A low-temperature and high-pressure immersion Raman probe

Abstract

The present invention provides a low-temperature, high-pressure immersion Raman probe, comprising a front mirror assembly, an optical fiber fixing assembly, an extended fixing assembly, a pressure-resistant outer shell, and a rear shell assembly. A window glass is provided at the front end of the pressure-resistant outer shell, the front mirror assembly, the optical fiber fixing assembly, and the extended fixing assembly are sequentially mounted within the pressure-resistant outer shell, and the rear shell assembly is mounted at the rear end of the pressure-resistant outer shell. The present invention utilizes a structural design in which the front mirror assembly, the optical fiber fixing assembly, and the extended fixing assembly are sequentially mounted within the pressure-resistant outer shell, thereby enabling the probe cavity to be subjected to low vacuum or low-boiling-point inert gas replacement treatment, thereby avoiding the problem of low-temperature condensation and adsorption of air, and enabling the optical system performance of the probe to remain consistent at any length. During detection, since the optical system of the probe is immersed in the liquid to be tested, the temperature stability is more stable than that of a probe with a rear optical system, and the data consistency is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of Raman probes, and in particular relates to a low-temperature and high-pressure immersion Raman probe. Background Art

[0002] The Raman effect refers to the phenomenon in which the frequency of light scattering changes when light interacts with matter. Discovered by Indian physicist Chandrasekhara Raman in 1928, the effect reveals the interaction between photons and molecular vibrational and rotational energy levels. The Raman effect can be used to analyze molecular structure, material composition, and crystal phases. Its non-destructive, rapid, and highly sensitive nature makes it an indispensable analytical tool in chemistry, biology, medicine, and the environment. A Raman probe focuses laser light onto a sample, collects the scattered Raman signal, and transmits it to a Raman spectrometer for analysis. Raman probes are categorized by whether they can be immersed in liquids: immersion probes and non-immersion probes. Operating temperature ranges include standard versions (non-corrosion-resistant, -50°C to 40°C); high-temperature versions (resistant to 300°C); and cryogenic probes (resistant to temperatures below -160°C). Conventional and high-temperature probes are more common commercially, but cryogenic probes remain a niche market.

[0003] The difference between low-temperature Raman probes and high-temperature and conventional probes is that when the probe operates at -160°C, the air inside the probe changes from gas to liquid, affecting the efficiency of the optical system and even damaging the probe. Material properties change in low-temperature environments. For example, commonly used optical glass BK7 and adhesives cannot be used, requiring optical system optimization and process adjustments for low temperatures. Given the different probe length requirements in different application scenarios, the conventional approach is to add a beam expander to the optical system to compress the divergence angle so that the energy distribution of different lengths is consistent. However, the added lenses increase the loss of transmitted and received light. Furthermore, for probes of different lengths, adding lenses reduces the transmission and reception efficiency and leads to inconsistent specifications.

[0004] Based on this, a low-temperature and high-pressure immersion Raman probe was proposed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-temperature and high-pressure immersion Raman probe in view of the above-mentioned deficiencies in the prior art, so as to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a low-temperature and high-pressure immersion Raman probe, comprising a front mirror assembly, an optical fiber fixing assembly, an extension fixing assembly, a pressure-resistant outer shell and a rear shell assembly;

[0007] The front end of the pressure-resistant outer shell is provided with a window glass, the front mirror assembly, the optical fiber fixing assembly and the extension fixing assembly are sequentially installed in the pressure-resistant outer shell, and the rear shell assembly is installed at the rear end of the pressure-resistant outer shell;

[0008] The front mirror assembly includes a lens frame, a spacer, a lens barrel, a conical fixing seat, a support tube and a front lens. The lens frame, front lens, spacer and support tube are sequentially installed in the lens barrel, the lens barrel is installed in the conical fixing seat, and the conical fixing seat is installed in the conical cavity of the pressure-resistant outer shell.

[0009] The optical fiber fixing assembly includes a transmitting lens barrel, a receiving lens barrel and an adapter seat. A transmitting mirror, a long spacer, an aperture and a filter are sequentially arranged on one side of the transmitting lens barrel and are pressed tightly by a pressure ring. A reflective lens is pasted on the outside of the pressure ring in the transmitting lens barrel, and an adjustment pad and an FC optical fiber head are arranged on the other side of the transmitting lens barrel.

