Signal detection system and method based on DBR laser

Abstract

The invention provides a signal detection system and method based on a DBR laser, and relates to the technical field of signal detection, and the system comprises a control module which is connected with three current control sources, and the three current control sources respectively send control signals to the Gain end, the Phase end and the Grading end of the DBR laser so as to adjust the gain current and two control current parameters of the DBR laser. The DBR laser emits laser signals to a detection target, the photodiode receives feedback of the target and converts the feedback into analog electric signals, the analog-to-digital converter converts the signals into digital signals and sends the digital signals to the data processing module for detection, and finally a detection result is output. The accuracy and reliability of the laser signal can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of signal detection, and in particular to a signal detection system and method based on a DBR laser. Background Art

[0002] In the field of industrial production and testing, accurate acquisition and analysis of high-frequency vibration signals or step signals are crucial for equipment status monitoring, fault diagnosis, and product quality control.

[0003] In the related art, by setting up devices such as lasers, receivers, processors, and a current control source, the collection and detection of high-frequency vibration signals or step signals are realized. In this technology, a current control source is used to drive the laser to emit a laser signal of a fixed wavelength to the device to be detected, and the processor is used to analyze the received feedback signal to determine whether the device has an abnormal high-frequency vibration signal or abnormal step signal. Since this technology uses a single current control source to drive the laser, the laser has limited control accuracy over the wavelength of the laser signal. When the wavelength of the laser signal needs to be finely controlled, the laser signal emitted by the laser has low accuracy and reliability, which in turn affects the accuracy and reliability of the detection results. Summary of the invention

[0004] In order to improve the accuracy and reliability of the detection results, the present application provides a signal detection system and method based on a DBR laser.

[0005] In the first aspect, the present application provides a signal detection system based on a DBR laser, which adopts the following technical solution: A signal detection system based on a DBR laser, comprising: A control module, connected to the first current control source, the second current control source and the third current control source respectively, and used to send a control signal; A first current control source is connected to the Gain terminal of the DBR laser and is used to control the gain current of the DBR laser according to a control signal; A second current control source is connected to the Phase end of the DBR laser and is used to send a first control current parameter to the DBR laser according to the control signal; a third current control source, connected to the Grating end of the DBR laser, and used to send a second control current parameter to the DBR laser according to the control signal; A DBR laser is used to send a laser signal to a detection target according to a first control current parameter and a second control current parameter; A photodiode is used to receive a feedback signal from a detection target and convert the feedback signal into an analog electrical signal; An analog-to-digital converter, used to convert analog electrical signals into digital signals and send the digital signals to a data processing module; The data processing module is used to detect the digital signal and output the detection result.

[0006] The present application sets up a control module, which is connected to three current control sources (respectively, the first current control source, the second current control source and the third current control source). These control sources respectively adjust the gain (Gain), phase (Phase) and grating (Grating) of the DBR laser. The DBR laser allows independent control of the gain (Gain), phase (Phase) and grating (Grating), thereby achieving high-precision laser output adjustment. The first current control source is connected to the Gain end of the DBR laser and is used to control the gain current of the DBR laser. By controlling the gain current of the DBR laser, the present application can directly control the output power of the DBR laser and adjust the intensity of the laser signal. The second current control source is connected to the Phase end of the DBR laser and is used to adjust the current in the phase zone of the DBR laser. By adjusting the current in the phase zone of the DBR laser, the present application can achieve precise synchronization or phase modulation of the laser signal. The third current control source is connected to the Grating end of the DBR laser to control the current parameters of the Grating end of the DBR laser. By adjusting the current parameters of the Grating end of the DBR laser, the present application can change the wavelength of the laser signal output by the DBR laser.

