Laser control system and spectral analysis system

Abstract

The invention discloses a laser control system and a spectral analysis system. The laser control system comprises an ARM module and a laser control module, the laser control module comprises a TEC module and a DA module; the TEC module is in communication connection with the ARM module, when the laser is started to work, the ARM module judges whether the detected laser shell temperature is within a preset range, if the detected laser shell temperature is within the preset range, the TEC module does not work, otherwise, the ARM module controls the TEC module to start to work until the TEC module reaches a preset target temperature, and stable work is kept; and the DA module is in communication connection with the ARM module, an LD current feedback circuit is arranged in the DA module, the ARM module calculates the error between the current power and the target power according to the current data acquired by the LD current feedback circuit, and then the DA module is driven to adjust the output power of the laser in real time, so that the laser stably operates near the target power. And the power loss of the laser is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of spectrum analysis, and in particular to a laser control system and a spectrum analysis system. Background Art

[0002] Lasers have been widely used in the fields of spectral analysis, precision machining, medical imaging, etc., especially in application scenarios that require high-precision optical measurement and control, the stability and controllability of lasers are crucial. At present, most laser control systems on the market rely on hardware circuits for control, which are characterized by fast response speed and relatively simple physical structure, but have the following shortcomings: Unstable laser output: When working, the output power of traditional lasers is unstable, and overcharging may occur as the laser is turned on and off. This may cause the semiconductor components of the laser to be impacted by excessive current, damage internal components, and affect the working efficiency and stability of the laser.

[0003] Poor environmental adaptability: Existing laser systems often rely on passive heat dissipation or simple air cooling systems for temperature control, and are unable to cope with extreme environments (such as extreme cold or high temperatures), resulting in unstable performance or even failure of the laser to work under these conditions.

[0004] Insufficient closed-loop control: The feedback control of traditional laser control systems is not perfect, and usually cannot adjust the output power and state of the laser in real time, which may cause unstable laser output, thus affecting the results of repeatable work consistency.

[0005] The above shortcomings limit the application of existing technologies in scenarios with high environmental requirements, especially for scenarios such as spectral analysis and precision processing that require high stability and high-precision control.

[0006] Therefore, it is necessary to provide a control system and spectrum analysis system for dual soft-controlled lasers based on the ARM system to achieve comprehensive control of the laser system, covering dual regulation of temperature and power, thereby reducing the power loss of the entire laser machine and improving the stability and reliability of the laser. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a laser control system and a spectrum analysis system, which can effectively reduce the power loss of the laser and improve the stability and reliability of the laser.

[0008] In order to solve the above technical problems, the present invention provides a control system for a laser, comprising: an ARM module and a laser control module; the laser control module comprises a TEC module and a DA module; the TEC module is connected to the ARM module for communication, and when the laser starts working, the ARM module determines whether the detected temperature of the laser housing is within a preset range, if it is within the preset range, the TEC module does not work, otherwise, the ARM module controls the TEC module to start working until the TEC module reaches a preset target temperature and keeps working stably; the DA module is connected to the ARM module for communication, and an LD current feedback circuit is arranged in the DA module, and the ARM module calculates the error between the current power and the target power according to the current data collected by the LD current feedback circuit, and then drives the DA module to adjust the output power of the laser in real time, so that the laser can operate stably near the target power.

[0009] Furthermore, the control method of the TEC module is as follows: when the laser starts working, the ARM module determines the difference between the detected laser housing temperature and the target temperature set by the TEC module. If the difference is within 35°C, the TEC module does not work; otherwise, the TEC target temperature is set to 25°C, and the TEC module is controlled to start working, so that the TEC module maintains stable operation after reaching the target temperature. When the laser stops and enters the working state again, the above steps are repeated.

[0010] Further, the control method of the TEC module is as follows: when the laser starts working, the ARM module determines the detected temperature of the laser housing, and when the ARM module detects that the temperature of the laser housing is between 0 and 35°C, the TEC module does not work; when the ARM module detects that the temperature of the laser housing is between -20°C and -10°C, the ARM module controls the TEC module to start working, and the target temperature of the TEC module is set to -10°C, so that the TEC module can maintain stable working after reaching the target temperature; when the ARM module detects that the temperature of the laser housing is between -10°C and 0°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0°C, so that the TEC module can maintain stable working after reaching the target temperature; when the ARM module detects that the temperature of the laser housing is higher than 35°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35°C, so that the TEC module can maintain stable working after reaching the target temperature; when the laser stops and enters the working state again, the above steps are repeated.