[0010] A receiving mirror, a short spacer, an aperture, a filter and a filter are sequentially arranged on one side of the receiving lens barrel and pressed tightly with a pressure ring. A dichroic lens is pasted on the outside of the pressure ring inside the receiving lens barrel. The transmitting lens barrel and the receiving lens barrel are respectively installed in the adapter and pressed tightly with screws.

[0011] The extended fixing assembly includes a middle support tube, a positioning tube, a first sealing plate and a second sealing plate. The front end of the middle support tube abuts against the optical fiber fixing assembly, the rear end of the middle support tube is installed in the positioning tube, and the other end of the positioning tube is installed with a middle tube flange seat. The first sealing plate and the second sealing plate are installed on the middle tube flange seat.

[0012] The rear shell assembly includes a rear shell, a cover plate, a circuit board, a photoelectric connector socket and a power indicator light. The rear shell is installed on the outside of the middle cylinder flange seat with screws. The circuit board, photoelectric connector socket and power indicator light are installed in the rear shell, and a cover plate is installed at the tail end of the rear shell.

[0013] As a further illustration of the present invention, a connecting spring is installed between the spacer tube and the support tube in the lens barrel.

[0014] As a further illustration of the present invention, a first pressure plate is provided at the front end of the transmitting lens barrel, and a second pressure plate is provided at the front end of the receiving lens barrel.

[0015] As a further illustration of the present invention, a sealing ring is installed in the sealing groove of the middle cylinder flange seat.

[0016] As a further illustration of the present invention, an exhaust hole is further provided in the middle tube flange seat, through which a low vacuum sealing process can be performed inside the probe.

[0017] As a further illustration of the present invention, a sealing gasket is provided at the connection between the rear shell and the cover plate.

[0018] As a further illustration of the present invention, the photoelectric connector socket is used to connect to a host, and includes a transmitting optical fiber, a receiving optical fiber, a chain signal line, and an indication signal line.

[0019] As a further illustration of the present invention, the power indicator light is used to indicate the working status. When there is laser in the probe, the indicator light is on, and when there is no laser in the probe, the indicator light is off.

[0020] As a further illustration of the present invention, the front end of the pressure-resistant outer shell is conical in design, a conical cavity is provided inside the pressure-resistant outer shell, and the pressure-resistant outer shell is made of C276 Hastelloy stainless steel, and the window glass is made of sapphire.

[0021] As a further explanation of the present invention, a middle flange is provided in the middle of the pressure-resistant outer shell, and the external connection operation of the pressure-resistant outer shell can be performed through the middle flange. A tail flange is provided at the tail of the pressure-resistant outer shell, and the tail flange is connected to the middle tube flange seat.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention provides a front mirror assembly at the front end of the pressure-resistant outer shell and adopts a front optical system design, so that the performance of the optical system of the probe is consistent at any length. During detection, since the optical system of the probe is immersed in the liquid to be measured, the temperature stability is more stable than that of the probe with a rear optical system, and the data consistency is higher.

[0024] 2. The present invention adopts a structural design in which the front mirror assembly, the optical fiber fixing assembly and the extension fixing assembly are sequentially installed in the pressure-resistant outer shell. This allows the inner cavity of the probe to be treated with low vacuum or low-boiling-point inert gas replacement, thereby avoiding the problem of low-temperature condensation and adsorption of air. In addition, a connecting spring is provided in the front mirror assembly, which can ensure that the optical axis can be aligned within a wider temperature range, thereby improving the environmental adaptability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the Raman probe of the present invention;

[0026] Figure 2 Schematic diagram of the internal structure of the Raman probe of the present invention;

[0027] Figure 3 Schematic diagram of the front mirror assembly of the Raman probe of the present invention;

[0028] Figure 4 Schematic diagram of the optical fiber fixing assembly of the Raman probe of the present invention;

[0029] Figure 5 Schematic diagram of the extended fixing assembly of the Raman probe of the present invention;

[0030] Figure 6 Schematic diagram of the rear housing assembly of the Raman probe of the present invention.

