A method and apparatus for correcting a modulation signal of a laser, and a readable storage medium
By splitting and delaying the laser optical signal and mixing it, the laser response signal is restored using the intermediate frequency signal, and the modulation signal is cyclically adjusted. This solves the problem of poor frequency modulation nonlinearity correction in the existing technology, achieving high-precision measurement and reducing hardware costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN WANJI INFORMATION TECH
- Filing Date
- 2021-12-22
- Publication Date
- 2026-07-17
AI Technical Summary
Existing frequency modulation nonlinearity correction methods are ineffective, leading to reduced measurement accuracy of frequency modulation continuous wave lidar and high hardware costs.
The optical signal emitted by the laser is split into two paths. One path is delayed and mixed with the other. The laser response signal is then restored using the intermediate frequency signal. The modulation signal is cyclically adjusted to achieve an ideal curve with an error less than the preset value.
It reduces hardware requirements, improves measurement accuracy, ensures that the error between the response curve and the ideal curve is less than the preset value, and avoids the problem of long lock-in cycles at high frequencies.
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Figure CN116345283B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of signal technology, and in particular relates to a method, apparatus and readable storage medium for modulating signal correction of a laser. Background Technology
[0002] Currently, the measurement accuracy of frequency-modulated continuous wave lidar is highly dependent on the frequency modulation nonlinearity of the laser. If the frequency modulation nonlinearity of the laser does not meet the requirements, the measurement accuracy will be reduced, resulting in very large calculation errors in the measurement results.
[0003] Existing methods for correcting frequency modulation nonlinearity involve nonlinear open-loop pre-correction or phase-locked loop correction. However, the nonlinear open-loop pre-correction method only corrects the modulation signal using the intermediate frequency signal obtained after mixing the two optical signals, resulting in poor correction performance. The phase-locked loop correction method has a long locking period when the modulation signal frequency is high and requires sophisticated hardware. Summary of the Invention
[0004] This application provides a method, apparatus, and readable storage medium for modulating signal correction of a laser, which can solve the problems of high hardware cost and poor correction effect.
[0005] The optical signal emitted by the laser and modulated by the current modulation signal is split into two paths. One of the optical signals is delayed to obtain a delayed modulation signal and a delay time. The other optical signal without delay is mixed with the delayed modulation signal to obtain an intermediate frequency signal.
[0006] The laser response signal is reconstructed based on the intermediate frequency signal;
[0007] The current modulation signal is adjusted according to the laser response signal to obtain the next modulation signal, and the laser is modulated using the next modulation signal to adjust the response curve of the laser.
[0008] Repeat the above steps until the error between the obtained response curve and the ideal curve is less than the preset value.
[0009] Furthermore, reconstructing the laser response signal based on the intermediate frequency signal includes:
[0010] Based on the intermediate frequency signal, determine the first time-frequency curve;
[0011] The first time-frequency curve is fitted into a polynomial to obtain the first polynomial and the first coefficients;
[0012] Based on the first coefficient, the delay time, and Pascal's triangle coefficient, the second coefficient and the second polynomial of the laser response signal are calculated to determine the laser response signal.
[0013] Furthermore, based on the first coefficient, the delay time, and Pascal's triangle coefficients, the second coefficients and the second polynomial of the laser response signal are calculated to determine the laser response signal, including:
[0014] Let the expression of the first polynomial be:
[0015]
[0016] Where n is the degree of the highest term, a i Let x be the i-th coefficient in the first coefficient set. i Let i be the i-th order independent variable;
[0017] Pascal's triangle, in an n x n matrix, is represented by the following:
[0018] Y(n, n);
[0019] Where the value of n is greater than or equal to 0;
[0020] Correspondingly, the second coefficient and the second polynomial are expressed as:
[0021]
[0022] Among them, a m Let x be the m-th coefficient in the first coefficient set. m Let Y be the m-th independent variable in the first polynomial, and let b be Pascal's triangle. i+1 Here, τ is the (i+1)th coefficient of the current modulated signal, and τ is the delay time.
[0023] Solve the n+1 equations of the second polynomial to obtain n+1 unknowns bn+1, where bn+1 are the coefficients of the response curve.