[0007] The photodiode can receive the reflected or scattered laser signal (i.e., feedback signal) from the detection target and convert it into an analog electrical signal to realize the conversion of optical signal to analog electrical signal. The analog-to-digital converter can convert the analog electrical signal output by the photodiode into a digital signal. The data processing module is responsible for receiving the digital signal output by the analog-to-digital converter and outputting the detection result. By precisely controlling the gain, phase, and wavelength of the DBR laser, the present application can emit a high-quality laser signal, and through photoelectric conversion and digital processing, achieve high-precision measurement or identification of the detection target.

[0008] Optionally, there are multiple third current control sources, the input end of each third current control source is connected to the output end of the control module, and the output end of each third current control source is connected in parallel to the Grating end of the DBR laser.

[0009] The present application sets up a plurality of third current control sources in parallel, and the input end of each third current control source is connected to the output end of the control module, so that each current control source can directly receive a signal from the control module. The output ends of all third current control sources are connected in parallel to the Grating end of the DBR laser. The present application can realize different precision control of the DBR laser by combining the output currents of different third current control sources, that is, by adjusting the output currents of different current sources to accurately control the current input to the DBR laser, and then adjust the output wavelength of the DBR laser. The present application can independently control multiple third current control sources, and can output more refined currents as needed, thereby realizing more refined control of the DBR laser. If one of the current sources fails, the other current sources can continue to work to improve the reliability of the DBR laser.

[0010] Optionally, the system further comprises a fourth current control source, the input end of the fourth current control source is connected to the output end of the control module, the output end of the fourth current control source is connected to the SOA end of the DBR laser, and is used to amplify the laser signal according to the control signal sent by the control module.

[0011] By adopting the above technical solution, the control module of the present application can control the DBR laser to amplify the laser signal by controlling the output signal of the fourth current control source.

[0012] In the second aspect, the present application provides a signal detection method based on a DBR laser, which adopts the following technical solution: A signal detection method based on a DBR laser applicable to the system of the first aspect, comprising: Tabulation: formulating a parameter table, the parameter table including: Phase parameters and Grating parameters; First control: the control module controls the second current control source to send the first control current parameter to the DBR laser according to the Phase parameter; the control module controls the third current control source to send the second control current parameter to the Grating end of the DBR laser according to the Grating parameter; Sending signal: the DBR laser sends a laser signal to the detection target according to the first control current parameter and the second control current parameter; Receiving signal: The photodiode receives the feedback signal from the detection target and converts the feedback signal into an analog electrical signal; Signal conversion: The analog-to-digital converter converts analog electrical signals into digital signals; Detection: The data processing module detects the digital signal and outputs the detection results.

[0013] The present application first sets the Phase parameter and the Grating parameter, and then the control module sends a control signal to the second current control source and the third current control source according to the preset Grating parameter and Phase parameter, and the second current control source and the third current control source adjust the current input to the DBR laser according to the control signal, thereby adjusting the wavelength and phase of the laser signal. This staged control method helps to accurately control the output of the DBR laser so that the wavelength and phase of the laser signal meet specific requirements. After that, the DBR laser sends a laser signal to the detection target according to the received control signal. After the laser signal is irradiated on the detection target, the detection target will reflect the laser signal (that is, the detection target will return a feedback signal), and then the photodiode receives the feedback signal from the detection target and converts it into an analog electrical signal. The analog-to-digital converter converts the analog electrical signal into a digital signal, and then the data processing module processes the digital signal and outputs the detection result. By formulating a parameter table, a staged control method, and the application of digital signal processing technology, the present application can achieve precise control of the laser signal and output the detection result.

[0014] Optionally, the parameter table further includes a Gain parameter and an output range of the third current control source. After executing the tabulation step and before executing the first control step, the method further includes: Second control: Control the DBR laser to reach the target current based on the Gain parameter; First calculation: determining the third current control source to be connected according to the Grating parameter and the output range, and recording the third current control source to be connected as the fifth current control source; In the first control step, the control module controls all fifth current control sources to send a second control current parameter to the Grating end of the DBR laser according to the Grating parameter.

