Switching type dual-wavelength Raman test probe

Abstract

The utility model belongs to the technical field of test equipment, and particularly relates to a switching type dual-wavelength Raman test probe, which comprises a shell, a coaxial excitation light path, a coaxial receiving light path and a limiting sliding component are arranged in the shell, one end of the shell is connected with a tube lens, the coaxial excitation light path comprises a first excitation light path and a second excitation light path which are coaxial, and the tube lens is connected with the tube lens. The coaxial receiving light path comprises a first receiving light path and a second receiving light path which are coaxial, the first exciting light path and the second exciting light path are switched through a limiting sliding assembly, and the first receiving light path and the second receiving light path are switched through the limiting sliding assembly. The optical path structure of the existing dual-wavelength Raman probe is simplified, dual-wavelength coaxial optical path switching type measurement is realized, the spatial layout of the probe is more compact, fewer optical devices are used, the detection efficiency is improved, the hardware cost is reduced, the economic benefit of the application field is favorably improved, and the dual-wavelength Raman probe has a wider application scene.

Description

Technical Field

[0001] This utility model belongs to the technical field of testing equipment, and in particular relates to a switching dual-wavelength Raman test probe. Background Technology

[0002] For Raman spectroscopy, the choice of excitation wavelength is a crucial factor. Raman signal intensity is inversely proportional to the fourth power of the excitation wavelength. At the same unit power, the Raman signal intensity obtained by 532nm laser excitation is 5 times that of 785nm and 16 times that of 1064nm. Using shorter wavelength excitation light can achieve higher Raman intensity. However, when 532nm laser excitation is applied to samples exhibiting fluorescence, the resulting high-intensity fluorescence can mask the Raman signal to some extent, affecting the detection results. To avoid this high-intensity fluorescence effect, 785nm or 1064nm are commonly used as excitation wavelengths to reduce background fluorescence and maintain a relatively high Raman intensity. Therefore, for different applications, it may be necessary to consider either high Raman scattering intensity or high fluorescence suppression, i.e., using different excitation wavelengths for Raman testing.

[0003] As research into the application of Raman detection technology continues to deepen, traditional single-wavelength Raman detection methods have limitations in practical applications, especially in mobile and in-situ detection fields that differ from traditional laboratory testing. Portable Raman devices that can provide multi-wavelength detection have enormous application potential and commercial value.

[0004] A dual-wavelength Raman test probe with patent number CN202011594176.6 includes four optical paths in its short-wavelength excitation circuit and long-wavelength excitation circuit. In the short-wavelength excitation circuit, the short wave enters from the first optical path, passes through the first narrow-linewidth filter (1), is reflected by the first laser reflector (5) to the third dichroic mirror (9), and is then reflected onto the object under test (10). The returning excitation light passes through the third dichroic mirror (9), strikes the second dichroic mirror (8), is reflected by the first dichroic mirror (7), and is then reflected by the third narrow-linewidth filter (3). Linewidth filter (3) exits from the third row of light wave path; long-wave excitation circuit: long waves enter from the second row of light wave path, pass through the second narrow linewidth filter (2), are reflected by the second laser reflector (6) to the first dichroic mirror (7), pass through the first dichroic mirror (7), are directly incident on the second dichroic mirror (8), are reflected to the third dichroic mirror (9), pass through the third dichroic mirror (9) and are incident on the object to be tested (10), the returning excitation light passes through the third dichroic mirror (9), is incident on the second dichroic mirror (8), passes through the second dichroic mirror (8) and exits from the fourth row of light wave path.

[0005] The aforementioned patent has the following defects:

[0006] 1. The probe has a large number of optical path channels, a complex structure, and uses a large number of lenses and dichroic mirrors. It also requires adjustment of a large number of optical components, making it difficult to manufacture and debug.

