Miniature assembly type self-focusing spatial offset Raman optical fiber probe and detection coupling system

Abstract

The invention discloses a miniature assembled self-focusing spatial offset Raman optical fiber probe and a detection coupling system, and relates to the technical field of Raman spectrum detection. Wherein the micro self-focusing optical fiber Raman probe can complete conventional Raman spectrum acquisition; the self-focusing spatial offset Raman optical fiber probe assembly and the micro self-focusing optical fiber Raman probe are combined to complete spatial offset Raman spectrum acquisition of continuous offset distances; the interface conversion assembly can be selected according to actual conditions, and is coupled with the micro self-focusing optical fiber Raman probe and the self-focusing space offset Raman optical fiber probe assembly so as to realize adaptation of optical fiber lasers and portable Raman spectrometers with different interface models. The miniaturized and universal design of the optical fiber Raman probe is realized, the spatial offset Raman spectrum can be efficiently acquired by combining the components, the probe is good in flexibility and high in sensitivity, automatic focusing detection can be realized, and the acquired spectrum is high in intensity and high in signal-to-noise ratio. The system has diversified application scenes, and is simple to operate and convenient to maintain.

Description

Technical Field

[0001] The present invention belongs to the field of Raman spectroscopy detection technology, and in particular relates to a miniature assembled self-focusing spatially offset Raman fiber probe and its detection coupling system that can meet the detection requirements in the fields of biomedicine, materials science, and pharmacy and can realize portable in-vivo in-situ detection of biological tissues. Background Art

[0002] Raman spectroscopy, as a detection and analysis technique, studies molecular vibrations by detecting changes in the frequency and intensity of light scattered by a sample. It can provide information on a sample's chemical bonds, functional groups, and molecular isomers, and can specifically identify molecular composition, hence the term "molecular fingerprint." It has been demonstrated to offer advantages such as high sensitivity, good accuracy, and non-invasiveness. It can complement infrared spectroscopy to obtain more comprehensive sample information. Currently, Raman spectroscopy has been widely applied in a variety of fields, including cultural relic research, gem identification, materials science, biomedicine, and disease detection, and holds broad application prospects.

[0003] The probability of Raman scattering is about 10 of that of Rayleigh scattering. -6 Therefore, the Raman scattering signal is extremely weak and lacks penetration, making it difficult to obtain signals from deep within the sample. In recent years, with the development of laser technology and manufacturing, Raman spectroscopy has also been greatly developed and widely used, and a variety of improved technologies have been derived. Among them, spatially offset Raman spectroscopy can significantly reduce the interference of surface signals of the sample by physically offsetting the spectral acquisition point relative to the excitation point, thus compensating for the lack of Raman spectroscopy's ability to obtain deep signals. However, current spatially offset Raman spectroscopy acquisition equipment is still imperfect, and most of it is achieved through simple construction of optical components, which has significant limitations in real-world detection scenarios.

[0004] The main Raman spectroscopy detection methods include macroscopic Raman detection, microscopic Raman detection, and probe Raman detection. Microscopic Raman detection uses an objective lens to focus the laser spot size to the micrometer level, facilitating the study of smaller sample areas and achieving better resolution. Probe Raman detection uses optical fibers to transmit the excitation light and Raman scattered light, which reduces resolution somewhat, expanding the application scope of Raman detection and offering greater convenience. Most existing Raman spectrometers in the biomedical field are large and require sampling and processing of the target before placing the sample on a fixed sample stage for Raman spectrum acquisition. These large spectrometers offer high detection accuracy but are limited in their application, primarily used for collecting Raman spectra of excised tissues. They can only meet the needs of scientific research and teaching, and are not suitable for in situ clinical testing. Fiber-optic Raman probes offer flexible layout and ease of use. Fiber-optic Raman probes currently available on the market can be structurally categorized into two types: non-imaging probes and focusing probes. Non-imaging probes primarily consist of excitation and collection fibers arranged in parallel, and various improvements are available. However, most lack spectral filtering, failing to remove fiber Raman signals and fluorescence background signals, resulting in poor spectral acquisition. Focusing probes, most equipped with replaceable focusing optical lens systems, offer improved signal detection performance, but their complex optical systems often result in larger and more expensive designs. Furthermore, the wide variety of spectrometer models on the market makes Raman probes incapable of coupling with spectrometers with different interfaces, and direct probe modification is costly.

