Blowtorch and plasma deposition apparatus

Abstract

A blowtorch (100) and a plasma deposition apparatus (200). The blowtorch (100) comprises a first pipe fitting (10), a second pipe fitting (20), a third pipe fitting (30), and an auxiliary air inlet pipe (40). The first pipe fitting (10) defines a feeding channel (11), and the first pipe fitting (10) has a feeding end (12) and a discharging end (13) which are oppositely arranged in the length direction of the first pipe fitting. The second pipe fitting (20) is sleeved on the outer side of the first pipe fitting (10), and the second pipe fitting (20) and the first pipe fitting (10) define an auxiliary channel (Q1). The third pipe fitting (30) is sleeved on the outer side of the second pipe fitting (20), and the third pipe fitting (30) and the second pipe fitting (20) define a first cooling channel (Q2). The auxiliary air inlet pipe (40) is connected to the second pipe fitting (20), and the radial distance between the auxiliary air inlet pipe (40) and the second pipe fitting (20) gradually decreases in a direction moving close to the discharging end. The blowtorch structure can improve the deposition efficiency of the blowtorch.

Description

Blowtorches and plasma deposition equipment

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on December 8, 2023, with application number 202311685414.8, and invention name “Blowtorch and plasma deposition equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of optical fiber manufacturing technology, and in particular to a blowtorch and plasma deposition equipment. Background Art

[0003] Optical fiber preforms typically consist of a core layer and a cladding layer, with the cladding layer doped to create a relative refractive index difference with the core. Some optical fiber preforms are fabricated using POD (plasma outside deposition), which typically uses a torch to generate plasma to deposit a highly fluorine-doped layer onto the core surface. However, some known torches suffer from low deposition efficiency.

[0004] Summary of the Invention

[0005] The present application provides a blowtorch and a plasma deposition device to solve the problem of low deposition efficiency of some known blowtorches.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect, the present application provides a blowtorch comprising a first pipe, a second pipe, a third pipe, and an auxiliary air inlet pipe.

[0008] The first pipe fitting defines a feed channel, and the first pipe fitting has a feed end and a discharge end arranged opposite to each other along its length. The second pipe fitting is sleeved on the outside of the first pipe fitting, and the second pipe fitting and the first pipe fitting form an auxiliary channel, and the auxiliary channel is used to pass auxiliary gas, and the end of the auxiliary channel close to the feed end is closed, and the end of the auxiliary channel close to the discharge end is open and forms a first air outlet. The third pipe fitting is sleeved on the outside of the second pipe fitting, and the third pipe fitting and the second pipe fitting form a first cooling channel, and the first cooling channel is used to pass cooling gas, and the end of the first cooling channel close to the feed end is closed, and the end of the first cooling channel close to the discharge end is open and forms a second air outlet. The auxiliary air inlet pipe is connected to the second pipe fitting and communicates with the auxiliary channel, and the auxiliary air inlet pipe has an auxiliary air inlet away from the second pipe fitting. The auxiliary air inlet pipe is tilted relative to the second pipe fitting and tilted in the direction where the auxiliary air inlet is away from the discharge end.

[0009] When the blowtorch of the present application is in operation, raw gas is introduced from the feed end, auxiliary gas is introduced from the auxiliary air inlet pipe, and cooling gas is introduced into the first cooling channel. The raw gas and auxiliary gas merge at the discharge end and are converted from a gaseous state to a plasma state after being heated. By changing the radial spacing between the auxiliary air inlet pipe and the second pipe, the auxiliary air inlet pipe is connected to the second pipe at an angle, and the auxiliary gas input into the auxiliary channel is easily spun, flowing toward the discharge end in a spiral flow. In this way, the possibility of the auxiliary gas forming turbulence can be greatly reduced, ensuring the flow stability during the auxiliary gas delivery process. At the same time, the rotation intensity of the auxiliary gas flow can be increased, and the raw gas discharged from the discharge end and the auxiliary gas discharged from the first outlet end are mixed more evenly, thereby improving the deposition and doping efficiency of the plasma formed by the raw gas.

[0010] At the same time, since the raw gas discharged from the discharge end and the auxiliary gas discharged from the first gas outlet require heating to form a plasma, the first, second, and third pipes are subjected to heat conduction and increase in temperature to achieve the heating of the raw gas and auxiliary gas. In this embodiment, by introducing cooling gas into the first cooling channel, the discharge end, the first gas outlet, and the second gas outlet can be cooled, thereby controlling the plasma formation area of ​​the raw gas and auxiliary gas, thereby ensuring that the plasma forms only in the target area and improving the deposition and doping efficiency. In addition, increasing the rotation intensity of the raw gas and auxiliary gas airflow can further improve the deposition efficiency.

[0011] In one possible implementation:

[0012] The blowtorch also includes a first cooling air inlet pipe, which is connected to the third pipe and connected to the first cooling channel. The first cooling air inlet pipe has a first air inlet away from the third pipe. The first cooling air inlet pipe is inclined relative to the third pipe and is inclined in the direction in which the first air inlet is away from the discharge end.

