A laser control system and a spectral analysis system

Abstract

The application discloses a kind of control system of laser and spectral analysis system, comprising: ARM module and laser control module;Laser control module, including TEC module and DA module;TEC module is connected with ARM module communication, when laser starts to work, ARM module judges whether the temperature of detected laser shell is in the preset range, if in the preset range, TEC module does not work, otherwise, ARM module controls TEC module to open work, until TEC module reaches the preset target temperature, and keep stable work;DA module is connected with ARM module communication, LD current feedback circuit is arranged in DA module, and the error of current power and target power is calculated according to the current data collected by LD current feedback circuit in ARM module, then DA module is driven to adjust the output power of laser in real time, so that laser is stably operated around target power.Effective reduction of the power loss of laser.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of spectral analysis, and particularly relates to a laser control system and a spectral analysis system. BACKGROUND

[0002] Laser has been widely used in the field of spectral analysis, precision machining, medical imaging, etc. Especially in the application scenarios that require high-precision optical measurement and control, the stability and controllability of laser are crucial. At present, most of the laser control systems on the market rely on hardware circuit to realize control, which has the characteristics of fast response speed and relatively simple physical structure, but has the following shortcomings:

[0003] Unstable laser output: The output power of traditional laser is unstable when it is working, and overcharging problem may occur when the laser is turned on and off. This may cause the semiconductor components of the laser to be impacted by excessive current, damage the internal components, and also affect the working efficiency and stability of the laser.

[0004] Poor environmental adaptability: The existing laser system often relies on passive heat dissipation or simple air cooling system for temperature control, which cannot cope with extreme environments (such as extreme cold or high temperature), resulting in unstable performance or even inability to work of the laser under these conditions.

[0005] Insufficient closed-loop control: The feedback control of traditional laser control system is not perfect, and it is usually unable to adjust the output power and state of the laser in real time, which may lead to unstable output of the laser and affect the consistency of the results of repeatable work.

[0006] The above shortcomings limit the application of existing technology in scenes with high environmental requirements, especially for scenes such as spectral analysis and precision machining that require high stability and high-precision control.

[0007] Therefore, it is necessary to provide a dual-soft control laser control system and spectral analysis system based on ARM system, which realizes comprehensive control of the laser system, covers dual regulation of temperature and power, and further reduces the power loss of the laser whole machine, improves the stability and reliability of the laser. SUMMARY

[0008] The technical problem to be solved by the present application is to provide a laser control system and spectral analysis system that can effectively reduce the power loss of the laser and improve the stability and reliability of the laser.

[0009] To solve the above technical problems, the application provides a control system of 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 in communication connection with the ARM module; when the laser starts to work, the ARM module judges whether the detected temperature of the laser shell is within a preset range; if yes, 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 then keeps stable work; 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 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 stably operates near the target power.

[0010] Further, the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the difference between the detected temperature of the laser shell and the target temperature set by the TEC module; if the difference is within 35 DEG C, the TEC module does not work; otherwise, the target temperature of the TEC module is set to 25 DEG C, and the TEC module is controlled to start to work, so that the TEC module keeps stable work after reaching the target temperature; when the laser stops and then enters the working state again, the above steps are recycled.

[0011] Further, the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the detected temperature of the laser shell; when the ARM module detects that the temperature of the laser shell is 0~35 DEG C, the TEC module does not work; when the ARM module detects that the temperature of the laser shell is-20 DEG C~-10 DEG C, the ARM module controls the TEC module to start to work, and the target temperature of the TEC module is set to-10 DEG C, so that the TEC module keeps stable work after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is-10 DEG C~0 DEG C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0 DEG C, so that the TEC module keeps stable work after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is higher than 35 DEG C, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35 DEG C, so that the TEC module keeps stable work after reaching the target temperature; when the laser stops and then enters the working state again, the above steps are recycled.

