Large-view-field multi-focus shimming laser spectrometer based on view field modulation

Abstract

The invention discloses a large-view-field multi-focus shimming laser spectrometer based on view field modulation. The large-view-field multi-focus shimming laser spectrometer comprises a laser light path module, a lighting light path module, a large-view-field multi-focus shimming light path module, a controller and a display module. The large-view-field multi-focus shimming light path module comprises a view field modulation module which is used for modulating and splitting an incident laser beam into a plurality of sub-laser beams with different view fields, and modulating and integrating sub-spectrum light beams generated by excitation of the sub-laser beams into a total spectrum light beam with the same view field; the modulated sub laser beams are focused on the surface of a sample to form a multi-focus laser array; and the sub-spectral light beams excited by the focus laser arrays return along an incident light path and are converged into a total spectral light beam, so that multi-focus laser spectrum acquisition is realized. According to the invention, the problem of low sample representativeness caused by small spot of the traditional single-focus laser is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic detection technology, specifically relating to a large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation. Background Technology

[0002] Laser spectroscopy is a spectroscopic detection technique that uses laser light as a light source, encompassing typical methods such as laser Raman spectroscopy, laser fluorescence spectroscopy, and laser-induced breakdown spectroscopy (LIBS). Benefiting from the monochromaticity, directionality, and high brightness of lasers, this technique offers significant advantages in scientific research and engineering. Traditional methods focus the laser on a single point on the sample for spectral acquisition. While increasing laser energy or power density can enhance signal intensity, it suffers from two inherent drawbacks: ① Micrometer-scale spot size limitation, resulting in an excessively small focused area (typically on the micrometer scale), making it difficult to characterize large-sized or heterogeneous samples; ② Risk of thermal damage, as locally ultra-high power density can easily trigger thermal effects, leading to denaturation or damage to sensitive samples.

[0003] To address the aforementioned issues, existing technologies employ scanning moving platforms or multiple measurement strategies, but these significantly increase detection time. See also patent documents (CN202020154359.5, CN202010081839.8, CN201710104524.9, CN202310616284.6, CN201910576546.4), which achieve uniform excitation through microlens arrays, but still suffer from the following limitations: high manufacturing costs and stringent requirements for optical component processing precision; limited spatial bandwidth and insufficient field-of-view expansion capability; difficulty in calibrating multifocal confocal surfaces and poor optical path stability; loss of beam splitting coupling efficiency and reduced effective excitation energy; and high system complexity, making integrated applications difficult. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides an XXX method, apparatus, system, and storage medium.

[0005] To achieve the above objectives, the present invention provides the following solution: A large field-of-view multifocal shimming laser spectrometer based on field-of-view modulation includes a large field-of-view multifocal shimming optical path module and a controller; wherein, the large field-of-view multifocal shimming optical path module includes a field-of-view modulation module for modulating and splitting a laser beam into multiple sub-laser beams with different fields of view, the sub-laser beams acting on the sample surface through a focusing lens to form a multifocal laser array, and the spectral signal received by the controller is the sum of the spectra generated by the multifocal laser array.

[0006] Preferably, the field-of-view modulation module is composed of a combination of polyhedral transmission prisms or polyhedral reflection prisms, and the effective aperture of each prism is consistent.

[0007] Preferably, the sub-laser beams generated by the field-of-view modulation module exhibit angular offsets in their propagation directions in the meridional (XOZ) and sagittal (YOZ) planes relative to the original incident laser beam. 、 When the field-of-view modulation module uses a polyhedral reflecting prism, the angular offset satisfies the following conditions: =2· Δ x , =2· Δ y , where Δ x、 Δ y These are the modulation and reflection angles of the sub-laser beam in the meridional and sagittal planes, respectively.

[0008] Preferably, the large field-of-view multi-focus shimming optical path module further includes: a focusing mirror, used to focus the sub-laser beam to form... m × n ( m , n ≥2) Multifocal laser array, of which m and n It is determined by the prism parameters of the field modulation module.

