Three-way structure for hollow-core optical fiber coupling and fluid injection and optical fiber unit for detection

Abstract

The invention relates to a three-way structure for hollow-core optical fiber coupling and fluid injection and an optical fiber unit for detection, belongs to the technical field of gas detection and ultrafast optical lasers, solves the technical problems that a phosgene coupling gas chamber is large in size and low in flexibility, and comprises a three-way main body and a ceramic sleeve. The three-way body is provided with three interfaces, the inflation channel interface is provided with an air chamber, an optical fiber coupling channel is arranged between the FC / APC optical fiber interface and the FC / PC optical fiber interface, the air chamber is communicated with the optical fiber coupling channel through the air chamber channel, the ceramic sleeve is located in the optical fiber coupling channel, and the first ceramic sleeve clamping groove and the second ceramic sleeve clamping groove are used for fixing the ceramic sleeve. The optical fiber unit for detection comprises a three-way structure, an FC / APC hollow optical fiber, an FC / PC hollow optical fiber and a plug. The invention discloses a liquid Raman detection system. A laser comprises an optical fiber unit for detection. The gas sensor is used for gas detection in the fields of environmental gas and medical and chemical engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of gas detection and ultrafast optics, and particularly relates to a tee structure for hollow-core fiber coupling and fluid injection and a fiber unit for detection. BACKGROUND

[0002] Optical fibers are widely used in various transmission systems due to their unique advantages. The high transmission efficiency of the optical fiber transmission system includes the transmission efficiency of the optical fiber and the coupling efficiency of the laser and the optical fiber. With the gradual maturity of the optical fiber processing technology, the transmission loss of the optical fiber has been greatly reduced. Therefore, the coupling problem of gas (liquid) and optical fiber is becoming more and more prominent.

[0003] The core part of the hollow-core optical fiber is air or a specific gas, which makes it quite different from the traditional solid optical fiber. It is surrounded by appropriate optical fiber material (such as glass) to form light transmission in the core area. Since the hollow-core optical fiber couples the transmission of light with the gas environment, the propagation of light in the optical fiber can better interact with the sensing target (gas molecules), and this interaction usually manifests as scattering, absorption or phase change of light.

[0004] The current light gas (liquid) coupling gas (liquid) filling scheme is mostly side punching or independent gas chamber filling, which has the problems of slow response speed, low coupling efficiency and complex collimation. This not only complicates the system structure, but also increases the instrument volume, making it difficult to take advantage of the advantages of lightweight and high integration of gas sensors constructed by hollow-core optical fibers.

[0005] The integrated hollow-core optical fiber filling scheme has low optical fiber reuse rate, and the optical fiber or gas chamber cannot be replaced in a plug-in manner, which makes the later maintenance difficult.

[0006] Liquid is introduced into the light guide inner hole of the hollow-core optical fiber to realize strong interaction of light and sample substances, and produce enhanced Raman signals. This Raman enhancement method essentially belongs to stimulated Raman enhancement. By using the tee structure suitable for hollow-core fiber coupling and fluid injection to inject liquid, the hollow-core optical fiber is also called liquid-core optical fiber, which makes it very convenient to replace the liquid in the inner hole and couple the light path at the port. It can even be compatible with traditional single-mode optical fiber light paths, and is very suitable for use as a liquid Raman detection reaction chamber.

[0007] The interaction of femtosecond laser and inert gas produces high-order harmonic waves, and arsecond-level ultrafast laser can be obtained. Through light gas (liquid) coupling, a good platform is provided for the generation, amplification and compression of ultrafast laser pulses, which promotes the development of fiber laser systems in the direction of generating high power, high pulse energy and short period pulses.

[0008] The use of air-filled HC-PCF to produce ultrafast ultraviolet lasers can eliminate the diffraction of light in the gas, so that the ultraviolet laser output has good beam quality. SUMMARY

[0009] In order to overcome the shortcomings of large volume and low flexibility of the phosgene coupling chamber or the light liquid coupling chamber, the application provides a tee structure for hollow core fiber coupling and fluid injection, and a detection fiber unit.

[0010] The application solves the technical problems by adopting the technical solutions of:

[0011] The tee structure for hollow core fiber coupling and fluid injection has three interfaces, namely an FC / PC fiber interface, an FC / APC fiber interface, and a gas (liquid) filling channel interface, and a gas (liquid) chamber.

[0012] The use of ceramic sleeves and fiber clamping grooves in the structure can fix and collimate the fiber and the ceramic sleeve, improve the stability and shock resistance of the tee structure, and use rubber gaskets at the FC / PC fiber interface and the FC / APC fiber interface to ensure the overall airtightness of the tee structure.

[0013] The plug-in tee structure allows the length of the hollow core fiber to be adjusted, and can form a simple and lightweight, highly integrated light gas integrated coupling structure.

[0014] The filling gas interface and plug-in gas tube joint can adapt to different caliber gas tubes, adjust the filling ratio of the light gas (liquid) coupling structure and the hollow core fiber, and the gas chamber has the advantages of fast filling speed and less required gas sample.