[0011] Furthermore, the relationship between the output power and the set voltage of the laser adopts an eighth-order calibration method: the ARM module sets the voltage to drive the laser, and the voltage is set starting from 0mv and increasing by 100mv in sequence to 2500mv. The voltage value is read through the LD feedback circuit, and the stabilized power value is recorded. The eighth-order calibration parameters between the output power and the set voltage are calculated according to the recorded 26 sets of values, and the eighth-order calibration parameters between the set voltage and the output power are read back. Then, these two sets of 8th-order calibration data are written into the flash memory of the ARM module, and the target power value is input. Then, the initial set voltage value to achieve the target power can be calculated according to the eighth-order calibration parameters between the output power and the set voltage.

[0012] Furthermore, the relationship between the output power of the laser and the set voltage is calibrated by a table lookup method: the ARM module sets the voltage to drive the laser, and the voltage is set from 0mv, increasing by 100mv in sequence to 2500mv, and the voltage is set to drive the laser, and the voltage value is read through the LD feedback circuit, and the optical power value measured by the optical power meter at this time is recorded, so that 26 groups of set voltage values, LD feedback voltage values, and optical power values ​​are obtained; the above data are stored in the flash memory of the ARM module, so that according to the set target power value, the set voltage range can be obtained by looking up the table, and at this time, the linear relationship between voltage and power can be approximately considered within a small voltage range, thereby calculating the initial set voltage value to achieve the target power.

[0013] Furthermore, a 12-bit DA module and a 12-bit ADC module are set in the ARM module. The output power of the laser is set through the 12-bit DA module. At the same time, the LD feedback current loop is collected in real time through the 12-bit ADC module. Combined with the PID control algorithm, the ARM module calculates the error between the current power and the target power according to the collected current data, and then drives the DA module to adjust the output power of the laser in real time, so that the laser can operate stably near the target power.

[0014] Furthermore, the ARM uses ADC and DMA cycle modes to obtain the temperature feedback value of the TEC module and the voltage feedback value of the LD feedback current loop in real time.

[0015] To solve the above problems, the present invention also provides a spectrum analysis system, including a spectrometer and a laser, the laser including the above-mentioned laser control system, the spectrometer including a spectrum acquisition module, the spectrum acquisition module including a CCD module and an FPGA module, the FPGA module generates a timing according to the received instructions to drive the CCD module to perform exposure for a certain integration time, the CCD module feeds back the collected analog quantity to the FPGA through an A / D conversion circuit, and the FPGA transmits the collected spectrum data to the ARM module for data processing.

[0016] Furthermore, the ARM module performs register configuration with the FPGA module via the SPI or MIPI protocol, and the FPGA module transmits the collected spectral data to the ARM module for data processing via the SPI or MIPI protocol.

[0017] Furthermore, the ARM module internally integrates a boxcar smoothing and stretching algorithm to process the collected spectral data, and the processed data is transmitted to a PC terminal or a handheld device terminal via USB or serial port communication.