[0024] Furthermore, the optical signal emitted by the laser modulated by the current modulation signal is split into two paths. One path of the optical signal is delayed to obtain a delayed modulation signal and a delay time. The other path of the optical signal, without delay, is mixed with the delayed modulation signal to obtain an intermediate frequency signal, including:
[0025] The polynomial expression of the current modulation signal is defined as follows:
[0026]
[0027] Where n+1 is the highest term count of the current modulation signal, b i Let x be the i-th coefficient of the current modulated signal. i Let i be the i-th order independent variable of the modulated signal;
[0028] The polynomial expression for the delayed modulation signal is then:
[0029]
[0030] Where n+1 is the highest term of the delayed modulation signal, b i Let (x-) be the i-th coefficient of the delayed modulation signal. i Let i be the i-th independent variable of the delayed modulation signal;
[0031] Correspondingly, the polynomial expression for the intermediate frequency signal is:
[0032]
[0033] Among them, a m Let x be the m-th coefficient in the first coefficient set. m Let Y be the m-th independent variable in the first polynomial, and let b be Pascal's triangle. i+1 τ is the (i+1)th coefficient of the current modulation signal, and τ is the delay time.
[0034] Furthermore, the calculation of the error between the response curve and the ideal curve includes:
[0035] The obtained response curve is measured to obtain a second time-frequency curve;
[0036] The error between the response curve and the ideal curve is determined by using the relative error between the second time-frequency curve and the ideal curve;
[0037] The relative error is expressed as follows:
[0038]
[0039] Among them, E r S is the relative error. l For the second time-frequency curve, S t This is the ideal curve.
[0040] Furthermore, modulating the laser using the next modulation signal to adjust the laser's response curve includes:
[0041] By balancing the correction efficiency and correction accuracy, a target correction optimization coefficient is obtained, wherein the correction optimization coefficient is positively correlated with the correction efficiency and negatively correlated with the correction accuracy.
[0042] The current modulation signal is adjusted according to the target correction optimization coefficient and the relative error to obtain the next modulation signal;
[0043] The laser is modulated using the next modulation signal to adjust the laser's response curve.
[0044] Further, adjusting the current modulation signal according to the target correction optimization coefficient and the relative error to obtain the next modulation signal includes:
[0045] Adjust using the following formula:
[0046] U t+1 = (1+E) r *cof)*U t ;
[0047] Among them, U t+1 For the next modulation signal, E r For the relative error, U t Here, cof is the target correction optimization coefficient;
[0048] The relative error is the error between the response curve and the ideal curve.
[0049] Secondly, embodiments of this application provide a modulation signal correction device for a laser, comprising:
[0050] The mixing unit is used to split the optical signal emitted by the laser and modulated by the current modulation signal into two paths, delay one of the optical signals to obtain a delayed modulation signal and a delay time, and mix the other optical signal without delay with the delayed modulation signal to obtain an intermediate frequency signal.
[0051] The restoration unit is used to restore the laser response signal based on the intermediate frequency signal;
[0052] The adjustment unit is used to adjust the current modulation signal according to the laser response signal to obtain the next modulation signal, and use the next modulation signal to modulate the laser to adjust the response curve of the laser. The process is repeated until the error between the obtained response curve and the ideal curve is less than a preset value.
[0053] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method as described in any one of the first aspects above.
[0054] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method as described in any one of the first aspects above.
[0055] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the method described in any one of the first aspects above.
[0056] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.
[0057] The beneficial effects of the embodiments in this application compared with the prior art are:
[0058] This embodiment of the application splits the optical signal emitted by the laser, which is modulated by the current modulation signal, into two paths. One path of the optical signal is delayed to obtain a delayed modulation signal and a delay time. The other path of the optical signal, which is not delayed, is mixed with the delayed modulation signal to obtain an intermediate frequency (IF) signal. Because the IF signal has a low frequency, the requirements for hardware equipment are reduced. The laser response signal is reconstructed based on the IF signal. The current modulation signal is adjusted based on the laser response signal to obtain the next modulation signal. The laser is then modulated using the next modulation signal to adjust the laser response curve. The above steps are repeated until the error between the obtained response curve and the ideal curve is less than a preset value. The reconstructed laser response signal is repeatedly used to adjust the modulation signal, which can better correct the modulation signal to obtain a modulation signal with the required nonlinearity. This can better correct the response curve, resulting in a response curve with an error less than the preset value from the ideal curve. Moreover, the situation of high modulation signal frequency and long lock-in period is avoided. Attached Figure Description
[0059] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0060] Figure 1 This is a schematic flowchart of a laser modulation signal correction method provided in an embodiment of this application;
[0061] Figure 2 This is a schematic flowchart of a laser modulation signal correction method provided in another embodiment of this application;
[0062] Figure 3 This is a schematic flowchart of a laser modulation signal correction method provided in another embodiment of this application;
[0063] Figure 4 This is a schematic diagram of the structure of the modulation signal correction device for a laser provided in an embodiment of this application;
[0064] Figure 5 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation
[0065] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.