[0013] In one possible implementation:

[0014] The third pipe fitting includes an inner pipe and an outer pipe, the inner pipe is sleeved on the outside of the second pipe fitting, and together with the second pipe fitting, forms the first cooling channel, the first cooling air inlet pipe is connected to the inner pipe, the outer pipe is sleeved on the outside of the inner pipe, and the outer pipe and the inner pipe form a second cooling channel, the second cooling channel is used to pass cooling air, one end of the second cooling channel close to the feed end is closed, and one end of the second cooling channel close to the discharge end is open to form a third air outlet.

[0015] In one possible implementation:

[0016] The third pipe also includes a second cooling air inlet pipe, which is connected to the outer pipe. The second cooling air inlet pipe has a second air inlet away from the third pipe. The second cooling air inlet pipe is inclined relative to the third pipe and is inclined in the direction in which the second air inlet is away from the discharge end.

[0017] In one possible implementation:

[0018] The blowtorch has a symmetrical structure, and the symmetry plane of the blowtorch is parallel to the length direction of the blowtorch; two second cooling air intake pipes are provided, and the two second cooling air intake pipes are connected to both sides of the outer tube, and the axes of the two second cooling air intake pipes are both located on the symmetry plane; two first cooling air intake pipes are provided, and the two first cooling air intake pipes are connected to both sides of the inner tube, and the axes of the two first cooling air intake pipes are located on both sides of the symmetry plane, and the projections of the axes of the two first cooling air intake pipes on the cross section of the blowtorch are parallel.

[0019] In one possible implementation:

[0020] The acute angle between the length direction of the auxiliary air intake pipe and the length direction of the second pipe is α, 15°≤α≤35°; and / or

[0021] An acute angle between a length direction of the first cooling air intake pipe and a length direction of the second pipe is β, and 15°≤β≤35°.

[0022] In one possible implementation:

[0023] There are two auxiliary air intake pipes, which are connected to both sides of the second pipe. The axes of the two auxiliary air intake pipes are parallel to each other, and the projections of the axes of the two auxiliary air intake pipes on the cross section of the first pipe are respectively located on both sides of the radial direction of the axis of the first pipe.

[0024] In one possible implementation:

[0025] The blowtorch also includes a protective cover, which is detachably connected to the second air outlet end. The protective cover defines a receiving cavity. The discharge end, the first air outlet and the second air outlet are respectively airtightly connected to the receiving cavity. The protective cover is used to install a heating component.

[0026] In a second aspect, the present application provides a plasma deposition device comprising a processing chamber and the aforementioned blowtorch, wherein the blowtorch is connected to the processing chamber, and the discharge end, the first gas outlet end, and the second gas outlet end of the blowtorch are all located in the processing chamber.

[0027] In one possible implementation:

[0028] The plasma deposition equipment also includes a premixing generator, which is arranged outside the processing chamber and connected to the feed end of the first pipe of the blowtorch. The premixing generator is used to mix the silicon compound, fluoride and carrier gas to form a uniform mixed gas, and transport the mixed gas into the first pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0030] FIG1 is a schematic structural diagram of a blowtorch according to an embodiment of the present application;

[0031] FIG2 is a schematic diagram of the structure of the blowtorch in FIG1 with the protective cover removed;

[0032] FIG3 is a radial cross-sectional view of the blowtorch of FIG2 with the protective cover removed;

[0033] FIG4 is an axial cross-sectional view of the blowtorch of FIG2 with the protective cover removed;

[0034] FIG5 is a cross-sectional view of a protective cover according to an embodiment of the present application;

[0035] FIG6 is a schematic structural diagram of a plasma deposition device according to an embodiment of the present application.

[0036] Description of main component symbols: DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be an element centered therein. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may also be an element centered therein. When an element is considered to be "set on" another element, it may be directly set on the other element or there may also be an element centered therein. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "or / and" as used herein includes any and all combinations of one or more of the relevant listed items.

[0040] Some embodiments of the present application are described in detail. In the absence of conflict, the following embodiments and features of the embodiments can be combined with each other.

[0041] 1 , this embodiment provides a blowtorch 100 , which includes a first pipe 10 , a second pipe 20 , a third pipe 30 , an auxiliary air intake pipe 40 , and a first cooling air intake pipe 50 .

[0042] The first pipe 10 defines a feed channel 11 and has a feed end 12 and a discharge end 13 disposed opposite each other along its length. A second pipe 20 is sleeved onto the outside of the first pipe 10. Together, the second pipe 20 and the first pipe 10 form an auxiliary channel Q1 for admitting auxiliary gas. The second pipe 20 has a first gas inlet end 21 and a first gas outlet end 22 disposed opposite each other along its length. The first gas inlet end 21 is connected to the feed end 12, and the first gas outlet end 22 and the discharge end 13 form a first gas outlet K1. The third pipe 30 is sleeved onto the outside of the second pipe 20. Together, they form a first cooling channel Q2, which is used to admit cooling air. The third pipe 30 has a second air inlet end 31 and a second air outlet end 32, positioned opposite each other along its length. The second air inlet end 31 is connected to the first air inlet end 21, and the second air outlet end 32 and the discharge end 13 form a second air outlet K2. An auxiliary air inlet pipe 40 is connected to the first air inlet end 21 and is located on the side of the second air inlet end 31 away from the second air outlet end 32. The radial spacing between the auxiliary air inlet pipe 40 and the second pipe 20 gradually decreases as it approaches the discharge end 13. The auxiliary air inlet pipe 40 communicates with the auxiliary channel Q1.