[0005] Therefore, it is necessary to design a high-resolution, cost-controlled, and flexible miniature self-focusing fiber Raman probe to achieve automatic focusing and spatially offset Raman spectrum acquisition, facilitate small area signal acquisition, and improve the deep signal acquisition capability of Raman spectroscopy. Summary of the Invention

[0006] Purpose of the invention: To overcome the shortcomings of existing focused fiber Raman probes and realize convenient high-resolution conventional Raman spectroscopy and spatially offset Raman spectroscopy acquisition and in situ detection of in vivo biological tissues, the present invention provides a miniature assembled self-focusing spatially offset Raman fiber probe and detection coupling system.

[0007] Technical solution: A miniature assembled self-focusing spatially offset Raman fiber probe, characterized in that it includes a miniature self-focusing fiber Raman probe, a self-focusing spatially offset Raman fiber probe assembly, and an interface conversion assembly, wherein the miniature self-focusing fiber Raman probe includes a first metal protective sleeve, a first metal hard tube, a central excitation fiber, a first collection fiber bundle, a handle, a connector, an excitation end coupling interface, and a first collection end coupling interface; the self-focusing spatially offset Raman fiber probe assembly includes an assembly box, a spatially offset Raman collection fiber probe; the interface conversion assembly includes a front-end coupling interface, a fiber bundle and its protective sleeve, and a rear-end coupling interface; the central excitation fiber and the collection fiber bundle both include a front end and a rear end, the first collection fiber bundle is arranged in a multi-layer ring around the central excitation fiber, the front ends of the two are wrapped by a metal protective sleeve, and are split at the connector, the rear end of the central excitation fiber is connected to the excitation end coupling interface, and the rear end of the first collection fiber bundle is connected to the first collection end coupling interface, and the miniature self-focusing fiber Raman probe is "Y"-shaped as a whole.

[0008] Preferably, a first lens, a first filter, a central excitation optical fiber and a collection optical fiber bundle are sequentially arranged inside the first metal protective sleeve.

[0009] Preferably, the first metal rigid tube is connected to the first metal protective sleeve, which wraps the central excitation optical fiber and the front of the first collection optical fiber bundle and extends to the handle. The diameter of the first metal protective sleeve depends on the diameter of the first lens, and the length of the first metal protective sleeve and the connected first metal rigid tube can be flexibly designed according to the detection position and scene.

[0010] Preferably, the first lens is a self-focusing lens, and the overall shape is cylindrical. The first lens can directly contact the object to be measured to achieve self-focusing of the excitation light and collimation of the scattered light.

[0011] Preferably, the first filter is a composite filter composed of a central circular area coated with a bandpass filter coating and an outer annular area coated with a longpass filter coating, which correspond to the central excitation optical fiber and the first collection optical fiber bundle respectively; two identical composite filters are stacked in the same direction to more effectively block interfering light and improve the efficiency of the central long-wave resistance and the outer ring short-wave resistance respectively.

[0012] Preferably, the assembly box includes an elastic interference fit structure, a transmission block, a screw, and a knob, and the miniature self-focusing fiber Raman probe and the assembly box can be assembled by interference fit; a strip groove is provided on the surface of the assembly box where the elastic interference fit structure is located, which runs through the box wall, so that the spatially offset Raman collection fiber optic probe can slide along the groove, and the spatially offset Raman collection fiber optic probe cooperates with the transmission block to achieve continuous spatial offset through screw transmission.

[0013] Preferably, the spatially offset Raman collection fiber probe and the miniature self-focusing fiber Raman probe both include a metal protective sleeve, a metal hard tube, a fiber bundle, and a coupling interface, and their arrangement is the same; the first filter in the miniature self-focusing fiber Raman probe is a composite filter, the fiber bundle is divided into a central excitation fiber and a first collection fiber bundle, and the fiber bundle is split into a "Y" shape at the connector; the second filter in the spatially offset Raman collection fiber probe is a long-pass filter, the fiber bundle is a second collection fiber bundle, and the fiber bundle is not split.

[0014] Preferably, the front-end coupling interface of the interface conversion component matches the probe coupling interface and can be connected to the excitation end coupling interface or the collection end coupling interface. The rear-end coupling interface can select different interfaces according to actual needs, and the two ends are connected by optical fiber and its protective cover.