[0015] The present application controls the DBR laser to reach the target current based on the Gain parameter in the parameter table, so that the DBR laser works in the best state to improve the stability and output quality of the DBR laser. The present application determines the third current control source that needs to be connected according to the Grating parameter and the output range of the third current control source, and records the third current control source that needs to be connected as the fifth current control source, so that each fifth current control source can operate within its output range. The present application controls the DBR laser by accumulating the output current of multiple fifth current control sources, instead of using an amplifier to amplify the output current of a current control source, and inputting the amplified current into the DBR laser to control the laser signal output by the DBR laser. The present application can not only overcome the defect that the amplifier can only amplify the output current of a fixed multiple, resulting in the current parameters input into the DBR laser being not accurate enough, but also improve the response speed and accuracy of the DBR laser.

[0016] Optionally, after performing the signal conversion step and before performing the detection step, the method further includes: Noise reduction: including delay, second calculation and third calculation; Delay: Input the digital signal into the shift register for delay processing, and obtain the digital signal after delay processing, which is recorded as the first signal; Second calculation: obtaining coefficients of the FIR filter corresponding to the first signal, and performing a product operation on the first signal and the corresponding coefficients of the FIR filter to obtain a product operation result; The third calculation: performing an accumulation operation on the product operation results to obtain an accumulation operation result, and using the accumulation operation result as a new digital signal.

[0017] The present application inputs the digital signal into the shift register for delay processing to introduce a certain time delay when processing the digital signal. Afterwards, the present application obtains the coefficients of the FIR (finite impulse response) filter corresponding to the first signal (i.e., the digital signal after delay processing), and multiplies the first signal with the coefficients of the corresponding FIR filter, and adjusts the coefficients of the FIR filter to achieve filtering of different frequency components, thereby removing noise or enhancing signals of specific frequencies. Afterwards, the present application performs an accumulation operation on the product operation results obtained in the second calculation, and uses the result of the accumulation operation as a new digital signal. By combining the FIR filter and the accumulation operation, the noise in the digital signal can be effectively reduced to obtain a higher quality digital signal.

[0018] Optionally, after performing the noise reduction step and before performing the detection step, the method further includes: Modeling: A mathematical model for fitting new digital signals is established using a Gaussian-polynomial algorithm. The mathematical model is as follows: ; ; ; in, is the function value when fitting a new digital signal; To fit the background components in the new digital signal; for Parameters of the nth harmonic; for The nth harmonic in ; is to fit the i-th Gaussian peak in the new digital signal; m is the number of Gaussian peaks; is the amplitude of the i-th Gaussian peak; is the position of the i-th Gaussian peak; is the width of the i-th Gaussian peak; Determine parameters: Minimize the sum of squares of the residuals using the least squares method. The calculation model is as follows: ; in, is the value of the new digital signal at the kth sampling point; is the function value when fitting the new digital signal at the kth sampling point; g is the number of sampling points; Construct a matrix: construct a Jacobian matrix, and obtain the direction and step size of each parameter update according to the Jacobian matrix, wherein the element in the pth row and the qth column of the Jacobian matrix represents the partial derivative of the pth mathematical model with respect to the qth parameter; Iteration: Use the direction and step size of each parameter update to update the corresponding parameters in the mathematical model, and iterate the steps from determining the parameters to building the matrix until the preset stop condition is met, and output the position, amplitude and width of each Gaussian peak.