[0066] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.
[0067] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0068] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."
[0069] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0070] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0071] Figure 1 This is a schematic flowchart of a laser modulation signal correction method according to an embodiment of this application. It is intended as an example and not a limitation. Figure 1 As shown, the method includes:
[0072] S101: The optical signal emitted by the laser and modulated by the current modulation signal is split into two paths. One path of the optical signal is delayed to obtain a delayed modulation signal and a delay time. The other path of the optical signal without delay is mixed with the delayed modulation signal to obtain an intermediate frequency signal.
[0073] Specifically, when the laser receives an optical signal modulated by the current modulation signal, it generates a laser response signal. The intermediate frequency signal is obtained by mixing the optical signal modulated by the current modulation signal, which provides the basis for reconstructing the laser response signal through the intermediate frequency signal.
[0074] Specifically, the polynomial expression for the current modulation signal is defined as follows:
[0075]
[0076] Where n+1 is the highest term of the current modulated signal, b i Let x be the i-th coefficient of the current modulated signal. i Let i be the i-th independent variable of the modulated signal;
[0077] The polynomial expression for the time-delayed modulated signal is:
[0078]
[0079] Where n+1 is the highest term of the delayed modulation signal, b i Let (x-τ) be the i-th coefficient of the time-delayed modulated signal. i Let i be the i-th independent variable of the time-delayed modulation signal;
[0080] Correspondingly, the polynomial expression for the intermediate frequency signal is:
[0081]
[0082] Among them, a m Let x be the coefficient of the m-th term of the polynomial of the intermediate frequency signal. m Let Y be the m-th independent variable of the polynomial of the intermediate frequency signal, and let b be Pascal's triangle. i+1 Let τ be the (i+1)th coefficient of the modulated signal, and τ be the delay time.
[0083] For example, the polynomial of the current modulated signal: f1 = b3x 3 +b2x 2 +b1x 1 +b0, the polynomial of the time-delayed modulation signal: f2=b3(x-τ) 3 +b2(x-τ) 2 +b1(x-τ)1 +b0, subtract the current modulation signal from the delayed modulation signal and take the absolute value to obtain the intermediate frequency (IF) signal. The polynomial of the IF signal is: a²x 2 =Y(4,2)b3(-τ) 1 x 2 =3b3(-τ) 1 x 2 ;
[0084] a1x 1 =(Y(3,2)b2(-τ) 1 +Y(4,2)b3(-τ) 2 )x 1 =(2b2(-τ) 1 +3b3(-τ) 2 )x 1 ;
[0085] a0 = Y(2, 2)b1(-τ) 1 +Y(3,3)b2(-τ) 2 +Y(4,4)b3(-τ) 3 =b1(-τ) 1 +b2(-τ) 2 +b3(-τ) 3 ;
[0086] S102: Reconstruct the laser response signal based on the intermediate frequency signal.
[0087] Specifically, firstly, the first time-frequency curve is determined based on the intermediate frequency signal.
[0088] The first time-frequency curve is determined by performing a Hilbert-Huang transform on the intermediate frequency signal.
[0089] Specifically, empirical mode decomposition is performed on the intermediate frequency signal to obtain the intrinsic mode functions. Then, Hilbert transform is performed on the intrinsic mode functions to obtain the Hilbert spectrum and time-frequency energy spectrum of the intermediate frequency signal, so as to analyze the intermediate frequency signal and determine the corresponding first time-frequency curve.
[0090] Next, the first time-frequency curve is fitted to a polynomial to obtain the first polynomial and the first coefficients.
[0091] For example, the first time-frequency curve can be fitted into a polynomial using curve fitting, and the fitted polynomial can be used as the first polynomial and the coefficients of the fitted polynomial can be used as the first coefficients.
[0092] Then, based on the first coefficient, the delay time, and Pascal's triangle coefficients, the second coefficient and the second polynomial of the laser response signal are calculated to determine the laser response signal.
