High-precision Fourier Raman displacement table correction device and multi-dimensional correction method

Abstract

The invention provides a high-precision Fourier Raman displacement table correction device and a multi-dimensional correction method. The high-precision Fourier Raman displacement table correction device comprises a single-mode laser, a beam splitter, a detector, a first reflector, a second reflector, a displacement table, a monopulse counter and a computer, generating a laser interference pattern; performing phase fitting to obtain a phase initial phase; performing phase unwrapping on the initial phase to obtain a moving path 1 of a displacement table, and obtaining a moving path 2 through a counter mode; respectively carrying out linear fitting on the moving path 1 and the moving path 2, comparing the maximum linear residual error of the moving path 1 and the moving path 2, and selecting the moving path of the displacement table with the minimum maximum linear residual error value for correcting the Raman spectrum. The most suitable path of the displacement table is selected by selecting the path of the displacement table, the Raman spectrum is corrected, the calibration of the high-precision path of the displacement table can be met, and the real-time and efficient calibration of the displacement table is realized.

Description

Technical Field

[0001] The present invention belongs to the field of optical technology, and in particular, to a high-precision Fourier Raman displacement stage calibration device and a multi-dimensional calibration method. Background Art

[0002] For Fourier Raman, the core problem lies in the walking accuracy and linearity of the displacement stage. Most displacement stages cannot perform a very accurate standard linear stepping path, resulting in poor Raman spectrum signal quality and low signal-to-noise ratio.

[0003] Therefore, the existing technology cannot meet the actual use environment, and it is necessary to correct its stepping path to improve the signal quality and intensity of the spectrum. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a high-precision Fourier Raman displacement stage calibration device and a multi-dimensional calibration method. Through scientific architecture design and an optimized calibration algorithm, by comparing the residual sizes of two displacement stage paths of phase fitting and single pulse counting, the most suitable path of the displacement stage is selected to calibrate the Raman spectrum, achieving real-time and efficient calibration of the displacement stage.

[0005] In a first aspect, a high-precision Fourier Raman displacement stage calibration device includes:

[0006] A single-mode laser, a beam splitter, a detector, a first mirror, a second mirror, a displacement stage, a single pulse counter, and a computer;

[0007] The single-mode laser: is used to emit single-mode laser;

[0008] The beam splitter: is used to split the single-mode laser, and finally generate optical interference to form interference fringes;

[0009] As an example, the beam splitter splits the single-mode laser according to a ratio of 50%, and finally returns to the beam splitter again through the first mirror and the second mirror to generate interference; forming bright and dark interference fringes, and finally the detector records the change in the intensity of the interference fringes to form an interferogram.

[0010] It is located between the single-mode laser and the first mirror in the horizontal direction;

[0011] It is located between the detector and the second mirror in the vertical direction;

[0012] The detector: is used to record the change in the intensity of the interference fringes;

[0013] As an example, the detector records the change in the intensity of the interference fringes, and finally forms an interferogram. The interferogram is transformed into a spectrum through Fourier transform.

[0014] The first mirror and the second mirror are symmetrically arranged;

[0015] The displacement stage: is arranged between the first mirror and the second mirror;

[0016] The single-pulse counter: is used to record the position pulse signal to obtain the trigger time;

[0017] The computer: is electrically connected to the single-pulse counter and has a processor and a memory for storing instructions executable by the processor built therein; wherein, the processor is configured to execute a multi-dimensional calibration method for a high-precision Fourier Raman displacement stage.

[0018] As an example, the beam splitter adopts: a 50% beam splitter.

[0019] In a second aspect, a multi-dimensional calibration method for a high-precision Fourier Raman displacement stage includes:

[0020] Step 1, generation of a laser interference pattern;

[0021] When the displacement stage is moving, it will interfere with the single-mode laser. At this time, continuously record the signal intensity of the interference points, and a laser interference pattern can be obtained;

[0022] Step 2, obtaining the initial phase of the phase through phase fitting;

[0023] Perform half-wavelength phase fitting of the cosine function on the laser interference pattern to obtain the initial phase of the laser interference pattern until the fitting reaches the end of the laser interference pattern;

[0024] Step 3, perform phase unwrapping on the initial phase of the phase to obtain the displacement stage movement path 1;

[0025] The formula for converting the phase result into the displacement stage position result is designed as follows:

[0026]

[0027] Where: Position(t) is the final position result, that is, the movement path 1; ρ(t) is the phase result after phase unwrapping, λ is the laser wavelength, and 8π is the phase period;

[0028] As an example, since the phase result is still the phase result after phase unwrapping, it is necessary to convert the phase result into the position result and perform conversion calculation through the above formula.