[0012] Further, the relationship between the output power of the laser and the set voltage adopts an eight-order calibration method: the ARM module sets the voltage to drive the laser, the set voltage starts from 0mv and increases by 100mv successively until 2500mv, the voltage value is read through the LD feedback circuit, the stable power value is recorded, the eight-order calibration parameters between the output power and the set voltage are calculated according to the recorded 26 groups of values, the eight-order calibration parameters between the set voltage and the output power are read back, and then the two groups of eight-order calibration data are written into the flash memory of the ARM module, so that the initial set voltage value reaching the target power can be calculated according to the eight-order calibration parameters between the output power and the set voltage.

[0013] Further, the relationship between the output power of the laser and the set voltage adopts a table lookup calibration method: the ARM module sets the voltage to drive the laser, the set voltage starts from 0mv and increases by 100mv successively until 2500mv, the set voltage drives the laser, 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 interval can be obtained by looking up the list according to the set target power value, at this time, the linear relationship between the voltage and the power can be approximately considered in a small voltage interval range, so as to calculate the initial set voltage value reaching the target power.

[0014] Further, the 12bit DA module and the 12bit ADC module are arranged in the ARM module, the output power of the laser is set through the 12bit DA module, the LD feedback current loop is collected in real time through the 12bit ADC module, the error between the current data collected and the target power is calculated according to the PID control algorithm, and the DA module is driven to adjust the output power of the laser in real time, so that the laser can stably operate near the target power.

[0015] Further, the ARM adopts the ADC and DMA cycle mode to acquire the temperature feedback value of the TEC module and the voltage feedback value of the LD feedback current loop in real time.

[0016] To solve the above problems, the application also provides a spectrum analysis system, comprising a laser control system and a spectrometer, wherein the laser control system comprises the above laser control system, and 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 drive according to a received instruction to expose the CCD module for a certain integration time, the CCD module feeds back collected analog quantities to the FPGA through an A / D conversion circuit, and the FPGA transmits collected spectrum data to an ARM module for data processing.

[0017] Further, the ARM module performs register configuration between the FPGA module through SPI or MIPI protocol, and the FPGA module transmits collected spectrum data to the ARM module for data processing through SPI or MIPI protocol.

[0018] Further, the ARM module internally integrates a boxcar smoothing and stretching algorithm to process collected spectrum data, and processed data is transmitted to a PC terminal or a handheld device terminal through USB or serial communication.

[0019] The laser control system and the spectrum analysis system provided by the application have the following advantages: the ARM module is used for digital signal processing, so that the system can quickly respond to user instructions and system changes, real-time adjustment and control of the laser are realized, and work efficiency is improved; the LD feedback loop is used to realize real-time monitoring and closed-loop adjustment of the output power of the laser, so that the stability of the laser output is ensured, the power and voltage can be quantitatively managed, and the accuracy and reliability of the system in long-time operation are ensured; the TEC module is used to realize bidirectional temperature control of the laser, so that accurate refrigeration and heating can be realized in extremely cold and high-temperature environments, and stable operation of the laser in extreme environments is ensured. The laser control system provided by the application has the functions of real-time monitoring and control parameter adjustment, can timely discover and process abnormal conditions of the laser, and ensures stable operation and long-term reliability of the laser. The laser double-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 of the ARM module significantly improve the cost-effectiveness of the entire laser control system, save the use of electrical components, optimize the board space, further reduce the hardware cost, realize the laser control system through software, facilitate integration into existing laser equipment, and the modular design of the system is also convenient for maintenance and upgrading, has high portability, saves development time. Therefore, the application provides a flexible, efficient and stable double-soft control laser control system, which is widely used in spectrum analysis, precision machining, medical imaging and other high-demand application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The framework diagram of the spectrum analysis system in the embodiment of the present application;

[0021] Figure 2 The laser control flow diagram in the embodiment of the present application;

[0022] Figure 3 The framework diagram of the spectrum analysis system in the embodiment of the present application;

[0023] Figure 4 The working flow diagram of the spectrum analysis system in the embodiment of the present application;