[0007] 2. When light signals pass through multiple lenses and dichroic mirrors, some light energy is lost, reducing light intensity;

[0008] 3. It uses a large number of optical components and their supporting devices, resulting in high manufacturing costs;

[0009] 4. The overall width and volume of this probe are twice that of a regular probe, which is not conducive to portable Raman testing. Summary of the Invention

[0010] In view of the above-mentioned problems in the prior art, this application provides a switching dual-wavelength Raman test probe that can achieve coaxial optical path switching measurement of dual wavelengths while having a more compact probe spatial layout.

[0011] To achieve the above-mentioned technical effects, the technical content of the present invention is as follows:

[0012] A switchable dual-wavelength Raman test probe includes a housing, within which are a coaxial excitation optical path, a coaxial receiving optical path, and a limiting sliding assembly. A tube lens is connected to one end of the housing. The coaxial excitation optical path includes a first coaxial excitation optical path and a second coaxial excitation optical path. The coaxial receiving optical path includes a first coaxial receiving optical path and a second coaxial receiving optical path. The first excitation optical path and the second excitation optical path are switched between each other via the limiting sliding assembly. The first receiving optical path and the second receiving optical path are also switched between each other via the limiting sliding assembly.

[0013] Furthermore, the coaxial excitation optical path and the coaxial receiving optical path have a double-layer structure, with the upper layer being the coaxial excitation optical path and the lower layer being the coaxial receiving optical path; or the upper layer being the coaxial receiving optical path and the lower layer being the coaxial excitation optical path.

[0014] Optionally, the coaxial excitation optical path and the coaxial receiving optical path are arranged in two parallel rows, with the left row being the coaxial excitation optical path and the right row being the coaxial receiving optical path.

[0015] Furthermore, the coaxial excitation optical path includes a first narrowband filter, a second narrowband filter, a first dichroic mirror, a second dichroic mirror, a reflecting mirror, and a collimating mirror, wherein the collimating mirror, the first narrowband filter, the reflecting mirror, and the first dichroic mirror are arranged in sequence to form the first excitation optical path; the collimating mirror, the second narrowband filter, the reflecting mirror, and the second dichroic mirror are arranged in sequence to form the second excitation optical path.

[0016] Further, the coaxial receiving optical path includes a first long-pass filter, a second long-pass filter, a first dichroic mirror, a second dichroic mirror, and a fiber optic coupler, wherein the fiber optic coupler, the first long-pass filter, and the first dichroic mirror are arranged in sequence to form the first receiving optical path; wherein the fiber optic coupler, the second long-pass filter, and the second dichroic mirror are arranged in sequence to form the second receiving optical path.

[0017] Receive optical path.

[0018] Furthermore, the limiting sliding assembly includes a first limiting sliding assembly and a second limiting sliding assembly. The first limiting sliding assembly switches between the first excitation optical path and the second excitation optical path, and the second limiting sliding assembly switches between the first receiving optical path and the second receiving optical path.

[0019] Furthermore, the first limiting sliding assembly includes a first slider, a first slider guide rail, a first switching button, and a first slider limiting group. The first slider includes a base and two bases fixed side by side on the base. The base is connected to the first slider guide rail and moves along the first slider guide rail. A first narrowband filter and a second narrowband filter are respectively fixedly installed on the two bases. The first slider limiting group includes a first limiting structure and a second limiting structure. The first switching button is fixedly connected to the first slider.

[0020] Furthermore, the second limiting sliding assembly includes a second slider, a second slider guide rail, a second switching button, and a second slider limiting group. The second slider includes a base and four bases fixed on the base in a square distribution. The base is connected to the second slider guide rail and can move along the second slider guide rail. A first long-pass filter and a second long-pass filter are fixedly installed in two bases in the row near the probe, respectively. A first dichroic mirror and a second dichroic mirror are fixedly installed in two bases in the row far from the probe, respectively. The second slider limiting group includes a third limiting structure and a fourth limiting structure. The second switching button is fixedly connected to the second slider.

[0021] Furthermore, the tube lens includes a metal tube and a focusing lens, with the near end of the metal tube connected to the light outlet of the housing and the far end of the metal tube fixed to the focusing lens.