[0043] During operation, the blowtorch 100 of this embodiment introduces raw gas from the feed end 12, auxiliary gas from the auxiliary gas inlet pipe 40, and cooling gas from the first cooling gas inlet pipe 50. The raw gas and auxiliary gas merge at the discharge end 13 and, after being heated, transform from a gaseous state to a plasma state. By varying the radial spacing between the auxiliary gas inlet pipe 40 and the second tube 20, the auxiliary gas inlet pipe 40 is tilted relative to the second tube 20, allowing the auxiliary gas entering the auxiliary channel Q1 to spin and flow in a spiral toward the discharge end 13. By varying the radial spacing between the first cooling gas inlet pipe 50 and the third tube 30, the first cooling gas inlet pipe 50 is tilted relative to the third tube 30, allowing the cooling gas entering the first cooling channel Q2 to spin and flow in a spiral toward the discharge end 13. This significantly reduces the likelihood of turbulence in the auxiliary gas and cooling gas, ensuring flow stability during auxiliary gas and cooling gas delivery. It also increases the rotational intensity of the auxiliary and cooling gas flows, allowing for more uniform mixing of the feed gas discharged from the discharge end 13 and the auxiliary gas discharged from the first gas outlet 22, thereby improving the deposition and doping efficiency of the plasma formed by the feed gas. Furthermore, the cooling gas spiraling to the discharge end 13 also improves the cooling efficiency of the first, second, and third pipes 10, 20, and 30.

[0044] At the same time, since the raw gas discharged from the discharge end 13 and the auxiliary gas discharged from the first gas outlet 22 require heating to form a plasma, the first pipe 10, the second pipe 20, and the third pipe 30 are subjected to heat conduction and increase in temperature to achieve the heating of the raw gas and auxiliary gas. In this embodiment, by passing cooling gas into the first cooling channel Q2, the discharge end 13, the first gas outlet 22, and the second gas outlet 32 ​​can be cooled, thereby controlling the plasma formation area of ​​the raw gas and auxiliary gas, thereby ensuring that the plasma is formed only in the target area and improving the deposition and doping efficiency. In addition, the rotation intensity of the raw gas, auxiliary gas, and cooling gas is increased to improve deposition efficiency.

[0045] In this embodiment, the raw material gas is a mixed gas comprising a silicon compound, a fluoride, and a carrier gas. The silicon compound can be SiCl4, the fluoride can be one or more of CF4, SF6, or SiF4, and the carrier gas can be an inert gas such as argon. When the raw material gas includes a fluoride, the auxiliary gas used in the deposition and doping operation of the blowtorch 100 can be oxygen, and the shielding gas can be an inert gas such as nitrogen.

[0046] In this embodiment, referring to Figures 1 to 3, the blowtorch 100 further includes a first cooling air inlet pipe 50, which is connected to the second air inlet end 31. The first cooling air inlet pipe 50 is connected to the first cooling channel Q2, and the radial spacing between the first cooling air inlet pipe 50 and the third pipe 30 gradually decreases in the direction approaching the discharge end 13.

[0047] By varying the radial spacing between the first cooling air inlet pipe 50 and the third pipe 30, the first cooling air inlet pipe 50 is connected to the third pipe 30 at an angle, allowing the cooling air input into the first cooling channel Q2 to spin easily, flowing in a spiral flow toward the discharge end 13. This significantly reduces the likelihood of cooling air turbulence, ensuring flow stability during cooling air delivery. It also increases the intensity of cooling air rotation, thereby improving the cooling efficiency of the cooling air on the first pipe 10, the second pipe 20, and the third pipe 30, and thereby enhancing deposition and doping efficiency.

[0048] In this embodiment, referring to FIG. 3 , the first pipe 10 , the second pipe 20 and the third pipe 30 are coaxially arranged and are all symmetrical structures and are symmetrical about the symmetry plane M to further improve the flow uniformity and stability of the airflow.

[0049] In this embodiment, referring to Figure 3, the third pipe fitting 30 includes an inner pipe 33 and an outer pipe 34. The inner pipe 33 is sleeved on the outside of the second pipe fitting 20, and together with the second pipe fitting 20, forms a first cooling channel Q2. The first cooling air inlet pipe 50 is connected to the inner pipe 33, and the outer pipe 34 is sleeved on the outside of the inner pipe 33. The outer pipe 34 and the inner pipe 33 form a second cooling channel Q3. The second cooling channel Q3 is used to pass cooling air. The outer pipe 34 has a second air inlet end 31 and a second air outlet end 32 arranged opposite to each other along its length direction. The second air inlet end 31 is connected to the first air inlet end 21, and the second air outlet end 32 and the discharge end 13 form a second air outlet K2.

[0050] By configuring the third tube 30 as an inner tube 33 and an outer tube 34, the third tube 30 jointly defines a first cooling channel Q2 and a second cooling channel Q3. The cooling gas in the first cooling channel Q2 and the cooling gas in the second cooling channel Q3 can improve the cooling effect, thereby achieving a sufficient cooling effect on the first tube 10 and the second tube 20, thereby better controlling the plasma formation area.