[0024] Figure 5a And Figure 5b The power consumption of the laser in the embodiment of the present application and the effect comparison diagram of the power consumption of the existing laser;

[0025] Figure 6a The silicon wafer test spectrum at normal temperature in the embodiment of the present application, Figure 6b The silicon wafer test spectrum at 46℃ in the embodiment of the present application, Figure 6c The silicon wafer test spectrum at 20℃ in the embodiment of the present application, Figure 6d The silicon wafer test spectrum at 0℃ in the embodiment of the present application, Figure 6e The silicon wafer test spectrum at -20℃ in the embodiment of the present application;

[0026] Figure 7a The wavelength deviation result at normal temperature in the embodiment of the present application, Figure 7b The wavelength deviation result at 46℃ in the embodiment of the present application, Figure 7c The wavelength deviation result at 20℃ in the embodiment of the present application, Figure 7d The wavelength deviation result at 0℃ in the embodiment of the present application, Figure 7e The wavelength deviation result at -20℃ in the embodiment of the present application;

[0027] Figure 8a The Raman signal spectrum of alcohol and acetone detected at 0℃ working temperature and after 2h low-temperature storage in the embodiment of the present application, Figure 8b The interface display of alcohol on the mobile terminal, Figure 8c The interface display of acetone on the mobile terminal;

[0028] Figure 9a The Raman signal spectrum of alcohol and acetone detected at 40℃ working temperature and after 2h high-temperature storage in the embodiment of the present application, Figure 9b The interface display of acetone on the mobile terminal, Figure 9c The interface display of alcohol on the mobile terminal;

[0029] Figure 10aFor the working temperature in the embodiment of the present application is 45℃, after 2h high temperature storage, the Raman signal spectrum of alcohol and acetone is detected, Figure 10b For the interface display of acetone on the mobile terminal, Figure 10c For the interface display of alcohol on the mobile terminal;

[0030] Figure 11a For the working temperature in the embodiment of the present application is -20℃, after 24h low temperature storage, after taking out, the Raman signal spectrum of alcohol and acetone is detected after recovery for 1h at room temperature, Figure 11b For the interface display of acetone on the mobile terminal, Figure 11c For the interface display of alcohol on the mobile terminal;

[0031] Figure 12a For the working temperature in the embodiment of the present application is 70℃, after 24h high temperature storage, after taking out, the Raman signal spectrum of alcohol and acetone is detected after recovery for 1h at room temperature, Figure 12b For the interface display of alcohol on the mobile terminal, Figure 12c For the interface display of acetone on the mobile terminal. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with the drawings and embodiments.

[0033] The purpose of the present application is to provide a kind of control system of double soft control laser based on ARM system.The control system takes ARM processor as control core, realizes the overall control of laser system, covers the double regulation of temperature and power, to reduce the power loss of complete machine in turn.The present application adopts two-way soft control closed loop control, one control laser TEC module, for maintaining the constant of working temperature;Another control laser DA module, for realizing the accurate output control of laser output power.

[0034] Please see Figure 1 、 Figure 2 And Figure 3 The present application provides a kind of control system of laser, including: ARM module (Advanced RISC Machines, high-level simple instruction set machine) and laser control module;The laser control module includes TEC module (Thermoelectric Cooler, thermoelectric cooler) and DA module (Digital to Analog Converter, digital analog converter).

[0035] The TEC module is in communication connection with the ARM module. When the laser starts to work, the ARM module judges whether the temperature of the laser shell is in a preset range. If the temperature is in 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 then keeps stable work. The bidirectional temperature control of the laser is realized by the TEC module, which can accurately cool and heat in extremely cold and high temperature environments, ensures the stable work of the laser in the extreme environment, and enhances the environmental adaptability of the laser.

[0036] The DA module is in communication connection with the ARM module. An LD current feedback circuit (Laser Diode) 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 stably operates near the target power. The real-time monitoring and closed-loop adjustment of the output power of the laser are realized by the LD current feedback loop, which ensures the stability of the output power of the laser and can quantitatively manage the power and voltage, thereby ensuring the precision and reliability of the system in long-time operation.