[0022] Furthermore, the reflector, the first dichroic mirror, and the second dichroic mirror are all installed and fixed at 45° to the incident light, while the collimating lens, the first long-pass filter, the second long-pass filter, the focusing lens, and the fiber optic coupler are all installed and fixed at 90° to the incident light.

[0023] The advantages of this application are:

[0024] 1. This utility model simplifies the optical path structure of existing dual-wavelength Raman probes, realizes coaxial optical path switching measurement of dual wavelengths, makes the probe spatial layout more compact, uses fewer optical components, improves detection efficiency, reduces hardware costs, and is conducive to improving the economic benefits of its application fields, and has a wider range of application scenarios.

[0025] 2. In this application, both the coaxial excitation optical path and the coaxial receiving optical path of the dual wavelengths are used to achieve dual-wavelength coaxial optical path switching Raman testing by switching optical elements with mechanical structure.

[0026] 3. The coaxial optical path design in this application simplifies the overall optical system, reduces the difficulty of processing technology, reduces assembly steps, and more importantly, reduces the number of optical components used, thereby reducing hardware costs and improving testing efficiency.

[0027] 4. The probe layout design of this application is relatively reasonable, making the spatial structure compact and more suitable for the application of portable Raman probes. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the dual-wavelength Raman test probe of this utility model.

[0029] Figure 2 This is a front view of the dual-wavelength Raman test probe of this utility model.

[0030] Figure 3 This is a top view of the first excitation optical path of the dual-wavelength Raman test probe of this utility model, showing only the upper structure.

[0031] Figure 4 This is a top view of the first receiving optical path of the dual-wavelength Raman test probe of this utility model, showing only the lower structure.

[0032] Figure 5 This is a top view of the second excitation optical path of the dual-wavelength Raman test probe of this utility model, showing only the upper structure.

[0033] Figure 6 This is a bottom view of the second receiving optical path of the dual-wavelength Raman test probe of this utility model, showing only the lower structure.

[0034] Figure 7 This is a schematic diagram of the first limiting sliding component of the dual-wavelength Raman test probe of this utility model.

[0035] Figure 8 This is a schematic diagram of the second limiting sliding component of the dual-wavelength Raman test probe of this utility model.

[0036] In the attached image:

[0037] 1-First narrowband filter, 2-Second narrowband filter, 3-Reflector, 4-Collimating lens, 5-First limiting sliding assembly, 6-First dichroic mirror, 7-Second dichroic mirror, 8-First long-pass filter, 9-Second long-pass filter, 10-Focusing lens, 11-Fiber optic coupler, 12-Second limiting sliding assembly, 13-First slider, 14-First slider guide rail, 15-First switching button, 16-First limiting structure, 17-Second limiting structure, 13'-Second slider, 14'-Second slider guide rail, 15'-Second switching button, 16'-Third limiting structure, 17'-Fourth limiting structure. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of this application, it should be noted that the terms "upper," "vertical," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] Example 1

[0044] like Figure 1 As shown, a switchable dual-wavelength Raman test probe is disclosed. This Raman probe has a coaxial optical path switching structure, which enables dual-wavelength Raman testing by switching the optical path. The Raman probe includes a housing, within which there are a coaxial excitation optical path, a coaxial receiving optical path, and a limiting sliding assembly. A tube lens is connected to one end of the housing.

[0045] The coaxial excitation optical path includes a first excitation optical path and a second excitation optical path, and the coaxial receiving optical path includes a first receiving optical path and a second receiving optical path. The first excitation optical path and the second excitation optical path are switched by a limiting sliding component, and the first receiving optical path and the second receiving optical path are switched by a limiting sliding component.

[0046] A coaxial optical path refers to a path where light rays propagate along the same axis. In this patent, the first excitation optical path and the second excitation optical path are coaxial, sharing the same optical path channel, and both light rays propagate along the same optical axis. This differs from patent CN202011594176.6, where the first and second excitation optical paths are two independent and different optical paths. Similarly, in this patent, the first receiving optical path and the second receiving optical path are also coaxial.