[0051] In this embodiment, the third pipe 30 also includes a second cooling air inlet pipe 35, which is connected to one end of the outer pipe 34 close to the feed end 12, and the radial spacing between the second cooling air inlet pipe 35 and the outer pipe 34 gradually decreases in the direction close to the discharge end 13.

[0052] By changing the radial spacing between the second cooling air inlet pipe 35 and the outer tube 34, the second cooling air inlet pipe 35 is connected to the outer tube 34 at an angle, and the cooling air input into the second cooling channel Q3 is easily spun and flows in a spiral flow toward the discharge end 13, thereby improving the cooling efficiency of the cooling air on the first pipe 10, the second pipe 20 and the third pipe 30, and can improve the flow stability of the cooling air discharged from the second air outlet K2, and improve the airflow rotation intensity of the raw gas, auxiliary gas and cooling gas, so as to improve the deposition efficiency.

[0053] In this embodiment, referring to Figures 3 and 4 , two second cooling air intake pipes 35 are provided. These two second cooling air intake pipes 35 are connected to either side of the outer tube 34. The projections of the axes of the two second cooling air intake pipes 35 on the cross section of the first tube 10 coincide with the axis of the first tube 10. Two first cooling air intake pipes 50 are provided. These two first cooling air intake pipes 50 are connected to either side of the inner tube 33. The axes of the two first cooling air intake pipes 50 are parallel to each other, and the projections of the axes of the two first cooling air intake pipes 50 on the cross section of the first tube 10 are respectively located on radially opposite sides of the axis of the first tube 10.

[0054] By limiting the projection of the axis of the second cooling air inlet pipe 35 located on the outside to coincide with the axis of the first pipe 10, and limiting the projection of the axis of the second cooling air inlet pipe 35 located on the inside to be located on both radial sides of the axis of the first pipe 10, the cooling air on the inside is more likely to form a spiral airflow than the cooling air on the outside. The different flow modes of the cooling air in the first cooling channel Q2 and the cooling air in the second cooling channel Q3 can further enhance the overall cooling effect of the third pipe 30, which can not only further improve the cooling protection effect of the blowtorch 100, but also better limit the plasma formation area, thereby improving the deposition doping efficiency.

[0055] Optionally, the length direction of the two first cooling air intake pipes 50 is tangent to the circumference of the inner tube 33, and the radial distance between the axis of the first cooling air intake pipe 50 and the inner tube 33 can be adjusted according to actual needs. In this embodiment, the radial distance between the axis of the first cooling air intake pipe 50 and the inner tube 33 is smaller than the radius of the inner tube 33.

[0056] In this embodiment, referring to Figures 3 and 4 , two auxiliary air inlet pipes 40 are provided, connected to either side of the first air inlet end 21. The axes of the two auxiliary air inlet pipes 40 are parallel to each other, and the projections of the axes of the two auxiliary air inlet pipes 40 on the cross-section of the first tube 10 are located radially on either side of the axis of the second tube 20. This further guides the auxiliary gas to flow in a spiral within the auxiliary channel Q1, creating a more swirling auxiliary gas flow, thereby further improving deposition efficiency.

[0057] Optionally, the length direction of the two auxiliary air intake pipes 40 is tangent to the circumference of the second pipe fitting 20, and the radial distance between the auxiliary air intake pipes 40 and the axis of the second pipe fitting 20 can be adjusted according to actual needs. In this embodiment, the radial distance between the auxiliary air intake pipes 40 and the axis of the second pipe fitting 20 is smaller than the radius of the second pipe fitting 20.

[0058] In this embodiment, the acute angle α between the longitudinal direction of the auxiliary air intake pipe 40 and the longitudinal direction of the second pipe member 20 is 15°≤α≤35°. α can be specifically set to 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34°, or 35°.

[0059] In this embodiment, the acute angle between the length direction of the first cooling air inlet pipe 50 and the length direction of the second pipe 20 is β, 15°≤β≤35°;

[0060] An acute angle γ between the length direction of the second cooling air inlet pipe 35 and the length direction of the second pipe member 20 is 15°≤γ≤35°.

[0061] β can be specifically set to 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°.

[0062] γ can be specifically set to 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31°, 32°, 33°, 34° or 35°.

[0063] 3 , along the length direction of the first pipe 10 , the first gas outlet 22 is located outside the discharge end 13 away from the feed end 12 , and the second gas outlet 32 ​​is located outside the first gas outlet 22 away from the first gas inlet 21 .

[0064] In this embodiment, referring to FIG3 , the width of the discharge end 13 gradually decreases in the direction away from the feed end 12. Thus, when the input speed of the raw gas is constant, the flow rate of the raw gas output from the discharge end 13 will increase under the action of the gradually shrinking discharge end 13, thereby generating a jet focusing phenomenon, which is beneficial to improving the mixing efficiency of the raw gas and the auxiliary gas, and thereby improving the deposition doping efficiency.

[0065] In this embodiment, referring to Figures 1 and 5, the blowtorch 100 further includes a protective cover 60, which is detachably connected to the second air outlet end 32. The protective cover 60 defines a receiving cavity, and the discharge end 13, the first air outlet K1 and the second air outlet K2 are respectively airtightly connected to the receiving cavity. The protective cover 60 is used to install the heating component.

