal into a tuning current, and drives the tuning electrode of the laser.

[0010] Preferably, the temperature control module includes an H-bridge drive circuit, a thermoelectric cooler (TEC), and a temperature control unit. The temperature control unit is electrically connected to the H-bridge drive circuit and a second temperature measurement circuit, respectively. The temperature control unit provides a PWM temperature drive signal to the H-bridge drive circuit, which bidirectionally drives the TEC to adjust the laser temperature according to the PWM temperature drive signal. The second temperature measurement circuit is used to acquire the real-time temperature of the laser. The temperature control unit is connected to the SOC via a communication port. The temperature control unit uses a closed-loop control and active compensation strategy to compensate for the cooling required by the laser.

[0011] More preferably, the temperature control unit employs a closed-loop control and active compensation strategy to compensate for the cooling required by the laser, including the following: estimating the heat generation power of the laser. P heat Then, the required cooling capacity for temperature compensation is calculated based on the heating power. Q c By combining the characteristic equation of the thermoelectric cooler (TEC), the driving voltage and duty cycle required for temperature compensation are obtained.

[0012] Preferably, the piezoelectric ceramic driving module includes a high-voltage power driving unit, a data acquisition and feedback unit, and a compensation and control unit; the high-voltage power driving unit is used to drive the piezoelectric ceramic; the data acquisition and feedback unit is used to acquire the deformation signal of the piezoelectric ceramic and the light intensity signal of the laser, and feed the deformation signal and light intensity signal back to the compensation and control unit; the compensation and control unit performs pre-distortion processing through a built-in simplified curve fitting dynamic model to eliminate the inherent hysteresis of the piezoelectric ceramic.

[0013] More preferably, the compensation control unit eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing using a built-in simplified curve-fitting dynamic model, including the following: definition n Prandtl-Ishlinskii model and its corresponding inverse model for each play operator. This is the output of the Prandtl-Ishlinskii model. This is the input to the Prandtl-Ishlinskii model; Acquire the main hysteresis loop data and control the driving voltage of the piezoelectric ceramic as input. A triangular wave scan was performed within the 0-150V range, and the feedback signal of the piezoelectric ceramic deformation was obtained simultaneously using strain gauges. Each cycle samples 500-1000 points; To obtain a family of first-order inversion curves, m voltage points are set at fixed intervals within the range of 0-150V. V kFor each voltage point, scan from 0V along the main rising curve to... V k Then, it scans in reverse to 0V, recording the complete scan curve; then it scans from 150V along the main descending curve to... V k Then, the reverse scan is performed to 150V, and the complete scan curve is recorded; a total of 2m first-order inversion curves are obtained, and each first-order inversion curve contains at least 100 points; To identify model parameters and directly obtain the inverse model, the input corresponding to each point is... and output The parameters of each first-order inverse curve are identified according to the Prandtl-Ishlinskii model to obtain an n-dimensional weight vector. Operators with weights less than a set threshold are deleted, and the parameters are converted into 16-bit integers to obtain a lightweight inverse model. The lightweight inverse model is dynamically updated using a feedforward combined with PID closed-loop method to counteract the inherent hysteresis of piezoelectric ceramics.

[0014] Preferably, it further includes an acousto-optic modulation driving module; the acousto-optic modulation driving module includes an FPGA control unit, a clock management unit, a DDS signal source unit, a driver source power closed-loop control unit, and a driver source output control unit. The clock management unit sends clock signals to the FPGA control unit and the DDS signal source unit respectively. The FPGA control unit is signal-connected to the DDS signal source unit and is used to control the output frequency and amplitude of the DDS signal source unit. The DDS signal source unit, the driver source power closed-loop control unit, and the driver source output control unit are sequentially electrically connected. The DDS signal source unit inputs a radio frequency signal to the driver source power closed-loop control unit. The driver source power closed-loop control unit sends the input radio frequency signal to the driver source output control unit on the one hand, and performs fixed coupling attenuation ratio processing on the input radio frequency signal on the other hand to obtain a sampled radio frequency signal, and outputs the equivalent analog voltage corresponding to the sampled radio frequency signal. The equivalent analog voltage is compared with the reference signal to generate a control voltage signal and adjust the closed-loop gain of the driver source power closed-loop control unit.

[0015] The modular laser controller provided by this invention has the following advantages compared to the prior art: 1. The main control module shapes the beat frequency feedback signal into a square wave through the SOC, and then uses a hysteresis comparator for shaping and frequency measurement. It compares the square wave with the set frequency difference to form a closed-loop frequency difference control, which significantly improves the stability of the laser frequency. The multi-channel transimpedance amplifier circuit synchronously acquires the laser current signal and beat frequency signal, converts them into voltage signals and sends them to the ADC channel of the SOC, which is beneficial for coordinated control.

[0016] 2. The switching drive unit of the laser driver module handles the steady-state DC component, significantly improving power efficiency and reducing overall power consumption and heat generation; the linear drive unit responds to ripple and transient components, ensuring high linearity and low noise of the laser current; the inductor L1 suppresses current surges during the switching process of the MOSFET device, reducing high-frequency ripple entering the laser; the dedicated current tuning unit converts the tuning voltage into tuning current, directly driving the laser tuning electrode, avoiding mutual interference with the main control current.

[0017] 3. The H-bridge drive circuit of the temperature control module can drive the TEC bidirectionally according to the direction of the PWM signal, realizing seamless switching between heating and cooling to adapt to different ambient temperature changes; the second MCU adjusts the PWM duty cycle in real time according to temperature feedback to achieve high-precision closed-loop temperature regulation; the active compensation strategy estimates the heat generation power of the laser, calculates the required cooling capacity, and then combines the TEC characteristic equation to back-calculate the drive voltage and duty cycle, thus compensating for changes in heat load in advance and reducing the impact of temperature fluctuations on the laser frequency.