[0093] Specifically, based on intermediate frequency signals: Involving the first coefficient, Pascal's triangle coefficient, delay time, and coefficients of the current modulation signal, by substituting the first coefficient, delay time, and Pascal's triangle coefficient into the polynomial calculation, the second coefficient and second polynomial of the laser response signal can be obtained, thereby determining the laser response signal.
[0094] S103: Adjust the current modulation signal according to the laser response signal to obtain the next modulation signal, and use the next modulation signal to modulate the laser in order to adjust the laser response curve.
[0095] S104: Repeat steps S101-S103 until the error between the obtained response curve and the ideal curve is less than the preset value.
[0096] Specifically, the error between the laser response signal's response curve and the ideal curve is fed back to the current modulation signal, thereby adjusting the current modulation signal. Adjusting the modulation signal based on the obtained laser response signal allows for better correction, reducing the nonlinearity of the next modulation signal (the adjusted modulation signal) and obtaining a complete modulation signal, thus achieving a more accurate signal change trend and modulation bandwidth. The laser is then modulated using the next modulation signal to adjust its response curve. This adjustment, based on the complete modulation signal, further refines the laser's response curve to more accurately reflect the error between the laser's response curve and the ideal curve.
[0097] Correspondingly, if the error between the response curve and the ideal curve is greater than or equal to a preset value, the process returns to the step of splitting the optical signal emitted by the laser and modulated by the current modulation signal into two paths, delaying one of the optical signals to obtain a delayed modulation signal and a delay time, and mixing the other undelayed optical signal with the delayed modulation signal to obtain an intermediate frequency signal. Then, steps S101-S103 are repeated to adjust the response curve so that the error between the response curve and the ideal curve is less than the preset value.
[0098] This embodiment splits the optical signal emitted by the laser, which is modulated by the current modulation signal, into two paths. One path of the optical signal is delayed to obtain a delayed modulation signal and a delay time. The other path of the optical signal, which is not delayed, is mixed with the delayed modulation signal to obtain an intermediate frequency (IF) signal. Because the IF signal has a low frequency, the requirements for hardware equipment are reduced. The laser response signal is reconstructed based on the IF signal. The current modulation signal is then adjusted based on the laser response signal to obtain the next modulation signal. The laser is then modulated using the next modulation signal to adjust the laser response curve. The above steps are repeated until the error between the obtained response curve and the ideal curve is less than a preset value. The reconstructed laser response signal is repeatedly used to adjust the modulation signal, which can better correct the modulation signal to obtain a modulation signal with the required nonlinearity. This can further correct the response curve, resulting in a response curve with an error less than the preset value from the ideal curve. Moreover, the situation of a high modulation signal frequency and a long lock-in period is avoided.
[0099] In another embodiment, the laser response signal is determined by calculating the second coefficients and the second polynomial based on the first coefficient, the delay time, and the Pascal's triangle coefficient, including:
[0100] Let the expression of the first polynomial be:
[0101]
[0102] Where n is the degree of the highest term, a i x is the coefficient of the i-th term in the first coefficient set. i Let be the i-th order independent variable.
[0103] Pascal's triangle, as an n x n matrix, can be represented by the following:
[0104] Y(n, n);
[0105] Where the value of n is greater than or equal to 0;
[0106] For example, in matrix form, Pascal's Triangle is expressed as follows: [1] [1 1] [1 2 1] [1 3 3 1] [1 4 6 4 1] [1 5 10 10 5 1] [...]
[0114] Correspondingly, the elements are written as: Y(1,1)=1, Y(2,1)=1, Y(2,2)=1, Y(3,1)=1, Y(3,2)=2, Y(3,3)=1, etc.
[0115] Correspondingly, the second coefficient and the second polynomial are expressed as:
[0116]
[0117] Among them, a m x is the coefficient of the m-th term in the first coefficient set. m Let Y be the m-th independent variable in the first polynomial, and let b be Pascal's triangle. i+1 Here, τ represents the (i+1)th coefficient of the current modulated signal, and τ is the delay time.
[0118] Solve the n+1 equations of the second polynomial to obtain n+1 unknowns bn+1, where bn+1 are the coefficients of the response curve.
[0119] Specifically, the first polynomial based on the intermediate frequency signal: And another polynomial expression for the intermediate frequency signal: The second polynomial of the laser response signal can be derived. And the corresponding second coefficient: By solving the (n+1) equations of the second polynomial, the (n+1) unknowns bn+1 are calculated, thereby determining the laser response signal and obtaining the coefficients of the response curve. The response curve is then obtained based on these coefficients. The laser response signal corresponds to the response curve.