[0037] In an embodiment, the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the difference between the detected temperature of the laser shell and the target temperature set by the TEC module. If the difference is within 35℃, the TEC module does not work. Otherwise, the target temperature of the TEC is set to 25℃, and the TEC module is controlled to start to work, so that the TEC module keeps stable work after reaching the target temperature. When the laser stops and then enters the working state again, the above steps are repeated. This control mode can input the target temperature of the TEC in manual mode, and the temperature of the laser shell can be detected by arranging a temperature sensor on the laser shell. The working temperature of the laser can be accurately adjusted by the PID control algorithm in the ARM module, so as to ensure the stable working state of the laser under various temperature conditions.

[0038] In another embodiment, the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the detected temperature of the laser shell, when the ARM module detects that the temperature of the laser shell is between 0-35℃, the TEC module does not work; when the ARM module detects that the temperature of the laser shell is between -20℃--10℃, the ARM module controls the TEC module to start to work, and the target temperature of the TEC module is set to -10℃, so that the TEC module is kept to work stably after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is between -10℃-0℃, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0℃, so that the TEC module is kept to work stably after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is higher than 35℃, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35℃, so that the TEC module is kept to work stably after reaching the target temperature. This mode can adopt an automatic mode, and a digital quantity TMPGD and an analog temperature acquisition quantity are used to judge whether the laser TEC is ready. Similarly, the PID control algorithm in the ARM module can be used to accurately adjust the working temperature of the laser, so as to ensure the stable working state of the laser under various temperature conditions.

[0039] In a specific embodiment, the laser device supports manual / automatic mode at the same time, the PID (Proportion, Integral and Derivative) drive TEC module is powered on by default, in the automatic mode, the target temperature is set to 25℃, after the device is started, the software control interface (i.e. manual mode) is entered, and the temperature is adjusted by the host computer through the USB interface to be 15-35℃. This flexible and adjustable design solves the problems of poor flexibility and large power consumption of the laser in cold or hot environment.

[0040] The influence of environmental temperature change found in the laser device test process is relatively large on the preset target temperature of the laser tube. The temperature difference between the preset target temperature and the environmental temperature should not be too large, otherwise the laser system is difficult to reach the preset target temperature, and the whole system is in a state of relatively large 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 logic 0, considering that the TEC module does not reach the best working state at this time, and the laser is started, which cannot drive the laser to work. There is another case, if the temperature feedback is at the critical value of the set target temperature, the laser will appear on-off during the device working. It is found through high and low temperature experiments that whether the TEC module is started or not has little influence on the Raman signal when the laser tube in the device works at 0-35℃. Therefore, how to efficiently control the laser and reduce the power consumption of the whole laser is the problem to be solved by the present application. The solution of the present application is to optimize the temperature control strategy of the TEC module of the laser. Whether the TEC module of the laser is ready is judged by one digital quantity TMPGD and one temperature acquisition analog quantity. If the preset value of the laser tube temperature is 25℃, if TMPGD=1, the laser device is in a normal state and can work, otherwise whether the difference between the target temperature of the TEC module and the environmental temperature (the temperature of the laser shell) is within ±10℃ is judged, if yes, the laser device is in a normal state, if no, the laser device waits for the TEC module to be ready. The present application uses the digital quantity TMPGD and the real-time temperature analog quantity feedback double conditions to comprehensively judge the working state of the TEC module, so as to realize 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 working of the device caused by temperature difference, and the handheld Raman device can normally work at 0-45℃ environment, which can be specifically seen in Figures 8a-12c .