[0015] Preferably, the miniature self-focusing fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly can be assembled through an elastic interference fit structure.

[0016] A miniature assembled self-focusing spatially offset Raman fiber probe and detection coupling system comprises a miniature self-focusing fiber Raman probe, a self-focusing spatially offset Raman fiber probe assembly, an interface conversion assembly, a fiber laser, and a portable Raman spectrometer. After the miniature self-focusing fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly are assembled, the fiber laser and the portable Raman spectrometer are coupled to an excitation end coupling interface and a first collection end coupling interface, respectively, to achieve spatially offset Raman spectrum acquisition. After the two are separated, the fiber laser and the portable Raman spectrometer are coupled to the excitation end coupling interface and the second collection end coupling interface, respectively, to achieve conventional Raman spectrum acquisition. The coupling interfaces used by the self-focusing micro-fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly can be flexibly configured according to the coupled laser and spectrometer. In this embodiment, an SMA905 interface is used. Laser light emitted by the fiber laser enters the excitation fiber through the coupling interface, excites a sample through a self-focusing lens, and is scattered. Raman scattered light collected by the probe passes through a collection fiber bundle and enters the portable Raman spectrometer through the coupling interface to be received.

[0017] Beneficial effects: The present invention provides a miniature assembled self-focusing spatially offset Raman fiber probe. Compared with the existing technology, the objective lens uses a self-focusing lens to solve the focusing problem and realize the collimation of scattered light, thereby improving the signal quality; the optical fiber is cleverly arranged, and a composite filter is used to improve the filtering efficiency. While greatly reducing the probe diameter to 2.5 mm, it can provide a higher Raman signal resolution; the front end of the probe is designed to be a slender hard tube structure, and a handle is added to facilitate the handheld probe for multi-scene applications and in-vivo detection of biological tissues; the miniature self-focusing fiber Raman probe can assemble / disassemble the self-focusing spatially offset Raman fiber probe assembly, and can realize the spatially offset Raman spectrum acquisition of continuous spatial offset; the probe can be configured with multiple interface conversion components adapted to different lasers and spectrometers, so as to achieve multi-scene applicability without modifying the probe. The probe has a sophisticated overall structure, a slender shape, high flexibility, controllable price, high resolution, and simple structural maintenance and operation. It fills the technical gaps in existing in-situ Raman spectroscopy detection, such as the difficulty in automatic focusing and collimation and the lack of dedicated spatial offset Raman spectroscopy acquisition equipment, and solves the problems of large size and strong background interference in existing Raman fiber optic probes.

[0018] The present invention provides a miniature assembled self-focusing spatially offset Raman fiber probe and detection coupling system, which achieves the coupling of the fiber Raman probe with a fiber laser and a portable Raman spectrometer. This system is highly versatile and expands the application range of the miniature self-focusing fiber Raman probe. While ensuring detection accuracy, the present invention simplifies the optical path as much as possible, reduces the number of optical components in the fiber Raman probe, reduces the Raman background noise generated by the system itself, improves the throughput rate of effective optical signals, and reduces the system loss of Raman scattered light. The system has a simple overall structure, is easy to operate and carry, and has high spectral quality and signal-to-noise ratio. It is suitable for a variety of application scenarios, addresses the need for convenient on-site detection, and fills a gap in this field. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 It is a schematic diagram of an embodiment of the micro-assembled self-focusing spatially offset Raman fiber probe and detection coupling system of the present invention.

[0021] Figure 2 The present invention is a schematic diagram of an embodiment of a miniature self-focusing fiber Raman probe in a miniature assembled self-focusing spatially offset Raman fiber probe and a miniature self-focusing fiber Raman probe in a detection coupling system.

[0022] Figure 3 The present invention is a schematic diagram of an embodiment of a micro-assembled self-focusing spatially offset Raman fiber probe and a self-focusing spatially offset Raman fiber probe assembly in a detection coupling system.

[0023] Figure 4 This is a schematic diagram of the internal structure of the first metal protective sleeve in the micro-assembled self-focusing spatially offset Raman optical fiber probe and detection coupling system of the present invention.

[0024] Figure 5 It is a schematic diagram of the internal structure of the second metal protective sleeve in the micro-assembled self-focusing spatially offset Raman optical fiber probe and the detection coupling system of the present invention.