[0018] Compared with the prior art, the present invention has the following advantages: the laser control system and spectrum analysis system provided by the present invention use the ARM module for digital signal processing, so that the system can quickly respond to user instructions and system changes, and realize real-time adjustment and control of the laser, thereby improving work efficiency; the LD feedback loop realizes real-time monitoring and closed-loop regulation of the laser output power to ensure the stability of the laser output, and can quantitatively manage the power and voltage to ensure the accuracy and reliability of the system during long-term operation; the TEC module realizes bidirectional temperature control of the laser, and can accurately cool and heat in extremely cold and high temperature environments to ensure the stable operation of the laser in extreme environments. The laser control system provided by the present invention has the function of real-time monitoring and control parameter adjustment, can promptly detect and handle abnormal conditions of the laser, and ensure the stable operation and long-term reliability of the laser. The laser dual-soft control system based on the ARM system has good flexibility and scalability, and can adapt to different laser control requirements; the high integration and low power consumption characteristics of the ARM module significantly improve the cost-effectiveness of the entire laser control system, save the use of electrical components, and optimize the board space, further reducing the hardware cost. The system that realizes laser control through software is easy to integrate into existing laser equipment. At the same time, the modular design of the system is also easy to maintain and upgrade, with high portability and saving development time. Therefore, the present invention provides a flexible, efficient and stable dual-soft-controlled laser control system, which is widely used in high-demand application scenarios such as spectral analysis, precision processing, and medical imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the framework of the spectrum analysis system in an embodiment of the present invention; Figure 2 This is a schematic diagram of the laser control process in an embodiment of the present invention; Figure 3 Schematic diagram of the framework of the spectrum analysis system in an embodiment of the present invention; Figure 4 Schematic diagram of the working process of the spectrum analysis system in an embodiment of the present invention; Figure 5a and Figure 5b This is a comparison diagram of the power consumption of the laser in the embodiment of the present invention and the power consumption of the existing laser; Figure 6a This is a graph of silicon wafer testing at room temperature in an embodiment of the present invention. Figure 6b This is the silicon wafer test spectrum at 46°C in the embodiment of the present invention. Figure 6c This is a silicon wafer test spectrum at 20°C in an embodiment of the present invention. Figure 6d This is the silicon wafer test spectrum at 0°C in the embodiment of the present invention. Figure 6e This is a silicon wafer test spectrum at -20°C in an embodiment of the present invention; Figure 7a is the wavelength deviation result at room temperature in the embodiment of the present invention, Figure 7b The wavelength deviation result at 46°C in the embodiment of the present invention is: Figure 7c is the wavelength deviation result at 20°C in the embodiment of the present invention, Figure 7d is the wavelength deviation result at 0°C in the embodiment of the present invention, Figure 7e The wavelength deviation result at -20°C in the embodiment of the present invention; Figure 8a The Raman signal spectrum of alcohol and acetone detected in the embodiment of the present invention is at a working temperature of 0°C and after 2 hours of low-temperature storage. Figure 8b The interface display of alcohol on mobile terminals, Figure 8c The interface display of acetone on the mobile terminal; Figure 9a In the embodiment of the present invention, the working temperature is 40°C, and after 2 hours of high temperature storage, the Raman signal spectrum of alcohol and acetone is detected. Figure 9b This is the interface display of acetone on the mobile terminal. Fig.9c The interface display of alcohol on mobile terminals; Fig.10a In the embodiment of the present invention, the working temperature is 45°C, and after 2 hours of high temperature storage, the Raman signal spectrum of alcohol and acetone is detected. Fig.10b This is the interface display of acetone on the mobile terminal. Fig.10c The interface display of alcohol on mobile terminals; Fig.11aIn the embodiment of the present invention, the working temperature is -20°C, after 24 hours of low-temperature storage, it is taken out and restored at room temperature for 1 hour, and the Raman signal spectrum of alcohol and acetone is detected. Fig.11b This is the interface display of acetone on the mobile terminal. Fig.11c The interface display of alcohol on mobile terminals; Fig.12a In the embodiment of the present invention, the working temperature is 70°C, after 24 hours of high temperature storage, it is taken out and restored at room temperature for 1 hour, and the Raman signal spectrum of alcohol and acetone is detected. Figure 12b The interface display of alcohol on mobile terminals, Fig.12c This is the interface display of acetone on a mobile terminal. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] The purpose of the present invention is to provide a control system for a dual soft-controlled laser based on an ARM system. The control system uses an ARM processor as the control core to achieve comprehensive control of the laser system, covering dual regulation of temperature and power, thereby reducing the power loss of the entire machine. The present invention adopts two-way soft-controlled closed-loop control, one way controls the TEC module of the laser to maintain a constant operating temperature; the other way controls the DA module of the laser to achieve precise output control of the laser output power.

[0022] See also Figure 1 , Figure 2 and Figure 3 The present invention provides a laser control system, comprising: an ARM module (Advanced RISC Machines) and a laser control module; the laser control module comprises a TEC module (Thermoelectric Cooler) and a DA module (Digital to Analog Converter).