[0041] In an embodiment, the relationship between the output power of the laser and the set voltage adopts an eight-order calibration mode: the ARM module sets the voltage to drive the laser, and the set voltage starts from 0mv and increases by 100mv successively until 2500mv, the voltage value is read through the LD feedback circuit, the power value after stabilization is recorded, the eight-order calibration parameters between the output power and the set voltage are calculated according to the recorded 26 groups of values, the eight-order calibration parameters between the read set voltage and the output power are calculated, and then the two groups of eight-order calibration data are written into the flash memory (FLASH) of the ARM module through USB / UART, which does not lose in power failure. In this way, the user inputs the target power value, and the initial set voltage value reaching the target power can be calculated according to the eight-order calibration parameters between the output power and the set voltage.

[0042] In another embodiment, the relationship between the output power of the laser and the set voltage adopts a table lookup calibration method: the ARM module sets the voltage to drive the laser, and the set voltage starts from 0 mv and increases by 100 mv successively until 2500 mv. The set voltage drives the laser, and the voltage value is read through the LD feedback circuit. The optical power value measured by the optical power meter at this time is recorded. In this way, 26 sets of set voltage values, LD feedback voltage values, and optical power values are obtained. The above data is stored in the FLASH of the ARM module. In this way, the target power value can be set, and the set voltage interval can be obtained by looking up the list. At this time, the linear relationship between the voltage and the power can be approximately considered in a small voltage interval 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 eight-order calibration method, and the multiplication operation of the multi-order calibration can be reduced, and the running efficiency of the ARM module is significantly improved.

[0043] In a specific embodiment, a 12-bit DA module and a 12-bit ADC module (Analog-to-Digital Converter Module) are arranged in the ARM module. The output power of the laser is set through the 12-bit DA module, and 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 stably operate near the target power.

[0044] The ARM adopts an ADC and DMA (Direct Memory Access) 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.

[0045] Further, the laser further comprises 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 and other backup storage areas; the SRAM module is used to store the 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 and the like. The device information monitoring module is composed of an RGB (Red Green Blue) indicator light and a PCB (Printed Circuit Board) temperature acquisition module, the RGB indicator light module is used for normal work and fault prompt. The fan module is used for heat dissipation of the laser, the fan auxiliary heat dissipation and the temperature acquisition module provide real-time temperature feedback, and the environmental adaptability of the system is further improved; the crystal oscillator module provides a heartbeat packet, which is divided by a PLL to generate a clock bus of different frequencies, and provides a clock for different module peripherals.

[0046] The specific working process of the control system of the dual-soft control laser based on the ARM system provided by the application is as follows:

[0047] Flow 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;

[0048] Flow 102: the system starts initialization. The USB module is initialized; the AD_TEC temperature acquisition module is initialized; the AD_power acquisition module is initialized; the DA_TEC temperature setting output module is initialized; the DA_power setting output module is initialized; the timer module is initialized; the fan module is initialized;

[0049] Flow 103: the ARM module starts the PID control by default after the system is started, controls the TEC temperature by driving the TEC module, and sets the target temperature to 25℃. The system is in a waiting state, waiting for the PC to send instructions through the USB interface;

[0050] Flow 104: once the ARM module receives the instruction sent by the PC from the USB module, the ARM module immediately receives and analyzes the instruction. According to the user instruction, corresponding operation is performed, for example, laser voltage power calibration parameter setting instruction, power setting instruction and TEC module opening / closing control instruction;

[0051] Flow 105: when the ARM module receives the power setting instruction, the PID drive DA module is started, the power output circuit is driven to control the power output module circuit, the LD current feedback circuit voltage value collected by the AD_power collection module is adjusted in real time to adjust the output power and frequency of the laser, so that the effect of accurate output of the laser power is achieved.

[0052] 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 application solves it from two aspects of circuit and drive: (1) the LD current feedback loop is added to the ARM module on the circuit, and the system forms a closed loop adjustment through the LD feedback circuit control to ensure the stability of the laser output power. (2) The ARM module is used as a controller, the power output of the laser is set through the 12bit DA module, and the LD current feedback loop is collected in real time through the 12bit ADC module. Combined with the PID control algorithm, the ARM calculates the error between the current and 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 as to ensure the stable operation of the laser near the target power. The existing laser is driven by a constant voltage value to output power, and the present application introduces the 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 can greatly improve the accuracy of the laser power output, and the error is controlled within ±1mW.

