Implantable atmosphere sensing device

Abstract

The invention discloses an implantable atmosphere sensing device, and belongs to the field of environmental atmosphere detection, the implantable atmosphere sensing device comprises a hollow-core coated optical fiber sensor and a portable Raman spectrum detector, the hollow-core coated optical fiber sensor is implanted in a sealed cavity, the hollow-core coated optical fiber sensor comprises a hollow-core coated optical fiber and a sensor sealing joint, and the sensor sealing joint is connected with the portable Raman spectrum detector. The hollow-core coated optical fiber sensor is connected with the portable Raman spectrum detector through a sensor sealing joint; the inner diameter of the hollow-core coated optical fiber is 0.3 mm-2mm, the inner surface of the hollow-core coated optical fiber is a metal reflective film layer, and the outer surface protection layer is a metal coating. The device realizes in-situ detection of the atmosphere in a closed space, is suitable for simultaneous detection of various gases, has the characteristics of small volume, high sensitivity, quantitability, good stability and the like, can be used for long-term monitoring of atmosphere change in a sealed cavity or an object to be detected, and particularly overcomes the difficulty of long-term atmosphere monitoring in a severe environment.

Description

Technical Field

[0001] The present invention relates to the field of environmental atmosphere detection, and in particular to an implantable atmosphere sensor device. Background Art

[0002] The environmental atmosphere has an important influence on the long-term reliable storage of materials. Mastering the environmental atmosphere analysis technology, especially the in-situ non-destructive online analysis method, is of great significance for predicting the corrosion state evolution and service life of materials. At present, the commonly used gas analysis technical means mainly include gas chromatography technology, infrared absorption spectroscopy technology, electrochemical atmosphere sensor and Raman spectroscopy technology. Among them, the electrochemical atmosphere sensor is mainly based on the principle of chemical sensing. It detects and senses a certain atmosphere through the interaction between special materials and atmosphere. If multiple atmospheres need to be sensed, multiple sensors need to be integrated, and the system is complex. This sensor based on signal intensity, wavelength / frequency changes is easily interfered by the outside world, such as other atmospheres interfering with the sensor, sensor material performance degradation, temperature and humidity changes, etc., making it difficult to achieve long-term stable monitoring of the atmosphere. Moreover, the current electrochemical atmosphere sensors are generally large in size, making it difficult to achieve implantable sensing, or have a significant impact on the function or performance of the object to be measured after implantation. Raman spectroscopy is a fingerprint spectrum that can specifically identify gases (except monatomic gases) and can be quantitatively analyzed through internal standards and control of measurement conditions. It is an ideal means to achieve long-term monitoring of complex atmospheres. Raman spectroscopy has the following advantages over other technologies: 1) It has no loss to gas, short detection time, and can be used for online monitoring of gas; 2) It can detect all gas molecules except monatomic gases, such as H2, O2, N2 and other isonuclear diatomic molecules; 3) It can detect multi-component mixed gases at the same time, and the Raman signal intensity of the gas is proportional to the concentration of each component.

[0003] However, the effect of Raman spectroscopy in the detection of low-concentration gases is not ideal. The main reason that limits the further development of gas Raman spectroscopy to the detection of low-concentration components is that its Raman scattering signal is extremely weak. The key factors causing this phenomenon are the tiny Raman scattering cross section and low molecular number density of the gas. Therefore, in order to improve the detection sensitivity of gas Raman spectroscopy, it is necessary to enhance the Raman scattering signal. Specifically, in addition to surface enhanced Raman spectroscopy, there are many other methods for enhancing Raman scattering signals, such as resonance Raman enhancement technology and physical optics enhancement technology. Among them, the most commonly used method of physical optics enhancement technology is to improve the gas Raman spectroscopy detection sensitivity through cavity enhancement and fiber enhancement. Cavity enhancement achieves Raman signal enhancement by increasing the laser power in the cavity, and fiber enhancement achieves enhancement by increasing the optical path and improving the signal collection efficiency.

