Optical fiber vacuum feedthrough

Abstract

The application discloses an optical fiber vacuum feedthrough, and belongs to the field of vacuum and optics, comprising: an optical fiber main body, the optical fiber main body comprising an optical fiber bare wire and a metal sleeve, both of which are fixed and sealed by a vacuum sealing glue; a through-hole screw, the screw being drilled with a through hole; a soft metal, the soft metal being drilled with a through hole and being a main sealing component; and a flange main body, the flange main body having an internal thread at the front part and being capable of cooperating with the through-hole screw, and the rear part being a standard CF flange and being capable of being connected with an external vacuum chamber. In the sealing use process, the application is not prone to generating stress on the optical fiber, and the service life of the optical fiber can be prolonged; compared with the integrated sealing optical fiber vacuum feedthrough on the market, the detachable structure can still be reused in the case that the optical fiber reaches the service life or is accidentally damaged.

Description

Technical Field

[0001] This invention relates to an optical fiber vacuum feedthrough, belonging to the field of vacuum applications. Background Technology

[0002] In most light-matter interaction experiments, lasers must pass through an ultra-high vacuum chamber. Although the beam can propagate freely in space through a glass viewing port, an increasing number of experiments, such as cold atom experiments, use optical fibers to carry or collect light into a well-defined region for atomic-surface interactions. Fiber optic vacuum feedthroughs, typically installed in various vacuum cavities of a vacuum system, are used for the transmission of light from the light source to the vacuum chamber and have wide applications in vacuum fields such as aerospace and semiconductors. Vacuum feedthroughs that introduce optical fibers into the vacuum chamber play a crucial role in the operation of the vacuum system, combining optical path feeding functionality with vacuum sealing performance.

[0003] In existing fiber optic feedthrough technology, a gas-sealed structure is directly created between the optical fiber and the encapsulation component using sealant. Since optical fibers are fragile structures, they cannot be replaced after sealing. If the optical fiber is damaged, the entire feedthrough device will be discarded. Summary of the Invention

[0004] The present invention aims to avoid the problems existing in the prior art by providing an optical fiber vacuum feedthrough, thereby enabling optical fiber replacement for optical fiber vacuum feedthrough.

[0005] To achieve its objectives, the present invention employs the following technical solution:

[0006] The present invention provides an optical fiber vacuum feedthrough, which enables the transmission of optical signals in the ultraviolet and extreme ultraviolet bands between components inside a sealed vacuum chamber connected on one side of a flange body and other devices configured on the other side of the flange body via bare optical fiber.

[0007] The fiber optic vacuum feedthrough of this invention is characterized by including:

[0008] This invention relates to an optical fiber vacuum feedthrough, which enables the transmission of optical signals in the ultraviolet and extreme ultraviolet bands between components inside a sealed vacuum chamber connected to one side of a flange body and other devices disposed on the other side of the flange body via bare optical fibers. The optical fiber vacuum feedthrough is characterized by comprising:

[0009] The optical fiber body consists of a bare optical fiber, a metal sleeve, and vacuum sealant on the outer surface of the bare optical fiber and the inner surface of the metal sleeve. The metal sleeve is tubular with a through hole and has an end on a first direction side in one direction of the axial direction and an end on a second direction side in the other direction of the axial direction. The metal sleeve is positioned with the end on the first direction side inside the flange body connecting to the vacuum chamber and with the end on the second direction side outside the vacuum chamber. The bare optical fiber can pass through the through hole of the metal sleeve. The outer circumferential surface of the bare optical fiber and the inner circumferential surface of the through hole of the metal sleeve are sealed and fixed by vacuum sealant.

[0010] The through-hole screw has fine threads and a fine thread through hole. The fine threads can engage with the fine internal threads of the threaded sleeve of the flange body. The optical fiber body can pass through the fine thread through hole of the through-hole screw.

[0011] A sealing soft metal has a through hole, cylindrical at both ends, and a frustum structure in the middle. The optical fiber body can pass through the through hole in the sealing soft metal, and the diameter of the through hole in the sealing soft metal is just enough to ensure that the metal sleeve of the optical fiber body can be inserted. The diameter of the cylindrical tail of the sealing soft metal is just enough to insert into the through hole of the through hole screw, and the tail end face of the through hole screw is in complete contact with the tail end face of the sealing soft metal. The diameter at the maximum diameter of the frustum structure of the sealing soft metal is smaller than the inner diameter of the fine-tooth internal thread section of the threaded sleeve of the flange body.