[0053] The present application adopts ARM+Free RTOS (lightweight real-time operating system kernel) architecture, creates TEC module temperature control task and power output control task, reasonably allocates task priority, introduces semaphore and message queue mechanism, supports interrupt and task priority preemption mechanism. The ADC+DMA cycle mode in the ARM module can obtain the TEC temperature feedback value and voltage feedback value in real time, and the introduction of DMA can effectively reduce the scheduling pressure of CPU, save CPU work load and improve data exchange efficiency.

[0054] The present application not only improves the stability and reliability of the laser system, but also realizes the optimization and control of the laser performance through the high processing capacity and intelligent control algorithm of the ARM system. Figure 5a and Figure 5b As shown in the drawings, the efficient control of the laser control system provided by the present application can reduce the energy consumption of the laser, reduce the output coupling loss and heat loss, and meet the requirements of modern industry for environmental protection and energy saving.

[0055] Please refer to Figure 1 , Figure 3 and Figure 4The embodiment also provides a spectrum analysis system, comprising a spectrometer and a laser, the laser comprising the laser control system, the spectrometer comprising a spectrum acquisition module, the spectrum acquisition module comprising a CCD module and an FPGA module, the FPGA module generating a timing drive for the CCD module to expose for a certain integration time according to a received instruction, the CCD module feeding back collected analog quantities to the FPGA through an A / D conversion circuit, and the FPGA transmitting collected spectrum data to an ARM module for data processing.

[0056] Further, the ARM module performs register configuration between the FPGA module through SPI or MIPI protocol, and the FPGA module transmits collected spectrum data to the ARM module for data processing through SPI or MIPI protocol.

[0057] Further, the ARM module internally integrates a boxcar smoothing and stretching algorithm to process collected spectrum data, and processed data is transmitted to a PC terminal or a handheld device terminal through USB, a serial port or a gigabit Ethernet communication, and real-time data transmission and remote control are performed with the PC terminal or the mobile terminal.

[0058] The spectrum analysis system provided by the embodiment supports multiple communication protocols, ensures that the system can perform real-time interaction with the PC terminal or the mobile terminal, and ensures data safety in a power-off condition through spectrum coefficients and parameters stored in the EEPROM.

[0059] The spectrum analysis system provided by the embodiment is used to test silicon wafers at room temperature, -20 DEG C, 0 DEG C, 20 DEG C and 46 DEG C respectively, and silicon wafer characteristic peak changes are observed. Figures 6a-6e The Raman peak of the silicon wafer is measured at 521 cm -1 at room temperature. The Raman peak of the silicon wafer is measured at 523 cm -1 at -20 DEG C, 0 DEG C, 20 DEG C and 46 DEG C, and the wavelength is offset by 2 cm -1 compared with that at room temperature.

[0060] Table 1. Spectrum peak deviation (cm -1 ) at different temperatures

[0061]

[0062] A mercury argon lamp is used to test wavelength deviation of the equipment at room temperature, -20 DEG C, 0 DEG C, 20 DEG C and 46 DEG C. Figures 7a-7eThe wavelength deviations of the four standard mercury sub-lamps at 811.531 nm, 826.452 nm, 842.465 nm and 912.297 nm at different temperatures are compared in Table 2. As shown in Table 2, the RSD values of each spectral line of 811.531 nm, 826.452 nm, 842.465 nm and 912.297 nm are small under the conditions of room temperature, -20 DEG C, 0 DEG C, 20 DEG C and 46 DEG C, indicating that the wavelength deviation is small under these temperature conditions.