[0019] The present application uses the Gaussian-polynomial algorithm to establish a mathematical model. The Gaussian function is used to describe the signal characteristics with peak value and width, and the polynomial function is used to describe the background component of the signal to accurately fit the complex new digital signal. Subsequently, the present application uses the least squares method to minimize the sum of squares of the residuals. By minimizing the residuals, the parameter value that minimizes the difference between the theoretical value and the actual value can be found, which helps the mathematical model to more accurately reflect the characteristics of the digital signal. Subsequently, the present application uses the Jacobian matrix to calculate the parameter update direction and step size. The elements of the Jacobian matrix represent the partial derivatives of the model to the parameters. It provides direct information about how the parameters affect the model prediction value. By constructing the Jacobian matrix, parameter optimization can be performed more effectively. Subsequently, the present application uses the direction and step size of the parameter update to update the parameters in the mathematical model, and iteratively executes the steps of optimizing the parameters until the preset stop condition (such as reaching the maximum number of iterations, the residual is less than a certain threshold, etc.) is met, so that the parameters of the mathematical model reach the optimal solution or close to the optimal solution. Finally, the position, amplitude and width of each Gaussian peak are output. The present application can more accurately fit digital signals, including their background components and Gaussian peak features, through the Gauss-polynomial algorithm and the least squares method. By constructing the Jacobian matrix and iterative optimization, the present application can more effectively find the optimal parameter values ​​and reduce computing time and resource consumption.

[0020] Optionally, after executing the tabulation step and before executing the first control step, the method further includes: First acquisition: obtain the temperature of the laser; Temperature judgment: judge whether the temperature is within the preset temperature range. If so, execute the first control step; if not, execute the first acquisition step after a preset time interval.

[0021] The present application first obtains the current temperature of the laser. Temperature is one of the important parameters for the operation of the laser. Too high or too low a temperature may affect the performance and stability of the laser. By regularly collecting temperature data, the system can understand the temperature state of the laser in real time. Subsequently, it is determined whether the temperature of the laser is higher than a preset temperature threshold. Only when the DBR laser is within the preset temperature range will the present application perform the first control step, thereby improving the stability and accuracy of the system.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. The control module of the present application can send out different control signals, which are received by three current control sources and converted into corresponding current parameters, thereby regulating the output characteristics of the DBR laser. The present application transmits the laser signal to the detection target, and the reflected or scattered signal is received by the photodiode and converted into an analog electrical signal. After analog-to-digital conversion, the analog electrical signal is processed by the data processing module to finally obtain the detection result.

[0023] 2. This application can emit high-quality laser signals by precisely controlling the gain, phase and wavelength of the DBR laser, and achieve high-precision measurement or identification of the detection target through photoelectric conversion and digital processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of Example 1 of the present application; Figure 2 This is a flow chart of the method of Example 2 of the present application; Figure 3 This is a flow chart of the method of Example 4 of the present application. DETAILED DESCRIPTION

[0025] The following combination Figures 1 to 3 This application is described in further detail.

[0026] Embodiment 1: This embodiment discloses a signal detection system based on a DBR laser, referring to Figure 1 , the system comprising: The control module is responsible for sending different control signals to unused current control sources to coordinate and manage the temperature of each current control source and the DBR laser. The control module is connected to the first current control source, the second current control source and the third current control source respectively, and is used to send different control signals to different current control sources at the same time to coordinate and manage the temperature of each current control source and the DBR laser. The control module is also connected to the temperature control end of the DBR laser to control the temperature of the DBR laser.

[0027] The first current control source is connected to the Gain terminal of the DBR laser and is used to control and adjust the gain current of the DBR laser according to the control signal, thereby controlling and adjusting the output optical power and spectral characteristics of the DBR laser.

[0028] The second current control source is connected to the Phase terminal of the DBR laser and is used to send a first control current parameter to the DBR laser according to the control signal. The first control current parameter is used to adjust the phase characteristic of the DBR laser to optimize the output of the DBR laser.

[0029] The third current control source is connected to the Grating end of the DBR laser and is used to send a second control current parameter to the Grating end of the DBR laser according to the control signal. The second control current parameter is used to adjust the reflection characteristics of the Bragg grating inside the DBR laser, thereby changing the wavelength of the laser signal.

[0030] In other embodiments, there may be multiple third current control sources, the input end of each third current control source is connected to the output end of the control module, and the output end of each third current control source is connected in parallel to the Grating end of the DBR laser.

[0031] The DBR laser is used to send a laser signal to a detection target according to a first control current parameter and a second control current parameter.