[0023] The TEC module is connected to the ARM module in communication. When the laser starts working, the ARM module determines whether the temperature of the laser housing is within a preset range. If it is within the preset range, the TEC module does not work. Otherwise, the ARM module controls the TEC module to start working until the TEC module reaches the preset target temperature and maintains stable operation. The TEC module realizes bidirectional temperature control of the laser, which can perform precise cooling and heating in extremely cold and high temperature environments, ensures the stable operation of the laser in extreme environments, and enhances the environmental adaptability of the laser.

[0024] The DA module is connected to the ARM module in communication. The DA module is provided with an LD current feedback circuit (LaserDiode). The ARM module calculates the error between the current power and the target power based on the current data collected by the LD current feedback circuit, and then drives the DA module to adjust the output power of the laser in real time, so that the laser can operate stably near the target power. The LD current feedback loop is used to realize real-time monitoring and closed-loop regulation of the laser output power, ensure the stability of the laser output power, and can quantitatively manage the power and voltage, ensuring the accuracy and reliability of the system during long-term operation.

[0025] In one embodiment, the control method of the TEC module is as follows: when the laser starts working, the ARM module determines the difference between the detected laser housing temperature and the target temperature set by the TEC module. If the difference is within 35°C, the TEC module does not work; otherwise, the TEC target temperature is set to 25°C, and the TEC module is controlled to start working, so that the TEC module maintains stable operation after reaching the target temperature, and the above steps are repeated when the laser stops and enters the working state again. This control method can use manual mode to input the TEC target temperature, and the laser housing temperature can be detected by setting a temperature sensor on the laser housing. The PID control algorithm inside the ARM module can be used to accurately adjust the laser operating temperature to ensure the stable working state of the laser under various temperature conditions.

[0026] In another embodiment, the control mode of the TEC module is as follows: when the laser starts working, the ARM module determines the detected laser housing temperature. When the ARM module detects that the laser housing temperature is between 0 and 35°C, the TEC module does not work; when the ARM module detects that the laser housing temperature is between -20°C and -10°C, the ARM module controls the TEC module to start working, and the target temperature of the TEC module is set to -10°C, so that the TEC module can maintain stable operation after reaching the target temperature; when the ARM module detects that the laser housing temperature is between -10°C and 0°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0°C, so that the TEC module can maintain stable operation after reaching the target temperature; when the ARM module detects that the laser housing temperature is higher than 35°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35°C, so that the TEC module can maintain stable operation after reaching the target temperature. This mode can adopt the automatic mode, and judge whether the laser TEC is ready through one digital quantity TMPGD and one temperature acquisition analog quantity. Similarly, the PID control algorithm inside the ARM module can be used to accurately adjust the laser operating temperature to ensure that the laser operates stably under various temperature conditions.

[0027] In a specific embodiment, the laser device supports both manual and automatic modes. When the PID (Proportion, Integral and Derivative) drive TEC module is powered on by default, the target temperature is set to 25°C in automatic mode. After the device is started, the software control interface (manual mode) is entered, and the host computer performs a custom temperature adjustment of 15-35°C through the USB interface. This flexible and adjustable design solves the problem of poor flexibility and high power consumption of lasers in cold or hot environments.

[0028] During the laser equipment testing process, it was found that the impact of ambient temperature changes on the preset target temperature of the laser tube is relatively large. The temperature difference between the preset target temperature and the ambient temperature should not be too large, otherwise the laser system will find it difficult to reach the preset target temperature, and the entire system will always be in a state of relatively high power consumption. The feedback signal TMPGD of the TEC module returns a digital quantity. At this time, the value obtained by the laser control system is logical 0. It is believed that the TEC module has not reached the optimal working state at this time. At this time, turning on the laser cannot drive the laser to work. In another case, if the temperature feedback is at the critical value of the set target temperature, the laser will turn on and off when the equipment is working. After high and low temperature experiments, it was found that the laser tube in the equipment works at 0-35°C, and whether the TEC module is turned on or not has almost no effect on the Raman signal. Therefore, how to efficiently control the laser and reduce the power consumption of the laser is the problem to be solved by the present invention. The solution of the present invention is to optimize the temperature control strategy of the laser TEC module. Whether the laser TEC module is ready is judged by a digital quantity TMPGD and a temperature acquisition analog quantity. Assuming that the preset laser tube temperature is 25°C, if TMPGD=1, the laser device is in normal state and can work. Otherwise, determine whether the difference between the TEC module target temperature and the ambient temperature (laser housing temperature) is within ±10°C. If so, the laser device is in normal state. If not, wait for the laser device TEC module to be ready. The present invention uses the dual conditions of TMPGD digital quantity and real-time temperature analog quantity feedback to comprehensively judge the working state of the TEC module, thereby realizing the control of the TEC module. The high and low temperature test results show that the TEC control strategy can effectively solve the problem of abnormal equipment operation caused by temperature difference, and the handheld Raman device can work normally in an environment of 0-45°C. For details, please refer to Figure 8a-Figure 12c .