[0018] 4. The piezoelectric ceramic drive module identifies the inverse model through the main hysteresis loop and the first-order inversion curve family, and directly constructs a lightweight PrandtlIshlinskii inverse model to achieve explicit compensation for the inherent hysteresis of piezoelectric ceramics; the feedforward inverse model cancels the main hysteresis nonlinearity, and the PID closed loop eliminates residual error and model uncertainty. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the composition structure of a modular laser controller according to the present invention; Figure 2 This is a schematic block diagram of the main control module of a modular laser controller according to the present invention; Figure 3 This is a schematic diagram of the transimpedance amplifier of a modular laser controller according to the present invention; Figure 4 This is a schematic diagram of the first temperature measurement circuit of a modular laser controller according to the present invention; Figure 5 This is a block diagram illustrating the composition principle of the power supply module of a modular laser controller according to the present invention. Figure 6 This is a block diagram illustrating the composition principle of the laser driver module of a modular laser controller according to the present invention. Figure 7 This is a schematic diagram of the current topology of the laser driving module of a modular laser controller according to the present invention; Figure 8 This is a block diagram illustrating the composition principle of the switch drive unit of a modular laser controller according to the present invention. Figure 9 This is a circuit diagram of the switching drive unit filter circuit of a modular laser controller according to the present invention. Figure 10 This is a block diagram illustrating the composition principle of a linear drive unit for a modular laser controller according to the present invention. Figure 11 This is a block diagram illustrating the composition principle of the current tuning unit of a modular laser controller according to the present invention. Figure 12 This is a block diagram illustrating the composition principle of the temperature control module of a modular laser controller according to the present invention. Figure 13 This is a schematic diagram of the H-bridge drive circuit of a modular laser controller according to the present invention; Figure 14 This is a block diagram illustrating the composition principle of a piezoelectric ceramic driving module for a modular laser controller according to the present invention. Figure 15 This is a schematic diagram of a high-voltage power drive unit for a modular laser controller according to the present invention; Figure 16 This is a block diagram of a piezoelectric ceramic control system for a modular laser controller according to the present invention; Figure 17 This is a system block diagram of an acousto-optic modulation drive module for a modular laser controller according to the present invention.

[0021] Reference numerals: 100, Chassis backplane; 200, Main control module; 300, Power supply module; 400, Laser driver module; 500, Temperature control module; 600, Piezoelectric ceramic driver module; 700, Acousto-optic modulation driver module; 401, Switch driver unit; 402, Linear driver unit; 403, Current tuning unit; 404, Coupling control and monitoring unit; 501, H-bridge driver circuit; 502, Temperature measurement circuit; 503, Temperature control unit; 601, High-voltage power driver unit; 602, Compensation control unit; 603, Acquisition and feedback unit; 701, FPGA control unit; 702, Clock management unit; 703, DDS signal source unit; 704, Driver source power closed-loop control unit; 705, Driver source output control unit. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Existing laser controllers suffer from the following shortcomings: low system integration, large size, and high cost. Switching constant current driven lasers offer advantages such as high efficiency, low heat generation, and suitability for high current output; however, they introduce switching ripple and high-frequency noise into the output current, leading to increased noise levels and linewidth broadening in the laser output signal, and even affecting the long-term stability of the system. Linear constant current driven lasers operate in the linear region, converting all voltage difference into heat loss, resulting in significant heat generation. Furthermore, piezoelectric ceramic drivers lack automatic calibration and compensation mechanisms, making them prone to displacement drift during long-term operation.

[0024] In view of this, such as Figure 1 As shown, the modular laser controller provided by this invention adopts a 3U chassis plug-in card structure, including a chassis backplane 100, a main control module 200, a power supply module 300, at least one laser driver module 400, at least one temperature control module 500, and a piezoelectric ceramic driver module 600, wherein: The chassis back panel 100 uses VPX connectors and has a total of 8 slots. Slots 1 and 2 are dedicated slots for connecting the main control module 200 and the power module 300, respectively. Slots 3 to 8 are general-purpose slots. The power, SPI and I2C bus signals of the general-purpose slots are in the same position, and laser driver module 400, temperature control module 500 or piezoelectric ceramic driver module 600 can be connected according to actual usage requirements.

[0025] The main control module 200 acquires the frequency difference signal output by the laser and performs closed-loop control based on this signal to achieve frequency locking and stabilization of the laser. The main control module 200 is the core of the entire laser controller's control and management. Figure 2 As shown, the main control module 200 includes a SOC, ADC, DAC, DDR, serial Flash, eMMC, Gigabit Ethernet PHY, RS485 transceiver circuit, several transimpedance amplifier circuits, a first temperature measurement circuit, a comparator circuit, a power supply and filter circuit, a clock circuit, an SPI interface, and I... 2The system includes C and JTAG interfaces. Several transimpedance amplifier circuits acquire the laser's output current signal, convert it into a voltage signal, and send it to the SOC. The transimpedance amplifier circuits also acquire the beat frequency feedback signal and send it to a comparator circuit. The comparator circuit shapes the beat frequency feedback signal into a square wave pulse signal and sends it to the SOC. The SOC measures the frequency of the square wave signal and compares it with a set frequency difference signal, outputting a frequency difference feedback value for frequency control via a closed-loop method. Several first temperature measurement circuits acquire the voltage signal corresponding to the ambient temperature and send it to the SOC. The RS485 transceiver circuit uses two RS485 transceivers and can be configured as two independent RS485 interfaces. 2 The C interface serves as a low-speed interface to communicate with modules in slots 2-8, obtaining information such as the type, parameters, and version of each module. The SPI interface serves as a backplane bus for high-speed data communication between the main control module 200 and the general-purpose slots, used to transmit large amounts of data. The SPI interface is implemented using SOC logic and communicates with the ARM core of the SOC through the on-chip AXI bus.

[0026] The laser driver module 400 adopts a switch-linear coupling architecture, which simultaneously provides response ripple and transient components corresponding to load changes, as well as steady-state DC components, to provide operating current for the laser. Temperature control module 500 is used to acquire the temperature signal when the laser is working and to achieve temperature control through a digital PID algorithm. The piezoelectric ceramic drive module 600 eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing based on a simplified curve fitting dynamic model. Power module 300 supplies power to main control module 200, laser driver module 400, temperature control module 500, and piezoelectric ceramic driver module 600. For example... Figure 5As shown, the power module 300 provides ±15V, +5V, +3.3V, +12V, +180V, and -24V DC power through a backplane power bus. ±15V and +5V power the analog circuits, +3.3V power the digital circuits, +12V power the TEC (thermal energy storage) for laser temperature control, and +180V and -24V power the piezoelectric ceramic driver module 600. Each module obtains its required power through a dedicated backplane connector. If a specific power supply is not needed, the corresponding pin in the connector is left floating. The power module 300 mainly consists of an input filter circuit, five DC / DC power modules 300, one DC / DC power circuit, six output filter circuits, an independent MCU, and a power monitoring circuit. The input filter circuit, implemented with common-mode inductors and capacitors, is specifically designed to suppress interference from the input power supply and absorb input voltage surges and spikes. The output filter circuit, implemented with inductors and large-capacity capacitors, is used to suppress DC / DC switching noise and reduce ripple noise. All five DC / DC power modules 300 utilize commercially available isolated DC / DC power modules 300. The +3.3V DC / DC power circuit employs a non-isolated DC / DC power management chip. The MCU uses an I / O-enabled... 2 The ARM or microcontroller implements the C interface and on-chip ADC, enabling and controlling the power supplies of each channel through I / O ports, monitoring voltage by acquiring voltage through the on-chip ADC, and controlling the voltage through I / O ports. 2 C communicates with the main control module 200 via I. 2 The controller (C) acquires commands and reports the status of each power supply. The power monitoring circuit is implemented using a resistor voltage divider. For positive voltages, the voltage is directly divided by resistors to ensure the divided voltage is lower than the maximum acquisition voltage of the ADC. For negative voltages, a resistor voltage divider is used, and a +3.3V power supply provides a positive bias voltage to ensure the voltage is positive and lower than the maximum acquisition voltage of the ADC. This modular structure designs laser driving, temperature control, and piezoelectric ceramic driving functions as independent modules, which users can configure as needed.

