Spectrum correction method, correction device and spectrum acquisition device

Abstract

The present application provides a spectrum correction method, correction device, and spectrum acquisition device. The method includes: obtaining the efficiency of a spectrum to be measured when it strikes different positions on a detector; constructing an inclined arc surface, and performing a correction operation on the spectrum to be measured based on the inclined arc surface, wherein the numerical correspondence between the length direction value and the height direction value of the inclined arc surface is determined by the efficiency of the spectrum to be measured when it strikes different positions on the detector. The present application can quickly, accurately, and conveniently correct the spectrum so that the efficiency of the current wavelength remains substantially consistent when it strikes different pixels on the detector, ultimately allowing two spectra to be perfectly spliced together.

Description

Technical Field

[0001] The present application relates to the field of optical imaging, and in particular to a spectrum correction method, a correction device, and a spectrum acquisition device. Background Art

[0002] When using a linear / area array detector (such as CCD, etc.) for spectrum acquisition, the range of a single spectrum shot by the spectrometer is limited. If the spectral band range to be scanned exceeds the range of a single spectrum shot by the spectrometer, the spectrometer needs to rotate the grating, take multiple spectrum shots, and then connect the spectra or use other methods to finally obtain the spectral band range to be scanned. However, since the current wavelength of light hits the pixels of the detector (the difference between pixels is negligible or spectral correction has been performed, the same below) at different positions when the grating is rotated to different angles, and its intensity is also different (such as Figure 3 As shown in the figure, the intensity values of the same wavelength on different curves are different), that is, the efficiency of the current wavelength hitting different pixels of the detector is different. Therefore, it is difficult to perfectly stitch together two spectra. The final spectrum will have steps at the joining position, which will cause spectrum distortion (such as Figure 4 The real spectral data cannot be obtained.

[0003] In the prior art, each wavelength in the spectral band to be scanned moves as the grating rotates and is detected by each pixel of the detector, and then the values of the current wavelength at each pixel are superimposed as the signal value of the current wavelength.

[0004] The inventors found that the technical solutions in the prior art require that each wavelength in the spectral band range move as the grating rotates to be detected by each pixel of the detector. When the detector is collecting data, the spectrometer needs to stop moving (otherwise the accuracy of the collected data will be affected). The number of start and stop movements of the spectrometer during the collection process of each wavelength is determined by the number of pixels in the detector, and the spacing of each movement must make the current wavelength move one pixel on the detector. This will greatly extend the collection time. In addition, high-precision rotation of the grating is required, and the grating rotation and CCD data collection must be coordinated at a high speed, which places high demands on both hardware and software. Since the grating dispersion corresponding to different wavelengths is different, the current grating movement distance corresponds to the current wavelength moving one pixel on the detector, but the distance moved on the detector for other wavelengths detected by the detector is no longer one pixel. Therefore, for each rotation of the grating, only the current wavelength can be used as the signal value of the current wavelength by superimposing its values at each pixel. If the other wavelength values scanned in the current cycle can also be used in adjacent cycles, then corresponding data processing is required before they can be used.

[0005] Therefore, the inventors, relying on their many years of experience and practice in related industries, have proposed a spectrum correction method, a correction device and a spectrum acquisition device to overcome the defects of the prior art. Summary of the Invention

[0006] In response to the problems in the prior art, the present application provides a spectral correction method, correction device and spectral acquisition device, which can quickly, accurately and conveniently correct the spectrum so that the efficiency of the current wavelength remains basically consistent when it hits different pixels of the detector, and ultimately the two spectra are perfectly spliced together.

[0007] To solve the above technical problems, this application provides the following technical solutions:

[0008] In a first aspect, the present application provides a spectrum correction method, the method comprising:

[0009] Obtain the efficiency of the measured spectrum when it hits the detector at different positions;

[0010] An oblique arc surface is constructed, and a correction operation is performed on the spectrum to be measured based on the oblique arc surface, wherein the numerical correspondence between the length direction value and the height direction value of the oblique arc surface is determined by the efficiency of the spectrum to be measured when it hits different positions of the detector.

[0011] In a second aspect, the present application provides a correction device, which is arranged on the imaging mirror input light path or the imaging mirror output light path of the imaging mirror in the spectrum acquisition device, and includes an inclined arc surface. The curvature of the inclined arc surface is determined by the efficiency of the measured spectrum passing through the grating in the spectrum acquisition device and the imaging mirror and hitting different positions of the detector.

[0012] Furthermore, the oblique arc curve satisfies the formula y=ax 4 +bx 3 +cx 2 +dx+e, wherein a, b, c, d, and e are dimensionless coefficients, x is the length direction value of the oblique arc surface, and y is the height direction value of the oblique arc surface.