[0029] In one embodiment, the relationship between the output power and the set voltage of the laser adopts an eight-step calibration method: the ARM module sets the voltage to drive the laser, and the voltage is set from 0mv, increasing by 100mv in sequence to 2500mv, and the voltage value is read through the LD feedback circuit, and the power value after stabilization is recorded. The eight-step calibration parameters between the output power and the set voltage are calculated according to the 26 sets of values ​​recorded, and the eight-step calibration parameters between the set voltage and the output power are read back, and then these two sets of 8-step calibration data are written to the flash memory (FLASH) of the ARM module through USB / UART, and the area is not lost when the power is off. In this way, when the user inputs the target power value, the initial set voltage value to achieve the target power can be calculated according to the eight-step calibration parameters between the output power and the set voltage.

[0030] In another embodiment, the relationship between the output power of the laser and the set voltage is calibrated by a table lookup method: the ARM module sets the voltage to drive the laser, and the voltage is set from 0mv, and increases by 100mv in sequence until 2500mv, and the voltage is set to drive the laser, and the voltage value is read through the LD feedback circuit, and the optical power value measured by the optical power meter at this time is recorded, so that 26 sets of set voltage values, LD feedback voltage values, and optical power values ​​are obtained; the above data are stored in the flash memory (FLASH) of the ARM module, so that the set voltage range can be obtained by looking up the table according to the set target power value, and at this time, the linear relationship between voltage and power can be approximated within a small voltage range, so as to calculate the initial set voltage value to reach the target power. The optical power value obtained in this way is more accurate than the eighth-order calibration method, and the multiplication operation of multi-order calibration can be reduced, which significantly improves the operating efficiency of the ARM module.

[0031] In a specific embodiment, a 12-bit DA module and a 12-bit ADC module (Analog-to-Digital Converter Module) are set in the ARM module. The output power of the laser is set by the 12-bit DA module. At the same time, the LD feedback current loop is collected in real time by the 12-bit ADC module. Combined with the PID control algorithm, the ARM module calculates the error between the current power and the target power according to the collected current data, and then drives the DA module to adjust the output power of the laser in real time, so that the laser can operate stably near the target power.

[0032] The ARM adopts ADC and DMA (Direct Memory Access) loop mode to obtain the temperature feedback value of the TEC module and the voltage feedback value of the LD feedback current loop in real time.

[0033] Furthermore, the laser also includes a storage module, a power module, a fan module, a device information monitoring module and a crystal oscillator module. The storage module is composed of an EEPROM module (Electrically Erasable Programmable Read-Only Memory) and an SRAM module (Static Random Access Memory). The EEPROM module is used to store the coefficients and calibration parameters of the spectrum, as well as other spare storage areas; the SRAM module is used to store spectrum data and perform spectrum storage analysis; the power module is composed of a DC-DC circuit, a filter circuit, and a protection circuit; the power module supplies power to the ARM module, the laser control module, the fan module, etc. The device information monitoring module is composed of an RGB (red, green, and blue) indicator light and a PCB (printed circuit board) temperature acquisition module. The RGB indicator light module is used for normal operation and fault prompts. The fan module is used for heat dissipation of the laser, and the fan assists in heat dissipation and the temperature acquisition module provides real-time temperature feedback to further enhance the environmental adaptability of the system; the crystal oscillator module provides a heartbeat packet, which is divided by the PLL to generate clock buses of different frequencies to provide clocks for different module peripherals. The specific working process of controlling the control system of the dual soft-controlled laser based on the ARM system provided by the present invention is as follows: Process 101: The system is powered on and each module is started: first the power module, then the ARM module, the laser control module and the fan module; Process 102: The system starts initializing. The initialization includes USB module initialization, AD_TEC temperature acquisition module initialization, AD_power acquisition module initialization, DA_TEC temperature setting output module initialization, DA_power setting output module initialization, timer module initialization, and fan module initialization. Process 103: After the system is started, the ARM module turns on PID control by default, controls the TEC temperature by driving the TEC module, and sets the target temperature to 25°C. The system is in a waiting state, waiting for the host computer to send instructions through the USB interface; Process 104: Once the ARM module receives the command sent by the PC host computer from the USB module, the ARM module immediately receives and parses the command. Perform corresponding operations according to the user's command, such as the laser voltage power calibration parameter setting command, power setting command, and TEC module on / off control command; Process 105: When the ARM module receives the power setting instruction, it starts the PID drive DA module, drives the power output circuit to control the power output module circuit, and adjusts the DA_power setting output module in real time according to the LD current feedback circuit voltage value collected by the AD_power acquisition module to control the output power and frequency of the laser, so as to achieve the effect of accurately outputting the laser power.