[0027] As described above, the main control module 200 not only performs communication and data acquisition functions, but also uses on-chip logic resources to achieve laser frequency locking / stabilization. The SOC uses on-chip logic to measure the frequency of the square wave signal output by the high-speed comparator circuit and compares it with a set frequency difference signal as feedback for closed-loop control. For example, Figure 3As shown, several transimpedance amplifier circuits each include a feedback resistor R and a first operational amplifier. The inverting input terminal of the first operational amplifier is electrically connected to the output terminal of the laser, and the non-inverting input terminal of the first operational amplifier is grounded. The two ends of the feedback resistor R are electrically connected to the output terminal and the inverting input terminal of the first operational amplifier, respectively. The output terminal of the first operational amplifier is electrically connected to the analog-to-digital conversion channel of the SOC, or the output terminal of the first operational amplifier is electrically connected to the input terminal of the comparator circuit, and the output terminal of the comparator circuit is electrically connected to the SOC. The comparator circuit is a hysteresis comparator. In this embodiment, the laser is selected as a laser diode (LD).

[0028] like Figure 4 As shown, several first temperature measurement circuits each include a first resistor R1, a second resistor R2, a third resistor R3, a first sampling resistor RT, a fourth resistor R4, and a second operational amplifier. One end of the first resistor R1 and one end of the second resistor R2 are both electrically connected to a reference power supply. The other end of the first resistor R1 is electrically connected to one end of the first sampling resistor RT and the inverting input terminal of the second operational amplifier, respectively. The other end of the second resistor R2 is electrically connected to one end of the third resistor R3 and the non-inverting input terminal of the second operational amplifier, respectively. The other ends of the first sampling resistor RT and the third resistor R3 are both grounded. The two ends of the fourth resistor R4 are electrically connected to the inverting input terminal and the output terminal of the second operational amplifier, respectively.

[0029] like Figure 6 As shown, the laser driving module 400 includes a switch driving unit 401, a linear driving unit 402, a current tuning unit 403, and a coupling control and monitoring unit 404. The coupling control and monitoring unit 404 is electrically connected to the enable terminal and the current setting terminal of the switch driving unit 401, and is also electrically connected to the enable terminal and the current setting terminal of the linear driving unit 402. The coupling control and monitoring unit 404 also acquires the current monitoring signals of the switch driving unit 401 and the linear driving unit 402, and provides a tuning voltage to the current tuning unit 403. The current tuning unit 403 provides a tuning current to the laser according to the input tuning voltage. The switch driving unit 401 and the linear driving unit 402 provide a switch driving current and a linear driving current to the laser, respectively.

[0030] Figure 7The diagram illustrates the current topology of the laser driver module 400. The laser's driving current includes a switching driving current, a linear driving current, and a tuning current. The laser's driving current is denoted as I. The currents corresponding to the switching driving unit 401, the linear driving unit 402, and the current tuning unit 403 are I1, I2, and I3, respectively. The diagram also shows the case where the switching driving unit 401 and the linear driving unit 402 share a single sampling resistor; in this case, the current across the sampling resistor is I. S The following relationship is satisfied: I = I1 + I2 + I3 = I S +I3. Due to the switching noise of the switching drive unit 401, the switching drive current I1 has ripple noise. When the closed-loop bandwidth of the linear drive unit 402 is high enough, a current signal with the same amplitude but opposite direction to the ripple noise will be generated on the linear drive current I2, causing the current I on the sampling resistor to... S Maintaining a constant level suppresses switching ripple noise.

[0031] like Figure 6 As shown, the coupling control and monitoring unit 404 includes a first MCU, a first ADC module, and a first DAC module. Both the first ADC module and the first DAC module are electrically connected to the first MCU, which is also connected to the SOC via a communication port. The first MCU allocates the drive current of the switch drive unit 401 and the linear drive unit 402 according to the laser's drive current I, and controls the drive current of the switch drive unit 401 and the linear drive unit 402 by outputting a voltage signal through the first DAC module. Simultaneously, the first MCU acquires the voltage signal through the first ADC module to monitor the drive current of the switch drive unit 401 and the linear drive unit 402. The first MCU can also control the enabling and disabling of the switch drive unit 401 and the linear drive unit 402 via I / O. The first ADC module converts the acquired voltage signal into a digital signal. The first DAC module outputs a voltage signal to set the drive current of the switch drive unit 401 and the linear drive unit 402. The EEPROM stores the module's type, version, and parameter information. When the load changes transiently, the linear drive unit 402 responds quickly to ripple and transient components due to its high bandwidth characteristics, while the switching drive unit 401 handles the steady-state DC component. This achieves a coupled drive effect that maintains switching efficiency and linearity while preserving noise.