[0012] The flange body comprises a standard CF flange and a threaded sleeve, the standard CF flange and the threaded sleeve being coaxial. The flange body has an end facing a first direction along the axial direction and an end facing a second direction along the axial direction. The flange body is sealed and fixed with a standard CF flange sealing structure at the end facing the second direction and a corresponding standard CF flange sealing structure on the outer side of the vacuum chamber. It also has a circular hole extending along the axial direction, starting from the end facing the second direction. This circular hole allows the insertion of an optical fiber body, and the end facing the first direction along the axial direction has a section of enlarged opening and a section of circular opening. The flange has a truncated cone hole that allows the insertion of a sealing soft metal. The end face of the cylindrical head of the sealing soft metal contacts the stepped surface formed by the truncated cone hole and the enlarged hole. The taper of the truncated cone hole is slightly larger than the taper of the truncated cone structure of the sealing soft metal. The end of the truncated cone hole on one side of the axial direction has a fine-tooth internal thread through hole that can be screwed into by a through-hole screw. The depth to which the through-hole screw is screwed into the threaded sleeve in conjunction with the fine-tooth internal thread through hole ensures that the tail end face of the through-hole screw is in complete contact with the tail end face of the soft metal. The manufacturing method of the flange body includes, but is not limited to, laser welding the threaded sleeve and the standard CF flange together or integrally forming them. The optical fiber body can penetrate the flange body.

[0013] The fiber optic vacuum feedthrough of this invention is also characterized by the fact that the fiber optic body is inserted into a through-hole screw and a sealing soft metal, and fixed to the flange body.

[0014] The fiber optic vacuum feedthrough of this invention is also characterized by the fact that the sealing soft metal is pressed into the flange body by the through-hole screw to form a metal seal.

[0015] The fiber optic vacuum feedthrough of this invention is also characterized by the following: the flange body is provided with a threaded sleeve, which cooperates with the through-hole screw to generate a preload.

[0016] In this invention, the flange body is composed of a standard vacuum CF flange and a threaded sleeve; its optical fiber consists of a bare optical fiber, a vacuum sealant covering the outer surface of the bare optical fiber, and a metal sleeve. The metal sleeve is inserted into the flange body, and a metal seal is formed between the metal sleeve and the flange body through the sealing soft metal under the action of the through-hole screw; the optical fiber is inserted into the through-hole screw and the sealing soft metal, and fixed to the flange body; compared with the prior art, the beneficial effects of this invention are reflected in:

[0017] 1. The optical fiber under sealed conditions of this invention does not experience stress concentration;

[0018] 2. The optical fiber in this invention can be replaced;

[0019] 3. The present invention uses a sealing soft metal seal, which can achieve an extremely low gas leakage rate. Attached Figure Description

[0020] Figure 1 This is a perspective view of the optical fiber feedthrough according to an embodiment of the present invention;

[0021] Figure 2 This is a front view of the optical fiber feedthrough in this invention;

[0022] Figure 3 This is a right view of the optical fiber feedthrough in this invention;

[0023] Figure 4 This is a cross-sectional view of the optical fiber feedthrough in this invention;

[0024] Figure 5 This is a three-dimensional perspective view of the fiber optic insertion through-hole screw and soft metal in a specific embodiment of the present invention.

[0025] The diagram is labeled as follows: 1a Fiber optic vacuum feedthrough, 1 Fiber optic body, 11 Bare fiber optic cable, 12 Metal sleeve, 13 Vacuum sealant, 2 Through-hole screw, 21 Fine thread, 22 Fine thread through-hole, 23 Screw head face, 24 Tail face, 3 Sealing soft metal, 31 Sealing soft metal tail cylinder, 32 Sealing soft metal tail face, 33 Sealing soft metal frustum structure, 34 Sealing soft metal head cylinder, 4 Flange body, 41 Flange body front face, 42 Flange through hole, 43 Stepped hole, 44 Frustum hole. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] The present invention and its embodiments are described below. This description is not restrictive, and actual embodiments are not limited thereto. In short, if those skilled in the art are inspired by this description and, without departing from the spirit of the invention, design similar structures and embodiments to this technical solution, such designs should fall within the protection scope of the present invention.

