Feeding device and optical fiber rare earth element doping device

Abstract

The invention relates to the technical field of special optical fiber manufacturing, and provides an optical fiber rare earth element doped feeding device and an optical fiber rare earth element doping device. The feeding device comprises a heat preservation box, the heat preservation box comprises an outer shell and an inner shell, a containing cavity is formed in the inner shell, a hollow interlayer is formed between the outer shell and the inner shell, a first circulating oil pipeline is arranged in the hollow interlayer, and the first circulating oil pipeline is used for maintaining the temperature in the containing cavity; the sublimation tank group is arranged in the accommodating cavity and is used for placing a rare earth compound and heating the rare earth compound; the gas collecting chamber is arranged in the containing cavity, a gas inlet of the gas collecting chamber is communicated with a gas outlet of the sublimation tank group, and a gas outlet of the gas collecting chamber is used for outputting required rare earth compound gas. According to the feeding device for doping the rare earth elements of the optical fibers, the problems that in the prior art, rare earth raw materials are heated unevenly, a pipeline is too long, so that a gas phase is condensed into solid particles, and a gas conveying channel is blocked can be effectively solved.

Description

Technical Field

[0001] This application relates to the field of special optical fiber manufacturing technology, and in particular to a feeding device and an optical fiber rare earth element doping device. Background Technology

[0002] Specialty optical fibers are now widely used in fiber optic communication, industrial lasers, fiber optic gyroscopes, beauty and skin care, and medical diagnostics and treatment. They are divided into two types: active optical fibers and passive optical fibers. Active optical fibers, as the gain medium of lasers, are an indispensable component of modern fiber lasers. Active optical fibers are specialty optical fibers doped with trace amounts of rare earth elements during the production of optical fiber preforms. Doping methods include liquid-phase doping, gas-phase doping, direct nanoparticle deposition, powder sintering, glass phase separation doping, and sol-gel processes. Among these, liquid-phase doping and gas-phase doping are the most commonly used and relatively mature processes for manufacturing specialty optical fibers. Gas-phase doping involves directly sublimating rare earth compound solid powder into a gas phase at high temperature, mixing it with a carrier gas, and then introducing it into the deposition reaction zone. This method allows for easy control of the doping concentration and can produce larger core rods, improving production efficiency and gaining importance in large-scale production.

[0003] There are two approaches to achieving vapor-phase doping. One approach is to pre-design a cavity within the deposition liner to store solid rare-earth compound powder, such as... Figure 1 As shown, the chamber is heated separately during deposition, causing the solid powder to sublimate into gas, which is then reacted with gases such as SiCl. 4 / GeCl4 / O2 or carrier gas can be introduced into the high-temperature reaction zone. Another approach is to use a separate high-temperature doping chamber for material supply, such as... Figure 2 As shown, the rare earth solid compounds are placed in separate sublimation tanks. The tanks are heated to sublimate the solid powder into gas, which is then carried by the carrier gas through a pipeline into the reaction liner. The gas is deposited on the inner surface of the liner along with the SiO2 / GeO2 particles generated in the reaction, and then melted into glass at high temperature.

[0004] In MCVD (Modified Chemical Vapor Deposition) deposition systems, although the high-temperature doping cabinets used in the existing technology can achieve vapor phase doping, in actual applications, the sublimation tank is heated by an electric heating belt, which results in uneven heating. Moreover, after the rare earth compounds sublimate, they are prone to condensation in the conveying channel, causing dust blockage and production interruption. Summary of the Invention

[0005] This application provides a feeding device for rare earth element doping in optical fibers, which solves the problems of uneven heating of rare earth raw materials and dust blockage in the prior art.

[0006] This application also provides a rare earth element doping device for optical fibers. A feeding device for rare earth element doping of optical fibers according to a first aspect embodiment of this application, the feeding device comprising: An insulated box includes an outer shell and an inner shell, wherein a receiving cavity is formed inside the inner shell, and a hollow interlayer is formed between the outer shell and the inner shell. A first circulating oil pipeline is provided inside the hollow interlayer, and the first circulating oil pipeline is used to maintain the temperature in the receiving cavity. A sublimation tank assembly, disposed within the containment cavity, is used to hold and heat rare earth compounds; A gas collecting chamber is disposed in the receiving cavity. The gas inlet of the gas collecting chamber is connected to the gas outlet of the sublimation tank assembly. The gas outlet of the gas collecting chamber is used to output the required rare earth compound gas.

[0007] According to one embodiment of this application, the feeding device for rare earth element doping of optical fibers further includes a preheating chamber, the outlet of which is connected to the inlet of the sublimation tank assembly, and the preheating chamber is configured to preheat the carrier gas entering the sublimation tank assembly through the preheating chamber.