[0032] like Figure 8 and Figure 9As shown, the switch driving unit 401 includes a PWM controller, a gate driving circuit, a first MOSFET device, an inductor L1, a first sampling resistor, a differential amplifier circuit, and a low-pass filter circuit. The coupling control and monitoring unit 404 directly provides an enable signal to the PWM controller. The coupling control and monitoring unit 404 provides a first set current signal to the PWM controller through a first DAC module. The output terminal of the PWM controller is electrically connected to the gate driving circuit for power amplification of the PWM controller's output signal. The output terminal of the gate driving circuit is electrically connected to the gate of the first MOSFET device. The drain of the first MOSFET device is electrically connected to the cathode of the laser through inductor L1, and the anode of the laser is electrically connected to the power supply Vdrive. The source of the first MOSFET device is electrically connected to one end of the first sampling resistor, and the other end of the first sampling resistor is grounded. One end of the first sampling resistor is electrically connected to one input terminal of the differential amplifier circuit, and the other end of the differential amplifier circuit receives a reference voltage. The output terminal of the differential amplifier circuit is electrically connected to the input terminal of the low-pass filter circuit, and the output terminal of the low-pass filter circuit is connected to one input terminal of the first ADC module. The circuit is electrically connected to the feedback terminal of the PWM controller; the first MOSFET device operates in the linear region, the first sampling resistor performs current-to-voltage conversion, and the voltage on the first sampling resistor is compared with the reference voltage in the differential amplifier circuit. The gate drive signal of the first MOSFET device is adjusted according to the comparison result; the inductor L1 is an energy storage inductor used to suppress the current surge when the first MOSFET device is turned on and off; the low-pass filter circuit includes a third operational amplifier, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, and a second capacitor C2. One end of the fourth resistor R4 is electrically connected to the output terminal of the differential amplifier circuit, and the other end of the fourth resistor R4 is electrically connected to one end of the fifth resistor R5 and one end of the first capacitor C1. The other end of the fifth resistor R5 is electrically connected to one end of the second capacitor C2 and the non-inverting input terminal of the third operational amplifier. The output terminal of the third operational amplifier is electrically connected to the other end of the first capacitor C1 and the inverting input terminal of the third operational amplifier. The other end of the second capacitor C2 is grounded, and the output terminal of the third operational amplifier serves as the output terminal of the low-pass filter circuit; when the load changes, the switch drive unit 401 assumes the steady-state DC component. The filter parameters are adjusted by changing the resistance values ​​of R1 and R2, and the capacitance values ​​of C1 and C2. In one embodiment, the resistance values ​​of the fourth resistor R4 and the fifth resistor R5 are both 10kΩ, the first capacitor C1 is 2.2nF, and the second capacitor C2 is 1.1nF. The first MOSFET device is an N-channel power MOSFET, which can achieve a drive current of over 10A.

[0033] like Figure 10As shown, the linear drive unit 402 includes a fourth operational amplifier, a fifth operational amplifier, a second MOSFET device, and a third MOSFET device; the coupling control and monitoring unit 404 inputs a second set current signal to the linear drive unit 402 through the first DAC module; the non-inverting input terminal of the fourth operational amplifier is electrically connected to one end of the sixth resistor R6, one end of the third capacitor C3, and the drain of the third MOSFET device, respectively; the other end of the sixth resistor R6 serves as the current setting terminal of the linear drive unit 402; the other end of the third capacitor C3 is grounded; the output terminal of the fourth operational amplifier is electrically connected to the gate of the second MOSFET device; the drain of the second MOSFET device is electrically connected to the cathode of the laser; the source of the second MOSFET device is electrically connected to one end of the second sampling resistor RS, the fourth operational amplifier... The inverting input terminal of the amplifier is electrically connected to the non-inverting input terminal of the fifth operational amplifier. The other end of the second sampling resistor RS is electrically connected to the inverting input terminal of the fifth operational amplifier through the eighth resistor R8. The output terminal and the inverting input terminal of the fifth operational amplifier are respectively electrically connected to the two ends of the ninth resistor R9. The output terminal of the fifth operational amplifier is electrically connected to the other input terminal of the first ADC module. The gate of the third MOSFET device is electrically connected to the coupling control and monitoring unit 404 as the enable terminal of the linear drive unit 402. The gate of the third MOSFET device is also electrically connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is electrically connected to the source of the third MOSFET device. The source of the third MOSFET device is grounded. When the load changes, the linear drive unit 402 responds to ripple and transient components.

[0034] The MOSFET device and operational amplifier in the linear drive unit 402 constitute a voltage-controlled current source. Its output is connected in parallel with the output of the switch drive unit 401 at the cathode node of the laser. The fourth operational amplifier, the second MOSFET device, the fifth operational amplifier, and the second sampling resistor RS form a current closed loop. The current is set by the voltage output from the first DAC module of the coupling control and monitoring unit 404, according to formula I. set =V set / RS calculates the set current I set V set The voltage output by the first DAC module, as analyzed above, shows that the first and second sampling resistors are shared. The resistance of the second sampling resistor RS ranges from tens to hundreds of milliohms. The fifth operational amplifier, the eighth resistor, and the ninth resistor constitute the sampling current amplification stage, with an amplification factor of A = (R8 + R9) / R8. The sixth resistor R6 and the third capacitor C3 constitute an RC filter stage, used to reduce high-frequency noise in the output voltage of the first DAC module. The third MOSFET device and the seventh resistor R7 constitute an enable circuit. When the gate is high, the third MOSFET device is turned on, forcing the set current I...set The noise level drops to 0. To reduce current noise, the fourth and fifth operational amplifiers are low-noise, high-bandwidth operational amplifiers.

[0035] like Figure 11 As shown, the current tuning unit 403 includes a sixth operational amplifier and a seventh operational amplifier. The inverting input terminal of the sixth operational amplifier is electrically connected to one end of the tenth resistor R10 and one end of the eleventh resistor R11. The other end of the tenth resistor R10 is grounded. The other end of the eleventh resistor R11 is electrically connected to the output terminal of the sixth operational amplifier. The output terminal of the sixth operational amplifier is electrically connected to one end of the fourteenth resistor R14. The other end of the fourteenth resistor R14 is electrically connected to the cathode of the laser and the non-inverting input terminal of the seventh operational amplifier. The inverting input terminal of the seventh operational amplifier is electrically connected to its output terminal. The non-inverting input terminal of the sixth operational amplifier is electrically connected to one end of the twelfth resistor R12 and one end of the thirteenth resistor R13. The other end of the twelfth resistor R12 receives the tuning voltage signal provided by the first DAC module. The other end of the thirteenth resistor R13 is electrically connected to the output terminal of the seventh operational amplifier. The current tuning unit 403 is used to convert the input tuning voltage signal into a tuning current to drive the tuning electrode of the laser. Figure 11 In this circuit, the resistance of the tenth resistor R10 is equal to the resistance of the twelfth resistor R12, and the resistance of the eleventh resistor R11 is equal to the resistance of the thirteenth resistor R13. The output tuning current I... mod With input tuning voltage V mod The relationship can be expressed by formula I mod =(R11 / (R10×R14)) ×V mod The sixth and seventh operational amplifiers are determined based on the tuning current and bandwidth used in actual applications. Here, the output tuning current I... mod that is Figure 7 The tuning current I3 in the middle.