[0015] Coating different materials on the inner layer of the light gas (liquid) coupling structure can meet the needs of various corrosive gas (liquid) detection, or enhance the binding of the light source.

[0016] By using the light gas (liquid) coupling tee structure, multiple fibers such as total internal reflection type, photonic bandgap type, and hollow core anti-resonance type metal oxide semiconductor fibers can be coupled to produce multi-band ultrafast laser, making the experimental structure more integrated and convenient, and applied to various light gas liquid coupling scenes.

[0017] The application has the following advantages:

[0018] The tee structure for hollow core fiber coupling and fluid injection has the advantages of high stability, easy coupling of the fiber gas chamber, and low manufacturing cost.

[0019] The tee structure for hollow core fiber coupling and fluid injection can replace the fiber and the gas (or liquid) conduit by plugging, and is a simple and lightweight, highly integrated light gas or light liquid integrated coupling tee structure.

[0020] A tee structure for hollow core fiber coupling and fluid injection, the gas (or liquid) chamber can be connected with FC / PC, FC / APC type hollow core fiber, combined with light source, detector, etc. can constitute a pluggable fiber sensing system, also can produce ultrafast laser pulse through ultrafast light source and filling gas. Solve the current light gas (or liquid) coupling gas chamber volume, low flexibility and other problems. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the embodiment of the tee body of the present application isometric view;

[0022] Figure 2 is the embodiment of the tee structure of the present application front view cross-sectional view;

[0023] Figure 3 is the embodiment of the tee structure of the present application pluggable FC / PC interface;

[0024] Figure 4 is the embodiment of the tee structure of the present application pluggable FC / APC interface;

[0025] Figure 5 is the embodiment of the ceramic sleeve of the present application top view cross-sectional view;

[0026] Figure 6 is the embodiment of the ceramic sleeve of the present application left view cross-sectional view;

[0027] Figure 7 is the embodiment of the tee body of the present application left view cross-sectional view.

[0028] Reference signs: 1. gas filling channel interface, 2. FC / APC optical fiber interface, 3. FC / PC optical fiber interface, 6. gas chamber channel, 7. optical fiber coupling channel, 8. ceramic sleeve first clamping groove, 9. ceramic sleeve second clamping groove, 10. gas chamber, 11. ceramic sleeve, 12. straight cut hollow core fiber interface, 13. bevel cut hollow core fiber interface. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0030] Embodiment one

[0031] A tee structure for hollow core fiber coupling and fluid injection, mainly used for detecting gas, which needs to be coupled and connected with FC / PC optical fiber, FC / APC optical fiber and gas filling tube, to form a light gas integrated coupling tee structure.

[0032] The tee structure for hollow core fiber coupling and fluid injection realizes pluggable gas filling coupling by combining FC / PC optical fiber, FC / APC optical fiber and gas filling tube.

[0033] The FC / PC optical fiber, FC / APC optical fiber external reinforcement method used in this embodiment is to use a metal sleeve, and the fastening method is screw buckle, which is matched with Figure 1 The threaded interface of the inflation channel interface 1, FC / APC optical fiber interface 2, and FC / PC optical fiber interface 3 is fastened, and a rubber pad is matched at the interface to ensure the overall airtightness of the tee structure. The optical fiber can be plugged and replaced through the FC / APC optical fiber interface 2 and the FC / PC optical fiber interface 3, and the connected plug-in inflation pipe interface can be replaced through the inflation channel interface 1, which is convenient for subsequent docking of different caliber air pipes.

[0034] Figure 5 For the ceramic sleeve, the ceramic sleeve slit is aligned with Figure 2 9 in 7, and the horizontal position of the ceramic sleeve is fixed through 8. The cross-sectional view of the inserted ceramic sleeve is shown in Figure 2 11.

[0035] Figure 3 and Figure 4 are FC / PC optical fiber and FC / APC optical fiber interfaces, respectively. Figure 3 12 is a straight-cut hollow core interface, Figure 4 13 is an oblique-cut hollow core interface, and Figure 3 The FC / PC optical fiber in 12 is inserted into the Figure 2 3 card slot, Figure 4 The FC / APC optical fiber in 13 (oblique-cut hollow core interface) is inserted into Figure 2 The first card slot 8 of the ceramic sleeve, The optical fiber is placed in the ceramic sleeve for fixation, and then fastened by screwing.

[0036] Figure 1 1 is connected to the plug-in inflation pipe interface, and Figure 2 10 is inflated to the air chamber, Figure 2 6 connects the air chamber and the hollow core optical fiber.

[0037] After the assembly connection is completed, the gas to be tested in this example is injected into the tee structure of the optical gas (liquid) coupling from the plug-in inflation pipe interface, and the gas flows through Figure 2 6 to the pluggable FC / PC and FC / APC hollow core optical fiber.