[0004] Fiber-enhanced Raman spectroscopy technology uses photonic crystal hollow-core fiber as a sensor, and hollow-core fiber as an air chamber and light-guiding medium, limiting the propagation of light within its central hole, achieving an extremely long optical path with a very small volume, thereby greatly enhancing the signal. In addition, it has strong anti-electromagnetic interference ability, light weight, thinness and flexibility, and is easy to implant in a sealed cavity. Compared with cavity enhancement technology, it has higher temporal stability and mechanical stability, and is more suitable for gas detection under in-situ working conditions. However, due to the small core diameter of photonic crystal fiber (generally less than 200μm), there is a slow gas exchange rate, which affects the response speed of the sensor, and is generally used for online monitoring of gas flow. In addition, due to the small numerical aperture (about 0.03mm) and small inner diameter of photonic crystal fiber, the coupling of light input and output is difficult, so the sensor, laser and detector are generally fixed as a whole, which requires high mechanical stability, and it is difficult to achieve plug-and-play optical path coupling, which is limited to application in laboratory environments. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems existing in the existing atmosphere detection sensors based on Raman spectroscopy technology, and to propose an implantable atmosphere sensing device based on a hollow-core coated optical fiber sensor combined with a portable Raman spectrometer. The hollow-core coated optical fiber is used as an atmosphere sensor, and the inner hole of the optical fiber is relatively large, and the light incident and output coupling efficiency is high, which improves the reliability of long-term monitoring under working conditions. At the same time, by optimizing the structure of the optical fiber sensor, the coupling joint structure and other measures, the spectral background is further reduced and the gas detection sensitivity is improved. A technical solution suitable for long-term and stable monitoring of complex atmospheres in confined spaces under working conditions is realized.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] An implantable atmosphere sensing device comprises a hollow-core coated optical fiber sensor and a portable Raman spectrometer, wherein the hollow-core coated optical fiber sensor is implanted in a sealed cavity, comprises a hollow-core coated optical fiber and a sensor sealing joint, and the hollow-core coated optical fiber sensor is connected or disconnected with the portable Raman spectrometer via the sensor sealing joint; the inner diameter of the hollow-core coated optical fiber is 0.3 mm-2 mm; the inner surface of the hollow-core coated optical fiber sensor is a metal film layer with high reflectivity; the outer surface of the hollow-core coated optical fiber is provided with a protective layer for increasing the strength of the optical fiber, and the protective layer is an organic coating or a metal coating.

[0008] In some preferred embodiments, the length of the hollow-core coated optical fiber is 5 mm-1000 mm.

[0009] In some preferred embodiments, a first reflector aligned with the axis direction of the optical fiber is disposed at the end of the hollow-core coated optical fiber, and a gas diffusion hole is disposed between the first reflector and the hollow-core coated optical fiber.

[0010] In some preferred embodiments, a fiber fixing device and an optical window are provided at the front end of the hollow-core coated optical fiber. The optical window serves as a seal to isolate the gas to be measured from the outside.

[0011] In some preferred embodiments, a shielding microhole is provided at the front end of the hollow-core coated optical fiber close to one side of the optical window, and its light-clearing aperture is slightly smaller than the inner diameter of the hollow-core optical fiber; the optical window is made of quartz, sapphire or diamond material with low fluorescence background.

[0012] In some preferred embodiments, the portable Raman spectrometer comprises a laser, a laser incident optical fiber, a coupling joint, a spectrum receiving optical fiber and a spectrometer connected in sequence, wherein the coupling joint is connected to the sensor sealing joint via a detachable connecting device.

[0013] In some preferred embodiments, the coupling joint can be disconnected from the hollow-core coated optical fiber sensor in a non-test state, and can be precisely docked again when needed to continue measuring; the coupling joint includes a laser excitation optical path and a spectrum collection optical path, wherein the laser excitation optical path includes an incident optical fiber coupling lens, a laser filter, a second reflector, a dichroic mirror, and a coupling lens connected in sequence, and the spectrum collection optical path includes a coupling lens, a dichroic mirror, a long-pass filter, a spatial filter, and a receiving optical fiber coupling lens connected in sequence; the coupling lens is connected to the hollow-core coated optical fiber.

[0014] In some preferred embodiments, the spatial filter comprises a pair of focusing lenses, with a small hole disposed between the two focusing lenses.

[0015] In some preferred embodiments, the laser incident optical fiber is a solid quartz optical fiber with a numerical aperture of NA0.1 and a core diameter of 0.1 mm, which can improve the efficiency of laser entering the hollow core optical fiber, and the numerical aperture of the spectrum receiving optical fiber is a solid quartz optical fiber with a numerical aperture of NA0.22, which can improve the collection efficiency of Raman signals.