[0047] The coaxial excitation optical path and coaxial receiving optical path have a two-layer structure, with the upper layer being the coaxial excitation optical path and the lower layer being the coaxial receiving optical path; or the upper layer being the coaxial receiving optical path and the lower layer being the coaxial excitation optical path. This vertical relationship can be adapted by changing the installation angle of the reflector 3. The accompanying drawings of this application show a two-layer structure design with the coaxial excitation optical path on the upper layer and the coaxial receiving optical path on the lower layer. Alternatively, it can also be a two-layer structure with the coaxial excitation optical path on the lower layer and the coaxial receiving optical path on the upper layer.

[0048] This invention simplifies the optical path structure of existing dual-wavelength Raman probes, enabling coaxial optical path switching measurement of dual wavelengths. This results in a more compact probe spatial layout, the use of fewer optical components, improved detection efficiency, and reduced hardware costs. It also enhances the economic benefits of its application fields and has a wider range of application scenarios.

[0049] Example 2

[0050] A switchable dual-wavelength Raman test probe is disclosed. This Raman probe features a coaxial optical path switching structure, enabling dual-wavelength Raman testing by switching the optical path. The Raman probe includes a housing containing a coaxial excitation optical path, a coaxial receiving optical path, and a limiting sliding assembly. A tube lens is connected to one end of the housing.

[0051] The coaxial excitation optical path includes a first excitation optical path and a second excitation optical path, and the coaxial receiving optical path includes a first receiving optical path and a second receiving optical path. The first excitation optical path and the second excitation optical path are switched by a limiting sliding component, and the first receiving optical path and the second receiving optical path are switched by a limiting sliding component.

[0052] A coaxial optical path refers to a path where light rays propagate along the same axis. In this patent, the first excitation optical path and the second excitation optical path are coaxial, sharing the same optical path channel, and both light rays propagate along the same optical axis. This differs from patent CN202011594176.6, where the first and second excitation optical paths are two independent and different optical paths. Similarly, in this patent, the first receiving optical path and the second receiving optical path are also coaxial.

[0053] The coaxial excitation optical path and the coaxial receiving optical path are arranged in two parallel rows, with the left row being the coaxial excitation optical path and the right row being the coaxial receiving optical path. Those skilled in the art can adapt the left-right relationship by changing the installation angle of the reflector 3; however, a specific left-right arrangement is not shown in this application.

[0054] Example 3

[0055] like Figure 1 As shown, a switchable dual-wavelength Raman test probe is disclosed. This Raman probe has a coaxial optical path switching structure, which enables dual-wavelength Raman testing by switching the optical path. The Raman probe includes a housing, within which there are a coaxial excitation optical path, a coaxial receiving optical path, and a limiting sliding assembly. A tube lens is connected to one end of the housing.

[0056] The coaxial excitation optical path includes a first excitation optical path and a second excitation optical path, and the coaxial receiving optical path includes a first receiving optical path and a second receiving optical path. The first excitation optical path and the second excitation optical path are switched by a limiting sliding component, and the first receiving optical path and the second receiving optical path are switched by a limiting sliding component.

[0057] A coaxial optical path refers to a path where light rays propagate along the same axis. In this patent, the first excitation optical path and the second excitation optical path are coaxial, sharing the same optical path channel, and both light rays propagate along the same optical axis. This differs from patent CN202011594176.6, where the first and second excitation optical paths are two independent and different optical paths. Similarly, in this patent, the first receiving optical path and the second receiving optical path are also coaxial.

[0058] Furthermore, the coaxial excitation optical path and the coaxial receiving optical path have a double-layer structure, with the upper layer being the coaxial excitation optical path and the lower layer being the coaxial receiving optical path; or the upper layer being the coaxial receiving optical path and the lower layer being the coaxial excitation optical path. The accompanying drawings of this application show a top-bottom structure design where the coaxial excitation optical path is on the upper layer and the coaxial receiving optical path is located in the lower two layers.