[0029] Step 4. Synchronously, at the first moment when the displacement stage moves, a start pulse is triggered to start the test by the single-pulse counter. Meanwhile, all pulse bandwidths are compressed and a delay function is added to ensure that the computer recording point moment is consistent with the movement of the displacement stage itself.

[0030] Step 5. Set that every time the displacement stage moves 100 nanometers, a position pulse with a pulse width of 10 microseconds is output, and the triggering time of this pulse is recorded by the single-pulse counter.

[0031] Since the moving interval between two data points of the displacement stage is set to a fixed value, the situation of the next moving path of the displacement stage can be obtained through calculation, denoted as moving path 2.

[0032] As an example, the moving distance of the displacement stage and the corresponding output position pulse can also be set to other corresponding values that meet the actual requirements.

[0033] Step 6. Perform linear fitting on the moving path 1 and the moving path 2 respectively, calculate the linear residuals of the two, and select the moving path of the displacement stage with the smallest maximum linear residual value by comparing the maximum linear residuals of the two for the calibration of the Raman spectrum.

[0034] In a third aspect, the present application discloses a non-transitory computer-readable storage medium, which enables an electronic device to execute the method described in any of the above aspects when the instructions in the storage medium are executed by a processor of the electronic device.

[0035] In a fourth aspect, the present application discloses a computer program product, which enables an electronic device to execute the method described in any of the above aspects when the instructions in the computer program product are executed by a processor of the electronic device.

[0036] Advantages of the present invention:

[0037] By comparing the residual sizes of two displacement stage paths of phase fitting and single-pulse counting, the present invention selects the most suitable path of the displacement stage to calibrate the Raman spectrum, which can meet the calibration of the high-precision displacement stage path and achieve real-time and efficient calibration of the displacement stage.

[0038] The overall structure of the present invention is designed scientifically and rigorously, the calibration method is safe and reliable, the implementation and operation are simple and convenient, and it is suitable for popularization and application. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of the overall structure of a high-precision Fourier Raman displacement stage calibration device of the present invention.

[0040] Figure 2Laser interference pattern (A1 and A2) of the multi-dimensional calibration method for a high-precision Fourier Raman displacement stage of the present invention

[0041] Figure 3 Initial phase diagram of the phase for the multi-dimensional calibration method of a high-precision Fourier Raman displacement stage of the present invention

[0042] Figure 4 Schematic diagram of the moving path 1 after phase unwrapping for the multi-dimensional calibration method of a high-precision Fourier Raman displacement stage of the present invention

[0043] Figure 5 Schematic diagram of the overall process for the multi-dimensional calibration method of a high-precision Fourier Raman displacement stage of the present invention

[0044] Figure 6 Data graph of the actual test results of Example 1 for the multi-dimensional calibration method of a high-precision Fourier Raman displacement stage of the present invention Detailed implementation mode

[0045] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application. Refer to Figures 1 to 6 as shown

[0046] Refer to Figure 1 , a high-precision Fourier Raman displacement stage calibration device, comprising:

[0047] A single-mode laser, a beam splitter, a detector, a first mirror, a second mirror, a displacement stage, a single-pulse counter, and a computer;

[0048] The single-mode laser: used to emit single-mode laser;

[0049] The beam splitter: splits the single-mode laser, and finally generates interference of light to form interference fringes;

[0050] Located horizontally between the single-mode laser and the first mirror;

[0051] Located vertically between the detector and the second mirror;

[0052] The detector: records the intensity change of the interference fringes;

[0053] The first mirror and the second mirror are symmetrically arranged;

[0054] The displacement stage: is arranged between the first mirror and the second mirror;

[0055] The single-pulse counter: used to record the position pulse signal to obtain the trigger time;

[0056] The computer: electrically connected to the single-pulse counter, with a processor and a memory for storing executable instructions of the processor built therein; wherein, the processor is configured to execute a multi-dimensional calibration method for a high-precision Fourier Raman displacement stage.

[0057] As an example, the beam splitter used is: a 50% beam splitter.