[0009] Preferably, the focusing lens is a single lens, a cemented doublet lens, a plan lens, or an achromatic plan lens.

[0010] Preferably, it also includes: a laser optical path module; wherein, the laser optical path module includes: a laser, a beam expander, an aperture, and a reflector; The laser is a continuous laser or a pulsed laser, used to generate a laser beam for detection.

[0011] The beam expander is used to increase the diameter of the laser beam, the aperture is a rectangular or circular mechanical aperture, and the reflector is used to adjust the direction of the optical path; The laser optical path module ensures that the energy of each sub-laser beam is consistent after field-of-view modulation.

[0012] Preferably, the system also includes a light-collecting optical path module; wherein the signal acquisition optical path module includes a coupling beam splitter, a light-collecting focusing lens, an optical fiber, and a spectrometer. The coupling beam splitter is used to couple and separate the laser optical path module and the light-collecting optical path module. Its types include dichroic mirrors, perforated mirrors, ring-coated mirrors, or center-coated mirrors.

[0013] The light-collecting focusing lens is used to couple the total spectral beam to the optical fiber; The light-collecting focusing lens can be a single lens, a cemented doublet lens, a plan lens, or an achromatic plan lens. The optical fiber is used to transmit the total spectral beam and includes single-mode fiber, multimode fiber, single-core fiber or multi-core fiber. The spectrometer is used to receive the total spectral signal transmitted through the optical fiber and to perform spectral dispersion and detection.

[0014] Preferably, the controller issues a synchronization command to start the laser and set the delay acquisition parameters of the spectral analysis unit. The laser emitted by the laser is collimated and expanded by the beam expander, shaped by the aperture, and the optical path is adjusted by the reflector before finally being incident on the coupling beam splitter. After being transmitted / reflected by the coupling beam splitter, the laser beam enters the field-of-view modulation module, which modulates and splits the incident laser into multiple sub-laser beams with different fields of view. The sub-laser beams are focused on the sample surface by the focusing lens to form a multi-focal laser array. The sub-spectral signals excited by each sub-laser focus are collected by the focusing objective and returned along the same path. The returned sub-laser spectra are then integrated by the field-of-view modulation module into a total spectral beam with the same field of view. The total spectral beam is reflected / transmitted by the coupling beam splitter to the light-collecting focusing lens, converged, and collected into the optical fiber. The optical fiber transmits the spectral signal to the spectrometer for spectroscopic detection, and the detection data is transmitted to the controller for chemical composition and content analysis. The spectral signal received by the controller is the sum of the spectra generated by the multi-focal laser array.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a field-of-view modulation module for laser beam splitting and spectral integration modulation. This allows the laser beam to be modulated and split into multiple sub-laser beams with different fields of view. These sub-spectral beams can then be tuned and integrated into a single total laser spectral beam with the same field of view. Therefore, this invention expands the single-detection coverage to m×n times that of traditional methods, disperses laser energy to reduce sample damage risk, and fuses the total spectral data from multiple laser focal points, improving the representativeness and reliability of the test results. Attached Figure Description

[0016] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a schematic diagram of the overall structure of a large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to the present invention; Figure 2 is a schematic diagram of the overall structure of a large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to the present invention; Figure 3 is a schematic diagram of the field modulation module implemented by combining two sets of trihedral reflecting prisms; Figure 4 is a schematic diagram of the 3×3 focal matrix presented by the field modulation module using a combination of two sets of trihedral reflecting prisms or transmission prisms. Figure 5 is a schematic diagram of a 4×4 focal matrix presented by the field modulation module using a combination of two sets of tetrahedral reflecting prisms or transmission prisms. Figure 6 is a schematic diagram of a 4×3 focal matrix presented by the field modulation module using a combination of a tetrahedral and a trihedral reflecting prism or a transmitting prism. Figure 7 is a schematic diagram of a trihedral reflecting prism and its cross-section; Figure 8 shows a schematic diagram of a trihedral transmission prism and its cross-section.