[0063] Table 2 Wavelength deviations of the handset inner core at different temperatures (nm)

[0064]

[0065] The spectrum analysis system provided by the application can work normally at different storage temperatures: using a high and low temperature box, the test equipment can work normally at storage temperatures of -20 DEG C, 0 DEG C, 40 DEG C, 45 DEG C and 70 DEG C. 3、

[0067]

[0068] The test results at a working temperature of 0 DEG C are shown in Table 3. Figures 8a-8c After 2h of low-temperature storage, the spectrum analysis system provided by the application can still detect the Raman signals of alcohol and acetone, and the spectrum analysis system provided by the application can work normally under this condition.

[0069] The test results at a working temperature of 40 DEG C are shown in Table 4. Figures 9a-9c After 2h of high-temperature storage, the spectrum analysis system provided by the application can still detect the Raman signals of alcohol and acetone, and the spectrum analysis system provided by the application can work normally under this condition.

[0070] The test results at a working temperature of 45 DEG C are shown in Table 5. Figures 10a-10c After 2h of high-temperature storage, the spectrum analysis system provided by the application can still detect the Raman signals of alcohol and acetone, and the spectrum analysis system provided by the application can work normally under this condition.

[0071] The test results after 24h of storage at -20 DEG C are shown in Table 6. Figures 11a-11c After 24h of low-temperature storage, the Raman signals of alcohol and acetone can be detected after 1h of recovery at room temperature, and the spectrum analysis system provided by the application can work normally under this condition.

[0072] The test results after 24h of storage at 70 DEG C are shown in Table 7. Figures 12a-12cAs shown, after high-temperature storage for 24 h, and after being taken out and recovered at room temperature for 1 h, the present application can still detect the Raman signals of alcohol and acetone, and the present application can still work normally after high-temperature storage.

[0073] Although the present application has been disclosed with reference to the preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the present application, and therefore the protection scope of the present application is defined by the claims.

Claims

1. A control system for a laser, characterized by The application relates to a laser temperature control system. The laser temperature control system comprises an ARM module and a laser control module, a PID control algorithm is arranged in the ARM 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 starts to work, the ARM module judges whether the detected laser shell temperature is in a preset range; if the laser shell temperature is in the preset range, the TEC module does not work; otherwise, the ARM module controls the TEC module to start to work, the PID control algorithm in the ARM module is used to accurately adjust the laser working temperature, and after the TEC module reaches the preset target temperature, the TEC module keeps stable working; the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the difference between the detected laser shell temperature and the target temperature set by the TEC module; if the difference is within 35 DEG C, the TEC module does not work; otherwise, the target temperature of the TEC module is set as 25 DEG C, and the TEC module is controlled to start to work; after the TEC module reaches the target temperature, the TEC module keeps stable working; when the laser stops and then enters the working state again, the above steps are circularly performed; 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 collected by the LD current feedback circuit, combines the PID control algorithm, and then drives the DA module to adjust the output power of the laser in real time, so that the laser stably operates near the target power; the relationship between the output power of the laser and the set voltage adopts an eight-order calibration mode: the ARM module sets the voltage to drive the laser; the set voltage starts from 0mv and increases by 100mv successively until 2500mv; the voltage value is read by the LD feedback circuit, and the power value after stabilization is recorded; 26 groups of values are recorded; the eight-order calibration parameters between the output power and the set voltage are calculated according to the recorded 26 groups of values; the eight-order calibration parameters between the set voltage and the output power are read back; then the two groups of eight-order calibration data are written into the flash memory of the ARM module; and the initial set voltage value reaching the target power can be calculated according to the eight-order calibration parameters between the output power and the set voltage; or, the relationship between the output power of the laser and the set voltage adopts a table lookup calibration mode: the ARM module sets the voltage to drive the laser; the set voltage starts from 0mv and increases by 100mv successively until 2500mv; the set voltage drives the laser; the voltage value is read by the LD feedback circuit; the optical power value measured by the optical power meter at the moment is recorded; thus 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; thus the set voltage interval can be obtained by looking up the list according to the set target power value; at this moment, the linear relationship between the voltage and the power can be approximately considered in the small voltage interval range, so that the initial set voltage value reaching the target power can be calculated.