[0008] According to one embodiment of this application, the feeding device for rare earth element doping of optical fibers further includes a feeding injection tube with a high-temperature oil jacket communicating with the gas outlet of the gas collecting chamber. The high-temperature oil jacket includes a first heating layer disposed outside the feeding injection tube and a second circulating oil pipeline disposed within the first heating layer.

[0009] According to one embodiment of this application, the sublimation tank group includes sublimation tanks, and the number of sublimation tanks is set to 1 to 6.

[0010] According to one embodiment of this application, when the sublimation tank is a one-time feeding type, the sublimation tank includes: The tank body is provided with a carrier gas inlet, a gas phase mixture outlet and a material inlet, wherein the carrier gas inlet forms the air inlet of the sublimation tank assembly and the gas phase mixture outlet forms the air outlet of the sublimation tank assembly; When the sublimation tank is a continuously feeding type, the sublimation tank further includes: The metering tube is connected at its lower end to the material inlet. The silo contains rare earth compounds, and the lower opening of the silo is connected to the upper end of the metering tube.

[0011] According to one embodiment of this application, the sublimation tank further includes: A metering screw is installed in the hopper, and part of it is located in the metering tube; the metering screw is configured to: when stationary, restrict the rare earth compounds in the hopper from falling into the tank, and when rotating, drive a portion of the rare earth compounds in the hopper into the tank; A drive motor drives the metering screw to rotate.

[0012] According to one embodiment of this application, the sublimation tank is covered with a second heating layer, and a third circulating oil pipeline is provided inside the second heating layer. The third circulating oil pipeline is used to heat the rare earth compound in the sublimation tank to sublimate it.

[0013] According to one embodiment of this application, the insulated box is a cuboid or a cylinder.

[0014] According to a second aspect of this application, a rare earth element doping device for optical fibers includes: Deposition lathe; A deposition liner is installed on the deposition lathe; it is equipped with a rare earth compound inlet, a main feed inlet, and a tail gas outlet; a feeding device is provided, with the gas outlet of the gas collection chamber connected to the rare earth compound inlet.

[0015] According to one embodiment of this application, the optical fiber rare earth element doping device further includes a high-temperature circulating oil system, which is connected to the first circulating oil pipeline, the second circulating oil pipeline and the third circulating oil pipeline respectively, for providing high-temperature circulating oil and maintaining the gas phase state after the rare earth compound sublimates. The high-temperature circulating oil system is separated from the insulation box to shorten the distance between the insulation box and the deposition liner.

[0016] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects: In the feeding device for rare earth element doping of optical fibers disclosed in this application, a first circulating oil pipeline is installed in the hollow jacket of an insulated box. This first circulating oil pipeline heats the sublimation tank assembly within the insulated box, causing the rare earth compounds in the sublimation tank assembly to sublimate, facilitating subsequent rare earth element doping processes. The first circulating oil pipeline creates a high-temperature environment throughout the insulated box, improving the uniformity and stability of heating, ensuring that the rare earth elements inside the sublimation tank assembly are uniformly heated and stably sublimated, guaranteeing a stable supply of vaporized rare earth compounds, and ensuring effective doping.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of one of the existing technologies for rare earth element vapor phase doping in optical fibers.

[0020] Figure 2 This is a schematic diagram of the structure of a gas-phase doping device commonly used in existing optical fiber rare earth elements.

[0021] Figure 3 This is a schematic diagram of the feeding device for rare earth element doping of optical fibers in this application.

[0022] Figure 4 This is a schematic diagram of the sublimation tank in this application. Figure 1 (Continuous feeding is achieved by using a metering screw and other structures).

[0023] Figure 5 This is a schematic diagram of the sublimation tank in this application. Figure 2 (One-time feeding; and the outer surface of the tank is covered with a third circulation oil pipeline).

[0024] Figure 6 This is a schematic diagram of the structure of the insulated box in this application. Figure 1 (Cylinder).

[0025] Figure 7 This is a schematic diagram of the insulation box structure in this application. Figure 2 (cuboid).

[0026] Figure 8 This is a schematic diagram of the structure of the optical fiber rare earth element gas phase feeding and delivery pipeline (including the feeding injection pipe with a high-temperature oil jacket) in this application.

[0027] Figure 9 This is a schematic diagram of the high-temperature circulating oil system in this application.