[0018] Wherein, 101—laser; 102—beam expander; 103—aperture; 104—mirror; 105—laser optical path module; 106—coupled beam splitter; 107—field-of-view modulation module; 108—focusing lens; 109—sample; 110—large field-of-view multi-focal shimming optical path module; 111—display module; 112—controller; 113—light-collecting optical path module; 114—light-collecting focusing lens; 115—optical fiber; 116—spectrometer; 117—multifocal laser array; 118—first trihedral reflecting prism; 119—second trihedral reflecting prism. (Detailed implementation details follow.) The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 like Figure 1 As shown, this invention provides a large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation. It employs a back-facing laser spectroscopy detection method and is suitable for detecting laser Raman spectroscopy, laser-induced breakdown spectroscopy, and laser-induced fluorescence spectroscopy. By modulating and splitting the laser beam, multiple sub-laser beams with different fields of view are formed. These sub-beams act on the sample (109) surface to form a multifocal laser array (117), dispersing the laser energy to reduce the risk of sample damage, increasing the laser spectral coverage, and improving the representativeness and reliability of the test results.

[0021] like Figure 1 , 2As shown, this embodiment of the invention provides a large field-of-view multi-focus shimming laser spectrometer based on field-of-view modulation, including: a laser optical path module (105), a light-collecting optical path module (113), a large field-of-view multi-focus shimming optical path module (110), a controller (112), and a display module (111). The large field-of-view multi-focus shimming optical path module (110) incorporates a field-of-view modulation module (107), which can modulate and split the laser beam into multiple sub-laser beams with different fields of view. The sub-laser beams act on the surface of the sample (109) through a focusing lens (108) to form a multi-focus laser array (117). The spectral signal received by the controller (112) is the sum of the spectra generated by the multi-focus laser array (117), thereby improving the laser spectral detection coverage and the representativeness and reliability of the test results.

[0022] The large field-of-view multi-focus uniform optical path module (110) includes a field-of-view modulation module (107) for modulating and splitting the incident laser beam into multiple sub-laser beams with different fields of view. The field-of-view modulation module (107) is used to integrate the sub-spectral beams excited by the multi-focus laser array (117) into a total spectral beam with the same field of view. The sub-laser beam is focused and acts on the surface of the sample (109) to form a multi-focus laser array (117). The field-of-view modulation module (107) is composed of a combination of polyhedral transmission prisms or polyhedral reflection prisms, and the effective aperture of each prism is... ∆d Maintain consistency, such as Figure 7 , Figure 8 As shown, .

[0023] like Figure 3 As shown, a field-of-view modulation module, using a combination of two sets of trihedral reflecting prisms, forms a 3×3 multifocal laser array (117) on the surface of the sample (109). The multifocal laser array (117) is as follows: Figure 4 As shown; The sub-laser beams generated by the field-of-view modulation module (107) have angular offsets in their propagation directions in the meridional plane (XOZ) and sagittal plane (YOZ) relative to the original incident laser beam. 、 ).

[0024] When the field-of-view modulation module (107) uses a polyhedral reflecting prism, the angular offset satisfies: =2· Δ x , =2· Δ y , where Δ x、 Δ yThese are the modulation and reflection angles of the sub-laser beam in the meridional and sagittal planes, respectively.

[0025] The large field-of-view multi-focus uniform optical path module (110) also includes a focusing lens (108) for focusing the sub-laser beam to form a focal length. m × n ( m , n ≥2) Multifocal laser array (117), where m and n It is determined by the prism parameters of the field modulation module.

[0026] The focusing lens (108) has a focal length of f Single lens, cemented doublet lens, plan lens or achromatic plan lens.

[0027] The distance between any sub-laser focusing spot and the center of the matrix in the multi-focus laser array (117) ,like Figure 4 , Figure 5 , Figure 6 .