[0032] The photodiode is used to receive the feedback signal from the detection target and convert the feedback signal into an analog electrical signal.

[0033] The analog-to-digital converter is used to convert analog electrical signals into digital signals and send the digital signals to the data processing module.

[0034] The data processing module is used to detect the digital signal and output the detection result.

[0035] In other embodiments, the system further includes a fourth current control source, the input end of the fourth current control source is connected to the output end of the control module, the output end of the fourth current control source is connected to the SOA end of the DBR laser, and is used to amplify the laser signal according to the control signal sent by the control module.

[0036] This embodiment achieves fine control and detection of the laser signal by precisely controlling multiple parameters of the DBR laser (such as gain current, phase current, grating current, etc.) and receiving and processing feedback signals through a photodiode and an analog-to-digital converter.

[0037] Example 2: Reference Figure 2 , this embodiment provides a signal detection method based on a DBR laser, comprising: S1 tabulation: In order to provide necessary parameters for the control of the DBR laser so that the DBR laser can emit a laser signal of a specific wavelength as expected, a parameter table is pre-formed in this embodiment. The parameter table includes: Phase parameters and Grating parameters.

[0038] The Phase parameter is used to adjust the phase zone in the DBR laser. By changing the current in the phase zone, the output wavelength of the DBR laser can be fine-tuned.

[0039] The Grating parameter is related to the grating structure in the DBR laser, which is responsible for reflecting light of a specific wavelength while allowing light of other wavelengths to pass through. By adjusting the current at the Grating end, the reflective characteristics of the grating can be changed, thereby further fine-tuning or selecting the output wavelength of the DBR laser.

[0040] S01 is the first acquisition, obtaining the temperature of the laser.

[0041] S02 Temperature judgment: the control module compares the current temperature of the DBR laser with a preset temperature range.

[0042] If the temperature of the DBR laser is within the preset temperature range, the first control is continued to be performed in S2.

[0043] If the temperature of the DBR laser is not within the preset temperature range, wait for a preset time (such as several minutes), and then re-execute the first acquisition in S01 to monitor the change of the DBR laser temperature.

[0044] S2 first control, the control module controls the second current control source according to the Phase parameter, and sends the first control current parameter to the phase area of ​​the DBR laser. The control module controls the third current control source according to the Grating parameter to send the second control current parameter to the Grating end of the DBR laser.

[0045] S3 sends a signal, and the DBR laser adjusts its internal structure according to the received first control current parameter and second control current parameter, and sends a laser signal of a specific wavelength to the detection target.

[0046] S4 receives the signal, and the photodiode receives the feedback signal from the detection target and converts the feedback signal into an analog electrical signal.

[0047] S5 signal conversion, the analog-to-digital converter converts analog electrical signals into digital signals.

[0048] S6 detection: the data processing module detects the digital signal and outputs the detection result.

[0049] The application formulates a parameter table including Phase parameters and Grating parameters, and controls the current source in parallel according to the parameter table, thereby controlling the output wavelength of the DBR laser. Before executing the first control step, the application first collects and determines whether the temperature of the DBR laser is within the preset temperature range, so that the DBR laser can work stably. Subsequently, the current source is controlled according to the parameter table to send a precise control current to the laser, so that it emits a laser signal of a specific wavelength. After the laser signal is irradiated to the detection target, the feedback signal is received by the photodiode and converted into an analog electrical signal, and then converted into a digital signal by an analog-to-digital converter for analysis by the data processing module, and finally the detection result is output. This embodiment realizes the precise control of the DBR laser and the accurate detection of the target.

[0050] Embodiment 3: The prior art uses a current control source to output a current signal, and uses an amplifier to amplify the current signal, and inputs the amplified current signal into the laser to control the laser to emit a laser signal. However, its disadvantage is that the accuracy is not enough. For example, the laser requires a current of 3.21A, and the output range of the current control source is 0-1A. The prior art will control the current control source to output a current of 0.32A, and select an amplifier that can amplify 10 times. In this way, the current input to the laser is 3.2A. Since the current input to the laser is not accurate enough, the laser signal output by the laser is not accurate enough.