[0036] like Figure 12 As shown, the temperature control module 500 includes an H-bridge drive circuit 501, a second temperature measurement circuit 502, a thermoelectric cooler (TEC), and a temperature control unit 503. The temperature control unit 503 is electrically connected to both the H-bridge drive circuit 501 and the second temperature measurement circuit 502. The temperature control unit 503 provides a PWM temperature drive signal to the H-bridge drive circuit 501, which bidirectionally drives the TEC to adjust the laser temperature according to the PWM temperature drive signal. The second temperature measurement circuit 502 is used to acquire the real-time temperature of the laser. The temperature control unit 503 is connected to the SOC via a communication port. The H-bridge drive circuit 501... Figure 13As shown, the H-bridge drive circuit 501 includes two gate drive sub-modules and four MOSFET devices. The input terminals of the first gate drive sub-module are connected to two PWM temperature drive signals, and the output terminals are electrically connected to the gates of the fourth and fifth MOSFET devices, respectively. The input terminals of the second gate drive sub-module are connected to two other PWM temperature drive signals, and the output terminals are electrically connected to the gates of the sixth and seventh MOSFET devices, respectively. The drains of the fourth and sixth MOSFET devices are both electrically connected to the power supply VCC. The source of the fourth MOSFET device is electrically connected to the drain of the fifth MOSFET device and one end of the second inductor. The other end of the second inductor is electrically connected to one end of the fifth capacitor C5 and one end of the thermoelectric cooler TEC, respectively. The source of the ET device is grounded. The source of the sixth MOSFET device is electrically connected to the drain of the seventh MOSFET device and one end of the third inductor. The other end of the third inductor is electrically connected to one end of the sixth capacitor C6 and the other end of the semiconductor cooler TEC. The other ends of the fifth capacitor C5 and the sixth capacitor C6 are both grounded. The second temperature measurement circuit 502 is a Wheatstone bridge circuit with the same circuit structure as the first temperature measurement circuit of the main control module 200. It is used to obtain the voltage signal corresponding to the laser's operating temperature and send it to the temperature control unit 503. The temperature control unit 503 includes a second MCU and a second ADC module. The second MCU is used to provide a PWM temperature drive signal to the H-bridge drive circuit 501. The output of the second temperature measurement circuit 502 is sent to the second ADC module and then sent to the second MCU after analog-to-digital conversion. The temperature control unit 503 adopts a closed-loop control and active compensation strategy to compensate for the cooling required by the laser.

[0037] The second MCU of the temperature control unit 503 is used for closed-loop temperature control. It acquires temperature feedback information through the second temperature measurement circuit 502 and the second ADC module, performs closed-loop control using a digital PID algorithm, and drives the H-bridge drive circuit 501 by outputting a PWM signal through a timer. The second ADC module converts the temperature signal from analog to digital. The EEPROM stores the module's type, version, and parameter information. The PID control loop runs at a 10Hz update rate in the module's built-in second MCU, outputting a PWM duty cycle signal to control the H-bridge drive circuit 501 to drive the thermoelectric cooler (TEC).

[0038] Reference Figure 4 The output voltage of the second temperature measuring circuit 502 V tmp The relationship between the resistance values ​​and the resistance of each resistor is: , Vref Using the reference power supply, the temperature measurement range and signal amplification factor can be adjusted by adjusting the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4. This second temperature measurement circuit 502 is suitable for temperature measurement using resistive temperature sensors such as NTC and PTC.

[0039] In the above content, the temperature control unit 503 adopts a closed-loop control and active compensation strategy to compensate for the cooling required by the laser, including the following: estimating the heat generation power of the laser. P heat ; , V pd It is the laser power detection voltage, which is the output voltage signal amplified by the transimpedance amplifier circuit of the laser power monitoring photodiode. k The constant is used to represent the relationship between optical power and laser power detection voltage. V pd The relationship between them is obtained through calibration; V ld It is the voltage across the laser. P elec Indicates the input power of the laser. P opt This represents the actual output power of the laser; the difference between the output power and the output power is the heating power. Laser anode voltage. V drive The current I across the sampling resistor is a fixed value. S Maintaining a constant voltage can be achieved by measuring the voltage drop across the second sampling resistor, which is the voltage across the laser. V ld pass V drive The result is obtained by subtracting the laser cathode voltage.

[0040] Then based on the heating power P heat To calculate the cooling capacity required for temperature compensation Q c ; , T ld The temperature of the laser, T amb For ambient temperature, R th The total passive thermal resistance from the laser to the environment, and the temperature of the laser. T ld and ambient temperature T amb Total passive thermal resistance measured by a temperature sensor; R thThis is related to the heat dissipation structure of the laser, and was obtained through calibration, assuming the thermoelectric cooler (TEC) does not provide temperature compensation. .

[0041] Characteristic equations of combined semiconductor coolers (TECs) To obtain the driving voltage and duty cycle required for temperature compensation. α The Seebeck coefficient, I tec This is the drive current for the thermoelectric cooler (TEC). T c This refers to the cold junction temperature of the thermoelectric cooler (TEC), which is the temperature of the laser. T ld ; R c For the resistor of the thermoelectric cooler (TEC), K m The thermal conductivity of a thermoelectric cooler (TEC) is given. T h This refers to the hot-end temperature of a thermoelectric cooler (TEC). , Q c The heat absorbed by the cold end of the thermoelectric cooler (TEC). Using the above relationship, the drive current of the TEC can be calculated. I tec Then, the driving voltage of the thermoelectric cooler (TEC) required for temperature compensation can be calculated. V tec Duty cycle. The above process is executed according to a specific cycle, and the duty cycle is output for active compensation. The temperature rise caused by laser heating is often rapid; active compensation can significantly improve temperature control accuracy.

[0042] As shown in Figure 14, the piezoelectric ceramic driving module 600 includes a high-voltage power driving unit 601, a data acquisition and feedback unit 603, and a compensation control unit 602. The high-voltage power driving unit 601 is used to drive the piezoelectric ceramic. The compensation control unit 602 includes a third MCU, a third ADC module, and a second DAC module. The data acquisition and feedback unit 603 is used to acquire the deformation signal of the piezoelectric ceramic and the light intensity signal of the laser. After feeding the deformation signal and the light intensity signal back to the compensation control unit 602, they are processed by the third ADC module. The compensation control unit 602 performs pre-distortion processing based on a simplified curve fitting dynamic model built into the third MCU to eliminate the inherent hysteresis of the piezoelectric ceramic. The data acquisition and feedback unit 603 includes a third temperature measurement circuit, a photodiode, and a transimpedance amplifier circuit. The third temperature measurement circuit here is exactly the same as the first temperature measurement circuit of the main control module 200.