[0059] Alternatively, the coaxial excitation optical path and the coaxial receiving optical path can be arranged in two parallel rows, with the left row being the coaxial excitation optical path and the right row being the coaxial receiving optical path. Those skilled in the art can adapt the coaxial excitation optical path and the coaxial receiving optical path to be either vertical or horizontal by changing the installation angle of the reflector 3. In this application, the illustration of the coaxial excitation optical path and the coaxial receiving optical path being horizontal is not shown.

[0060] The coaxial excitation optical path includes a first narrowband filter 1, a second narrowband filter 2, a first dichroic mirror 6, a second dichroic mirror 7, a reflecting mirror 3, and a collimating mirror 4. The collimating mirror 4, the first narrowband filter 1, the reflecting mirror 3, and the first dichroic mirror 6 are arranged in sequence to form the first excitation optical path; the collimating mirror 4, the second narrowband filter 2, the reflecting mirror 3, and the second dichroic mirror 7 are arranged in sequence to form the second excitation optical path.

[0061] The coaxial receiving optical path includes a first long-pass filter 8, a second long-pass filter 9, a first dichroic mirror 6, a second dichroic mirror 7, and an optical fiber coupler 11. The optical fiber coupler 11, the first long-pass filter 8, and the first dichroic mirror 6 are arranged in sequence to form the first receiving optical path; the optical fiber coupler 11, the second long-pass filter 9, and the second dichroic mirror 7 are arranged in sequence to form the second receiving optical path.

[0062] The limiting sliding assembly includes a first limiting sliding assembly 5 and a second limiting sliding assembly 12. The first limiting sliding assembly 5 switches between the first excitation optical path and the second excitation optical path, and the second limiting sliding assembly 12 switches between the first receiving optical path and the second receiving optical path.

[0063] The first limiting sliding assembly 5 includes a first slider 13, a first slider guide rail 14, a first switching button 15, and a first slider limiting group. The first slider 13 includes a base and two bases fixed side by side on the base. The base is connected to the first slider guide rail 14 and moves along the first slider guide rail 14. The two bases are respectively fixedly installed with a first narrowband filter 1 and a second narrowband filter 2. The first slider limiting group includes a first limiting structure 16 and a second limiting structure 17. The first switching button 15 is fixedly connected to the first slider 13. Pushing the first switching button 15 will move the first slider 13 along the first slider guide rail 14 until the first switching button 15 reaches the first limiting structure 16 or the second limiting structure 17, thereby realizing the switching measurement of the first narrowband filter 1 and the second narrowband filter 2.

[0064] The second limiting sliding assembly 12 includes a second slider 13', a second slider guide rail 14', a second switching button 15', and a second slider limiting group. The second slider 13' includes a base and four bases fixed on the base in a square distribution. The base is connected to the second slider guide rail 14' and can move along the second slider guide rail 14'. A first long-pass filter 8 and a second long-pass filter 9 are fixedly installed in the two bases in the row near the probe, respectively. A first dichroic mirror 6 and a second dichroic mirror 7 are fixedly installed in the two bases in the row far from the probe, respectively. The second slider limiting group includes a third limiting structure 16' and a fourth limiting structure 17'. The second switching button 15' is fixedly connected to the second slider 13'. Pushing the second switching button 15' will move the second slider 13' on the second slider guide rail 14' until the second switching button 15' reaches the third limit structure 16' or the fourth limit structure 17', thereby realizing the switching measurement between the first long-pass filter 8 and the first dichroic mirror 6, and the second long-pass filter 9 and the second dichroic mirror 7.