[0051] The difference between this embodiment and embodiment 2 is that the parameter table also includes the Gain parameter and the output range of the third current control source. The Gain parameter is used to control the gain region current of the DBR laser. By adjusting the Gain parameter, the laser can reach the required target optical power to meet different application requirements. The output range of the third current control source refers to the current output range that the third current control source can provide, that is, the maximum and minimum current values ​​that it can send to the Grating end of the DBR laser. This embodiment also uses a current control source with a range of 0-1A (i.e., the third current control source). If the DBR laser requires a current of 3.21A, this embodiment can choose to connect multiple third current control sources so that the sum of the currents output by the connected third current control sources is equal to 3.21A.

[0052] After executing S1 tabulation and before executing S2 first control, the method further includes: S11 second control, the control module sends a control signal to the first current control source according to the Gain parameter. The first current control source adjusts its output current according to the received signal so that the gain region current of the DBR laser reaches the target value, thereby making the output optical power of the laser reach a predetermined level.

[0053] S12: First calculation, the control module first determines the total value of the required second control current parameter according to the Grating parameter.

[0054] According to the output range of the third current control source, the number of third current control sources that need to be connected and the current value that each third current control source should provide are calculated, and finally the third current control source that needs to be connected is recorded as the fifth current control source.

[0055] In the first control of S2, the control module sends a control signal to all the fifth current control sources according to the Grating parameter and the working state of the fifth current control source calculated previously, so that the sum of the second control current parameters jointly sent by them to the Grating end of the DBR laser is equal to the current value required by the DBR laser, thereby accurately controlling the output wavelength of the DBR laser.

[0056] Based on the original parameter table, this embodiment adds the Gain parameter and the output range of the third current control source. This embodiment first controls the DBR laser to reach the target optical power through the Gain parameter. Then, according to the Grating parameter and the output range of the third current control source, the number and working status of the third current control source (recorded as the fifth current control source) that needs to be connected are calculated. In the first control step, the control module not only adjusts the phase zone current of the laser according to the Phase parameter, but also controls all the fifth current control sources according to the Grating parameter to jointly send a control current to the Grating end of the laser, thereby more accurately controlling the output wavelength of the DBR laser.

[0057] Example 4: Reference Figure 3 The difference between this embodiment and embodiment 2 is that this embodiment implements a direct FIR filter in FPGA, and uses a shift register chain and a parallel multiplication-accumulation structure to implement convolution operations. The FPGA includes a multiplier and a multi-stage adder (tree structure), one multiplier corresponds to a tap in the FIR filter (implemented by DSP Slice), and the multi-stage adder is used to accumulate the multiplication results step by step. The data flow of this embodiment is: input digital signal, shift register chain, each multiplier multiplied by the coefficient of the FIR filter, accumulation tree summation, and output of a new digital signal.

[0058] After performing S5 signal conversion and before performing S6 detection, it also includes: S8 noise reduction, including S81 delay, S82 second calculation and S83 third calculation.

[0059] S81 delays, inputs the digital signal into the shift register for delay processing, and obtains the digital signal after delay processing, which is recorded as the first signal.

[0060] S82 is a second calculation, obtaining the coefficients of the FIR filter corresponding to the first signal, and performing a product operation on the first signal and the corresponding coefficients of the FIR filter to obtain a product operation result.

[0061] FIR (Finite Impulse Response) filter is a digital filter whose core principle is based on the impulse response of finite length and realizes signal processing through convolution operation. The impulse response of FIR filter decays to zero in a finite time, and the system only depends on the current and past input samples without feedback loop. FIR filter transfer function The calculation model is as follows: ; in, is the filter coefficient, is the order of the FIR filter.

[0062] Output signal of FIR filter The calculation model is as follows: .