[0016] It should be further explained that the technical features corresponding to the above embodiments can be combined or replaced with each other to form a new technical solution without conflict.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention uses hollow-core coated optical fiber as a sensor. Due to the large inner aperture of the hollow-core coated optical fiber, compared with the photonic crystal fiber with a small core diameter, the light incident and outgoing coupling efficiency between the hollow-core coated optical fiber and the portable Raman spectrometer is high, the optical path coupling is stable, and the disturbance of the coupled optical path has little effect on the measurement, which improves the reliability of long-term monitoring under working conditions. At the same time, the large inner diameter is also conducive to improving the response speed of the atmosphere sensor in the sealed space (with a small pressure difference). At the same time, using a portable Raman spectrometer as a detector can realize long-term in-situ detection of the atmosphere in a confined space, especially long-term monitoring of complex atmospheres under harsh working conditions. It can also realize plug-and-play non-destructive detection of the atmosphere through a detachable connection device.

[0019] 2. In one example, the inner surface of the hollow-core coated optical fiber of the present invention is coated with a high-reflectivity film layer, which prevents the laser from directly hitting the optical fiber matrix, so that the laser is reflected in the hollow-core optical fiber, and the laser repeatedly excites the atmosphere in the hollow-core optical fiber, thereby reducing the background interference and increasing the signal strength. As an optimization, the outer surface protective layer is a metal coating, which can further reduce the fluorescence background interference caused by the optical fiber itself and improve the sensitivity of weak signal detection.

[0020] 3. In one example, the present invention further reduces the spectral background and improves the gas detection sensitivity by optimizing the structure of the hollow-core coated optical fiber, such as adding an end reflector and a front-end shielding microhole.

[0021] 4. In one example, the coupling joint of the present invention is structurally optimized and designed to match two different optical fiber numerical apertures and achieve efficient optical path coupling. The coupling joint adds a spatial filter and adopts a reflective lens, which can reduce the influence of the background of components in the optical path and improve the signal-to-noise ratio of the gas Raman signal.

[0022] 5. In one example, the detection lower limit of the present invention can reach 300ppm (1 bar pressure), the repeatability error is less than 1%, the linearity is better than 0.999, and the atmosphere detection range can reach 0.03%-100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of an implantable atmosphere sensor device according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of a hollow-core coated optical fiber sensor according to an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of shielding microholes and their positions shown in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of a portable Raman spectrometer according to an embodiment of the present invention.

[0027] Figure 5 A schematic diagram of detection results of a mixed atmosphere by an implantable atmosphere sensor device according to an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of the detection results of trace gases by an implantable atmosphere sensor device according to an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of repeatability measurement results shown in an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of linearity measurement results shown in an embodiment of the present invention.

[0031] Numbers in the figure: 1-hollow-core coated optical fiber sensor; 2-portable Raman spectrometer; 3-sealed cavity; 4-sensor sealing joint; 5 detachable connecting device; 11 hollow-core coated optical fiber; 12-first reflector 12; 13-gas diffusion hole; 14-optical fiber fixing device; 15-optical window; 16-shielding micropore; 17-sealing ring; 18-vent; 21 laser; 22-laser incident optical fiber; 23-coupling joint; 24-spectral receiving optical fiber; 25-spectrometer; 231-incident optical fiber coupling lens; 232-laser filter; 233-second reflector; 234-dichroic mirror; 235-coupling lens; 236-long-pass filter; 237-focusing lens; 238-receiving optical fiber coupling lens. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various configurations. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] It should be noted that the defects existing in the solutions in the above-mentioned prior art are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above-mentioned problems and the solutions proposed in the embodiments of the present application for the above-mentioned problems below should all be the contributions made by the inventor to the present application in the process of invention and creation, and should not be understood as technical contents known to technical personnel in this field.

[0034] like Figure 1-2As shown, the implantable atmosphere sensing device includes a hollow-core coated optical fiber sensor 1 and a portable Raman spectrometer 2, wherein the hollow-core coated optical fiber sensor 1 is implanted in a sealed cavity 3, wherein the hollow-core coated optical fiber sensor 1 includes a hollow-core coated optical fiber 11 and a sensor sealing joint 4, wherein the hollow-core coated optical fiber sensor 1 is connected to and disconnected from the portable Raman spectrometer 2 via the sensor sealing joint 4; the portable Raman spectrometer 2 includes a laser 21, a laser incident optical fiber 22, a coupling joint 23, a spectrum receiving optical fiber 24 and a spectrometer 25 which are connected in sequence, wherein the coupling joint 23 is connected to the sensor sealing joint 4 via a detachable connecting device 5.