[0025] Figure 6 It is a schematic diagram of an embodiment of an interface conversion component in a micro-assembled self-focusing spatially offset Raman fiber probe and a detection coupling system of the present invention.

[0026] In the figure: 1. first metal protective sleeve; 1-1. first lens; 1-2. first optical filter; 1-3. central excitation optical fiber; 1-4. first collecting optical fiber bundle; 2. first metal rigid tube; 3. handle; 4. connector; 5. excitation end coupling interface; 6. first collecting end coupling interface; 7. laser; 8. Raman fiber spectrometer; 9. second metal protective sleeve; 9-1. second lens; 9-2. second optical filter; 9-3. second collecting optical fiber bundle; 10. second metal rigid tube; 11. second collecting end coupling interface; 12. assembly box; 12-1. elastic interference fit structure; 12-2. transmission block; 12-3. screw rod; 12-4. knob; 13. front-end coupling interface; 14. optical fiber bundle and its protective sleeve; 15. rear-end coupling interface.

[0027] The first metal protective sleeve 1 encloses the first lens 1-1 and the first optical filter 1-2, extending to the first metal rigid tube 2. The first metal rigid tube 2 encloses the central excitation fiber 1-3 and the front portion of the first collection fiber bundle 1-4, and extends to the connector 4. The first metal protective sleeve 1 and the first metal rigid tube 2 are made of rigid metal material, effectively protecting the probe and preventing foreign matter from entering during detection. Their high hardness prevents deformation, and their miniature outer diameter meets the requirements of complex detection scenarios.

[0028] The second metal protective sleeve 9 encloses the second lens 9-1 and the second filter 9-2 and extends to the second metal rigid tube 10. The second metal rigid tube 10 encloses the front portion of the second collection optical fiber bundle 9-3. The second metal protective sleeve 9 and the second metal rigid tube 10 are made of the same materials and have the same functions as the first metal protective sleeve 1 and the first metal rigid tube 2.

[0029] The first lens 1-1 and the second lens 9-1 serve as the front-end objective lenses of the probe. Self-focusing lenses are selected to utilize their nonlinear optical properties to smoothly focus the excitation light and collimate the scattered light, thus avoiding the problem of difficulty in focusing. They can directly contact the object to be tested, improve the quality and stability of Raman signal acquisition, and accurately focus detection can be achieved by lightly touching the sample with the front end of the probe.

[0030] The central excitation optical fiber 1-3, the first collection optical fiber bundle 1-4 and the second collection optical fiber bundle 9-3 are all step-type multimode optimized quartz optical fibers with a core diameter of 200 μm. The first collection optical fiber bundle 1-4 is arranged in a ring around the central excitation optical fiber 1-3, and the 27 collection optical fibers are equally divided into three layers and tightly arranged to maximize the compression of the probe outer diameter; the second collection optical fiber bundle 9-3 is arranged in the same manner as the first collection optical fiber bundle 1-4 and the central excitation optical fiber 1-3, but the central optical fiber serves as the collection optical fiber.

[0031] The first filter 1-2 is a composite filter composed of a circular bandpass filter area and an annular longpass filter area. The central excitation fiber 1-3 and the first collection fiber bundle 1-4 both include a front end and a rear end. The first lens 1-1 and the first filter 1-2 are arranged at the front ends of the fibers 1-3 and 1-4, and the first filter 1-2 is arranged between the first lens 1-1 and the fibers 1-3 and 1-4. The circular bandpass filter area is arranged at the front end of the central excitation fiber 1-3, and the annular longpass filter area is arranged at the front end of the first collection fiber bundle 1-4, which can fully utilize the filtering effect of the filter. The probe is compact and has a compact size. Two identical composite filters are stacked in the same direction, balancing cost control and stray light filtering efficiency. A first metal rigid tube 2 is installed along optical fibers 1-3 and 1-4, and a handle 3 is added behind the first metal rigid tube 2 to make the probe more convenient to use. A connector 4 separates the central excitation fiber 1-3 from the first collection fiber bundle 1-4 at an appropriate distance from the front end. The rear ends of the central excitation fiber 1-3 and the first collection fiber bundle 1-4 are connected to coupling interfaces, defining them as the excitation end coupling interface 5 and the first collection end coupling interface 6, respectively. The miniature self-focusing fiber Raman probe is Y-shaped, with a compact overall structure and a wide range of applications.