[0038] Example Two

[0039] A tee structure for hollow core optical fiber coupling and fluid injection, which realizes pluggable liquid filling coupling by combining SMF, HC-PCF optical fiber and liquid conduit.

[0040] The portable coupling mode is introduced into the Raman detection system, although the complicated pretreatment process is required, including fiber etching, fine adjustment insertion, end face cutting, and point gluing packaging, etc. However, the reaction chamber obtained finally has the advantages of portability and high detection sensitivity, and can perform some complex Raman substance detection operations.

Claims

1. A tee structure for hollow core fiber coupling and fluid injection, characterized by, The three-way body includes a ceramic sleeve (11); The three-way body is of an integral structure and is provided with three interfaces, namely, an inflation channel interface (1) for connecting with a trachea, an FC / APC optical fiber interface (2) for connecting with an FC / APC optical fiber, and an FC / PC optical fiber interface (3) for connecting with an FC / PC optical fiber; the FC / APC optical fiber interface (2) and the FC / PC optical fiber interface (3) are coaxially opposite to each other, and the FC / APC optical fiber interface (2), the FC / PC optical fiber interface (3), and the inflation channel interface (1) form a T-shaped structure; the inflation channel interface (1), the FC / APC optical fiber interface (2), and the FC / PC optical fiber interface (3) are all threaded interfaces and can be connected in a pluggable manner. A gas chamber (10) is arranged at the lower side of the inflation channel interface (1), and the gas chamber (10) is a cylindrical cavity; a fiber coupling channel (7) is arranged between the FC / APC optical fiber interface (2) and the FC / PC optical fiber interface (3), and the fiber coupling channel (7) is a cylindrical cavity; a gas chamber channel (6) is arranged between the gas chamber (10) and the fiber coupling channel (7), and the gas chamber channel (6) communicates the gas chamber (10) with the fiber coupling channel (7). A ceramic sleeve first clamping groove (8) and a ceramic sleeve second clamping groove (9) are arranged at both ends of the coupling channel (7), the ceramic sleeve first clamping groove (8) is located at one end of the FC / PC optical fiber interface (3), and the ceramic sleeve second clamping groove (9) is located at one end of the FC / APC optical fiber interface (2); the ceramic sleeve first clamping groove (8) and the ceramic sleeve second clamping groove (9) are used for fixing the ceramic sleeve (11). The ceramic sleeve (11) is located in the fiber coupling channel (7), the outer shape of the ceramic sleeve (11) is matched with the structure of the fiber coupling channel (7); the ceramic sleeve (11) is a circular tube with an axial slit; the center line of the gas chamber channel (6) intersects the center line of the ceramic sleeve (11), and the gas chamber (10) and the ceramic sleeve (11) are communicated through the gas chamber channel (6).

2. The tee structure of claim 1, wherein A metal sleeve is further arranged between the trachea and the inflation channel interface (1), and the two ends of the metal sleeve are matched and connected with the trachea and the inflation channel interface (1), respectively.

3. Tee structure according to claim 1 or 2, characterized in that A rubber pad is further arranged at the inflation channel interface (1), the FC / APC optical fiber interface (2), and the FC / PC optical fiber interface (3), and is used for sealing connection of the three interfaces.

4. The tee structure of claim 1 wherein, The length of the ceramic sleeve (11) is 11.4±0.1mm, the inner diameter is 2.493mm, the outer diameter is 3.2±0.02mm, and the slit width is 0.5±0.1mm.

5. The tee structure of claim 1 wherein, The inner diameter of the ceramic sleeve (11) is 2.5mm, the outer diameter is 3.45mm, and the slit width is 0.5mm. The diameter of the gas chamber (10) is 7.47mm, and the height is 9mm; the diameter of the gas chamber channel (6) is 1mm.

6. The tee structure of claim 1, wherein The inner walls of the three-way body and the ceramic sleeve (11) are coated, which is used for resisting corrosion of corrosive gas or liquid and can also be used for enhancing the binding of the light source.

7. A detecting optical fiber unit characterized by comprising: The detection fiber unit comprises a three-way structure, FC / APC hollow optical fiber, FC / PC hollow optical fiber, and a plug; the three-way structure is the three-way structure for hollow optical fiber coupling and fluid injection as claimed in any one of claims 1-6; The FC / APC hollow optical fiber is connected with the FC / APC optical fiber interface (2) of the three-way structure, and the FC / PC hollow optical fiber is connected with the FC / PC optical fiber interface (3) of the three-way structure; the plug is used for plugging the aeration channel interface (1); the three-way structure is filled with a to-be-detected gas or a coupling liquid.

8. A liquid Raman detection system, characterized by, The detection fiber unit comprises the three-way structure filled with a coupling liquid as claimed in claim 7.

9. A laser characterized by, The detection fiber unit comprises the three-way structure filled with an inert gas as claimed in claim 7, and the inert gas is used for interacting with a laser to generate high-order harmonics or for eliminating diffraction of the laser in the gas.

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