[0035] The specific structure of the hollow core coated optical fiber sensor 1 is as follows: Figure 2 As shown, it is mainly composed of a hollow-core coated optical fiber 11, a first reflector 12, a shielding microhole 16, an optical fiber fixing device 14, a sealing ring 17 and an optical window 15. Among them, the hollow-core coated optical fiber sensor 1 includes a hollow-core coated optical fiber 11, the inner diameter of the hollow-core coated optical fiber 11 is 0.3mm-2mm, and the length of the hollow-core coated optical fiber 11 is 5mm-1000mm. Compared with the photonic crystal fiber with a small core diameter, the inner diameter of the hollow-core coated optical fiber 11 of the present application is larger. Increasing the inner hole of the optical fiber can increase the mechanical tolerance when docking with the plug-in Raman probe, improve the docking position accuracy of the optical fiber and the Raman probe, and make the coupling efficiency of the optical fiber and the Raman probe higher, thereby resulting in high light incident and outgoing coupling efficiency.

[0036] Furthermore, the inner surface of the hollow-core coated optical fiber 11 is coated with a gold film or a silver film with a high reflectivity, which prevents the laser from directly hitting the optical fiber matrix. The optical fiber matrix has a very strong fluorescent background, and the gold film and the silver film have a high reflectivity, so that the laser will be reflected in the hollow-core optical fiber, and the laser repeatedly excites the atmosphere in the hollow-core optical fiber, thereby making the background lower and the signal higher. The outer surface of the hollow-core coated optical fiber is provided with a protective layer (cladding), and the protective layer is an organic coating or a metal coating.

[0037] Secondly, the front end of the hollow-core coated optical fiber 11 is provided with an optical fiber fixing device 14 and an optical window 15, wherein the front end of the hollow-core coated optical fiber 11 close to the optical window 15 is provided with a shielding microhole 16 (such as Figure 3 The shielding microhole 16 can also prevent the laser from hitting the quartz matrix at the end face of the optical fiber to generate fluorescence background interference, thereby reducing the spectral background and improving the detection signal-to-noise ratio.

[0038] Then, a first reflector 12 is provided at the end of the hollow-core coated optical fiber 11, which is collimated with the optical fiber axis direction, so that the laser in the optical fiber can be reflected back into the hollow-core coated optical fiber 11, so that the laser can excite the atmosphere in the hollow-core optical fiber again, thereby increasing the Raman signal intensity of the gas, and at the same time, it can prevent the laser coupled from the hollow-core coated optical fiber 11 from hitting other substances (the substance will have a Raman signal, and there is a high probability that the fluorescence background will increase), thereby further reducing the signal of fluorescence and stray light, and can further improve the detection sensitivity when the optical fiber length is limited, which helps to reduce the volume of the sensor. Preferably, in some examples, the length of the optical fiber sensor is about 200 mm. A gas diffusion hole 13 is provided between the first reflector 12 and the hollow-core coated optical fiber 11. The gas diffuses into the interior of the sensor through the gas diffusion hole 13.

[0039] Furthermore, a sealing ring 17 and an optical window 15 are added to the front end of the hollow-core coated optical fiber 11 for sealing. The optical window 15 is made of low-fluorescence, high-light-transmittance material (quartz, sapphire, diamond, etc.), which can transmit laser and gas Raman spectrum signals and isolate the gas to achieve sealing; there is a sealing ring 17 (rubber ring or indium wire sealing, welding) between the optical window 15 and the optical fiber fixing device 14, so that the trace atmosphere in the sealed container will not be disturbed by the external atmosphere. There are vents 18 on the optical fiber fixing device 14, which can realize gas exchange inside the sealed cavity, so that the trace atmosphere can diffuse into the hollow-core optical fiber, and the trace gas can be detected.