[0034] There is a large error between the laser output power and the preset power. In order to improve the accuracy of the output power, the present invention solves the problem from two aspects: circuit and drive: (1) The LD current feedback loop is added to the ARM module in the circuit, and the system forms a closed-loop regulation through the LD feedback circuit control to ensure the stability of the laser output power. (2) The ARM module is used as the controller, and the power output of the laser is set through the 12-bit DA module, while the LD current feedback loop is collected in real time through the 12-bit ADC module. Combined with the PID control algorithm, ARM calculates the error between the current and the target power based on the collected current data, and then drives the DA module to adjust the output power of the laser in real time to ensure stable operation near the target power of the laser. Existing lasers are all set to a constant voltage value to drive the laser output power. The present invention introduces a PID closed-loop algorithm to adjust the output of the DA module in real time, which can not only effectively reduce the instantaneous overshoot of the laser power output, but also greatly improve the accuracy of the laser power output, and the error is controlled within ±1mW.

[0035] The present invention adopts ARM+Free RTOS (lightweight real-time operating system kernel) architecture, creates TEC module temperature control tasks and power output control tasks, reasonably allocates task priorities, introduces semaphore and message queue mechanisms, and supports interrupt and task priority preemption mechanisms. The ADC+DMA cycle mode in the ARM module obtains TEC temperature feedback values ​​and voltage feedback values ​​in real time. The introduction of DMA can effectively reduce the CPU scheduling pressure, save CPU workload, and improve data exchange efficiency.

[0036] The present invention not only improves the stability and reliability of the laser system, but also optimizes and controls the laser performance through the efficient processing capability and intelligent control algorithm of the ARM system. Figure 5a and Figure 5b As shown, the efficient control of the laser control system provided by the present invention can reduce the energy consumption of the laser, reduce output coupling loss and heat loss, and meet the requirements of modern industry for environmental protection and energy saving.

[0037] See also Figure 1 , Figure 3 and Figure 4This embodiment also provides a spectrum analysis system, including a spectrometer and a laser, wherein the laser includes the above-mentioned laser control system, the spectrometer includes a spectrum acquisition module, and the spectrum acquisition module includes a CCD module and an FPGA module. The FPGA module generates a timing according to the received instructions to drive the CCD module to perform exposure for a certain integration time. The CCD module feeds back the collected analog quantity to the FPGA through the A / D conversion circuit, and the FPGA transmits the collected spectrum data to the ARM module for data processing.

[0038] Furthermore, the ARM module performs register configuration with the FPGA module via the SPI or MIPI protocol, and the FPGA module transmits the collected spectral data to the ARM module for data processing via the SPI or MIPI protocol. When the system is working, the ARM module can control the FPGA reset pin to synchronously control the communication between the ARM and the FPGA.

[0039] Furthermore, the ARM module integrates a boxcar smoothing and stretching algorithm to process the collected spectral data, and the processed data is transmitted to a PC terminal or a handheld device terminal via USB, serial port or Gigabit Ethernet communication, and performs real-time data transmission and remote control with the PC or mobile terminal.