[0013] Furthermore, the correction device is made of aluminum, and light-absorbing paper is pasted on the light-facing surface of the correction device.

[0014] In a third aspect, the present application provides a spectrum acquisition device, comprising:

[0015] The device body, a grating arranged in the device body for splitting the spectrum to be measured and an imaging mirror for focusing the spectrum to be measured, and the imaging mirror input light path or the imaging mirror output light path of the imaging mirror are provided with the correction device as described above for efficiency correction of the spectrum to be measured.

[0016] Furthermore, it also includes a detector, which is connected to the device body and is used to receive the spectrum to be measured after efficiency correction by the correction device.

[0017] Furthermore, the device body is also provided with an incident slit for the spectrum to be measured to enter.

[0018] Furthermore, a collimating reflector for converting the spectrum to be measured from non-parallel light to parallel light is also provided in the main body of the device.

[0019] Furthermore, a reflector for reflecting the spectrum to be measured is also provided in the main body of the device, and the reflector is provided between the incident slit and the collimating reflector.

[0020] Furthermore, the correction device is arranged on the imaging mirror by adhesive connection.

[0021] Furthermore, the correction device is arranged on the imaging mirror incident light path between the imaging mirror and the grating.

[0022] It can be seen from the above technical solution that the present application provides a spectrum correction method, correction device and spectrum acquisition device. By setting the correction device, the spectrum can be corrected quickly, accurately and conveniently so that the efficiency of the current wavelength when it hits different pixels of the detector remains basically consistent, and finally the two spectra are perfectly spliced together. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 This is a schematic structural diagram of the spectrum acquisition device described in this application;

[0025] Figure 2 This is a schematic structural diagram of the correction device described in this application;

[0026] Figure 3 Spectral images of different central wavelengths for this application;

[0027] Figure 4 This is the conventional connection spectrum diagram for this application;

[0028] Figure 5 Spectral images of different central wavelengths after adding a correction device to the optical path of this application;

[0029] Figure 6This is the spectrum diagram after adding a correction device to the optical path of this application;

[0030] Figure 7 Schematic diagram of the process of the spectrum correction method described in this application. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] In this application, terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "center," "vertical," "horizontal," "transverse," and "longitudinal" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are primarily intended to better describe this application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed or operated in a specific orientation.

[0034] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0035] Furthermore, the terms "installed," "disposed," "provided with," "connected," "connected," and "socketed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integral structures; mechanical connections or electrical connections; direct connections, indirect connections through an intermediary, or internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0036] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] Considering that the technical solutions in the prior art require that each wavelength in the spectral band range move as the grating rotates to be detected by each pixel of the detector, the spectrometer needs to stop moving when the detector is collecting data (otherwise the accuracy of the collected data will be affected). The number of start and stop movements of the spectrometer during the collection process of each wavelength is determined by the number of pixels in the detector, and the spacing of each movement must be such that the current wavelength moves one pixel on the detector. This will greatly increase the collection time. In addition, high-precision rotation of the grating and high-speed coordination of grating rotation and CCD data collection are required, which places high demands on both hardware and software. Since the grating dispersion corresponding to different wavelengths is different, the current grating movement distance corresponds to the current wavelength moving one pixel on the detector, but the distance moved on the detector for other wavelengths detected by the detector is no longer one pixel. Therefore, for each rotation of the grating, only the current wavelength can be used as the signal value of the current wavelength by superimposing its values at each pixel. If the other wavelength values scanned in the current cycle can also be used in adjacent cycles, then corresponding data processing is required before they can be used.

[0038] In order to quickly, accurately and conveniently calibrate the spectrum so that the efficiency of the current wavelength when hitting different pixels of the detector remains basically consistent, and finally the two spectra are perfectly spliced together, the present application provides an embodiment of a spectrum correction method, see Figure 7 , the spectrum correction method comprises:

[0039] Step S101: Obtaining the efficiency of the spectrum to be measured when it hits different positions of the detector.

[0040] Step S102: constructing an oblique arc surface, and performing a correction operation on the spectrum to be measured based on the oblique arc surface, wherein the numerical correspondence between the length direction value and the height direction value of the oblique arc surface is determined by the efficiency of the spectrum to be measured when it hits different positions of the detector.

