Wave number correction device for confocal microscopic Raman spectrometer
By using a calibration device consisting of a laser, lens, mirror, and slit in a Raman spectrometer, the laser wavelength is automatically calibrated, solving the problems of sample dependence and time-consuming calibration in existing technologies, and achieving high-precision, fast wavenumber correction and wide-band testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- OPTOSKY (XIAMEN) PHOTONICS INC
- Filing Date
- 2025-04-03
- Publication Date
- 2026-05-08
AI Technical Summary
Existing Raman spectrometer calibration methods rely on standard samples. Surface defects on the samples affect calibration accuracy, and the process is time-consuming and labor-intensive. Furthermore, the narrow spectral range makes it difficult to meet the requirements for wide-band testing.
A calibration device consisting of a laser, lens assembly, mirror assembly, attenuator, and slit automatically calibrates the laser wavelength by adjusting the angle of the rotating grating assembly and detecting Rayleigh scattering light, achieving high-precision wavenumber calibration without the need for samples.
It enables rapid and accurate wavenumber correction without samples, simplifies the calibration process, improves calibration accuracy and band range, and avoids the influence of sample surface defects.
Smart Images
Figure CN224216557U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of Raman spectroscopy detection technology, and in particular to a wavenumber correction device for a confocal micro Raman spectrometer. Background Technology
[0002] Confocal micro Raman spectrometry achieves high-resolution spectral analysis through grating-based spectral dispersion. Existing grating spectrometers require long-focal-length lenses to improve resolution, but high-resolution spectrometers have narrow wavelength ranges, insufficient for sample testing. Therefore, a wider wavelength range is achieved by rotating the grating, enabling Raman testing within the 0-5000 cm⁻¹ range. -1 However, deviations in laser wavelength can lead to errors in the wavenumber calibration of the sample's characteristic peaks, thus requiring subsequent calibration to ensure the overall wavenumber accuracy.
[0003] In the existing technology, the calibration of Raman spectrometers mainly involves calibrating the wavenumber of the instrument using known standard samples. The core idea is to adjust the wavenumber using the known characteristic peaks of the standard samples to ensure the wavenumber accuracy of the spectrometer.
[0004] However, calibration using standard samples requires a smooth and clean sample surface. Scratches, contamination, or other defects on the surface can cause the shape of the Raman peaks to become blurred or shifted, affecting the accuracy of wavenumber calibration. Furthermore, calibration using standard samples is a time-consuming and labor-intensive process.
[0005] To address the above issues, a wavenumber correction device for a confocal micro Raman spectrometer was designed. Utility Model Content
[0006] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a wavenumber correction device for a confocal micro Raman spectrometer, which makes the calibration process convenient and fast and improves the calibration accuracy.
[0007] To achieve the aforementioned objectives of this utility model, the present disclosure adopts the following technical solution:
[0008] A wavenumber correction device for a confocal micro Raman spectrometer, the correction device comprising:
[0009] A laser, used to emit laser light;
[0010] A lens assembly, comprising a plurality of lenses, wherein the lens assembly is used to collimate and focus the laser;
[0011] A reflector assembly includes multiple reflectors, with multiple lenses and multiple reflectors arranged alternately, and the reflector assembly is used to adjust the optical path direction of the laser.
[0012] An attenuator is disposed in the reflected light path within the reflector assembly, and the attenuator is used to attenuate the energy of the laser.
[0013] A slit, located at a confocal position within the lens assembly, is used to filter Rayleigh scattered light from the attenuated laser beam.
[0014] The mirror assembly reflects the Rayleigh scattered light onto the rotating grating assembly inside the spectrometer.
[0015] In one exemplary embodiment of this disclosure, the reflector assembly includes at least a first reflector, a second reflector, and a third reflector;
[0016] The first reflector is not perpendicular to the emission direction of the laser, the second reflector is not perpendicular to the reflected light path of the first reflector, and the third reflector is not perpendicular to the reflected light path of the second reflector.
[0017] In one exemplary embodiment of this disclosure, the first reflector is arranged at a 45-degree angle to the emission direction of the laser, and the second reflector is arranged at a 45-degree angle to the reflected light path of the first reflector.