[0032] The second filter 9-2 is a circular long-pass filter, the second lens 9-1 and the second filter 9-2 are arranged at the front end of the second collection optical fiber bundle 9-3, and the second filter 9-2 is arranged between the second lens 9-1 and the optical fiber 9-3; two identical long-pass filters are selected and stacked in the same direction, a second metal rigid tube is installed along the optical fiber 9-3, and the rear end of the optical fiber 9-3 is connected to the second collection end coupling interface.

[0033] In this embodiment, the excitation end coupling interface 5 , the first collection end coupling interface 6 and the second collection end coupling interface 11 all adopt standard SMA905 interfaces, which can meet the requirements of most commercial Raman spectrometers and improve the versatility of the probe.

[0034] like Figure 1 、 6As shown, the interface adapter assembly can be selectively used depending on the actual situation. The excitation end coupling interface 5, the first collection end coupling interface 6, and the second collection end coupling interface 11 of the miniature self-focusing fiber Raman probe can all be connected to the front-end adapter interface 13 of the interface conversion assembly. The back-end adapter interface 15 can select different coupling interfaces based on the model of the external laser or spectrometer. The introduction of the interface conversion assembly increases the versatility of the probe while avoiding probe modification, saving costs and reducing design complexity.

[0035] like Figure 1 、 6 As shown, the miniature assembled self-focusing spatially offset Raman fiber probe and detection coupling system includes a miniature self-focusing micro-fiber Raman probe, a self-focusing spatially offset Raman fiber probe assembly, an interface conversion assembly, a fiber laser 7, and a portable Raman spectrometer 8. The fiber laser 7 is connected to the miniature self-focusing fiber Raman probe via an excitation end coupling interface 5, and the portable Raman spectrometer 8 is connected to the self-focusing fiber Raman probe via a first collection end coupling interface 6 or to the self-focusing spatially offset Raman fiber probe assembly via a second collection end coupling interface 11.

[0036] like Figure 1 As shown, the operating principle and process of the miniature assembled self-focusing spatially offset Raman fiber probe and detection coupling system are as follows: After the excitation light is emitted by the fiber laser 7, it enters the central excitation fiber 1-3 and enters the probe for transmission. After passing through the circular bandpass filter area of ​​the composite filter 1-2 and the lens 1-1, it excites the sample to be measured. After the excitation light interacts with the sample to be measured and produces Raman scattering, the following procedures are performed: 1. Conventional Raman spectrum acquisition. The Raman scattered light passes through the first lens 1-1 for collimation. After the annular longpass filter area of ​​the first filter 1-2 removes stray light, it is collected by the first collection fiber bundle 1-4 and emitted into the portable Raman spectrometer 8 to achieve Raman spectrum detection of the sample; 2. Spatially offset Raman spectrum acquisition. The miniature self-focusing fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly are assembled using an interference fit structure. The Raman scattered light passes through the second lens 9-1 for collimation. After the second filter 9-2 removes stray light, it is collected by the second collection fiber bundle 9-3 and emitted into the portable Raman spectrometer 8 to achieve spatially offset Raman spectrum detection of the sample.

[0037] Matters not covered by the present invention are known technologies.

[0038] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A miniature assembled self-focusing spatially offset Raman fiber probe, characterized in that: The invention comprises a miniature self-focusing fiber Raman probe, a self-focusing spatially offset Raman fiber probe assembly, and an interface conversion assembly, wherein the miniature self-focusing fiber Raman probe comprises a first metal protective sleeve, a first metal hard tube, a central excitation fiber, a first collection fiber bundle, a handle, a connector, an excitation end coupling interface, and a first collection end coupling interface; the self-focusing spatially offset Raman fiber probe assembly comprises an assembly box, a spatially offset Raman collection fiber probe; the interface conversion assembly comprises a front-end coupling interface, a fiber bundle and its protective sleeve, and a rear-end coupling interface; the central excitation fiber and the collection fiber bundle both comprise a front end and a rear end, the first collection fiber bundle is arranged in a multi-layer ring around the central excitation fiber, the front ends of the two are wrapped by a metal protective sleeve, and are bundled at the connector, the rear end of the central excitation fiber is connected to the excitation end coupling interface, and the rear end of the first collection fiber bundle is connected to the first collection end coupling interface, and the miniature self-focusing fiber Raman probe is in a "Y" shape as a whole.