2. A control system for a laser, characterized in that The application relates to a laser temperature control system. An ARM module and a laser control module; a PID control algorithm is arranged in the ARM 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 starts to work, the ARM module judges whether the detected temperature of the laser shell is in a preset range; if yes, the TEC module does not work; otherwise, the ARM module controls the TEC module to start to work; the working temperature of the laser is accurately adjusted by the PID control algorithm in the ARM module until the TEC module reaches the preset target temperature and keeps stable work; the control mode of the TEC module is as follows: when the laser starts to work, the ARM module judges the detected temperature of the laser shell; when the ARM module detects that the temperature of the laser shell is 0-35℃, the TEC module does not work; when the ARM module detects that the temperature of the laser shell is-20℃--10℃, the ARM module controls the TEC module to start to work, and the target temperature of the TEC module is set to-10℃, so that the TEC module keeps stable work after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is-10℃-0℃, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 0℃, so that the TEC module keeps stable work after reaching the target temperature; when the ARM module detects that the temperature of the laser shell is higher than 35℃, the ARM module controls the TEC module to work, and the target temperature of the TEC module is set to 35℃, so that the TEC module keeps stable work after reaching the target temperature; when the laser stops and then enters the working state again, the above steps are repeated. 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 data collected by the LD current feedback circuit and the target power according to a PID control algorithm, and then drives the DA module to adjust the output power of the laser in real time, so that the laser is stably operated near the target power; the relationship between the output power of the laser and the set voltage adopts an eight-order calibration mode: the ARM module sets the voltage to drive the laser, the set voltage starts from 0mv and increases by 100mv successively until 2500mv, the voltage value is read by the LD feedback circuit, the power value after stabilization is recorded, the eight-order calibration parameters between the output power and the set voltage are calculated according to the 26 groups of recorded values, the eight-order calibration parameters between the set voltage and the output power are read back, and then the two groups of eight-order calibration data are written into the flash memory of the ARM module, and the initial set voltage value reaching the target power can be calculated according to the eight-order calibration parameters between the output power and the set voltage; or, the relationship between the output power of the laser and the set voltage adopts a table lookup calibration mode: the ARM module sets the voltage to drive the laser, the set voltage starts from 0mv and increases by 100mv successively until 2500mv, the laser is driven by the set voltage, the voltage value is read by 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 interval can be obtained by looking up the list according to the set target power value, at this time, the linear relationship between the voltage and the power can be approximately considered in a small voltage interval range, and thus the initial set voltage value reaching the target power can be calculated.

3. The control system of claim 1 or 2, wherein, The 12bit DA module and the 12bit ADC module are arranged in the ARM module, the output power of the laser is set by the 12bit DA module, the LD feedback current loop is collected in real time by the 12bit ADC module, the error between the current data collected by the 12bit ADC module and the target power is calculated according to a PID control algorithm, and then the DA module is driven to adjust the output power of the laser in real time, so that the laser is stably operated near the target power.

4. The control system of claim 1 or 2, wherein, The ARM module adopts an ADC and DMA cycle mode to acquire the temperature feedback value of the TEC module and the voltage feedback value of the LD feedback current loop in real time.

5. A spectroscopic analysis system characterized by, The laser includes the control system of the laser according to any one of claims 1-4, and the spectrometer includes a spectrum acquisition module, the spectrum acquisition module includes a CCD module and an FPGA module, the FPGA module generates a timing to drive the CCD module to expose for a certain integration time according to a received instruction, the CCD module feeds back collected analog quantities to the FPGA through an A / D conversion circuit, and the FPGA transmits the collected spectrum data to the ARM module for data processing.

6. The optical spectral analysis system of claim 5, wherein, The ARM module is configured with registers between the FPGA module through SPI or MIPI protocol, and the FPGA module transmits the collected spectral data to the ARM module for data processing through SPI or MIPI protocol.

7. The optical spectral analysis system of claim 5, wherein, 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 through USB or serial communication.

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