[0028] The laser optical path module (105) includes a laser, a beam expander, an aperture, and a reflector; The laser (101) is a continuous laser or a pulsed laser, used to generate a laser beam for detection.

[0029] The beam expander (102) is used to expand the diameter of the laser beam, the aperture (103) is a rectangular or circular mechanical hole, and the reflector (104) is used to adjust the direction of the optical path; The laser optical path module (105) ensures that the energy of each sub-laser beam is consistent after field-of-view modulation.

[0030] The light-collecting optical path module (113) includes a coupling beam splitter (106), a light-collecting focusing lens (114), an optical fiber (115), and a spectrometer (116). The coupling beam splitter (106) is used to couple and separate the laser optical path module (105) and the light-collecting optical path module (113), and its type includes dichroic mirror, perforated mirror, ring-coated mirror or center-coated mirror.

[0031] The coupling beam splitter (106) can transmit spectral reflected laser light, such as Figure 1 As shown; The coupling beam splitter (106) can transmit the laser reflection spectrum, such as Figure 2 As shown; The light-collecting focusing lens (114) is used to couple the total spectral beam to the optical fiber; The light-collecting focusing lens (114) can be a single lens, a cemented doublet lens, a plan lens, or an achromatic plan lens; The optical fiber (115) is used to transmit the total spectral beam and includes single-mode fiber, multimode fiber, single-core fiber or multi-core fiber. The spectrometer (116) is used to receive the total spectral signal transmitted by optical fiber and to perform spectral dispersion and detection.

[0032] The controller (112) and display module (111) include: a collaborative control program, a multi-channel interface, and a user command interaction unit; The collaborative control program is used to control the laser switching, spectral acquisition, and data display; The multi-channel interface is used to power the laser and spectrometer, and to receive and analyze their output signals. The user command interaction unit is used to provide feedback on test data and charts.

[0033] The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation of this invention operates according to the following steps: The controller issues a synchronization command to start the laser and set the delay acquisition parameters for the spectral analysis unit. The laser beam emitted by the laser is sequentially collimated and expanded by the beam expander, shaped by the aperture, and its optical path direction adjusted by the reflector before finally being incident on the coupling beam splitter. After transmission / reflection by the coupling beam splitter, the laser beam enters the field-of-view modulation module, which modulates and splits the incident laser into multiple sub-laser beams with different fields of view. The sub-laser beams are focused onto the sample surface by the focusing lens, forming a multi-focal laser array. The sub-spectral signals excited by each sub-laser focus are collected by the focusing objective and returned along the same path. The returned sub-laser spectra are then integrated again by the field-of-view modulation module into a total spectral beam with the same field of view. The total spectral beam is reflected / transmitted by the coupling beam splitter to the light-collecting focusing lens, where it is converged and collected into the optical fiber. The optical fiber transmits the spectral signals to the spectrometer for spectroscopic detection, and the detection data is transmitted to the controller for chemical composition and content analysis.

[0034] The spectral signal received by the controller is the sum of the spectra generated by the multi-focus laser array, thereby improving the coverage of laser spectral detection and the representativeness and reliability of the test results.

[0035] This invention introduces a field-of-view modulation module into the laser optical path, modulating the laser field and splitting it into multiple sub-laser beams with different fields of view. These sub-beams are then focused to form a spatially controllable multi-focus uniform field laser array. This design simultaneously achieves: ① increasing the excitation range and expanding the laser coverage area compared to a traditional single point. m × n times ( m , n≥2); ② Suppress thermal damage, disperse laser energy density, and avoid local thermal enrichment; ③ Improve data representativeness, simultaneously acquire spectral information of multi-focus uniform laser array, and enhance the reliability and representativeness of heterogeneous sample analysis.