[0120] For example, the first polynomial of the intermediate frequency signal is: f a (x)=a2x 2 +a1x 1 +a0, based on the expression a2x of another polynomial 2 =3b3(-τ) 1 x 2 a1x 1 =(2b2(-τ) 1 +3b3(-τ) 2 )x 1 a0 = b1(-τ) 1 +b2(-τ) 2 +b3(-τ) 3 Thus, the second polynomial of the laser response signal is derived: 3b³(-τ) 1 x 2 =a2x 2 ,(2b2(-τ) 1 +3b3(-τ) 2 )x 1 =a1x 1 , b1(-τ) 1 +b2(-τ) 2 +b3(-τ) 3 =a0, from 3b3(-τ) 1x 2 =a2x 2 We calculate b3 and substitute it into (2b2(-τ)). 1 +3b3(-τ) 2 )x 1 =a1x 1 Calculate b2, then substitute b2 and b3 into b1(-τ). 1 +b2(-τ) 2 +b3(-τ) 3 =Calculate b1 from a0, and solve the three unknowns bi by solving the three equations in the second polynomial, thereby determining the laser response signal and obtaining the coefficients of the response curve.
[0121] Understandably, the operations in a polynomial are point-to-point operations on discrete points of the signal.
[0122] Figure 2 This is a schematic flowchart of a laser modulation signal correction method provided in another embodiment of this application. Figure 2 As shown, the calculation of the error between the response curve and the ideal curve includes:
[0123] S201: Measure the obtained response curve to obtain the second time-frequency curve.
[0124] Specifically, time-frequency analysis is performed on the obtained response curve to measure the second time-frequency curve.
[0125] S202: Determine the error between the response curve and the ideal curve using the relative error between the second time-frequency curve and the ideal curve;
[0126] The relative error is expressed as follows:
[0127]
[0128] Among them, E r S represents the relative error. l For the second time-frequency curve, S t This is the ideal curve.
[0129] This embodiment determines the error between the response curve and the ideal curve by using the relative error between the second time-frequency curve and the ideal curve, thereby obtaining an accurate error between the response curve and the ideal curve.
[0130] Figure 3 This is a schematic flowchart of a laser modulation signal correction method provided in another embodiment of this application. Figure 3 As shown, the laser is modulated using a next modulation signal to adjust the laser's response curve, including:
[0131] S301: Balance correction efficiency and correction accuracy to obtain the target correction optimization coefficients.
[0132] Among them, the correction optimization coefficient is positively correlated with the correction efficiency, and negatively correlated with the correction accuracy.
[0133] Specifically, the calibration optimization coefficient is used to adjust calibration accuracy and calibration efficiency. The calibration optimization coefficient is positively correlated with calibration efficiency and negatively correlated with calibration accuracy. In other words, by adjusting the value of the calibration optimization coefficient, a balance can be struck between calibration accuracy and efficiency. Increasing the value of the calibration optimization coefficient speeds up calibration efficiency but decreases calibration accuracy; conversely, decreasing the value improves calibration accuracy but slows down calibration efficiency. The target calibration optimization coefficient can be determined based on the actual usage scenario to balance calibration accuracy and efficiency and meet calibration requirements.
[0134] S302: Adjust the current modulation signal according to the target correction optimization coefficient and the relative error to obtain the next modulation signal.
[0135] Specifically, adjust using the following formula:
[0136] U t+1 = (1+E) r *cof)*U t ;
[0137] Among them, U t+1 For the next modulation signal, E r For relative error, U t Here, cof represents the current modulation signal, and cof represents the target correction optimization coefficient.
[0138] The relative error is then used as the error between the response curve and the ideal curve.
[0139] S303: Modulate the laser using the next modulation signal to adjust the laser's response curve.
[0140] Specifically, the laser's optical signal is modulated using the next modulation signal. After receiving the optical signal modulated by the next modulation signal, the laser generates a laser response signal, which is the adjusted laser response signal, thereby adjusting the laser's response curve.
[0141] This embodiment obtains the target calibration optimization coefficient by balancing calibration efficiency and calibration accuracy. Based on the target calibration optimization coefficient and relative error, the current modulation signal is adjusted to obtain the next modulation signal. The laser is then modulated using the next modulation signal to adjust the laser's response curve. This approach can balance calibration accuracy and calibration efficiency during the calibration process, thereby better calibrating the current modulation signal and thus better adjusting the laser's response curve.