[0018] In one exemplary embodiment of this disclosure, the surfaces of the first reflector, the second reflector, and the third reflector are all coated with a high-reflectivity film.
[0019] In one exemplary embodiment of this disclosure, the attenuator is disposed in the optical path between the first reflector and the second reflector, and the attenuator is perpendicular to the optical path.
[0020] In one exemplary embodiment of this disclosure, the attenuator is a 99.9% attenuator.
[0021] In one exemplary embodiment of this disclosure, the lens assembly includes at least a first lens, a second lens, and a third lens;
[0022] The first lens is vertically disposed in the optical path between the laser and the first reflector, and the second lens and the third lens are sequentially vertically disposed in the optical path between the second reflector and the third reflector;
[0023] Among them, the first lens, the second lens, and the third lens are all aspherical lenses.
[0024] In one exemplary embodiment of this disclosure, both the first lens and the third lens are collimating lenses, and the second lens is a focusing lens;
[0025] The second lens and the third lens are confocal.
[0026] In one exemplary embodiment of this disclosure, the slit is disposed at the confocal point of the second lens and the third lens;
[0027] The slit is a circular slit.
[0028] In one exemplary embodiment of this disclosure, the calibration device further includes a housing;
[0029] The laser, lens assembly, reflector assembly, attenuator, and slit are all installed inside the housing.
[0030] The beneficial effects of this disclosure are:
[0031] (1) This disclosure achieves wavenumber correction by pre-adjusting the angle of the rotating grating assembly to the zero wavenumber position, reflecting the Rayleigh scattered light to the grating when the peak value is reached, adjusting the rotation angle of the rotating grating assembly according to the display result of the Rayleigh scattered light on the rotating grating assembly, calibrating the wavelength position deviation of the laser, and recalculating the wavenumber through the calibrated laser wavelength. The structure is simple, the operation is convenient, no external sample is required for calibration, it is not affected by the accuracy of the sample, and the calibration accuracy is high.
[0032] (2) This disclosure detects the display result of Rayleigh scattering peak by controlling the component, automatically adjusts the rotation angle of the rotating grating component according to the detection result, and automatically recalculates the wavenumber according to the calibrated laser wavelength to achieve automatic calibration, making the calibration process convenient and fast. Attached Figure Description
[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.
[0034] Figure 1 This is a schematic diagram of the wavenumber correction device for a confocal micro Raman spectrometer according to one embodiment of the present disclosure.
[0035] Explanation of reference numerals in the attached figures:
[0036] 1. Laser; 2. Attenuator; 3. Slit; 4. First reflector; 5. Second reflector; 6. Third reflector; 7. First lens; 8. Second lens; 9. Third lens; 10. Housing. Detailed Implementation
[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.
[0038] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.
[0039] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.
[0040] This disclosure provides a wavenumber correction device for a confocal micro Raman spectrometer. See also... Figure 1 The correction device includes: a laser 1 for emitting laser light; a lens assembly including multiple lenses for collimating and focusing the laser light; a mirror assembly including multiple mirrors, with the multiple lenses and mirrors arranged alternately, for adjusting the direction of the laser light path; an attenuator 2 disposed in the reflected light path within the mirror assembly, for attenuating the energy of the laser light; and a slit 3 disposed at a confocal position within the lens assembly, for filtering Rayleigh scattered light from the attenuated laser light; wherein the mirror assembly reflects the Rayleigh scattered light onto a rotating grating assembly within the spectrometer.