[0063] If the coefficients satisfy h[j]=h[N-1-j], the number of multipliers can be reduced by 50% by combining the input data of the symmetrical taps.

[0064] S83 is a third calculation, in which the product operation result is accumulated to obtain an accumulated operation result, and the accumulated operation result is used as a new digital signal.

[0065] This embodiment also implements the Gaussian-polynomial fitting peak-finding algorithm through FPGA, and the process is: receiving the original data (such as the sampling value of the analog-to-digital converter) and performing preprocessing (filtering, denoising). After that, the polynomial background and Gaussian peak parameter estimation are processed separately. After that, iterative algorithms such as Levenberg-Marquardt (LM) are used to achieve nonlinear optimization. Finally, the peak position (μ), amplitude (A), width (σ) and background parameters are output. The data flow is: input a new digital signal, preprocess the new digital signal, estimate the background component in the new digital signal, detect the Gaussian peak, optimize the parameters of the mathematical model, and output the result.

[0066] S91 modeling uses a Gaussian-polynomial algorithm to establish a mathematical model that fits the new digital signal. The mathematical model is as follows: ; ; ; in, is the function value when fitting a new digital signal; To fit the background components in the new digital signal; for Parameters of the nth harmonic; for The nth harmonic in ; is to fit the i-th Gaussian peak in the new digital signal; m is the number of Gaussian peaks; is the amplitude of the i-th Gaussian peak; is the position of the i-th Gaussian peak; is the width of the i-th Gaussian peak.

[0067] S92 determines the parameters, and minimizes the sum of squares of the residuals by the least square method, thereby determining the various parameters in the mathematical model. The calculation model in this step is as follows: ; in, is the value of the new digital signal at the kth sampling point; is the function value when fitting the new digital signal at the kth sampling point; g is the number of sampling points.

[0068] S93 constructs a matrix, constructs a Jacobian matrix, and obtains the direction and step size of each parameter update through the Jacobian matrix. The element in the pth row and qth column of the Jacobian matrix represents the partial derivative of the pth mathematical model with respect to the qth parameter.

[0069] S94 iterates, updates the corresponding parameters in the mathematical model using the direction and step size of each parameter update, and iteratively executes S92 to determine the parameters and S93 to construct the matrix until the preset stop condition is met, and outputs the position of each Gaussian peak, the amplitude of each Gaussian peak, and the width of each Gaussian peak.

[0070] This embodiment realizes the processing of new digital signals through noise reduction, peak finding and fitting, and more accurately fits digital signals, including their background components and Gaussian peak characteristics, through Gauss-polynomial algorithm and least squares method. By constructing Jacobian matrix and iterative optimization, this embodiment can more effectively find the optimal parameter value and reduce computing time and resource consumption.

[0071] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A signal detection system based on DBR laser, characterized in that: include: A control module, connected to the first current control source, the second current control source and the third current control source respectively, and used to send a control signal; A first current control source is connected to the Gain terminal of the DBR laser and is used to control the gain current of the DBR laser according to a control signal; A second current control source is connected to the Phase end of the DBR laser and is used to send a first control current parameter to the DBR laser according to the control signal; a third current control source, connected to the Grating end of the DBR laser, and used to send a second control current parameter to the DBR laser according to the control signal; A DBR laser is used to send a laser signal to a detection target according to a first control current parameter and a second control current parameter; A photodiode is used to receive a feedback signal from a detection target and convert the feedback signal into an analog electrical signal; An analog-to-digital converter, used to convert analog electrical signals into digital signals and send the digital signals to a data processing module; The data processing module is used to detect the digital signal and output the detection result.

2. The signal detection system based on DBR laser according to claim 1, characterized in that: There are multiple third current control sources, and the input end of each third current control source is connected to the output end of the control module, and the output end of each third current control source is connected in parallel to the Grating end of the DBR laser.

3. The signal detection system based on DBR laser according to claim 2, characterized in that: The system also includes a fourth current control source, the input end of the fourth current control source is connected to the output end of the control module, the output end of the fourth current control source is connected to the SOA end of the DBR laser, and is used to amplify the laser signal according to the control signal sent by the control module.