[0065] Specifically, when the first switching button 15 reaches the first limiting structure 16 and the second switching button 15' reaches the third limiting structure 16', the first narrowband filter 1 is aligned with the collimating lens 4 and the reflecting mirror 3, and forms a first excitation optical path with the first dichroic mirror 6; the first long-pass filter 8, the first dichroic mirror 6, and the fiber optic coupler 11 are aligned to form a first receiving optical path. When the first switching button 15 reaches the second limiting structure 17 and the second switching button 15' reaches the fourth limiting structure 17', the second narrowband filter 2 is aligned with the collimating lens 4 and the reflecting mirror 3, and forms a second excitation optical path with the second dichroic mirror 7; the second long-pass filter 9, the second dichroic mirror 7, and the fiber optic coupler 11 are aligned to form a second receiving optical path.

[0066] The tube lens includes a metal tube and a focusing lens 10. The near end of the metal tube is connected to the light outlet of the housing via a threaded structure, and the far end of the metal tube is detachably fixed with the focusing lens 10 for laser excitation and Raman light collection. In this embodiment, the tube lens consists of a metal tube and a focusing lens 10 installed at the tail end of the metal tube. Both laser excitation and Raman light collection are performed through the tube lens; that is, the tube lens is the excitation light emission end of the excitation light path and also the Raman light entry end of the receiving light path.

[0067] The reflector 3, the first dichroic mirror 6, and the second dichroic mirror 7 are all installed and fixed at 45° to the incident light. The collimating mirror 4, the first long-pass filter 8, the second long-pass filter 9, the focusing lens 10, and the fiber optic coupler 11 are all installed and fixed at 90° to the incident light.

[0068] Example 4

[0069] A switching dual-wavelength Raman test probe is provided. The structure of the Raman test probe is the same as that of the Raman test probe described in any of the embodiments 1-3, and will not be described again here.

[0070] Furthermore, the collimating lens 4 is used in the beam transmission system to shape the beam passing through the collimating lens 4 in order to maintain the collimation of the beam transmission.

[0071] The first narrowband filter 1 and the second narrowband filter 2 can precisely select light signals of a specific wavelength band to pass through, while light signals on both sides that deviate from this wavelength band are blocked, thereby improving the monochromaticity and stability of the light beam.

[0072] The first long-pass filter 8 and the second long-pass filter 9 allow light with wavelengths greater than a certain specific wavelength to pass through, while light with wavelengths less than that wavelength is blocked. They are mainly used to filter out short-wavelength background light.

[0073] The reflector 3 is a silver-plated reflector 3, which is made by vacuum depositing a thin film of metallic silver. The working wavelength range is 400nm-2000nm, and the reflectivity reaches more than 96%. By using the law of light reflection, the incident angle and reflection angle are controlled to change the propagation direction of the light beam and guide the light to the desired position.

[0074] The main function of the first dichroic mirror 6 and the second dichroic mirror 7 is to reflect light with a wavelength shorter than a certain specific wavelength and transmit light with a wavelength longer than that specific wavelength.

[0075] The focusing lens 10 focuses the incident laser beam passing through it along the axis into a spot with a diameter of 5-10 μm. After the laser interacts with the object under test, the focusing lens 10 simultaneously collects the Raman scattered light signal and enters the receiving optical path of the probe.

[0076] The fiber optic coupler 11 focuses and couples the Raman light passing through the long-pass filter into the receiving fiber with a coupling efficiency of not less than 80%. The Raman light is then transmitted through the receiving fiber into the Raman spectrometer.

[0077] Example 5

[0078] A switching dual-wavelength Raman test probe is provided. The structure of the Raman test probe is the same as that of the Raman test probe described in any of the embodiments 1-4, and will not be described again here.

[0079] Furthermore, the first narrowband filter 1 is a 532nm narrowband filter, and the second narrowband filter 2 is a 785nm narrowband filter; the first dichroic mirror 6 is a 532nm dichroic mirror, and the second dichroic mirror 7 is a 785nm dichroic mirror; the first long-pass filter 8 is a 532nm long-pass filter, and the second long-pass filter 9 is a 785nm long-pass filter.

[0080] The working principle of the Raman test probe of this patent is explained using the first excitation wavelength of 532nm and the second excitation wavelength of 785nm as examples.