[0028] Figure 1 As shown, as a specific embodiment of the present invention, an optical fiber vacuum feedthrough is disclosed, which can be used in aerospace, semiconductor and vacuum fields. The optical fiber vacuum feedthrough 1a includes an optical fiber body 1, a through-hole screw 2, a sealing soft metal 3 and a flange body 4.

[0029] like Figures 1 to 3As shown, in this embodiment, the optical fiber feedthrough 1a is penetrated by the optical fiber body 1, and the flange body 4 is fixedly sealed to the wall of the vacuum chamber or similar surface through its standard CF vacuum flange sealing surface. If the flange body 4 is fixed to the corresponding standard CF flange interface of the vacuum chamber, the positions of the standard CF flange structure on the flange body 4 and the standard CF flange structure on the vacuum chamber are relatively fixed. The flange body 4 is fixed to the vacuum chamber using screws or bolts, and simultaneously forms a vacuum seal with the vacuum chamber through the wedge-shaped cutting edge on the standard CF flange.

[0030] In a preferred embodiment, such as Figure 4 As shown, the bare optical fiber 11 is inserted into the metal sleeve 12, with the outer diameter of the bare optical fiber slightly smaller than the inner diameter of the metal sleeve 12. The bare optical fiber 11 and the metal sleeve 12 are kept coaxial. Vacuum sealant is injected at the vacuum sealant 13 position, filling a portion of the gap between the bare optical fiber 11 and the metal sleeve 12. Features are as follows. Figure 4 As shown. After the vacuum sealant cures, a gas seal is achieved at both ends of the bare optical fiber 11 within the metal sleeve 12. The sealing effect depends on the type of vacuum sealant, the actual operating conditions, and the length of the vacuum sealant 13 formed between the metal sleeve 12 and the bare optical fiber 11. An appropriate length will result in better sealing, while a longer length of sealant will generate stress on the bare optical fiber, failing to guarantee the desired optical characteristics of the fiber and producing a large amount of outgassing, affecting vacuum performance.

[0031] In addition, such as Figure 4 As shown, the inner diameter of the fine-pitch threaded through-hole 22 of the through-hole screw 2 is larger than the inner diameter of the metal sleeve 12 and slightly larger than the outer diameter of the cylindrical tail of the sealing soft metal 3. The fine-pitch thread 21 on the through-hole screw 2 mates with the fine-pitch internal thread of the flange body 4. During tightening, the fine-pitch threaded through-hole 21 produces a uniform and stable mechanical effect on the sealing soft metal as it is screwed in. The distance from the tail end face 24 to the screw head end face 23 of the through-hole screw 2 is greater than the distance from the front end face 41 of the flange body to the tail end face 32 of the sealing soft metal to ensure that no interference occurs during tightening.

[0032] The sealing soft metal 3 is inserted into the flange body 4, and the structure of the sealing soft metal is as follows: Figure 5As shown, the sealing soft metal structure consists of cylinders at both ends and a frustum structure in the middle. The entire sealing soft metal structure has through holes, the diameter of which is approximately equal to the outer diameter of the metal sleeve. The through hole of the threaded portion of the through-hole screw can be fitted into the tail cylinder 31 of the sealing soft metal, the outer diameter of which is slightly smaller than the inner diameter of the through-hole screw 2. The sealing soft metal head cylinder 34 of the sealing soft metal 3 can be inserted into the stepped hole 43 inside the flange body 4, the inner diameter of which is approximately equal to the outer diameter of the sealing soft metal head cylinder 34. The sealing soft metal frustum structure 33 of the sealing soft metal 3 mates with the corresponding frustum hole 44 inside the flange body 4. The difference is that the taper of the frustum hole 44 is slightly larger than the taper of the sealing soft metal frustum structure 33. This ensures that the end face of the sealing soft metal head cylinder 34 fits tightly with the end face of the stepped hole 43 in the flange body 4, preventing the formation of dead space that traps a large amount of gas.

[0033] As described above, the tightening process of the through-hole screw 2 applies sufficient force to the sealing soft metal 3 through the end face of the fine-threaded through-hole 21, causing it to fit tightly against the flange body 4 to form a vacuum seal. At the same time, due to the interaction between the frustum structure 33 of the sealing soft metal and the frustum hole 44 of the flange body 4, a compressive force is generated on the metal sleeve 12, thereby forming a vacuum seal between the sealing soft metal 3 and the metal sleeve 12. Due to the rigidity of the metal sleeve 12, concentrated stress is avoided on the bare optical fiber 11 during the compression process.