[0066] By providing the additional protective cover 60 and mounting the heating assembly thereon, the plasma formation area is primarily concentrated within the protective cover 60. The cooling air cools the air inlet, first air outlet 22, and second air outlet 32, maintaining them within a relatively low temperature range. This protects the first, second, and third pipes 10, 20, and 30, thereby extending the service life of the blowtorch 100. Furthermore, the protective cover 60 and third pipe 30 are detachably connected, facilitating replacement of the protective cover 60, thereby reducing maintenance costs and improving the ease of maintenance of the blowtorch 100.

[0067] In this embodiment, referring to FIG1 , the protective cover 60 can be directly sleeved on the third pipe 30 or can be screwed to the third pipe 30 . There are many ways to detachably connect the protective cover 60 and the third pipe 30 , which will not be described here.

[0068] In this embodiment, referring to FIG5 , the protective cover 60 includes a connecting section 61, an expansion section 62, and a protective section 63. The connecting section 61 is detachably connected to the second air outlet 32. One end of the expansion section 62 is connected to the connecting section 61, and the inner diameter of the expansion section 62 gradually increases in a direction away from the connecting section 61. The protective section 63 is connected to the other end of the expansion section 62 and is used to mount the heating assembly.

[0069] The width of the expansion section 62 gradually increases as it approaches the protective section 63, facilitating plasma diffusion. This increases the contact area between the plasma and the core rod 300, increasing the effective cross-sectional area for plasma deposition and doping, and thus improving deposition and doping efficiency. By placing the heating assembly within the protective section 63, a gap is created between the reaction chamber Q4 within the protective section 63 and the feed end 12, thereby reducing the temperature transmitted from the reaction chamber Q4 to the feed end 12. This protects the first, second, and third tubes 10, 20, and 30, thereby extending the service life of the burner 100.

[0070] In this embodiment, the transition between the widths of the two ends of the expansion section 62 is a constant width increase. In other embodiments, the transition between the widths of the two ends of the expansion section 62 can also be set to a nonlinear width increase, such as a curve or a step.

[0071] In this embodiment, referring to Figures 1 and 2 , an abutment portion 36 is provided on the outer wall of the second outlet end 32. The connecting section 61 is sleeved onto the second outlet end 32 of the third pipe member 30. The end of the connecting section 61, which is away from the protective section 63, abuts against the abutment portion 36, thereby limiting the installation of the protective cover 60. Furthermore, the thickness of the expansion section 62 is greater than that of the connecting section 61, and the end of the second outlet end 32 also abuts against the expansion section 62, thereby also limiting the installation of the protective cover 60.

[0072] 6 , the present application also provides a plasma deposition device 200. The plasma deposition device 200 includes a processing chamber 201 and the aforementioned blowtorch 100. The processing chamber 201 defines a processing cavity 202, which is used to accommodate a core rod 300. The blowtorch 100 is connected to the processing chamber 201, and the discharge end 13, the first gas outlet end 22, and the second gas outlet end 32 of the blowtorch 100 are all located in the processing cavity 202. When the plasma deposition device 200 is in operation, the raw gas and the auxiliary gas are output from the discharge end 13 and the first gas outlet end 22 into the processing cavity 202, the auxiliary gas receives free electrons and forms plasma, and the raw gas enters the plasma and is deposited on the core rod 300.

[0073] The plasma deposition device 200 includes the torch 100 of any of the above embodiments, and thus has the beneficial effects of the torch 100 of any of the above embodiments, which will not be described in detail here.

[0074] In this embodiment, referring to FIG6 , the plasma deposition apparatus 200 further includes two chucks 203 , which are spaced apart from each other. Each chuck 203 clamps a tail handle 400 , and the core rod 300 is connected between the two tail handles 400 . The blowtorch 100 is movably arranged along the length direction of the core rod 300 to achieve deposition at different positions along the length direction of the core rod 300 .

[0075] In this embodiment, referring to FIG6 , the plasma deposition apparatus 200 further includes a premixing generator 207, which is located outside the processing chamber 201 and is connected to the feed end 12 of the first pipe 10 of the blowtorch 100. The premixing generator 207 is used to mix the silicon compound, the fluoride, and the carrier gas so that they can be fully purified and mixed to form a uniform mixed gas. In this embodiment, the silicon compound can be SiCl4. At the same time, the premixing generator 207 also has a heating structure, which is used to heat the mixed gas so that the mixed gas can be more stably input into the feed channel 11, greatly reducing the possibility of turbulence during the mixed gas transportation process, thereby improving the deposition fluorine doping efficiency.

[0076] In this embodiment, referring to FIG6 , the plasma deposition device 200 further includes an induction coil 206 , which is wound around the protective cover 60 of the blowtorch 100 . The induction coil 206 is used to energize the airflow in the reaction chamber Q4 of the protective cover 60 , and can apply electric sparks in a short time to introduce free electrons into the airflow, thereby exciting the airflow to form plasma.