[0081] The 532nm excitation optical path and the 532nm receiving optical path are as follows: Figure 4 , Figure 5 As shown, a 532nm laser beam is transmitted into the probe via an incident fiber. The divergent laser beam is shaped by a collimating lens 4 to form a collimated beam before being directed towards a narrowband filter 1. Passing through the narrowband filter 1 effectively reduces stray light and improves the monochromaticity of the excitation light. After passing through the narrowband filter 1, the beam is directed towards a reflecting mirror 3, which changes the beam's transmission direction, directing it towards a first dichroic mirror 6. Due to the dichroic mirror principle, the first dichroic mirror 6 transmits light with wavelengths greater than 532nm and reflects light with wavelengths less than 532nm. The 532nm laser beam is almost completely reflected at the first dichroic mirror 6 and directed towards a focusing lens 10. The 532nm laser beam is focused onto the object under test, where Raman and Rayleigh scattering occur. The focusing lens 10 collects the scattered light, which then enters the probe and is directed towards the first dichroic mirror 6. Only light with wavelengths greater than 532nm can almost completely pass through the first dichroic mirror 6; light with wavelengths less than 532nm is reflected. The transmitted light is directed to the first long-pass filter 8, which filters out the background light with a wavelength not greater than 532nm. The light is then focused and coupled into the outgoing optical fiber by the fiber optic coupler 11.

[0082] The 785nm excitation optical path and the 785nm receiving optical path are as follows: Figure 6 , Figure 7 As shown, a 785nm laser beam is transmitted into the probe via an incident fiber. The divergent laser beam is shaped by a collimating lens 4 to form a collimated beam before being directed towards a narrowband filter 2. Passing through the narrowband filter 2 effectively reduces stray light and improves the monochromaticity of the excitation light. After passing through the narrowband filter 2, the beam is directed towards a reflecting mirror 3, which changes the beam's transmission direction, directing it towards a second dichroic mirror 7. Due to the dichroic mirror principle, the second dichroic mirror 7 transmits light with wavelengths greater than 785nm and reflects light with wavelengths less than 785nm. The 785nm laser beam is almost completely reflected at the second dichroic mirror 7 and directed towards a focusing lens 10. The 785nm laser beam is focused onto the object under test, undergoing Raman and Rayleigh scattering. The focusing lens 10 collects the scattered light, which then enters the probe and is directed towards the second dichroic mirror 7. Only light with wavelengths greater than 785nm can almost completely pass through the second dichroic mirror 7; light with wavelengths less than 785nm is reflected. The transmitted light is directed to the second long-pass filter 9, which filters out the background light with a wavelength not greater than 785nm again. The light is then focused and coupled into the outgoing optical fiber by the fiber optic coupler 11.

[0083] The excitation optical paths for 532nm and 785nm are designed as coaxial excitation optical paths. The first narrowband filter 1 and the second narrowband filter 2 are switched by the first limiting sliding component 5 to form the 532nm excitation optical path and the 785nm excitation optical path, respectively.

[0084] The 532nm and 785nm receiving optical paths are designed as coaxial receiving optical paths. The combination of the first dichroic mirror 6 and the first long-pass filter 8, and the combination of the second dichroic mirror 7 and the second long-pass filter 9 are controlled by the second limiting sliding component 12 to form the 532nm receiving optical path and the 785nm receiving optical path, respectively.

Claims

1. A switching dual-wavelength Raman test probe, comprising a housing, characterized in that: The housing contains a coaxial excitation optical path, a coaxial receiving optical path, and a limiting sliding assembly. One end of the housing is connected to a tube lens. The coaxial excitation optical path includes a coaxial first excitation optical path and a coaxial second excitation optical path. The coaxial receiving optical path includes a coaxial first receiving optical path and a coaxial second receiving optical path. The first excitation optical path and the second excitation optical path are switched between each other through the limiting sliding assembly. The first receiving optical path and the second receiving optical path are also switched between each other through the limiting sliding assembly.