[0041] In a feasible embodiment of the present application, it is assumed that when the wavelength of the current spectrum to be measured hits the x1th pixel position of the detector, its efficiency is η1, when it hits the x2th pixel position, its efficiency is η2, when it hits the x3th pixel position, its efficiency is η3, and when it hits the x4th pixel position, its efficiency is η4. n When the pixel position is n , from this we can know that η1~η n The minimum value of η min , we can get the following equations (1):

[0042]

[0043] Among them, x1~x n Represents the first pixel to the nth pixel position, η1~η n Indicates that the current wavelength is between x1 and x n The corresponding efficiency on each pixel, a, b, c, d, e represent dimensionless coefficients, and thus the application can solve the values of a, b, c, d, e by the least squares method, and then obtain the final curve equation y=ax 4 +bx 3 +cx 2 +dx+e, where x is the length direction value of the device and y is the height direction value of the device.

[0044] In another feasible embodiment of the present application, it is assumed that when the wavelength of the current spectrum to be measured hits the x1th pixel position of the detector, its efficiency is η1, when it hits the x2th pixel position, its efficiency is η2, when it hits the x3th pixel position, its efficiency is η3, and when it hits the x4th pixel position, its efficiency is η4. n When the pixel position is n , we can get the following equations (2):

[0045]

[0046] Similarly, the values of a, b, c, d, and e can be solved by the least squares method, and the final curve equation y=ax is obtained. 4 +bx 3 +cx 2 +dx+e, where x is the pixel position and y is the efficiency value corresponding to the x pixel (obtained by fitting).

[0047] At the same time, it is understandable that in actual use, the data actually guessed by the detector after collecting the data is recorded as: (x1, p1), (x2, p2), (x3, p3), ..., (x n ,p n ), where p1~p n Corresponding to x1~xn The signal intensity collected by each pixel, therefore, the present application can also perform spectral correction by data processing, specifically referring to the following equation group (3):

[0048]

[0049] Therefore, after this calculation, the application can obtain a new array: (x1, p1′), (x2, p2′), (x3, p3′), ..., (x n ,p n ′), the array is the array after the spectrum correction is performed by data processing, and the spectrum correction operation is completed at this time.

[0050] As can be seen from the above description, the spectral correction method provided in this application can quickly, accurately and conveniently correct the spectrum by setting a correction device, so that the efficiency of the current wavelength when it hits different pixels of the detector remains basically consistent, and ultimately the two spectra are perfectly spliced together.

[0051] In order to be able to quickly, accurately and conveniently calibrate the spectrum so that the efficiency of the current wavelength when hitting different pixels of the detector remains basically consistent, and finally the two spectra are perfectly spliced together, the present application provides an embodiment of a spectrum acquisition device, see Figure 2 In this embodiment, the spectrum acquisition device specifically includes a device body, a grating 6 arranged in the device body for splitting the spectrum to be measured, and an imaging mirror 4 for focusing the spectrum to be measured. A correction device 5 for performing efficiency correction on the spectrum to be measured is arranged on the imaging mirror 4 input light path or the imaging mirror 4 output light path.

[0052] Optionally, although the efficiency of the current wavelength of the spectrum to be measured is different when it hits different pixels of the detector 7, the efficiency of the current wavelength of the spectrum to be measured changes regularly with the position of the current wavelength on the detector 7. Therefore, the present application designs a correction device 5 (such as Figure 2 As shown), the correction device 5 is set in the optical path between the grating 6 and the detector 7 (as shown Figure 1 The optical path is shown in FIG. 1 , and the efficiency of the spectrum to be measured is finally changed so that it hits different positions of the detector 7 and its efficiency remains consistent.

[0053] Combine Figure 1For example, the spectrum to be measured first enters the main body of the device of the present application through the incident slit 2, and then is reflected by the reflector 1 and hits the collimating reflector 31. The collimating reflector 31 converts the incident non-parallel light into parallel light and hits the grating 6. The grating 6 performs spectroscopic processing on the spectrum to be measured. The spectrum to be measured passing through the grating 6 hits the imaging mirror 4. The imaging mirror 4 converges light of different wavelengths onto the detector 7. The detection of the spectrum is finally completed through the detection of the detector 7 and related software.

[0054] Among them, the present application sets up a correction device 5 installed on the incident light path of the imaging mirror 4 or the outgoing light path of the imaging mirror 4, that is, the spectrum to be measured is spectrally corrected through the correction device 5.

[0055] Optionally, the correction device 5 of the present application may also be directly disposed on the imaging mirror 4 .

[0056] join Figure 5 and Figure 6 Through the correction device 5 in the main body of the device of the present application, the two spectra are finally perfectly spliced together, and the wide range spectrum acquisition is completed quickly, solving the technical problem of inaccurate spectrum splicing.

[0057] It can be understood that the spectrum acquisition device of the present application is suitable for wide-range spectrum acquisition, but is not limited to wide-range spectrum acquisition.