[0058] Refer to Figure 5 As shown, a multi-dimensional calibration method for a high-precision Fourier Raman displacement stage includes:

[0059] Step 1, generation of a laser interference pattern;

[0060] When the displacement stage is moving, it will interfere with the single-mode laser. At this time, continuously record the signal intensity of the interference points to obtain the laser interference pattern, as shown in detail in Figure 2 shown;

[0061] Step 2, obtain the initial phase of the phase through phase fitting;

[0062] Perform half-wavelength phase fitting of the cosine function on the laser interference pattern to obtain the initial phase of the laser interference pattern, refer to Figure 3 shown, until the fitting reaches the end of the laser interference pattern;

[0063] Step 3, perform phase unwrapping on the initial phase of the phase to obtain the moving path 1 of the displacement stage;

[0064] The formula for converting the phase result into the displacement stage position result is designed as follows:

[0065]

[0066] Where: Position(t) is the final position result, that is, the moving path 1; ρ(t) is the phase result after phase unwrapping, λ is the laser wavelength, and 8π is the phase period;

[0067] As an example, since the phase result is still the phase result after phase unwrapping, it is necessary to convert the phase result into the position result and perform the conversion calculation through the above formula.

[0068] Step 4, synchronously, at the first moment when the displacement stage moves, that is, trigger a start pulse to the single-pulse counter to start the test, and at the same time compress the entire pulse bandwidth and increase the delay function to ensure that the computer recording point time is consistent with the self-movement of the displacement stage;

[0069] Step 5: Set that every time the displacement stage moves 100 nanometers, a position pulse with a pulse width of 10 microseconds is output, and the trigger time of this pulse is recorded by a single-pulse counter.

[0070] Since the moving interval between two data points of the displacement stage is set to a fixed value, the situation of the next moving path of the displacement stage can be obtained through calculation, denoted as moving path 2.

[0071] As an example, the moving distance of the displacement stage and the corresponding output position pulse can also be set to other corresponding values that meet the actual requirements.

[0072] Step 6: Perform linear fitting on the moving path 1 and the moving path 2 respectively, calculate the linear residuals of the two, and by comparing the maximum linear residuals of the two, select the displacement stage moving path with the smallest maximum linear residual value for the correction of Raman spectra.

[0073] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it realizes each process of the above method embodiment and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0074] Among them, the computer-readable storage medium, such as a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc, etc.

[0075] The present application also shows a computer program product. When the instructions in the computer program product are executed by the processor of an electronic device, the electronic device can execute the method described in any of the above aspects.

[0076] Through the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases, the former is a better implementation method. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions to enable a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0077] To better illustrate the remarkable progress and advantages of the present invention, through specific embodiments, further referring to the actual test results, the working principle of the present invention is described.

[0078] Example 1: Taking the calibration of single-mode laser Raman spectroscopy as an example;

[0079] Two methods are respectively used to obtain moving path 1 ( Figure 6 (A1)) and moving path 2 ( Figure 6 (B1)), where:

[0080] Moving path 1: Adopting the method of phase fitting;

[0081] Moving path 2: Adopting the single-pulse counting method;

[0082] Linear fitting is respectively performed on moving path 1 and moving path 2, and the residuals of the two are calculated; it can be seen from Figure 6 that:

[0083] ① For the path residual obtained by using phase fitting, the maximum value is: 5×10 -5 (cm), that is, 500 nm;

[0084] ② For the path residual obtained by using the single-pulse counting method, the maximum value is: 1×10 -4 is (cm), that is, 1 μm;

[0085] It can be seen that the path obtained by using the phase fitting method is better.

[0086] Spectral correction is respectively performed on the two paths ( Figure 6 (A2)(B2)), and it can be found that the correction result using phase fitting is better than that of single-pulse counting;

[0087] Because after single-pulse counting correction, there is only one obvious laser peak position in the laser spectrum, while although the laser peak position is still obvious in the phase fitting method, there are other interfering spikes.

[0088] The above Example 1 is only one case among many examples. Sometimes, the maximum value of the residual of the single-pulse counting method is lower than that of the phase fitting method. In this case, the path of single-pulse counting is selected to correct the spectrum.

[0089] It should be noted that for the method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all optional embodiments, and the actions involved are not necessarily essential to the present application.

[0090] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including one..." does not exclude the presence of additional identical elements in the process, method, article or device including such element.