[0077] In this embodiment, referring to FIG6 , the plasma deposition apparatus 200 further includes an exhaust port 204 and a pressure gauge 205. The exhaust port 204 is disposed in the processing chamber 201 and communicates with the processing cavity 202. The exhaust port 204 can be closed to seal the processing cavity 202. The pressure gauge 205 is used to detect the pressure within the processing cavity 202, thereby cooperating with the exhaust port 204 to adjust the pressure of the processing cavity 202 according to actual deposition requirements.

[0078] Example 1

[0079] A core rod 300 is prepared, and both ends of the core rod 300 are polished. The outer diameter of the core rod 300 is 35 mm, and the length of the core rod 300 can be set to 700 mm.

[0080] The core rod 300 is clamped between two chucks 203 . The rotation speed of the chucks 203 is set to 45 rpm, and the pressure of the processing chamber 202 is set to -2 Pa.

[0081] The aforementioned blowtorch 100 is used for ignition. In the blowtorch 100 of Example 1, α is 25°, β is 25°, γ is 25°, and the power of the induction coil 206 is set to 60 kW to 80 kW.

[0082] A mixed gas including SiCl4, fluoride and argon is introduced into the feed channel 11, and the mixed gas is mixed and preheated by the premixing generator 207, wherein the flow rate of SiCl4 is 20g / min, the flow rate of fluoride is 150mL / min (fluoride can be one of CF4, SF6 or SiF4), and the flow rate of argon is 8L / min.

[0083] Oxygen was introduced into the auxiliary channel Q1 at a flow rate of 25 L / min.

[0084] Nitrogen gas was introduced into the first cooling channel Q2 at a flow rate of 45 L / min, and nitrogen gas was introduced into the second cooling channel Q3 at a flow rate of 75 L / min.

[0085] During the deposition process, deposition is performed by reciprocating the chucks 203 on both sides, with the interface between one end of the core rod 300 and the tail handle 400 as the starting point and the other end of the core rod 300 as the return point. The chuck 203 first moves from the starting point at a moving speed of 85 mm / min. After reaching the return point, the mixed gas input from the feed channel 11 is stopped, and polishing is performed. The polishing power is 30 kW, and the moving speed of the chuck 203 is 280 mm / min until it returns to the starting point. The above steps are repeated for multiple rounds of deposition and polishing until the deposited weight of the core rod 300 reaches 4.5 kg, thereby obtaining a deposited preform rod.

[0086] After deposition, the preform cooled to room temperature. A PK2600 instrument was used to measure the refractive index every 100 mm along the preform's axis. The relative refractive index difference Δn and the numerical aperture (NA) were calculated at each point. The mean relative refractive index difference, the difference between its maximum and minimum values, and the mean numerical aperture, the difference between its maximum and minimum values, were also measured. This process was repeated three times, and the mean values ​​of these test parameters were obtained.

[0087] Example 2

[0088] A core rod 300 is prepared, and both ends of the core rod 300 are polished. The outer diameter of the core rod 300 is 40 mm, and the length of the core rod 300 can be set to 700 mm.

[0089] The core rod 300 is clamped between two chucks 203 . The rotation speed of the chucks 203 is set to 40 rpm, and the pressure of the processing chamber 202 is set to -4 Pa.

[0090] The aforementioned blowtorch 100 is used for ignition. In the blowtorch 100 of Example 1, α is 25°, β is 25°, γ is 25°, and the power of the induction coil 206 is set to 60 kW to 80 kW.

[0091] A mixed gas including SiCl4, fluoride and argon is introduced into the feed channel 11, and the mixed gas is mixed and preheated by the premixing generator 207, wherein the flow rate of SiCl4 is 30g / min, the flow rate of fluoride is 180mL / min (fluoride can be one of CF4, SF6 or SiF4), and the flow rate of argon is 10L / min.

[0092] Oxygen was introduced into the auxiliary channel Q1 at a flow rate of 30 L / min.

[0093] Nitrogen gas was introduced into the first cooling channel Q2 at a flow rate of 50 L / min, and nitrogen gas was introduced into the second cooling channel Q3 at a flow rate of 80 L / min.

[0094] During the deposition process, deposition is performed by reciprocating the chucks 203 on both sides, with the interface between one end of the core rod 300 and the tail handle 400 as the starting point and the other end of the core rod 300 as the return point. The chuck 203 first moves from the starting point at a moving speed of 75 mm / min. After reaching the return point, the mixed gas input from the feed channel 11 is stopped, and polishing is performed. The polishing power is 35 kW, and the moving speed of the chuck 203 is 250 mm / min until it returns to the starting point. The above steps are repeated for multiple rounds of deposition and polishing until the deposited weight of the core rod 300 reaches 6.1 kg, thereby obtaining a deposited preform rod.

[0095] After deposition, the preform cooled to room temperature. A PK2600 instrument was used to measure the refractive index every 100 mm along the preform's axis. The relative refractive index difference Δn and the numerical aperture (NA) were calculated at each point. The mean relative refractive index difference, the difference between its maximum and minimum values, and the mean numerical aperture, the difference between its maximum and minimum values, were also measured. This process was repeated three times, and the mean values ​​of these test parameters were obtained.

[0096] Example 3

[0097] A core rod 300 is prepared, and the two ends of the core rod 300 are polished. The outer diameter of the core rod 300 is 45 mm, and the length of the core rod 300 can be set to 700 mm.