[0041] In this embodiment, the wavenumber correction device for the confocal micro Raman spectrometer comprises a laser 1, a lens assembly, a mirror assembly, an attenuator 2, and a slit 3. The lens assembly, mirror assembly, attenuator 2, and slit 3 form an optical path to guide the laser emitted by the laser 1 along the optical path. A rotating grating assembly is pre-driven to rotate, adjusting its angle to the zero wavenumber position corresponding to the Rayleigh scattering peak. The laser 1 emits laser light, multiple lenses collimate and focus the laser light emitted by the laser 1, multiple mirrors reflect the collimated laser light to adjust the optical path direction, the attenuator 2 attenuates the laser energy, and the slit 3 filters the Rayleigh scattered light from the attenuated laser light. The mirror assembly reflects the filtered Rayleigh scattered light onto the rotating grating assembly inside the spectrometer. Based on the display result of the Rayleigh scattered light on the rotating grating assembly, the angle of the rotating grating assembly is adjusted to calibrate the wavelength position deviation of the laser 1. Then, based on the calibrated laser wavelength, the wavenumber is calculated using the wavenumber calculation formula. Recalculate the wavenumber; where the rotating grating assembly is in Figure 1 Not shown in the image.
[0042] Compared to existing methods that use standard samples for calibration, this confocal micro Raman spectrometer wavenumber correction device has a simple structure, is easy to operate, requires no samples for calibration, is not affected by the accuracy of the samples, and has high calibration accuracy.
[0043] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The calibration device also includes a housing 10; the laser 1, lens assembly, mirror assembly, attenuator 2, and slit 3 are all installed inside the housing 10. This allows for a tight fit between the laser 1, lens assembly, mirror assembly, attenuator 2, and slit 3, facilitating the calibration of the spectrometer wavenumber.
[0044] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The reflector assembly includes at least a first reflector 4, a second reflector 5, and a third reflector 6. The first reflector 4 is not perpendicular to the emission direction of the laser 1, the second reflector 5 is not perpendicular to the reflected light path of the first reflector 4, and the third reflector 6 is not perpendicular to the reflected light path of the second reflector 5. This allows for adjustment of the optical path of the aligned laser, facilitating the reflection of Rayleigh scattered light onto the rotating grating assembly.
[0045] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The first reflector 4 is set at a 45-degree angle to the emission direction of the laser 1, and the second reflector 5 is set at a 45-degree angle to the reflected light path of the first reflector 4. In this way, a 90-degree change in the laser light path can be achieved, making the outgoing light path and the returning light path parallel to each other, thereby compressing the light path space.
[0046] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The surfaces of the first reflector 4, the second reflector 5, and the third reflector 6 are all coated with a high-reflectivity film. This improves the reflectivity of the first reflector 4, the second reflector 5, and the third reflector 6 to laser light.
[0047] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The attenuator 2 is positioned in the optical path between the first reflector 4 and the second reflector 5, and is perpendicular to the optical path. This facilitates the attenuation of laser energy by the attenuator 2, thereby improving the attenuation rate of the laser energy.
[0048] In one embodiment of this disclosure, the attenuator 2 is a 99.9% attenuator. This minimizes the laser power, prevents oversaturation in the spectrometer, and facilitates the rotating grating assembly's reception of the returned Rayleigh scattered light.
[0049] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The lens assembly includes at least a first lens 7, a second lens 8, and a third lens 9. The first lens 7 is vertically disposed in the optical path between the laser 1 and the first reflector 4, and the second lens 8 and the third lens 9 are sequentially vertically disposed in the optical path between the second reflector 5 and the third reflector 6. This allows for adjustment of the laser's state within the optical path, facilitating laser processing.
[0050] Optionally, the first lens 7, the second lens 8, and the third lens 9 are all aspherical lenses. This avoids optical path distortion.
[0051] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 Both the first lens 7 and the third lens 9 are collimating lenses, and the second lens 8 is a focusing lens; wherein the second lens 8 and the third lens 9 are confocal. This allows for collimation and focusing of the laser in the optical path, facilitating adjustment of the laser's state at different positions along the optical path.
[0052] In one embodiment of this disclosure, see [link to relevant documentation]. Figure 1 The slit 3 is located at the confocal point of the second lens 8 and the third lens 9; the slit 3 is a circular slit. In this way, non-confocal stray light in the laser can be filtered out to the greatest extent, and Rayleigh scattered light in the attenuated laser can be filtered out.