[0142] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0143] For ease of explanation, only the parts related to the embodiments of this application are shown in the methods described in the above embodiments.
[0144] Figure 4 This is a schematic diagram of the structure of the modulation signal correction device for a laser provided in an embodiment of this application. Figure 4 As shown, the device includes:
[0145] The mixing unit 10 is used to split the optical signal emitted by the laser and modulated by the current modulation signal into two paths, delay one of the optical signals to obtain a delayed modulation signal and a delay time, and mix the other optical signal without delay with the delayed modulation signal to obtain an intermediate frequency signal.
[0146] The restoration unit 11 is used to restore the laser response signal based on the intermediate frequency signal;
[0147] The adjustment unit 12 is used to adjust the current modulation signal according to the laser response signal to obtain the next modulation signal, and use the next modulation signal to modulate the laser in order to adjust the response curve of the laser. The process is repeated until the error between the obtained response curve and the ideal curve is less than a preset value.
[0148] In another embodiment, the restoration unit is specifically used to determine a first time-frequency curve based on the intermediate frequency signal;
[0149] Specifically, it is used to fit the first time-frequency curve into a polynomial to obtain the first polynomial and the first coefficients;
[0150] Specifically, it is used to calculate the second coefficient and the second polynomial of the laser response signal based on the first coefficient, the delay time, and Pascal's triangle coefficient, so as to determine the laser response signal.
[0151] In another embodiment, the adjustment unit is specifically used to balance correction efficiency and correction accuracy to obtain the target correction optimization coefficient;
[0152] Among them, the correction optimization coefficient is positively correlated with the correction efficiency, and negatively correlated with the correction accuracy.
[0153] Specifically, it is used to adjust the current modulation signal based on the target correction optimization coefficient and the relative error to obtain the next modulation signal;
[0154] Specifically, it is used to modulate the laser using the next modulation signal in order to adjust the laser's response curve.
[0155] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 5 As shown, the electronic device 2 of this embodiment includes: at least one processor 20 ( Figure 5 (Only one is shown in the diagram), memory 21, and computer program 22 stored in said memory 21 and executable on said at least one processor 20, wherein said processor 20 executes said computer program 22 to implement the steps in any of the above method embodiments.
[0156] The electronic device 2 can be a desktop computer, laptop, or handheld computer, or other computing device. The electronic device 2 may include, but is not limited to, a processor 20 and a memory 21. Those skilled in the art will understand that... Figure 5 This is merely an example of electronic device 2 and does not constitute a limitation on electronic device 2. It may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, it may also include input / output devices, network access devices, etc.
[0157] The processor 20 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.
[0158] In some embodiments, the memory 21 may be an internal storage unit of the electronic device 2, such as a hard disk or memory of the electronic device 2. In other embodiments, the memory 21 may be an external storage device of the electronic device 2, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the electronic device 2. Furthermore, the memory 21 may include both internal and external storage units of the electronic device 2. The memory 21 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory 21 can also be used to temporarily store data that has been output or will be output.
[0159] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.
[0160] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.
[0161] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the steps in the above-described method embodiments.
[0162] This application provides a computer program product that, when run on a mobile terminal, enables the mobile terminal to implement the steps described in the various method embodiments.
[0163] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.
[0164] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0165] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0166] In the embodiments provided in this application, it should be understood that the disclosed apparatus / network devices and methods can be implemented in other ways. For example, the apparatus / network device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.
[0167] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0168] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A method for correcting the modulation signal of a laser, characterized in that, include: The optical signal emitted by the laser and modulated by the current modulation signal is split into two paths. One of the optical signals is delayed to obtain a delayed modulation signal and a delay time. The other optical signal without delay is mixed with the delayed modulation signal to obtain an intermediate frequency signal. The laser response signal is reconstructed based on the intermediate frequency signal; The current modulation signal is adjusted according to the laser response signal to obtain the next modulation signal, and the laser is modulated using the next modulation signal to adjust the response curve of the laser. Repeat the above steps until the error between the obtained response curve and the ideal curve is less than the preset value; The step of reconstructing the laser response signal based on the intermediate frequency signal includes: Based on the intermediate frequency signal, determine the first time-frequency curve; The first time-frequency curve is fitted into a polynomial to obtain the first polynomial and the first coefficients; The second coefficient and the second polynomial of the laser response signal are calculated based on the first coefficient, the delay time, and the Pascal's triangle coefficient to determine the laser response signal.