[0098] The core rod 300 is clamped between two chucks 203 . The rotation speed of the chucks 203 is set to 35 rpm, and the pressure of the processing chamber 202 is set to -6 Pa.

[0099] The aforementioned blowtorch 100 is used for ignition. In the blowtorch 100 of Example 1, α is 25°, β is 25°, γ is 25°, and the power of the induction coil 206 is set to 60 kW to 80 kW.

[0100] A mixed gas including SiCl4, fluoride and argon is introduced into the feed channel 11, and the mixed gas is mixed and preheated by the premixing generator 207, wherein the flow rate of SiCl4 is 40g / min, the flow rate of fluoride is 200mL / min (the fluoride can be one of CF4, SF6 or SiF4), and the flow rate of argon is 13L / min.

[0101] Oxygen was introduced into the auxiliary channel Q1 at a flow rate of 35 L / min.

[0102] Nitrogen gas was introduced into the first cooling channel Q2 at a flow rate of 55 L / min, and nitrogen gas was introduced into the second cooling channel Q3 at a flow rate of 85 L / min.

[0103] During the deposition process, deposition is performed by reciprocating the chucks 203 on both sides, with the interface between one end of the core rod 300 and the tail handle 400 as the starting point and the other end of the core rod 300 as the return point. The chuck 203 first moves from the starting point at a moving speed of 65 mm / min. After reaching the return point, the mixed gas input from the feed channel 11 is stopped, and polishing is performed. The polishing power is 40 kW, and the moving speed of the chuck 203 is 220 mm / min until it returns to the starting point. The above steps are repeated for multiple rounds of deposition and polishing until the deposited weight of the core rod 300 reaches 7.4 kg, thereby obtaining a deposited preform rod.

[0104] After deposition, the preform cooled to room temperature. A PK2600 instrument was used to measure the refractive index every 100 mm along the preform's axis. The relative refractive index difference Δn and the numerical aperture (NA) were calculated at each point. The mean relative refractive index difference, the difference between its maximum and minimum values, and the mean numerical aperture, the difference between its maximum and minimum values, were also measured. This process was repeated three times, and the mean values ​​of these test parameters were obtained.

[0105] Table 1 shows the data of relevant parameters of the preform rods in Examples 1, 2 and 3.

[0106] Table 1

[0107] It can be seen from the data of Examples 1 to 3 that under different production process conditions, such as the chuck rotation speed, the pressure of the processing chamber, the intake flow rate of the mixed gas, the intake flow rate of the auxiliary gas, the intake flow rate of the cooling gas, and different deposition weights, the relative refractive index difference and the numerical aperture of the preform rod can be maintained within a good quality range.

[0108] Comparative Example 1

[0109] The structure of the blowtorch of Comparative Example 1 is substantially the same as that of Example 3, except that the angles α, β, and γ of the blowtorch of Comparative Example 1 are 10°, 10°, and 10°, respectively. Comparative Sample 1 was obtained by processing the blowtorch of Comparative Example 1 according to the processing steps of Example 3.

[0110] Comparative Example 2

[0111] The structure of the blowtorch of Comparative Example 2 is substantially the same as that of Example 3, except that the angles α, β, and γ of the blowtorch of Comparative Example 2 are 30°, 30°, and 30°, respectively. Comparative Sample 2 was obtained by processing the blowtorch of Comparative Example 2 according to the processing steps of Example 3.

[0112] Comparative Example 3

[0113] The structure of the blowtorch of Comparative Example 3 is substantially the same as that of Example 3, except that the angles α, β, and γ of the blowtorch of Comparative Example 3 are 55°, 55°, and 55°, respectively. Comparative Sample 3 was obtained by processing the blowtorch of Comparative Example 3 according to the processing steps of Example 3.

[0114] Comparative Example 4

[0115] The structure of the blowtorch of Comparative Example 4 is substantially the same as that of Example 3, except that the axes of the second cooling air inlet pipes in Comparative Example 4 are also located on opposite sides of the plane of symmetry, and the projections of the axes of the two second cooling air inlet pipes onto the cross section of the blowtorch are parallel. Comparative Sample 4 was produced using the blowtorch of Comparative Example 4 and the same processing steps as in Example 3.

[0116] Comparative Example 5

[0117] The structure of the blowtorch of Comparative Example 5 is substantially the same as that of Example 3, except that the axis of the first cooling air inlet pipe of the blowtorch of Comparative Example 4 is located on the symmetry plane. Comparative Sample 5 was obtained by processing the blowtorch of Comparative Example 4 according to the processing steps of Example 3.

[0118] Table 2 shows the data of relevant parameters of the preforms in Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5.

[0119] It can be seen from Table 2 that when α, β, and γ are all set to 25°, the deposition rate of the preform is the largest. Therefore, by limiting the angles between the auxiliary air inlet pipe, the first cooling air inlet pipe, the second cooling air inlet pipe, and the first pipe member, the auxiliary gas and the cooling gas can be made to flow in a spiral flow toward the discharge end during the flow process, thereby making the gases evenly mixed and improving the deposition and doping efficiency.

[0120] At the same time, after changing the positional relationship of the two first cooling air intake pipes or the two second cooling air intake pipes, the deposition efficiency decreases. This is because the position setting of the first cooling air intake pipe and the second cooling air intake pipe in this embodiment can further improve the cooling effect to further improve the deposition efficiency.