[0031] Description of reference numerals:

[0032] 1. Front mirror assembly; 1-1. Mirror frame; 1-2. Spacer; 1-3. Mirror barrel; 1-4. Conical fixing seat; 1-5. Support tube; 1-6. Connecting spring; 1-7. Front mirror; 2. Fiber fixing assembly; 2-1. Adapter seat; 2-2. First pressure plate; 2-3. Reflector lens; 2-4. Pressure ring; 2-5. Filter; 2-6. Aperture; 2-7. Long spacer; 2-8. Transmitter mirror; 2-9. Transmitter barrel; 2-10. Adjustment pad; 2-11. FC fiber head; 2-12. Receiving barrel; 2-13. Receiving mirror; 2-14. Short spacer; 2-15. Filter; 2-16, filter; 2-17, dichroic lens; 2-18, second pressure plate; 3, extended fixing assembly; 3-1, middle support tube; 3-2, positioning tube; 3-3, middle tube flange seat; 3-4, sealing ring; 3-5, first sealing disk; 3-6, second sealing disk; 3-7, exhaust hole; 4, pressure-resistant outer shell; 4-1, middle flange; 4-2, tail flange; 5, rear shell assembly; 6, window glass; 5-1, rear shell; 5-2, cover; 5-3, sealing gasket; 5-4, circuit board; 5-5, optoelectronic connector socket; 5-6, power indicator light. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] like Figure 1-6 As shown, the present invention provides a technical solution: a low-temperature and high-pressure immersion Raman probe, comprising a front mirror assembly 1, an optical fiber fixing assembly 2, an extension fixing assembly 3, a pressure-resistant outer shell 4 and a rear shell assembly 5;

[0035] The front end of the pressure-resistant outer shell 4 is provided with a window glass 6, the front mirror assembly 1, the optical fiber fixing assembly 2 and the extension fixing assembly 3 are sequentially installed in the pressure-resistant outer shell 4, and the rear shell assembly 5 is installed at the rear end of the pressure-resistant outer shell 4;

[0036] Among them, the front mirror assembly 1 includes a mirror frame 1-1, a spacer 1-2, a lens barrel 1-3, a conical fixing seat 1-4, a support tube 1-5 and a front lens 1-7. The mirror frame 1-1, the front lens 1-7, the spacer 1-2 and the support tube 1-5 are installed in the lens barrel 1-3 in sequence. A connecting spring 1-6 is also installed in the lens barrel 1-3 between the spacer 1-2 and the support tube 1-5. The structure has appropriate strength to ensure the coaxiality of the optical system at different temperatures and prevent the optical axis from being deflected due to drastic temperature changes.

[0037] The lens barrel 1-3 is installed in a conical fixing seat 1-4, and the conical fixing seat 1-4 is installed in the conical cavity of the pressure-resistant outer shell 4.

[0038] The optical fiber fixing assembly 2 includes a transmitting lens barrel 2-9, a receiving lens barrel 2-12 and an adapter seat 2-1, and a transmitting mirror 2-8, a long spacer 2-7, an aperture 2-6 and a filter 2-5 are sequentially arranged on one side of the transmitting lens barrel 2-9 and are pressed tightly by a pressure ring 2-4. A reflecting lens 2-3 is pasted on the outside of the pressure ring 2-4 in the transmitting lens barrel 2-9, and an adjustment pad 2-10 and an FC optical fiber head 2-11 are arranged on the other side of the transmitting lens barrel 2-9; the thickness of the adjustment pad 2-10 can be adjusted to adjust the interval between the reflecting lens 2-3 and the FC optical fiber head 2-11 to achieve the optimal distance.

[0039] A receiving mirror 2-13, a short spacer 2-14, an aperture 2-6, a filter 2-15 and a filter 2-16 are sequentially arranged on one side of the receiving lens barrel 2-12 and are pressed tightly by a pressure ring 2-4. A dichroic lens 2-17 is pasted on the outside of the pressure ring 2-4 in the receiving lens barrel 2-12, and an adjustment pad 2-10 and an FC fiber optic head 2-11 are arranged on the other side of the receiving lens barrel 2-12; the thickness of the adjustment pad 2-10 can be adjusted to adjust the spacing between the dichroic lens 2-17 and the FC fiber optic head 2-11 to achieve the optimal distance.