[0091] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can still make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

[0092] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in connection with the embodiments disclosed in the present application can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0093] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0094] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in an electrical, mechanical or other form.

[0095] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0096] In addition, each functional unit in various embodiments of the present application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0097] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0098] The above are only the preferred embodiments of the present invention. It should be understood that the description of the above embodiments is only used to help understand the method and its core idea of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision Fourier Raman translation stage calibration device, characterized in that: include: A single-mode laser, a beam splitter, a detector, a first reflecting mirror, a second reflecting mirror, a translation stage, a single pulse counter and a computer; The single-mode laser is used to emit single-mode laser; The beam splitter is used to split the single-mode laser and finally generate light interference to form interference fringes; it is located between the single-mode laser and the first reflector in the horizontal direction; and is located between the detector and the second reflector in the vertical direction; The detector is used to record the intensity changes of the interference fringes; The first reflector and the second reflector are symmetrically arranged; The displacement stage is arranged between the first reflector and the second reflector; The single pulse counter is used to record the position pulse signal and obtain the trigger time; The computer is electrically connected to the single pulse counter and has a built-in processor and a memory for storing processor executable instructions; wherein the processor is configured to execute a multi-dimensional calibration method for a high-precision Fourier Raman shift stage.

2. A high-precision Fourier Raman translation stage calibration device according to claim 1, characterized in that: The beam splitter splits the single-mode laser in a 50% ratio, and finally returns to the beam splitter through the first reflector and the second reflector to generate interference; forming interference fringes of alternating light and dark, and finally the detector records the intensity changes of the interference fringes to form an interference pattern.

3. The high-precision Fourier Raman translation stage calibration device according to claim 1, characterized in that: The beam splitter used is: 50% beam splitter.

4. The high-precision Fourier Raman translation stage calibration device according to claim 1, characterized in that: The detector records the changes in the strength of the interference fringes, and finally forms an interference pattern, which is converted into a spectrum after Fourier transformation.

5. A multi-dimensional calibration method for a high-precision Fourier Raman translation stage, characterized in that: include: Step 1: Generation of laser interference pattern; When the translation stage is moving, it will interfere with the single-mode laser. At this time, the signal strength of the interference point is continuously recorded to obtain the laser interference pattern. Step 2: Obtain the initial phase through phase fitting; Performing half-wavelength phase fitting of a cosine function on the laser interference pattern to obtain an initial phase of the laser interference pattern, until fitting to the laser interference pattern is completed; Step 3, performing phase expansion on the initial phase to obtain a moving path 1 of the translation stage; The formula for converting the phase result into the position result of the translation stage is designed as follows: Where: Position(t) is the final position result, i.e., moving path 1; ρ(t) is the phase result after phase unwrapping, λ is the laser wavelength, and 8π is the phase period; Step 4: synchronously, at the first moment of the movement of the translation stage, a start pulse is triggered to start the test of the single pulse counter, and at the same time, the whole pulse bandwidth is compressed and a delay function is added to ensure that the computer recording point time is consistent with the movement of the translation stage itself; Step 5: Set the displacement stage to output a position pulse with a pulse width of 10 microseconds every time it moves 100 nanometers, and the pulse is recorded by a single pulse counter to obtain its trigger time; Since the moving interval between two data points of the translation stage is set to a fixed value, the next moving path of the translation stage can be obtained by calculation, which is recorded as moving path 2; Step 6: Perform straight line fitting on the moving path 1 and the moving path 2 respectively, calculate the straight line residuals of the two, and select a translation stage moving path with the smallest maximum straight line residual value by comparing the maximum straight line residuals of the two for correction of Raman spectrum.

6. The multi-dimensional calibration method of a high-precision Fourier Raman translation stage according to claim 5, characterized in that: Because the phase result is still a phase result after phase unwrapping, the phase result needs to be converted into a position result.

7. The multi-dimensional calibration method of a high-precision Fourier Raman translation stage according to claim 5, characterized in that: The moving distance of the translation stage and the corresponding output position pulse can be set to other values.

8. A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by a processor of an electronic device, enables the electronic device to execute the method as described in any one of claims 5 to 7.

9. A computer program product, when instructions in the computer program product are executed by a processor of an electronic device, enables the electronic device to perform the method as claimed in any one of claims 5 to 7.

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