[0053] In one embodiment of this disclosure, the rotating grating assembly includes a rotating component, a grating, and a limiting component. The grating is mounted on the top of the rotating component, and the limiting component is mounted on the rotating component. The grating is located on the reflected light path of the third reflector 6. The rotating component is used to drive the grating to rotate in order to adjust the angle of the grating, and the limiting component is used to limit the rotation angle of the rotating component.
[0054] Optionally, the rotating assembly includes a motor with a turntable mounted on the motor's output shaft, and a grating mounted on the turntable to drive the grating to rotate.
[0055] Optionally, the motor is a high-precision stepper motor.
[0056] Optionally, the grating and turntable can be detached and installed.
[0057] Optionally, the limiting component is a limit switch.
[0058] In one embodiment of this disclosure, the rotating grating assembly is electrically connected to the control assembly. The control assembly is disposed within the spectrometer and includes a detection assembly, a processor, a memory, and a display. The processor is electrically connected to the motor, the detection assembly, the memory, and the display. The detection assembly is used to detect the display result of Rayleigh scattered light on the grating. The processor starts the motor based on the data detected by the detection assembly to precisely adjust the rotation angle of the grating. The memory is used to store the detection data, and the display is used to display the data detected by the detection assembly.
[0059] Optionally, the control components also include an encoder, which is electrically connected to both the processor and the rotating grating assembly. This allows for micrometer-level angle adjustment of the grating.
[0060] Understandably, the processor automatically recalculates the wavenumber using the wavenumber calculation formula based on the calibrated laser wavelength.
[0061] In one embodiment of this disclosure, see Figure 1 Along the direction of laser output from laser 1, a first lens 7 and a first reflector 4 are arranged sequentially. The first lens 7 is perpendicular to the optical path, and the first reflector 4 is set at a 45-degree angle to the laser input direction. An attenuator 2 and a second reflector 5 are arranged sequentially on the reflected optical path of the first reflector 4. The attenuator 2 is perpendicular to the reflected optical path of the first reflector 4, and the second reflector 5 is set at a 45-degree angle to the reflected optical path of the first reflector 4. A second lens 8, a slit 3, a third lens 9, and a third reflector 6 are arranged sequentially on the reflected optical path of the second reflector 5. The second lens 8, slit 3, and third lens 9 are perpendicular to the reflected optical path of the second reflector 5, while the third reflector 6 is not perpendicular to the reflected optical path of the second reflector 5. The slit 3 is located at the confocal position of the second lens 8 and the third lens 9.
[0062] Optionally, the rotating grating assembly is located on the reflected light path of the third mirror 6.
[0063] Optionally, the reflected light paths of the third reflector 6 and the second reflector 5 are set at a 45-degree angle.
[0064] In one embodiment of this disclosure, see Figure 1Laser 1, third reflector 6, third lens 9 and slit 3 are installed on the same side inside housing 10, first reflector 4, attenuator 2 and second reflector 5 are installed on the other side inside housing 10, and first lens 7 and second lens 8 are installed in the middle inside housing 10.
[0065] In one embodiment of this disclosure, see Figure 1 The working process of the wavenumber correction device of the confocal micro Raman spectrometer is briefly described as follows:
[0066] In use, this disclosure first drives the rotating grating assembly to rotate via a control component, positioning it at the zero wavenumber position corresponding to the Rayleigh scattering peak. Then, laser 1 is activated to output excitation light. The first lens 7 collimates the excitation light output by laser 1 into parallel light. The first reflector 4 adjusts the optical path direction, reflecting the parallel light to the attenuator 2, which attenuates the energy of the parallel light. The second reflector 5 adjusts the optical path direction, reflecting the attenuated parallel light to the second lens 8, which focuses the parallel light. The circular slit 3 filters out non-confocal stray light from the laser to the maximum extent, filtering the Rayleigh scattered light from the attenuated laser to achieve the peak value. The third lens 9 then focuses the circular slit 3. The Rayleigh scattered light at slit 3 is re-collimated and sent to the third reflecting mirror 6. The third reflecting mirror 6 adjusts the optical path direction and reflects the collimated Rayleigh scattered light to the rotating grating assembly inside the spectrometer. The control assembly detects the wavelength position of the Rayleigh scattering peak. If the grating is at the zero wavenumber position, the wavelength corresponding to the Rayleigh scattering peak should be consistent with the nominal wavelength of the laser, that is, the excitation wavelength (λ excitation) and the characteristic peak wavelength (λ characteristic peak) are equal. If a deviation is detected (such as λ excitation ≠ λ characteristic peak), the control assembly adjusts the grating angle to match the two, thereby calibrating the wavelength position deviation of laser 1 and calibrating the laser wavelength. Then, the control assembly calculates the wavelength using the wavenumber formula based on the calibrated laser wavelength. The wavenumber is recalculated to correct for the wavenumber. At this point, the characteristic peak wavelength in the formula is the measured λ.