[0043] High-voltage power drive unit 601 reference Figure 15This includes an eighth operational amplifier, a first MOSFET Q1, a second MOSFET Q2, a third MOSFET Q3, a first diode D1, and a second diode D2. One end of the fifteenth resistor R15 is electrically connected to the output of the second DAC module, and the other end of the fifteenth resistor R15 is electrically connected to the non-inverting input of the eighth operational amplifier and one end of the twentieth resistor R20. The inverting input of the eighth operational amplifier is grounded. The output of the eighth operational amplifier is electrically connected to one end of the sixteenth resistor R16, and the other end of the sixteenth resistor R16 is electrically connected to the cathode of the first diode D1 and the emitter of the first MOSFET Q1. The base of the first MOSFET Q1 and the anode of the first diode D1 are both grounded. The collector of the first MOSFET Q1 is connected to one end of the seventh capacitor C7 and the seventeenth resistor R10. One end of resistor R17 is electrically connected to the base of the third MOSFET Q3. The other end of resistor R17 is grounded to the emitter of the third MOSFET Q3. The other end of capacitor C7 is electrically connected to the collector of the third MOSFET Q3, the cathode of the second diode D2, one end of resistor R18, and the base of the second MOSFET Q2. The anode of the second diode D2 is electrically connected to the emitter of the second MOSFET Q2, the other end of resistor R20, and one end of resistor R19. The collector of the second MOSFET Q2 and the other end of resistor R18 are both electrically connected to the +180V power supply. The two ends of resistor R20 are also electrically connected to the two ends of capacitor C8. The other end of resistor R19 serves as the output terminal of high-voltage power drive unit 601. High-voltage power drive unit 601 has a gain of 60 times and can amplify voltages from 0 to 2.5V to 0 to 150V.

[0044] The compensation control unit 602 eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing using a built-in simplified curve-fitting dynamic model, including the following: definition n Prandtl-Ishlinskii model of a play operator For output, For input, , It is determined by parameters The defined play operator function, For the first i The threshold of the play operator For serial number, For the first i The weights of the play operator, and the corresponding inverse model are: , For inverse operators, , ; Acquire the main hysteresis loop data and control the driving voltage of the piezoelectric ceramic as input. A triangular wave scan was performed within the 0-150V range, and the feedback signal of the piezoelectric ceramic deformation was obtained simultaneously using strain gauges. Each cycle samples 500-1000 points; To obtain a family of first-order inversion curves, m voltage points are set at fixed intervals within the range of 0-150V. V k For each voltage point, scan from 0V along the main rising curve to... V k Then, it scans in reverse to 0V, recording the complete scan curve; then it scans from 150V along the main descending curve to... V k Then, the reverse scan is performed to 150V, and the complete scan curve is recorded; a total of 2m first-order inversion curves are obtained, and each first-order inversion curve contains at least 100 points; To identify model parameters and directly obtain the inverse model, the input corresponding to each point is... and output The parameters of each first-order inverse curve are identified according to the Prandtl-Ishlinskii model to obtain an n-dimensional weight vector. Operators with weights less than a set threshold are deleted, and the parameters are converted into 16-bit integers to obtain a lightweight inverse model. After obtaining the inverse model, such as Figure 16 As shown, the lightweight inverse model is dynamically updated using a feedforward combined with PID closed-loop method to counteract the inherent hysteresis of piezoelectric ceramics.

[0045] The specific implementation process is as follows: After power-on, switch S1 switches to the output of the third ADC module, and switch S2 switches to the output of the scan control. A triangular wave scan is performed within the range of 0-150V, and the output voltage of each scan is compared. u ( t and inverse model output u’ ( t ), calculate the model error during the inverse model validation stage. e ( t )= u ( t )- u’ ( t If a cycle is completed, if all model errors... e ( t If all values ​​are less than a specific threshold, the inverse model is considered valid, and switch S1 is switched to... y set Switch S2 to the output of the inverse model and digital PID, perform feedforward control and PID closed-loop control, and obtain the feedforward result. uff ( t ) and feedback u fb ( t ); feedforward u ff ( t ) and feedback u fb ( t Synthesis; if any issues arise during the scanning process e ( t If the value exceeds a certain threshold, it indicates a change in the hysteresis characteristics of the piezoelectric ceramic, requiring a model update. This is achieved by re-obtaining the inverse model through inverse model solving and lightweighting steps, updating the inverse model, and then switching switch S1 back to... y set Switch S2 to the output of the inverse model and digital PID for feedforward and PID closed-loop control. y set Set the desired output value for the system.

[0046] For the feedforward channel, the desired output setpoint of the system is... y set As input, it is fed into the calibrated inverse model to directly calculate the theoretical driving voltage. u ff ( k That is, the output of the inverse model. u’ ( t Actual output y ( t The error signal is obtained through strain gauges, and the closed-loop channel error signal is... e pid ( t )= y set - y ( t Perform digital PID calculation: , These are the proportional, integral, and differential coefficients, all of which take real numbers; This is the error signal of the closed-loop channel at the previous sampling time. The final synthesized control quantity... This achieves closed-loop operation. When the model fails, it is re-identified, and the above calculation process is fully implemented.

[0047] like Figure 17As shown, it also includes an acoustic-optic modulation driving module 700; the acoustic-optic modulation driving module 700 includes an FPGA control unit 701, a clock management unit 702, a DDS signal source unit 703, a driving source power closed-loop control unit 704, and a driving source output control unit 705. The clock management unit 702 sends clock signals to the FPGA control unit 701 and the DDS signal source unit 703 respectively; the FPGA control unit 701 is signal-connected to the DDS signal source unit 703 and is used to control the output frequency and amplitude of the DDS signal source unit 703; the DDS signal source unit 703 and the driving source power closed-loop control unit 705... The power closed-loop control unit 704 and the drive source output control unit 705 are electrically connected in sequence. The DDS signal source unit 703 inputs a radio frequency signal to the drive source power closed-loop control unit 704. The drive source power closed-loop control unit 704 sends the input radio frequency signal to the drive source output control unit 705 on the one hand, and performs fixed coupling attenuation ratio processing on the input radio frequency signal on the other hand to obtain a sampled radio frequency signal. It then outputs the equivalent analog voltage corresponding to the sampled radio frequency signal. The equivalent analog voltage is compared with the reference signal to generate a control voltage signal and adjust the closed-loop gain of the drive source power closed-loop control unit 704.