2. The miniature self-focusing fiber Raman probe according to claim 1, characterized in that: A first lens, a first filter, a central excitation optical fiber and a collection optical fiber bundle are sequentially arranged inside the first metal protection sleeve.

3. The miniature self-focusing fiber Raman probe according to claim 1, characterized in that: The first metal rigid tube is connected to the first metal protective sleeve, which wraps the central excitation optical fiber and the front of the first collection optical fiber bundle and extends to the handle. The diameter of the first metal protective sleeve depends on the diameter of the first lens, and the length of the first metal rigid tube and the connected first metal rigid tube can be flexibly designed according to the detection position and scene.

4. The miniature self-focusing fiber Raman probe according to any one of claims 1 to 3, characterized in that: The first lens is a self-focusing lens with an overall cylindrical shape. The first lens can directly contact the object to be measured to achieve self-focusing of the excitation light and collimation of the scattered light.

5. The miniature self-focusing fiber Raman probe according to any one of claims 1 to 3, characterized in that: The first filter is a composite filter consisting of a central circular area coated with a bandpass filter coating and an outer annular area coated with a longpass filter coating, which correspond to the central excitation fiber and the first collection fiber bundle respectively.

6. The self-focusing spatially offset Raman fiber probe assembly according to claim 1, characterized in that: The assembly box includes an elastic interference fit structure, a transmission block, a screw, and a knob. The miniature self-focusing fiber Raman probe and the assembly box can be assembled by interference fit. A strip groove is provided on the surface of the assembly box where the elastic interference fit structure is located, which runs through the box wall, so that the spatially offset Raman collection fiber optic probe can slide along the groove. The spatially offset Raman collection fiber optic probe cooperates with the transmission block and realizes continuous spatial offset through screw transmission.

7. The miniature assembled self-focusing spatially offset Raman fiber probe according to claim 1, characterized in that: The spatially offset Raman collection fiber probe and the miniature self-focusing fiber Raman probe both include a metal protective sleeve, a metal rigid tube, a fiber bundle, and a coupling interface, and their arrangement is the same; the first filter in the miniature self-focusing fiber Raman probe is a composite filter, the fiber bundle is divided into a central excitation fiber and a first collection fiber bundle, and the fiber bundle is split into a "Y" shape at the connector; the second filter in the spatially offset Raman collection fiber probe is a long-pass filter, the fiber bundle is a second collection fiber bundle, and the fiber bundle is not split.

8. The miniature assembled self-focusing spatially offset Raman fiber probe according to claim 1, characterized in that: The front-end coupling interface of the interface conversion component matches the probe coupling interface and can be connected to the excitation end coupling interface or the collection end coupling interface. The rear-end coupling interface can select different interfaces according to actual needs. The two ends are connected by optical fiber and its protective cover.

9. The miniature assembled self-focusing spatially offset Raman fiber probe according to claim 1, characterized in that: The miniature self-focusing optical fiber Raman probe and the self-focusing spatially offset Raman optical fiber probe assembly can be assembled through an elastic interference fit structure.

10. A micro-assembled self-focusing spatially offset Raman fiber probe and a detection coupling system according to claim 1, characterized in that: The invention comprises a miniature self-focusing fiber Raman probe, a self-focusing spatially offset Raman fiber probe assembly, an interface conversion assembly, a fiber laser, and a portable Raman spectrometer. After the miniature self-focusing fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly are assembled, the fiber laser and the portable Raman spectrometer are respectively coupled to the excitation end coupling interface and the second collection end coupling interface to realize spatially offset Raman spectrum acquisition. After the two are separated, the fiber laser and the portable Raman spectrometer are respectively coupled to the excitation end coupling interface and the first collection end coupling interface to realize conventional Raman spectrum acquisition. The coupling interface used in the self-focusing micro-fiber Raman probe and the self-focusing spatially offset Raman fiber probe assembly can be flexibly configured according to the coupled laser and spectrometer. This embodiment uses an SMA905 interface. The laser light emitted by the fiber laser enters the excitation fiber through the coupling interface and is scattered by the self-focusing lens to excite the sample. The Raman scattered light collected by the probe is received by the portable Raman spectrometer through the collection fiber bundle and the coupling interface.

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