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation, characterized in that, It includes a large field-of-view multi-focus shimming optical path module and a controller; wherein, the large field-of-view multi-focus shimming optical path module includes a field-of-view modulation module, which is used to modulate and split the laser beam into multiple sub-laser beams with different fields of view. The sub-laser beams act on the sample surface through a focusing lens to form a multi-focus laser array. The spectral signal received by the controller is the sum of the spectra generated by the multi-focus laser array.

2. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 1, characterized in that, The field-of-view modulation module is composed of a combination of polyhedral transmission prisms or polyhedral reflection prisms, and the effective aperture of each prism is consistent.

3. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 2, characterized in that, The sub-laser beams generated by the field-of-view modulation module exhibit angular offsets in their propagation directions in the meridional (XOZ) and sagittal (YOZ) planes relative to the original incident laser. 、 When the field-of-view modulation module uses a polyhedral reflecting prism, the angular offset satisfies the following conditions: =2· Δ x , =2· Δ y , where Δ x、 Δ y These are the modulation and reflection angles of the sub-laser beam in the meridional and sagittal planes, respectively.

4. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 3, characterized in that, The large field-of-view multi-focus shimming optical path module also includes a focusing mirror for focusing the sub-laser beam to form a focal length. m × n ( m , n ≥2) Multifocal laser array, of which m and n It is determined by the prism parameters of the field modulation module.

5. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 4, characterized in that, The focusing lens is a single lens, a cemented doublet lens, a plan lens, or an achromatic plan lens.

6. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 5, characterized in that, Also includes: A laser optical path module; wherein the laser optical path module includes: a laser, a beam expander, an aperture, and a reflector; The laser is a continuous laser or a pulsed laser, used to generate a laser beam for detection; The beam expander is used to increase the diameter of the laser beam, the aperture is a rectangular or circular mechanical aperture, and the reflector is used to adjust the direction of the optical path; The laser optical path module ensures that the energy of each sub-laser beam is consistent after field-of-view modulation.

7. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 7, characterized in that, Also includes: A light-collecting optical path module; wherein, the signal acquisition optical path module includes: a coupling beam splitter, a light-collecting focusing lens, an optical fiber, and a spectrometer; The coupling beam splitter is used to couple and separate the laser optical path module and the light-collecting optical path module. Its types include dichroic mirrors, perforated mirrors, ring-coated mirrors, or center-coated mirrors. The light-collecting focusing lens is used to couple the total spectral beam to the optical fiber; The light-collecting focusing lens can be a single lens, a cemented doublet lens, a plan lens, or an achromatic plan lens. The optical fiber is used to transmit the total spectral beam and includes single-mode fiber, multimode fiber, single-core fiber or multi-core fiber. The spectrometer is used to receive the total spectral signal transmitted through the optical fiber and to perform spectral dispersion and detection.

8. The large field-of-view multifocal uniform laser spectrometer based on field-of-view modulation according to claim 7, characterized in that, The controller issues a synchronization command to start the laser and set the delay acquisition parameters for the spectral analysis unit. The laser emitted by the laser is collimated and expanded by the beam expander, shaped by the aperture, and its optical path is adjusted by the reflector before finally being incident on the coupling beam splitter. After being transmitted / reflected by the coupling beam splitter, the laser beam enters the field-of-view modulation module, which modulates and splits the incident laser into multiple sub-laser beams with different fields of view. The sub-laser beams are focused onto the sample surface by the focusing lens to form a multi-focal laser array. The sub-spectral signals excited by each sub-laser focus are collected by the focusing objective and returned along the same path. The returned sub-laser spectra are then integrated by the field-of-view modulation module into a total spectral beam with the same field of view. The total spectral beam is reflected / transmitted by the coupling beam splitter to the light-collecting focusing lens, converged, and collected into the optical fiber. The optical fiber transmits the spectral signal to the spectrometer for spectroscopic detection, and the detection data is transmitted to the controller for chemical composition and content analysis. The spectral signal received by the controller is the sum of the spectra generated by the multi-focal laser array.

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