[0040] Furthermore, if Figure 3 As shown, the purpose of setting the shielding microhole 16 is to shield the spectral background interference of the optical fiber cladding and the hollow-core optical fiber matrix material. In the experiment, it was found that the organic cladding on the outer surface of the hollow-core optical fiber and the hollow-core optical fiber matrix have obvious fluorescence, which brings obvious spectral background interference to the detection of low-concentration gas. The signal-to-noise ratio can be effectively improved by setting the shielding microhole 16. The light-transmitting area (inner diameter) of the shielding microhole 16 is slightly smaller than the inner diameter of the hollow-core coated optical fiber 11. Preferably, the inner diameter of the hollow-core coated optical fiber 11 is 500μm, and the inner diameter of the shielding microhole 16 is 450μm. The outer diameter of the shielding microhole 16 is larger than the outer diameter of the optical fiber, thereby effectively shielding the fluorescence of the organic cladding on the outer surface of the hollow-core optical fiber and the hollow-core optical fiber matrix. When the optical fiber cladding material is replaced with a metal coating, the interference of the organic cladding on the measurement can be significantly reduced, which is a preferred solution. At this time, setting the shielding microhole 16 can also serve the purpose of shielding the fluorescence of the optical fiber quartz matrix. Setting shielding microholes and using metal optical fiber cladding can obtain a better detection signal-to-noise ratio.

[0041] Furthermore, the coupling connector 23 in the portable Raman spectrometer 2 has been specifically designed and optimized for optical purposes, thereby achieving effective excitation and collection of hollow-core optical fiber sensor signals. Figure 4As shown, the coupling joint 23 includes a laser excitation optical path and a spectrum collection optical path, wherein the laser excitation optical path includes an incident fiber coupling lens 231, a laser filter 232, a second reflector 233, a dichroic mirror 234 and a coupling lens 235 connected in sequence, and the spectrum collection optical path includes a coupling lens 235, a dichroic mirror 234, a long-pass filter 236, a spatial filter and a receiving fiber coupling lens 238 connected in sequence; the coupling lens 235 is connected to the hollow-core coated optical fiber 11. The spatial filter includes a pair of focusing lenses 237, and a small hole is provided between the two focusing lenses 237.

[0042] Specifically, the laser emitted by the laser 21 (a 532nm laser is used in this example) enters the coupling joint 23 through the laser incident fiber 22 (a conventional solid quartz fiber with a core diameter of 50-100μm), is converted into a parallel beam through the incident fiber coupling lens 231, passes through the laser filter 232, the second reflector 233 and the dichroic mirror 234, and is incident on the detection probe (fiber sensor) through the coupling lens 235. The incident light spot diameter is smaller than the inner diameter of the shielding microhole 16, which is matched with the hollow-core fiber. (NA=0.03) and the numerical aperture of the incident optical fiber (NA=0.22 or 0.12). In this example, the numerical aperture of the laser incident optical fiber 22 is NA0.1, and the core diameter is 50-100μm. The spectrum receiving optical fiber 24 is also a conventional solid quartz optical fiber with a numerical aperture of NA0.22 and a core diameter of 200μm, which can improve the collection efficiency of Raman signals. In addition, in order to collect Raman signals transmitted by high-order modes of hollow-core optical fibers, the numerical aperture NA of the coupling lens 235 is greater than 0.3.

[0043] The coupling lens 235 can be an off-axis parabolic lens or a low-fluorescence lens. The collected Raman spectrum signal is converted into parallel light through the coupling lens 235, and the laser is filtered through the dichroic mirror 234 and the long-pass filter 236. In order to further reduce the interference of optical components (coupling lens 235, dichroic mirror 234 and optical window 15 on the probe), a spatial filter (comprising a pair of focusing lenses 237 and a small hole) is set to further enhance the detection capability of trace gases; the gas Raman signal enters the spectrum receiving optical fiber 24 (a conventional solid optical fiber with a core diameter of 200μm) after passing through the receiving optical fiber coupling lens 238, and finally enters the spectrometer 25. In this example, the spectrometer 25 is a high-throughput spectrometer using a transmission grating and a scientific-grade CCD.

[0044] The implantable atmosphere sensor device of the present invention is used to analyze the mixed gas. The results are as follows: Figure 5The implantable atmosphere sensor device of the present invention can be used to analyze the mixed gas of H2 (1%), D2 (1%) and N2 (98%) under 1 Bar gas pressure, and the mixed gas of CO2 (1%), O2 (1%) and N2 (98%), and can effectively distinguish the characteristic signals of different gases.

[0045] The implantable atmosphere sensor device of the present invention is used to analyze the configured trace gas, and the results are as follows: Figure 6 The implantable atmosphere sensor device of the present invention is used to analyze the mixed gas of CO2 (0.1%) and N2 (99.9%) at 1 Bar gas pressure, and the mixed gas of CH4 (0.08%) and N2 (99.92%). The Raman spectrum signals of low concentration CO2 and CH4 gases are clear. After calculation, the detection limit is better than 0.03% (300ppm).