[0040] The present invention supports multiple communication protocols to ensure that the system can interact with a PC or a mobile terminal in real time. At the same time, the spectral coefficients and parameters stored in the EEPROM ensure data security in the event of a power outage.

[0041] The spectrum analysis system provided by the present invention is used to test silicon wafers at room temperature, -20°C, 0°C, 20°C, and 46°C, respectively, to observe the changes in the characteristic peaks of the silicon wafers. The peak deviation test results at -20°C-46°C are shown in Table 1, and the test spectra are shown in Table 2. Figure 6a-6e The Raman peak of the silicon wafer was measured at 521cm at room temperature. -1 ; The Raman peak of the silicon wafer was measured at 523cm at -20℃, 0℃, 20℃ and 46℃ -1 , the wavelength is shifted by 2cm compared to room temperature -1 ; The spectral peak deviation is small.

[0042] Table 1 Spectral peak deviations (cm -1 ) The wavelength deviation test of the equipment was carried out at room temperature, -20℃, 0℃, 20℃, and 46℃ using a mercury argon lamp. The wavelength deviation test results at -20℃-46℃ are shown in Table 2, and the original test spectrum is shown in Figure 7a-7eTable 2 compares the changes of 4 standard mercury sub-lamp values ​​811.531nm, 826.452nm, 842.465nm, and 912.297nm at different temperatures. It can be seen from Table 2 that under the conditions of room temperature, -20℃, 0℃, 20℃, and 46℃, the RSD value of each spectral line of 811.531nm, 826.452nm, 842.465nm, and 912.297nm is small, indicating that the wavelength deviation is not large under these temperature conditions.

[0043] Table 2 Wavelength deviation of the handheld device core at different temperatures (nm) The spectral analysis system provided by the present invention can work normally at different storage temperatures: using a high and low temperature box and referring to the national standard, the test equipment can work normally at storage temperatures of -20°C, 0°C, 40°C, 45°C, and 70°C. 3. The test results at working temperature of 0℃ are as follows Figure 8a-8c As shown, after 2 hours of low-temperature storage, the spectral analysis system provided by the present invention can still detect the Raman signals of alcohol and acetone. Under this condition, the spectral analysis system provided by the present invention can work normally.

[0045] The test results at an operating temperature of 40°C are as follows Figure 9a-9c As shown, after 2 hours of high-temperature storage, the spectral analysis system provided by the present invention can still detect the Raman signals of alcohol and acetone. Under this condition, the spectral analysis system provided by the present invention can work normally.

[0046] The test results at an operating temperature of 45°C are as follows Figure 10a-Figure 10c As shown, after 2 hours of high-temperature storage, the spectral analysis system provided by the present invention can still detect the Raman signals of alcohol and acetone. Under this condition, the spectral analysis system provided by the present invention can work normally.

[0047] The test results of storage at -20℃ for 24h are as follows Figure 11a-Figure 11c As shown, after 24 hours of low-temperature storage and recovery at room temperature for 1 hour, the Raman signals of alcohol and acetone can be detected. Under this condition, the spectral analysis system provided by the present invention can work normally.

[0048] The test results of storage at 70℃ for 24h are as follows: Figure 12a-12c As shown, after 24 hours of high-temperature storage and recovery at room temperature for 1 hour, the present invention can still detect the Raman signals of alcohol and acetone, and the present invention can still work normally after high-temperature storage.

[0049] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.

Claims

1. A laser control system, characterized in that: include: ARM module and laser control module; The laser control module includes a TEC module and a DA module; The TEC module is connected to the ARM module for communication. When the laser starts working, the ARM module determines whether the detected temperature of the laser housing is within a preset range. If it is within the preset range, the TEC module does not work. Otherwise, the ARM module controls the TEC module to start working until the TEC module reaches the preset target temperature and keeps working stably. The DA module is communicatively connected with the ARM module. An LD current feedback circuit is arranged in the DA module. The ARM module calculates the error between the current power and the target power according to the current data collected by the LD current feedback circuit, and then drives the DA module to adjust the output power of the laser in real time so that the laser can operate stably near the target power.