[0040] The transmitting lens barrel 2-9 and the receiving lens barrel 2-12 are respectively installed in the adapter 2-1 and tightened with screws. The front end of the transmitting lens barrel 2-9 is provided with a first pressing plate 2-2, and the front end of the receiving lens barrel 2-12 is provided with a second pressing plate 2-18.

[0041] The extension fixing assembly 3 includes a middle support tube 3-1, a positioning tube 3-2, a first sealing disk 3-5, and a second sealing disk 3-6. The front end of the middle support tube 3-1 is against the optical fiber fixing assembly 2, and the rear end of the middle support tube 3-1 is installed in the positioning tube 3-2. The other end of the positioning tube 3-2 is installed with a middle tube flange seat 3-3. The first sealing disk 3-5 and the second sealing disk 3-6 are installed on the middle tube flange seat 3-3. A sealing ring 3-4 is installed in the sealing groove of the middle tube flange seat 3-3. During installation, the sealing ring 3-4 is installed in the sealing groove of the middle tube flange seat 3-3 and the screws are tightened. At this time, the interior of the entire pressure-resistant outer shell 4 becomes a closed cavity. The middle tube flange seat 3-3 is also provided with an exhaust hole 3-7. The exhaust hole 3-7 can be used to perform low-vacuum sealing treatment inside the probe. Finally, the rear shell assembly 5 is installed.

[0042] The rear shell assembly 5 includes a rear shell 5-1, a cover plate 5-2, a circuit board 5-4, a photoelectric connector socket 5-5 and a power indicator light 5-6. The rear shell 5-1 is installed on the outside of the middle tube flange seat 3-3 by screws. The circuit board 5-4, the photoelectric connector socket 5-5 and the power indicator light 5-6 are installed in the rear shell 5-1. The photoelectric connector socket 5-5 is used to connect to the host and includes a transmitting optical fiber, a receiving optical fiber, a chain signal line and an indication signal line.

[0043] The power indicator lights 5-6 are used to indicate the working status. When there is laser in the probe, the indicator lights are on, and when there is no laser in the probe, the indicator lights are off.

[0044] A cover plate 5-2 is installed at the tail end of the rear shell 5-1, and a sealing gasket 5-3 is provided at the connection between the rear shell 5-1 and the cover plate 5-2. A middle flange 41 is provided in the middle of the pressure-resistant outer shell 4, and the external connection operation of the pressure-resistant outer shell 4 can be performed through the middle flange 41. A tail flange 42 is provided at the tail of the pressure-resistant outer shell 4, and the tail flange 42 is connected to the middle tube flange seat 3-3.

[0045] The front end of the pressure-resistant outer shell 4 is conical in design, a conical cavity is provided in the pressure-resistant outer shell 4, and the pressure-resistant outer shell 4 is made of C276 Hastelloy stainless steel, and the window glass 6 is made of sapphire.

[0046] In this embodiment, a front mirror assembly 1 is arranged at the front end of the pressure-resistant outer shell 4. The front lenses 1-7 are focusing lenses, and the optical fiber fixing assembly 2 is respectively the transmitting and receiving optical paths. The excitation optical fiber and the signal receiving optical fiber pass through the hollow structure and are sealed at the middle tube flange seat 3-3. This can ensure that the performance indicators of the optical system can be maintained at any insertion rod length. The optical system and assembly process have been optimized for low temperature, which is convenient for promotion and use.