[0046] By using the implantable atmosphere sensor device of the present invention, the air is repeatedly measured as a sample, such as Figure 7 As shown, the measurement result band is less than 1%, with good repeatability.

[0047] The implantable atmosphere sensor device of the present invention is used to measure (eg Figure 8 As shown in the figure, the signal intensity of the measured gas has a good linear relationship with the integration time and the laser power, and the linearity is >0.999. Therefore, by adjusting the measurement parameters, the detection of mixed gas components with a wide range of different atmosphere concentrations (0.03%-100%) can be achieved.

[0048] It should be noted that in other instances, Figure 1 The portable Raman spectrometer in the invention does not use optical fiber transmission, but uses a miniaturized, integrated portable Raman spectrometer, that is, the laser, spectrometer and coupling joint are used as a whole (without optical fiber in the middle). The hollow-core coated optical fiber is replaced by a hollow-core coated glass tube and a hollow thin metal tube, and the principle is the same as that of the present invention.

[0049] The above specific implementation methods are detailed descriptions of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions and substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. An implantable atmosphere sensor device, characterized in that: It includes a hollow-core coated optical fiber sensor and a portable Raman spectrometer. The hollow-core coated optical fiber sensor is implanted in a sealed cavity. The hollow-core coated optical fiber sensor includes a hollow-core coated optical fiber and a sensor sealing joint. The hollow-core coated optical fiber sensor is connected and disconnected with the portable Raman spectrometer through the sensor sealing joint as needed. The inner diameter of the hollow-core coated optical fiber is 0.3mm-2mm.

2. The implantable atmosphere sensor device according to claim 1, characterized in that: The inner surface of the hollow-core coated optical fiber sensor is a metal film layer with high reflectivity; the outer surface of the hollow-core coated optical fiber is provided with a protective layer, and the protective layer is an organic coating or a metal coating.

3. The implantable atmosphere sensor device according to claim 1, characterized in that: The length of the hollow-core coated optical fiber is 5 mm-1000 mm.

4. The implantable atmosphere sensor device according to claim 1, characterized in that: A first reflector aligned with the axis direction of the optical fiber is disposed at the end of the hollow-core coated optical fiber, and a gas diffusion hole is disposed between the first reflector and the hollow-core coated optical fiber.

5. The implantable atmosphere sensor device according to claim 4, characterized in that: The front end of the hollow-core coated optical fiber is provided with an optical fiber fixing device and an optical window. The optical window plays a sealing role and is used to isolate the gas to be measured from the outside world.

6. The implantable atmosphere sensor device according to claim 5, characterized in that: A shielding microhole is provided at the front end of the hollow-core coated optical fiber close to one side of the optical window, and its light-clearing aperture is smaller than the inner diameter of the hollow-core optical fiber; the optical window is made of quartz, sapphire or diamond material with low fluorescence background.

7. The implantable atmosphere sensor device according to claim 1, characterized in that: The portable Raman spectrometer comprises a laser, a laser incident optical fiber, a coupling joint, a spectrum receiving optical fiber and a spectrometer which are connected in sequence, wherein the coupling joint is connected to the sensor sealing joint via a detachable connecting device.

8. The implantable atmosphere sensor device according to claim 7, characterized in that: The coupling joint can be disconnected from the hollow-core coated optical fiber sensor in a non-testing state, and can be precisely docked again when needed to continue measuring; the coupling joint includes a laser excitation optical path and a spectrum collection optical path, wherein the laser excitation optical path includes an incident optical fiber coupling lens, a laser filter, a second reflector, a dichroic mirror, and a coupling lens connected in sequence, and the spectrum collection optical path includes a coupling lens, a dichroic mirror, a long-pass filter, a spatial filter, and a receiving optical fiber coupling lens connected in sequence; the coupling lens is connected to the hollow-core coated optical fiber.

9. The implantable atmosphere sensor device according to claim 8, characterized in that: The spatial filter comprises a pair of focusing lenses, and a small hole is arranged between the two focusing lenses.

10. The implantable atmosphere sensor device according to claim 7, characterized in that: The laser incident optical fiber is a solid quartz optical fiber with a numerical aperture of NA0.1 and a core diameter of 0.1 mm. The spectrum receiving optical fiber is a solid quartz optical fiber with a numerical aperture of NA0.22.

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