[0121] In addition, in Example 3, the average numerical aperture NA is relatively high, which indicates that in Example 3, the fluorine doping amount of the cladding of the preform can reach the target value, so that the refractive index difference between the core layer and the cladding meets the requirement, and the higher average numerical aperture NA can further reduce the optical power loss generated by the optical fiber made of the preform during the transmission process, so as to further improve the preparation quality of the preform.

[0122] Table 2

[0123] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A blowtorch, characterized in that, it includes: A first pipe fitting that defines a feed channel, and the first pipe fitting has a feed end and a discharge end that are oppositely arranged along its length direction; A second pipe fitting that is sleeved outside the first pipe fitting, and the second pipe fitting and the first pipe fitting enclose an auxiliary channel for introducing auxiliary gas. One end of the auxiliary channel close to the feed end is closed, and one end of the auxiliary channel close to the discharge end is open and forms a first air outlet; A third pipe fitting that is sleeved outside the second pipe fitting, and the third pipe fitting and the second pipe fitting enclose a first cooling channel for introducing cooling gas. One end of the first cooling channel close to the feed end is closed, and one end of the first cooling channel close to the discharge end is open and forms a second air outlet; An auxiliary intake pipe that is connected to the second pipe fitting and communicates with the auxiliary channel. The auxiliary intake pipe has an auxiliary air inlet away from the second pipe fitting. The auxiliary intake pipe is inclined relative to the second pipe fitting and is inclined in the direction away from the discharge end at the auxiliary air inlet.

2. The blowtorch according to claim 1, characterized in that: The blowtorch further includes a first cooling intake pipe that is connected to the third pipe fitting and communicates with the first cooling channel. The first cooling intake pipe has a first air inlet away from the third pipe fitting. The first cooling intake pipe is inclined relative to the third pipe fitting and is inclined in the direction away from the discharge end at the first air inlet.

3. The blowtorch according to claim 2, characterized in that: The third pipe fitting includes an inner pipe and an outer pipe. The inner pipe is sleeved outside the second pipe fitting and encloses the first cooling channel with the second pipe fitting. The first cooling intake pipe is connected to the inner pipe. The outer pipe is sleeved outside the inner pipe, and the outer pipe and the inner pipe enclose a second cooling channel for introducing cooling gas. One end of the second cooling channel close to the feed end is closed, and one end of the second cooling channel close to the discharge end is open and forms a third air outlet.

4. The blowtorch according to claim 3, characterized in that: The third pipe fitting further includes a second cooling intake pipe that is connected to the outer pipe. The second cooling intake pipe has a second air inlet away from the third pipe fitting. The second cooling intake pipe is inclined relative to the third pipe fitting and is inclined in the direction away from the discharge end at the second air inlet.

5. The blowtorch according to claim 4, characterized in that: The blowtorch is of a symmetrical structure, and the symmetry plane of the blowtorch is parallel to the length direction of the blowtorch; There are two second cooling intake pipes. The two second cooling intake pipes are connected to both sides of the outer pipe, and the axes of the two second cooling intake pipes are both located on the symmetry plane; There are two first cooling inlet pipes, and the two first cooling inlet pipes are connected to both sides of the inner pipe. The axes of the two first cooling inlet pipes are located on both sides of the symmetry plane, and the projections of the axes of the two first cooling inlet pipes on the cross-section of the blowtorch are parallel.

6. The blowtorch according to claim 1, characterized in that: the acute angle between the length direction of the auxiliary inlet pipe and the length direction of the second pipe fitting is α, and 15° ≤ α ≤ 35°; and / or the acute angle between the length direction of the first cooling inlet pipe and the length direction of the second pipe fitting is β, and 15° ≤ β ≤ 35°.

7. The blowtorch according to claim 1, characterized in that: There are two auxiliary inlet pipes, and the two auxiliary inlet pipes are connected to both sides of the second pipe fitting. The axes of the two auxiliary inlet pipes are parallel to each other, and the projections of the axes of the two auxiliary inlet pipes on the cross-section of the first pipe fitting are respectively located on the radial two sides of the axis of the first pipe fitting.

8. The blowtorch according to claim 1, characterized in that: The blowtorch further includes a protective cover, the protective cover is detachably connected to the second air outlet end, the protective cover defines a receiving cavity, the discharge end, the first air outlet and the second air outlet are respectively hermetically communicated with the receiving cavity, and the protective cover is used for installing a heating component.

9. A plasma deposition device, characterized in that, comprising: a processing chamber that defines a processing cavity; a blowtorch as described in any one of claims 1 to 8, the blowtorch is connected to the processing chamber, and the discharge end, the first air outlet end and the second air outlet end of the blowtorch are all located in the processing cavity.

10. The plasma deposition device according to claim 9, characterized in that: The plasma deposition device further includes a premixing and generating device, the premixing and generating device is arranged outside the processing chamber and is communicated with the feed end of the first pipe fitting of the blowtorch, and the premixing and generating device is used for mixing a silicon compound, a fluoride and a carrier gas to form a uniform mixed gas and conveying the mixed gas into the first pipe fitting.

Images