[0058] As can be seen from the above description, according to the spectrum acquisition device provided in the embodiment of the present application, by setting the correction device 5, the spectrum can be corrected quickly, accurately and conveniently, so that the efficiency of the current wavelength when it hits different pixels of the detector 7 remains basically consistent, and ultimately the two spectra are perfectly spliced together.

[0059] As a preferred embodiment, the device further includes a detector 7 , which is connected to the device body and is used to receive the spectrum to be measured after efficiency correction by the correction device 5 .

[0060] As a preferred embodiment, the correction device 5 is provided with an oblique arc surface, the curvature of which is determined by the efficiency of the spectrum to be measured passing through the grating and the imaging mirror and hitting different positions of the detector. Specifically, y=ax 4 +bx 3 +cx 2 +dx+e, a, b, c, d, e are dimensionless coefficients, x is the length direction value of the oblique arc surface, and y is the height direction value of the oblique arc surface.

[0061] As a preferred embodiment, the correction device 5 is made of aluminum, and light-absorbing paper is pasted on the light-facing surface of the correction device, but the present application is not limited to the aluminum material. The aluminum material is only an example with better effect. The correction device 5 of the present application can also be made of other materials.

[0062] As a preferred embodiment, the device body is further provided with an incident slit 2 for the spectrum to be measured to enter.

[0063] As a preferred embodiment, a collimating reflector 31 is further provided in the main body of the device for converting the spectrum to be measured from non-parallel light to parallel light.

[0064] As a preferred embodiment, a reflector 1 for reflecting the spectrum to be measured is further provided in the device body, and the reflector 1 is provided between the incident slit 2 and the collimating reflector 31 .

[0065] As a preferred embodiment, the correction device 5 is arranged on the imaging mirror 4 by an adhesive connection, but it can be understood that the correction device 5 of the present application is not limited to being installed at the position of the imaging mirror 4. The correction device 5 can also be installed at any applicable position in the optical path between the grating 6 and the detector 7. For example, the correction device 5 is arranged on the optical path of the imaging mirror 4 between the imaging mirror 4 and the grating 6.

[0066] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A spectrum correction method, characterized in that: The method comprises: Obtain the efficiency of the measured spectrum when it hits the detector at different positions; Construct an oblique arc surface, and perform a correction operation on the spectrum to be measured based on the oblique arc surface, wherein the numerical correspondence between the length direction value and the height direction value of the oblique arc surface is determined by the efficiency of the spectrum to be measured when it hits different positions of the detector; the curve of the oblique arc surface satisfies the formula y=ax 4 +bx 3 +cx 2 +dx+e, wherein a, b, c, d, and e are dimensionless coefficients, and the values of a, b, c, d, and e are obtained by least squares method, wherein x is the length direction value of the oblique arc surface, and y is the height direction value of the oblique arc surface.

2. A calibration device, characterized in that: The imaging mirror provided in the spectrum acquisition device includes an oblique arc surface on the imaging mirror input light path or the imaging mirror output light path. The curvature of the oblique arc surface is determined by the efficiency of the spectrum to be measured passing through the grating in the spectrum acquisition device and the imaging mirror and hitting different positions of the detector. The curve of the oblique arc surface satisfies the formula y=ax 4 +bx 3 +cx 2 +dx+e, wherein a, b, c, d, and e are dimensionless coefficients, and the values of a, b, c, d, and e are obtained by least squares method, wherein x is the length direction value of the oblique arc surface, and y is the height direction value of the oblique arc surface.

3. The correction device according to claim 2, characterized in that The correction device is made of aluminum, and light-absorbing paper is pasted on the light-facing surface of the correction device.

4. A spectrum acquisition device, characterized in that: include: A device body, a grating arranged in the device body for splitting the spectrum to be measured, and an imaging mirror for focusing the spectrum to be measured, wherein the imaging mirror input light path or the imaging mirror output light path of the imaging mirror is provided with a correction device as described in any one of claims 2 to 3 for performing efficiency correction on the spectrum to be measured.

5. The spectrum acquisition device according to claim 4, characterized in that: It also includes a detector connected to the device body, and the detector is used to receive the spectrum to be measured after efficiency correction by the correction device.

6. The spectrum acquisition device according to claim 4, characterized in that: The device body is also provided with an incident slit for the spectrum to be measured to be incident.

7. The spectrum acquisition device according to claim 6, characterized in that: The device body is also provided with a collimating reflector for converting the spectrum to be measured from non-parallel light to parallel light.

8. The spectrum acquisition device according to claim 7, characterized in that: A reflector for reflecting the spectrum to be measured is also provided in the device body, and the reflector is provided between the incident slit and the collimating reflector.

9. The spectrum acquisition device according to claim 4, characterized in that: The correction device is arranged on the imaging mirror by adhesive connection.

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