[0067] It is understandable that, based on the zero-wavenumber characteristic of Rayleigh scattering, the relationship between wavelength and wavenumber can be established: The unit of wavelength is nm; when the grating is at the zero wavenumber position, That is, the excitation wavelength is equal to the characteristic peak wavelength; the control component detects the deviation between the excitation wavelength and the characteristic peak wavelength, and automatically drives the rotating grating component to rotate according to the deviation, adjusts the grating angle, corrects the wavelength position deviation of laser 1, and performs wavenumber conversion according to the corrected laser wavelength value to complete the wavenumber correction.
[0068] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.
Claims
1. A wavenumber correction device for a confocal micro Raman spectrometer, characterized in that, The correction device includes: Laser (1), used to emit laser light; A lens assembly, comprising a plurality of lenses, wherein the lens assembly is used to collimate and focus the laser; A reflector assembly includes multiple reflectors, with multiple lenses and multiple reflectors arranged alternately, and the reflector assembly is used to adjust the optical path direction of the laser. An attenuator (2) is disposed in the reflected light path within the reflector assembly, and the attenuator (2) is used to attenuate the energy of the laser. A slit (3) is provided at a confocal position within the lens assembly, and the slit (3) is used to filter Rayleigh scattered light in the attenuated laser. The mirror assembly reflects the Rayleigh scattered light onto the rotating grating assembly inside the spectrometer.
2. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 1, characterized in that, The reflector assembly includes at least a first reflector (4), a second reflector (5), and a third reflector (6); The first reflector (4) is not perpendicular to the emission direction of the laser (1), the second reflector (5) is not perpendicular to the reflected light path of the first reflector (4), and the third reflector (6) is not perpendicular to the reflected light path of the second reflector (5).
3. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 2, characterized in that, The first reflector (4) is set at a 45-degree angle to the emission direction of the laser (1), and the second reflector (5) is set at a 45-degree angle to the reflected light path of the first reflector (4).
4. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 2, characterized in that, The surfaces of the first reflector (4), the second reflector (5), and the third reflector (6) are all coated with a high-reflection film.
5. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 2, characterized in that, The attenuator (2) is disposed in the optical path between the first reflector (4) and the second reflector (5), and the attenuator (2) is perpendicular to the optical path.
6. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 1, characterized in that, The attenuator (2) is a 99.9% attenuator.
7. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 2, characterized in that, The lens assembly includes at least a first lens (7), a second lens (8), and a third lens (9); The first lens (7) is vertically disposed in the optical path between the laser (1) and the first reflector (4), and the second lens (8) and the third lens (9) are vertically disposed in the optical path between the second reflector (5) and the third reflector (6); Among them, the first lens (7), the second lens (8), and the third lens (9) are all aspherical lenses.
8. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 7, characterized in that, Both the first lens (7) and the third lens (9) are collimating lenses, and the second lens (8) is a focusing lens; The second lens (8) and the third lens (9) are confocal.
9. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 8, characterized in that, The slit (3) is located at the confocal point of the second lens (8) and the third lens (9); The slit (3) is a circular slit.
10. The wavenumber correction device for a confocal micro Raman spectrometer according to claim 1, characterized in that, The calibration device also includes a housing (10); The laser (1), lens assembly, mirror assembly, attenuator (2), and slit (3) are all installed inside the housing (10).