4. The DBR laser-based signal detection system according to any one of claims 1 to 3, characterized in that: The control module is also connected to the temperature control end of the DBR laser and is used to control the temperature of the DBR laser.

5. A signal detection method based on DBR laser, the method is applicable to the system according to any one of claims 1 to 4, characterized in that: include: Tabulation: formulating a parameter table, the parameter table including: Phase parameters and Grating parameters; First control: the control module controls the second current control source to send the first control current parameter to the DBR laser according to the Phase parameter; the control module controls the third current control source to send the second control current parameter to the Grating end of the DBR laser according to the Grating parameter; Sending signal: the DBR laser sends a laser signal to the detection target according to the first control current parameter and the second control current parameter; Receiving signal: The photodiode receives the feedback signal from the detection target and converts the feedback signal into an analog electrical signal; Signal conversion: The analog-to-digital converter converts analog electrical signals into digital signals; Detection: The data processing module detects the digital signal and outputs the detection results.

6. The signal detection method based on DBR laser according to claim 5, characterized in that: The parameter table also includes a Gain parameter and an output range of the third current control source. After executing the step of tabulating and before executing the step of first controlling, the method further includes: Second control: Control the DBR laser to reach the target current based on the Gain parameter; First calculation: determining the third current control source to be connected according to the Grating parameter and the output range, and recording the third current control source to be connected as the fifth current control source; In the first control step, the control module controls all fifth current control sources to send a second control current parameter to the Grating end of the DBR laser according to the Grating parameter.

7. The signal detection method based on DBR laser according to claim 5, characterized in that: After the step of performing signal conversion and before the step of performing detection, the method further includes: Noise reduction: including delay, second calculation and third calculation; Delay: Input the digital signal into the shift register for delay processing, and obtain the digital signal after delay processing, which is recorded as the first signal; Second calculation: obtaining coefficients of the FIR filter corresponding to the first signal, and performing a product operation on the first signal and the corresponding coefficients of the FIR filter to obtain a product operation result; The third calculation: performing an accumulation operation on the product operation results to obtain an accumulation operation result, and using the accumulation operation result as a new digital signal.

8. The signal detection method based on DBR laser according to claim 7, characterized in that: After the step of performing noise reduction and before the step of performing detection, the method further includes: Modeling: A mathematical model for fitting new digital signals is established using a Gaussian-polynomial algorithm. The mathematical model is as follows: ； ； ； in, is the function value when fitting a new digital signal; To fit the background components in the new digital signal; for Parameters of the nth harmonic; for The nth harmonic in ; is to fit the i-th Gaussian peak in the new digital signal; m is the number of Gaussian peaks; is the amplitude of the i-th Gaussian peak; is the position of the i-th Gaussian peak; is the width of the i-th Gaussian peak; Determine parameters: Minimize the sum of squares of the residuals using the least squares method. The calculation model is as follows: ； in, is the value of the new digital signal at the kth sampling point; is the function value when fitting the new digital signal at the kth sampling point; g is the number of sampling points; Construct a matrix: construct a Jacobian matrix, and obtain the direction and step size of each parameter update according to the Jacobian matrix, wherein the element in the pth row and the qth column of the Jacobian matrix represents the partial derivative of the pth mathematical model with respect to the qth parameter; Iteration: Use the direction and step size of each parameter update to update the corresponding parameters in the mathematical model, and iterate the steps from determining the parameters to building the matrix until the preset stop condition is met, and output the position, amplitude and width of each Gaussian peak.

9. The signal detection method based on DBR laser according to claim 5, characterized in that: After executing the tabulation step and before executing the first control step, the method further includes: First acquisition: obtain the temperature of the laser; Temperature judgment: judge whether the temperature is within the preset temperature range. If so, execute the first control step; if not, execute the first acquisition step after a preset time interval.

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