2. The control system according to claim 1, characterized in that: The control method of the TEC module is as follows: when the laser starts working, the ARM module determines the difference between the detected laser housing temperature and the target temperature set by the TEC module. If the difference is within 35°C, the TEC module does not work; otherwise, the TEC target temperature is set to 25°C, and the TEC module is controlled to start working, so that the TEC module maintains stable operation after reaching the target temperature. When the laser stops and enters the working state again, the above steps are repeated.

3. The control system according to claim 1, characterized in that: The control mode of the TEC module is as follows: when the laser starts working, the ARM module determines the detected temperature of the laser housing. When the ARM module detects that the temperature of the laser housing is between 0 and 35°C, the TEC module does not work; when the ARM module detects that the temperature of the laser housing is between -20°C and -10°C, the ARM module controls the TEC module to start working, and the target temperature of the TEC module is set to -10°C, so that the TEC module can maintain stable working after reaching the target temperature; when the ARM module detects that the temperature of the laser housing is between -10°C and 0°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0°C, so that the TEC module can maintain stable working after reaching the target temperature; when the ARM module detects that the temperature of the laser housing is higher than 35°C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35°C, so that the TEC module can maintain stable working after reaching the target temperature; when the laser stops and enters the working state again, the above steps are repeated.

4. The control system according to claim 1, characterized in that: The relationship between the output power and the set voltage of the laser adopts an eighth-order calibration method: the ARM module sets the voltage to drive the laser, and the voltage is set from 0mv, increasing by 100mv in sequence to 2500mv, and the voltage value is read through the LD feedback circuit, and the stabilized power value is recorded, and the eighth-order calibration parameters between the output power and the set voltage are calculated according to the recorded 26 sets of values, and the eighth-order calibration parameters between the set voltage and the output power are read back, and then these two sets of 8th-order calibration data are written into the flash memory of the ARM module, and the target power value is input, and the initial set voltage value to achieve the target power can be calculated according to the eighth-order calibration parameters between the output power and the set voltage.

5. The control system according to claim 1, characterized in that: The relationship between the output power of the laser and the set voltage is calibrated by a table lookup method: the ARM module sets the voltage to drive the laser, and the voltage is set from 0mv, and increases by 100mv in sequence to 2500mv. The voltage is set to drive the laser, and the voltage value is read through the LD feedback circuit, and the optical power value measured by the optical power meter at this time is recorded, so that 26 groups of set voltage values, LD feedback voltage values, and optical power values ​​are obtained; the above data are stored in the flash memory of the ARM module, so that the set voltage range can be obtained according to the set target power value by looking up the table, and at this time, the linear relationship between voltage and power can be approximately considered within a small voltage range, thereby calculating the initial set voltage value to reach the target power.

6. The control system according to claim 1, characterized in that: A 12-bit DA module and a 12-bit ADC module are set in the ARM module. The output power of the laser is set through the 12-bit DA module. At the same time, the LD feedback current loop is collected in real time through the 12-bit ADC module. Combined with the PID control algorithm, the ARM module calculates the error between the current power and the target power according to the collected current data, and then drives the DA module to adjust the output power of the laser in real time, so that the laser can run stably near the target power.

7. The control system according to claim 1, characterized in that: The ARM adopts ADC and DMA cycle mode to obtain the temperature feedback value of the TEC module and the voltage feedback value of the LD feedback current loop in real time.

8. A spectrum analysis system, characterized in that: The invention comprises a spectrometer and a laser, wherein the laser comprises the laser control system according to any one of claims 1 to 7, the spectrometer comprises a spectrum acquisition module, the spectrum acquisition module comprises a CCD module and an FPGA module, the FPGA module generates a timing according to the received instruction to drive the CCD module to perform exposure for a certain integration time, the CCD module feeds back the collected analog quantity to the FPGA through the A / D conversion circuit, and the FPGA transmits the collected spectrum data to the ARM module for data processing.

9. The spectrum analysis system according to claim 8, characterized in that: The ARM module performs register configuration with the FPGA module via the SPI or MIPI protocol, and the FPGA module transmits the collected spectral data to the ARM module for data processing via the SPI or MIPI protocol.

10. The spectrum analysis system according to claim 8, characterized in that: The ARM module integrates a boxcar smoothing and stretching algorithm to process the collected spectral data, and the processed data is transmitted to a PC terminal or a handheld device terminal via USB or serial communication.

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