[0048] like Figure 17As shown, the FPGA control unit 701 uses a ZYNQ 7020 or similar SOC chip to control the output frequency and amplitude of the DDS signal source, as well as to interact with the external main control unit. The clock management unit 702 includes a temperature-controlled crystal oscillator, a clock generator, and a clock buffer. The clock generator multiplies the low-frequency reference clock signal output from the temperature-controlled crystal oscillator to hundreds of MHz, and then distributes it to the FPGA and DDS chip as a high-frequency clock reference signal via the clock buffer. The DDS signal source unit 703 includes a DDS chip and peripheral circuitry. It can use an AD9959 or AD9914 direct digital frequency synthesizer, and through SPI control, the DDS chip can output RF signals up to several GHz. The driver power closed-loop control unit 704 includes a low-pass filter, a variable gain amplifier, an RF power sampling circuit, a detector circuit, and an analog PID circuit. The low-pass filter suppresses harmonics in the DDS output signal, resulting in a cleaner RF source. The RF power sampling circuit extracts the real-time RF signal from the main RF transmission path via directional coupling. After processing with a fixed coupling attenuation ratio, it outputs a low-power RF feedback sampling signal with a coupling level no higher than -10dB, which is simultaneously sent to the back-end power detector circuit. The power detector circuit performs linear detection, envelope restoration, and noise floor suppression on the received small-amplitude sampled RF signal, outputting the equivalent analog voltage corresponding to the RF sampling signal in real time, achieving continuous online high-precision power monitoring and acquisition. The analog voltage output from the RMS detector circuit is compared with the externally input amplitude reference signal by the analog PID circuit, and PID processing is performed to generate a control voltage signal, which is then sent to the gain-controlled adjustment pin of the variable gain amplifier. This ensures that the RF output power of the acousto-optic modulation driver module 700 is stabilized within the preset target power range, ultimately achieving stable output and adjustable amplitude of the acousto-optic modulated diffracted light power.

[0049] This invention utilizes modular and flexible configuration to separate functions such as laser drive, temperature control, piezoelectric ceramic drive, and acousto-optic modulator into independent modules, allowing users to select and expand upon them as needed. The laser drive module 400 employs a parallel coupling architecture of switching power supply and linear power supply, satisfying high current output requirements while effectively suppressing current ripple and noise, ensuring laser frequency stability. The temperature control module 500 adopts an active compensation and closed-loop control method, adding active compensation to traditional closed-loop control to significantly reduce the impact of laser heating on temperature and improve the laser's temperature control accuracy. The Prandtl-Ishlinskii model has been lightweighted and optimized to reduce resource consumption, enabling it to run on a microcontroller. Although the simplified model has a certain degree of reduced accuracy, combined with digital PID closed-loop control, it can still achieve a small control effect. Simultaneously, the closed-loop system can identify errors in the hysteresis inverse model upon power-up. Once the error exceeds a specified threshold, the model parameters can be re-acquired and updated via online scanning, effectively suppressing the nonlinear hysteresis and long-term drift of the piezoelectric ceramic and ensuring the long-term accuracy of micro-displacement control.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A modular laser controller, characterized in that, include: The main control module acquires the frequency difference signal output by the laser and performs closed-loop control based on the frequency difference signal to achieve frequency locking and frequency stabilization of the laser. The laser driver module adopts a switch-linear coupling architecture, which simultaneously provides the response ripple and transient components corresponding to load changes, as well as the steady-state DC component, to provide the operating current for the laser. The temperature control module is used to acquire the temperature signal when the laser is working and to achieve temperature control through a digital PID algorithm. The piezoelectric ceramic drive module eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing based on a simplified curve fitting dynamic model. The power supply module is used to supply power to the main control module, laser driver module, temperature control module and piezoelectric ceramic driver module.

2. A modular laser controller according to claim 1, characterized in that, The main control module includes a State Controller (SOC), several transimpedance amplifier circuits, several first temperature measurement circuits, and a comparator circuit. The several transimpedance amplifier circuits are used to acquire the current signal output by the laser and convert it into a voltage signal before sending it to the SOC. The transimpedance amplifier circuits also acquire the beat frequency feedback signal and send it to the comparator circuit. The comparator circuit shapes the beat frequency feedback signal into a square wave pulse signal and sends it to the SOC. The SOC measures the frequency of the square wave signal and compares it with a set frequency difference signal to output a frequency difference feedback quantity. Frequency control is performed through a closed-loop method. The several first temperature measurement circuits are used to acquire the voltage signal corresponding to the ambient temperature and send it to the SOC.

3. A modular laser controller according to claim 2, characterized in that, Each of the aforementioned transimpedance amplifier circuits includes a feedback resistor R and a first operational amplifier. The inverting input terminal of the first operational amplifier is electrically connected to the output terminal of the laser, and the non-inverting input terminal of the first operational amplifier is grounded. The two ends of the feedback resistor R are electrically connected to the output terminal and the inverting input terminal of the first operational amplifier, respectively. The output terminal of the first operational amplifier is electrically connected to the analog-to-digital conversion channel of the SOC, or the output terminal of the first operational amplifier is electrically connected to the input terminal of the comparator circuit, and the output terminal of the comparator circuit is electrically connected to the SOC. The comparator circuit is a hysteresis comparator.

4. A modular laser controller according to claim 2, characterized in that, The laser driving module includes a switch driving unit, a linear driving unit, a current tuning unit, and a coupling control and monitoring unit. The laser's driving current includes a switch driving current, a linear driving current, and a tuning current. The coupling control and monitoring unit is electrically connected to the enable terminal and the current setting terminal of the switch driving unit, and is also electrically connected to the enable terminal and the current setting terminal of the linear driving unit. The coupling control and monitoring unit also acquires the current monitoring signals from the switch driving unit and the linear driving unit, and provides a tuning voltage to the current tuning unit. The current tuning unit provides a tuning current to the laser based on the input tuning voltage. The switch driving unit and the linear driving unit provide the switch driving current and the linear driving current to the laser, respectively.