[0047] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A low-temperature, high-pressure immersion Raman probe, characterized by: It comprises a front mirror assembly (1), an optical fiber fixing assembly (2), an extension fixing assembly (3), a pressure-resistant outer shell (4) and a rear shell assembly (5); The front end of the pressure-resistant outer shell (4) is provided with a window glass (6); the front mirror assembly (1), the optical fiber fixing assembly (2) and the extension fixing assembly (3) are sequentially installed in the pressure-resistant outer shell (4); and the rear shell assembly (5) is installed at the rear end of the pressure-resistant outer shell (4); The front mirror assembly (1) comprises a mirror frame (1-1), a spacer (1-2), a lens barrel (1-3), a conical fixing seat (1-4), a support tube (1-5) and a front lens (1-7); the mirror frame (1-1), the front lens (1-7), the spacer (1-2) and the support tube (1-5) are sequentially mounted in the lens barrel (1-3); the lens barrel (1-3) is mounted in the conical fixing seat (1-4); and the conical fixing seat (1-4) is mounted in the conical cavity of the pressure-resistant outer shell (4); The optical fiber fixing assembly (2) comprises a transmitting lens barrel (2-9), a receiving lens barrel (2-12) and an adapter seat (2-1); a transmitting lens (2-8), a long spacer (2-7), an aperture (2-6) and a filter (2-5) are sequentially arranged on one side of the transmitting lens barrel (2-9) and are compressed by a pressing ring (2-4); a reflecting lens (2-3) is adhered to the outside of the pressing ring (2-4) in the transmitting lens barrel (2-9); and an adjustment pad (2-10) and an FC optical fiber head (2-11) are arranged on the other side of the transmitting lens barrel (2-9); A receiving lens (2-13), a short spacer (2-14), an aperture (2-6), a filter (2-15) and a filter (2-16) are sequentially arranged on one side of the receiving lens barrel (2-12) and are compressed by a pressing ring (2-4). A dichroic lens (2-17) is adhered to the outside of the pressing ring (2-4) in the receiving lens barrel (2-12). An adjustment pad (2-10) and an FC fiber head (2-11) are also arranged on the other side of the receiving lens barrel (2-12). The transmitting lens barrel (2-9) and the receiving lens barrel (2-12) are respectively installed in the adapter (2-1) and compressed by screws. The extended fixing assembly (3) comprises a middle support tube (3-1), a positioning tube (3-2), a first sealing disk (3-5) and a second sealing disk (3-6); the front end of the middle support tube (3-1) abuts against the optical fiber fixing assembly (2); the rear end of the middle support tube (3-1) is installed in the positioning tube (3-2); the other end of the positioning tube (3-2) is installed with a middle tube flange seat (3-3); the first sealing disk (3-5) and the second sealing disk (3-6) are installed on the middle tube flange seat (3-3); The rear housing assembly (5) comprises a rear housing (5-1), a cover plate (5-2), a circuit board (5-4), a photoelectric connector socket (5-5) and a power indicator light (5-6); the rear housing (5-1) is mounted on the outside of the middle cylinder flange seat (3-3) by means of screws; the circuit board (5-4), the photoelectric connector socket (5-5) and the power indicator light (5-6) are mounted inside the rear housing (5-1); and a cover plate (5-2) is mounted at the rear end of the rear housing (5-1).

2. A low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: A connecting spring (1-6) is also installed inside the lens barrel (1-3) between the spacer barrel (1-2) and the support barrel (1-5).

3. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: A first pressing plate (2-2) is provided at the front end of the transmitting lens barrel (2-9), and a second pressing plate (2-18) is provided at the front end of the receiving lens barrel (2-12).

4. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: A sealing ring (3-4) is installed in the sealing groove of the middle cylinder flange seat (3-3).

5. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: An exhaust hole (3-7) is also provided in the middle cylinder flange seat (3-3), and a low vacuum sealing process can be performed on the inside of the probe through the exhaust hole (3-7).

6. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: A sealing gasket (5-3) is provided at the connection between the rear shell (5-1) and the cover plate (5-2).

7. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: The photoelectric connector socket (5-5) comprises a transmitting optical fiber, a receiving optical fiber, a chain signal line and an indication signal line, and is used for connecting to a host.

8. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: The power indicator light (5-6) is used to indicate the working state. When there is laser in the probe, the indicator light is on, and when there is no laser in the probe, the indicator light is off.

9. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: The front end of the pressure-resistant outer shell (4) is of conical design, a conical cavity is provided in the pressure-resistant outer shell (4), and the pressure-resistant outer shell (4) is made of C276 Hastelloy stainless steel, and the window glass (6) is made of sapphire.

10. The low-temperature and high-pressure immersion Raman probe according to claim 1, characterized in that: A middle flange (41) is provided in the middle of the pressure-resistant outer shell (4), and external connection operations of the pressure-resistant outer shell (4) can be performed through the middle flange (41). A tail flange (42) is provided at the tail of the pressure-resistant outer shell (4), and the tail flange (42) is connected to the middle tube flange seat (3-3).

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