[0034] When in use, the tail of the flange body 4 is a standard CF flange with six standard flange through holes 42 and a wedge-shaped knife edge sealing surface, which facilitates connection with the external vacuum chamber and forms a good vacuum seal.

Claims

1. An optical fiber vacuum feedthrough for transmitting an optical signal in the ultraviolet and extreme ultraviolet wavelength bands via an optical fiber strand (11) between an internal element of a sealed vacuum chamber connected on one side to a flange body (4) and other equipment arranged on the other side of the flange body (4), characterized in that, The optical fiber vacuum feedthrough comprises: An optical fiber body (1) composed of an optical fiber bare wire (11), a metal sleeve (12) and a vacuum sealing glue (13) between the outer surface of the optical fiber bare wire (11) and the inner surface of the metal sleeve (12), wherein the metal sleeve (12) is tubular with a through hole, the metal sleeve (12) has an end on the first direction side of one direction of the axial direction and an end on the second direction side of the other direction of the axial direction, the metal sleeve (12) can be connected to the inside of the vacuum chamber with the end on the first direction side and to the outside of the vacuum chamber with the end on the second direction side, the optical fiber bare wire (11) can pass through the through hole of the metal sleeve (12), and the outer circumferential surface of the optical fiber bare wire (11) and the inner circumferential surface of the through hole of the metal sleeve (12) are sealingly fixed by the vacuum sealing glue (13); A through hole screw (2) provided with fine thread (21) and fine thread through hole (22), the fine thread (21) can be matched with the fine internal thread of the threaded sleeve of the flange body (4), and the optical fiber body (1) can pass through the fine thread through hole (22) of the through hole screw (2); A sealing soft metal (3) provided with a through hole, both ends are cylindrical, and the middle is a circular truncated cone structure, the optical fiber body (1) can pass through the through hole of the sealing soft metal (3), and the diameter of the through hole of the sealing soft metal (3) is just enough to ensure that the metal sleeve (12) of the optical fiber body (1) is inserted, the diameter of the sealing soft metal tail cylinder (31) is just enough to insert the through hole of the through hole screw (2), and the tail end surface (24) of the through hole screw (2) is in full contact with the sealing soft metal tail end surface (32), and the diameter of the circular truncated cone structure (33) at the maximum diameter is smaller than the inner diameter of the fine internal thread segment of the threaded sleeve of the flange body (4). Flange body (4) is composed of standard CF flange and threaded sleeve, the standard CF flange and the threaded sleeve are coaxial, the flange body (4) has the end of the first direction side as one direction of the axis direction and the end of the second direction side as the other direction of the axis direction, the flange body is sealed and fixed with the corresponding standard CF flange sealing structure outside the vacuum chamber with the standard CF flange sealing structure of the end of the second direction side, and has a circular hole starting from the end of the second direction side of the axis direction in one direction of the axis direction, the circular hole can insert the optical fiber body (1), and the circular hole has a hole expansion and a circular cone hole in one direction of the axis direction with the end of the first direction side of the axis direction in one direction of the axis direction, and can insert sealing soft metal; the end surface of the sealing soft metal head cylinder (34) contacts the stepped surface formed by the circular hole and the hole expansion, the taper of the circular cone hole is slightly larger than the taper of the sealing soft metal circular cone structure (33), the circular cone hole has a fine internal thread through hole in one direction of the axis direction with the end of the first direction side of the axis direction in one direction of the axis direction, and can screw into the through hole screw, the through hole screw (2) is screwed into the threaded sleeve (41) with the fine internal thread through hole, and the depth can ensure that the tail end surface (24) of the through hole screw (2) is in full contact with the soft metal tail end surface (32), the manufacturing method of the flange body (4) includes but is not limited to laser welding splicing or integrated processing forming of the threaded sleeve and the standard CF flange, and the optical fiber body (1) can penetrate the flange body (4).

2. The optical fiber vacuum feedthrough of claim 1, wherein, The optical fiber body (1) is inserted into the through hole screw (2) and the sealing soft metal (3), and is fixed on the flange body (4).

3. The optical fiber vacuum feedthrough of claim 2, wherein, The sealing soft metal (3) is pressed into the flange body (4) by the through hole screw (2) to form a metal seal.

4. The optical fiber vacuum feedthrough of claim 3, wherein, The threaded sleeve is arranged on the flange body (4) and cooperates with the through hole screw (2) to generate a pre-tightening force.

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