5. A modular laser controller according to claim 4, characterized in that, The coupling control and monitoring unit includes a first MCU, a first ADC module, and a first DAC module; both the first ADC module and the first DAC module are electrically connected to the first MCU, and the first MCU is also connected to the SOC via a communication port. The switching drive unit includes a PWM controller, a gate drive circuit, a first MOSFET device, an inductor L1, a first sampling resistor, a differential amplifier circuit, and a low-pass filter circuit. The coupling control and monitoring unit directly provides an enable signal to the PWM controller. The coupling control and monitoring unit also provides a first set current signal to the PWM controller through a first DAC module. The output terminal of the PWM controller is electrically connected to the gate drive circuit for power amplification of the PWM controller's output signal. The output terminal of the gate drive circuit is electrically connected to the gate of the first MOSFET device. The drain of the first MOSFET device is electrically connected to the cathode of the laser through inductor L1, and the anode of the laser is electrically connected to the power supply Vdrive. The source of the first MOSFET device is electrically connected to one end of the first sampling resistor. The other end of the first sampling resistor is grounded; one end of the first sampling resistor is electrically connected to one input terminal of the differential amplifier circuit, the other end of the differential amplifier circuit receives a reference voltage, the output terminal of the differential amplifier circuit is electrically connected to the input terminal of the low-pass filter circuit, and the output terminal of the low-pass filter circuit is electrically connected to one input terminal of the first ADC module and the feedback terminal of the PWM controller; the first MOSFET device operates in the linear region, the first sampling resistor performs current-to-voltage conversion, compares the voltage on the first sampling resistor with the reference voltage in the differential amplifier circuit, and adjusts the gate drive signal of the first MOSFET device according to the comparison result; the inductor L1 is an energy storage inductor used to suppress current surges when the first MOSFET device is turned on and off; when the load changes, the switching drive unit takes over the steady-state DC component; The linear drive unit includes a fourth operational amplifier, a fifth operational amplifier, a second MOSFET device, and a third MOSFET device; the coupling control and monitoring unit inputs a second set current signal to the linear drive unit through the first DAC module; the fourth operational amplifier, the second MOSFET device, the fifth operational amplifier, and the second sampling resistor RS form a current closed loop, and the third MOSFET device forms an enable circuit; when the load changes, the linear drive unit responds to ripple and transient components. The current tuning unit acquires the tuning voltage signal provided by the first DAC module, converts the input tuning voltage signal into a tuning current, and drives the tuning electrode of the laser.

6. A modular laser controller according to claim 2, characterized in that, The temperature control module includes an H-bridge drive circuit, a semiconductor cooler TEC, and a temperature control unit. The temperature control unit is electrically connected to the H-bridge drive circuit and the second temperature measurement circuit, respectively. The temperature control unit provides a PWM temperature drive signal to the H-bridge drive circuit, which is used to bidirectionally drive the semiconductor cooler TEC to adjust the temperature of the laser according to the PWM temperature drive signal. The second temperature measurement circuit is used to obtain the real-time temperature of the laser; the temperature control unit is connected to the SOC via a communication port; the temperature control unit adopts a closed-loop control and active compensation strategy to compensate for the cooling required by the laser.

7. A modular laser controller according to claim 6, characterized in that, The temperature control unit employs a closed-loop control and active compensation strategy to compensate for the cooling required by the laser, including the following: estimating the heat generation power of the laser. P heat Then, the required cooling capacity for temperature compensation is calculated based on the heating power. Q c ; By combining the characteristic equation of a thermoelectric cooler (TEC), the driving voltage and duty cycle required for temperature compensation are obtained.

8. A modular laser controller according to claim 3, characterized in that, The piezoelectric ceramic driving module includes a high-voltage power driving unit, an acquisition and feedback unit, and a compensation and control unit. The high-voltage power driving unit is used to drive the piezoelectric ceramic. The acquisition and feedback unit is used to acquire the deformation signal of the piezoelectric ceramic and the light intensity signal of the laser, and feeds the deformation signal and light intensity signal back to the compensation and control unit. The compensation and control unit performs pre-distortion processing through a built-in simplified curve fitting dynamic model to eliminate the inherent hysteresis of the piezoelectric ceramic.

9. A modular laser controller according to claim 8, characterized in that, The compensation control unit eliminates the inherent hysteresis of piezoelectric ceramics through pre-distortion processing using a built-in simplified curve-fitting dynamic model, including the following: definition n Prandtl-Ishlinskii model and corresponding inverse model of each play operator This is the output of the Prandtl-Ishlinskii model. This is the input to the Prandtl-Ishlinskii model; Acquire the main hysteresis loop data and control the driving voltage of the piezoelectric ceramic as input. A triangular wave scan was performed within the 0-150V range, and the feedback signal of the piezoelectric ceramic deformation was obtained simultaneously using strain gauges. Each cycle samples 500-1000 points; To obtain a family of first-order inversion curves, m voltage points are set at fixed intervals within the range of 0-150V. V k For each voltage point, scan from 0V along the main rising curve to... V k Then, it scans in reverse to 0V, recording the complete scan curve; then it scans from 150V along the main descending curve to... V k Then, the reverse scan is performed to 150V, and the complete scan curve is recorded; a total of 2m first-order inversion curves are obtained, and each first-order inversion curve contains at least 100 points; To identify model parameters and directly obtain the inverse model, the input corresponding to each point is... and output The parameters of each first-order inverse curve are identified according to the Prandtl-Ishlinskii model to obtain an n-dimensional weight vector. Operators with weights less than a set threshold are deleted, and the parameters are converted into 16-bit integers to obtain a lightweight inverse model. The lightweight inverse model is dynamically updated using a feedforward combined with PID closed-loop method to counteract the inherent hysteresis of piezoelectric ceramics.

10. A modular laser controller according to claim 2, characterized in that, It also includes an acousto-optic modulation driving module; the acousto-optic modulation driving module includes an FPGA control unit, a clock management unit, a DDS signal source unit, a driver source power closed-loop control unit, and a driver source output control unit. The clock management unit sends clock signals to the FPGA control unit and the DDS signal source unit respectively. The FPGA control unit is signal-connected to the DDS signal source unit and is used to control the output frequency and amplitude of the DDS signal source unit. The DDS signal source unit, the driver source power closed-loop control unit, and the driver source output control unit are electrically connected in sequence. The DDS signal source unit inputs a radio frequency signal to the driver source power closed-loop control unit. The driver source power closed-loop control unit sends the input radio frequency signal to the driver source output control unit on the one hand, and performs fixed coupling attenuation ratio processing on the input radio frequency signal on the other hand to obtain a sampled radio frequency signal, and outputs the equivalent analog voltage corresponding to the sampled radio frequency signal. The equivalent analog voltage is compared with the reference signal to generate a control voltage signal and adjust the closed-loop gain of the driver source power closed-loop control unit.

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