2. The method as described in claim 1, characterized in that, Based on the first coefficient, the delay time, and Pascal's triangle coefficients, the second coefficients and the second polynomial of the laser response signal are calculated to determine the laser response signal, including: Let the expression of the first polynomial be: ； Where n is the degree of the highest term. Let i be the i-th coefficient in the first coefficient. Let i be the i-th order independent variable; Pascal's triangle, in an n x n matrix, is represented by the following: Y(n, n); Where the value of n is greater than or equal to 0; Correspondingly, the second coefficient and the second polynomial are expressed as: ； in, This is the m-th coefficient in the first coefficient set. Let Y be the m-th independent variable in the first polynomial, and let Y be Pascal's triangle. Let τ be the i-th coefficient of the current modulated signal, and τ be the delay time; Solve the (n+1) equations of the second polynomial to obtain the (n+1) unknowns b. n+1 The b n+1 These are the coefficients of the response curve.
3. The method as described in claim 1, characterized in that, The optical signal emitted by the laser, modulated by the current modulation signal, is split into two paths. One path of the optical signal is delayed to obtain a delayed modulation signal and a delay time. The other path of the optical signal, without delay, is mixed with the delayed modulation signal to obtain an intermediate frequency signal, including: The polynomial expression of the current modulation signal is defined as follows: ； Where n+1 is the highest term count of the current modulation signal. Let i be the i-th coefficient of the current modulation signal. Let i be the i-th order independent variable of the modulated signal; The polynomial expression for the delayed modulation signal is then: ； Wherein, n+1 is the highest term of the delayed modulation signal. Let i be the i-th coefficient of the delay modulation signal. Let i be the i-th independent variable of the delayed modulation signal; Correspondingly, the polynomial expression for the intermediate frequency signal is: ； in, This is the m-th coefficient in the first coefficient set. Let Y be the m-th independent variable in the first polynomial, and let Y be Pascal's triangle. τ is the (i+1)th coefficient of the current modulation signal, and τ is the delay time.
4. The method as described in claim 2, characterized in that, The calculation of the error between the response curve and the ideal curve includes: The obtained response curve is measured to obtain a second time-frequency curve; The error between the response curve and the ideal curve is determined by using the relative error between the second time-frequency curve and the ideal curve; The relative error is expressed as follows: ； in, The relative error is... This is the second time-frequency curve. This is the ideal curve.
5. The method according to claim 4, characterized in that, Modulating the laser using the next modulation signal to adjust the laser's response curve includes: To balance correction efficiency and correction accuracy, a target correction optimization coefficient is obtained, wherein the correction optimization coefficient is positively correlated with correction efficiency and negatively correlated with correction accuracy. The current modulation signal is adjusted according to the target correction optimization coefficient and the relative error to obtain the next modulation signal; The laser is modulated using the next modulation signal to adjust the laser's response curve.
6. The method as described in claim 5, characterized in that, Adjusting the current modulation signal according to the target correction optimization coefficient and the relative error to obtain the next modulation signal includes: Adjust using the following formula: ； in, The next modulation signal, The relative error is... The current modulation signal, The target is adjusted and optimized using the coefficients. The relative error is the error between the response curve and the ideal curve.
7. A modulation signal correction device for a laser, characterized in that, include: The mixing unit is used to split the optical signal emitted by the laser and modulated by the current modulation signal into two paths, delay one of the optical signals to obtain a delayed modulation signal and a delay time, and mix the other optical signal without delay with the delayed modulation signal to obtain an intermediate frequency signal. A restoration unit is configured to restore the laser response signal based on the intermediate frequency signal; wherein, the restoration of the laser response signal based on the intermediate frequency signal includes: Based on the intermediate frequency signal, determine the first time-frequency curve; The first time-frequency curve is fitted into a polynomial to obtain the first polynomial and the first coefficients; Based on the first coefficient, the delay time, and Pascal's triangle coefficient, the second coefficient and the second polynomial of the laser response signal are calculated to determine the laser response signal; The adjustment unit is used to adjust the current modulation signal according to the laser response signal to obtain the next modulation signal, and use the next modulation signal to modulate the laser to adjust the response curve of the laser. The process is repeated until the error between the obtained response curve and the ideal curve is less than a preset value.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 6.
9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.