2. The switching dual-wavelength Raman test probe according to claim 1, characterized in that: The coaxial excitation optical path and the coaxial receiving optical path have a double-layer structure, with the upper layer being the coaxial excitation optical path and the lower layer being the coaxial receiving optical path; or the upper layer being the coaxial receiving optical path and the lower layer being the coaxial excitation optical path.

3. The switching dual-wavelength Raman test probe according to claim 1, characterized in that: The coaxial excitation optical path and the coaxial receiving optical path are arranged in two parallel rows, with the left row being the coaxial excitation optical path and the right row being the coaxial receiving optical path.

4. The switching dual-wavelength Raman test probe according to claim 2, characterized in that: The coaxial excitation optical path includes a first narrowband filter (1), a second narrowband filter (2), a first dichroic mirror (6), a second dichroic mirror (7), a reflecting mirror (3), and a collimating mirror (4). The collimating mirror (4), the first narrowband filter (1), the reflecting mirror (3), and the first dichroic mirror (6) are arranged in sequence to form the first excitation optical path. The collimating mirror (4), the second narrowband filter (2), the reflecting mirror (3), and the second dichroic mirror (7) are arranged in sequence to form the second excitation optical path.

5. A switching dual-wavelength Raman test probe according to claim 4, characterized in that: The coaxial receiving optical path includes a first long-pass filter (8), a second long-pass filter (9), a first dichroic mirror (6), a second dichroic mirror (7), and a fiber optic coupler (11). The fiber optic coupler (11), the first long-pass filter (8), and the first dichroic mirror (6) are arranged in sequence to form the first receiving optical path. The fiber optic coupler (11), the second long-pass filter (9), and the second dichroic mirror (7) are arranged in sequence to form the second receiving optical path.

6. A switching dual-wavelength Raman test probe according to any one of claims 1-5, characterized in that: The limiting sliding assembly includes a first limiting sliding assembly and a second limiting sliding assembly. The first limiting sliding assembly switches between a first excitation optical path and a second excitation optical path, and the second limiting sliding assembly switches between a first receiving optical path and a second receiving optical path.

7. A switching dual-wavelength Raman test probe according to claim 6, characterized in that: The first limiting sliding assembly includes a first slider (13), a first slider guide rail (14), a first switching button (15), and a first slider limiting group. The first slider (13) includes a base and two bases fixed side by side on the base. The base is connected to the first slider guide rail (14) and moves along the first slider guide rail (14). The two bases are respectively fixedly installed with a first narrowband filter (1) and a second narrowband filter (2). The first slider limiting group includes a first limiting structure (16) and a second limiting structure (17). The first switching button (15) is fixedly connected to the first slider (13).

8. A switching dual-wavelength Raman test probe according to claim 6, characterized in that: The second limiting sliding assembly includes a second slider (13'), a second slider guide rail (14'), a second switching button (15'), and a second slider limiting group. The second slider (13') includes a base and four bases fixed on the base in a square distribution. The base is connected to the second slider guide rail (14') and moves along the second slider guide rail (14'). A first long-pass filter (8) and a second long-pass filter (9) are fixedly installed in two bases in the near end of the probe, and a first dichroic mirror (6) and a second dichroic mirror (7) are fixedly installed in two bases in the far end of the probe, respectively. The second slider limiting group includes a third limiting structure (16') and a fourth limiting structure (17'). The second switching button (15') is fixedly connected to the second slider (13').

9. A switching dual-wavelength Raman test probe according to claim 5, characterized in that: The tube lens includes a metal tube and a focusing lens (10). The near end of the metal tube is connected to the light outlet of the housing, and the far end of the metal tube is fixed to the focusing lens (10).

10. A switching dual-wavelength Raman test probe according to claim 9, characterized in that: The reflector (3), the first dichroic mirror (6) and the second dichroic mirror (7) are all installed and fixed at 45° to the incident light. The collimating mirror (4), the first long-pass filter (8), the second long-pass filter (9), the focusing lens (10), and the fiber optic coupler (11) are all installed and fixed at 90° to the incident light.

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