[0028] Figure label: 1. Insulated box; 11. Outer shell; 12. Inner shell; 13. Receiving cavity; 14. First circulating oil pipeline; 141. Circulating oil inlet; 142. Circulating oil outlet; 15. First thermocouple; 16. Insulation layer; 2. Sublimation tank assembly; 21. Sublimation tank; 211. Tank body; 212. Metering tube; 213. Hopper; 2131. Feeding port; 214. Metering screw; 215. Drive motor; 22. Third circulating oil pipeline; 3. Gas collecting chamber; 31. Gas inlet of gas collecting chamber; 32. Gas outlet of gas collecting chamber; 33. Feed injection pipe; 331. Second circulation... Oil pipeline; 332, rotary joint; 4, preheating chamber; 41, air inlet of preheating chamber; 42, air outlet of preheating chamber; 51, rare earth compound; 52, carrier gas; 61, deposition lathe; 611, guide rail; 612, feeding trolley; 62, deposition liner; 63, high-temperature circulating oil system; 631, circulating oil return port; 632, circulating pump; 633, heat exchanger; 634, throttle valve; 635, condenser; 636, compressor; 637, second thermocouple; 638, circulating oil outlet; 639, filler neck; 71, reaction zone; 72, exhaust gas. Detailed Implementation

[0029] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0030] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0032] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples. The term "multiple" in the embodiments of this application should be understood as two or more.

[0034] In addition to the problems described in the background art, the existing MCVD deposition systems also have the following technical problems: 1. The rare earth element dopant cabinet and the deposition lathe are independently set up and separated by a considerable distance. The sublimated rare earth compounds need to be transported via pipeline. Because the pipeline for transporting the rare earth compound gas is long and needs to be maintained at a constant high temperature, coupled with defects in the insulation design at the pipe joints, the temperature inside the pipeline drops rapidly. This causes the vaporized rare earth compounds to condense again, forming solid particles and ultimately blocking the pipeline, especially at pipe joints and bends. 2. The cabinet occupies a relatively large space, resulting in poor convenience during actual operation. 3. The connection between the inlet pipe and the lathe has structural design flaws, making it easy for the waste gas generated by the reaction gas to backflow and leak, polluting the working environment.

[0035] like Figure 2 As shown, in actual production, the original rare earth compound gas phase feeding system frequently malfunctions, requiring frequent shutdowns to clean the pipelines, making it difficult to form a continuous production process and greatly affecting production efficiency.

[0036] According to an embodiment of the first aspect of this application, a feeding device for rare earth element doping of optical fibers is provided, such as... Figure 3 As shown, the feeding device includes: an insulated box 1, including an outer shell 11 and an inner shell 12, with a receiving cavity 13 formed inside the inner shell 12, and a hollow interlayer formed between the outer shell 11 and the inner shell 12, with a first circulating oil pipeline 14 provided inside the hollow interlayer, the first circulating oil pipeline 14 being used to maintain the temperature in the receiving cavity 13; a sublimation tank group 2, provided in the receiving cavity 13, for placing rare earth compound 51 and heating it; and a gas collecting chamber 3, provided in the receiving cavity 13, with the gas inlet 31 of the gas collecting chamber connected to the gas outlet of the sublimation tank group 2, and the gas outlet 32 ​​of the gas collecting chamber connected to the jacketed feeding injection pipe (33), for outputting the required rare earth compound 51 gas to the inlet of the deposition liner pipe 62.

[0037] The insulated box 1 adopts a double-layer structure of outer shell 11 and inner shell 12. The hollow sandwich formed between the two provides installation space for the first circulating oil pipeline 14. This double-layer structure itself can form a basic heat insulation barrier, reducing the heat loss from the containment cavity 13 to the outside, and laying the foundation for maintaining a high-temperature environment. The first circulating oil pipeline 14 set in the hollow sandwich can heat the containment cavity 13 through the heat transfer of circulating oil. Compared with the electric heating belt heating method used in the traditional sublimation tank 21, the heat distribution of circulating oil is more uniform, which can avoid the problems of local overheating or insufficient heating. At the same time, the heating stability of circulating oil is higher, which can effectively reduce the risk of production interruption due to heating element failure, and solve the technical problems of uneven heating and easy failure of traditional heating methods.

[0038] Sublimation tank assembly 2 is located within the containment cavity 13 of the insulated box 1, and can be directly placed in the uniform high-temperature environment constructed by the first circulating oil pipeline 14. This allows the rare earth compound 51 within the sublimation tank assembly 2 to be uniformly heated, thereby achieving stable sublimation. A stable gas supply ensures the consistency of doping concentration in the subsequent rare earth element doping process for optical fibers, thereby improving the doping effect of optical fiber products and solving the technical problems of pipeline blockage and unstable material supply in traditional transportation processes.

[0039] The gas collection chamber 3 is also located within the receiving cavity 13, and its inlet is connected to the outlet of the sublimation tank group 2. This allows for the centralized collection of rare earth compound 51 gas generated by the sublimation tank group 2 before it is output through the outlet. This centralized collection and output design reduces the risk of gas leakage during transport, effectively improving the working environment compared to the traditional connection structure between the inlet pipe and the MCVD lathe, which is prone to backflow and leakage. Furthermore, the gas collection chamber 3 ensures more stable gas output, further enhancing the stability of the material supply. Simultaneously, the integrated design of the insulation box 1, the sublimation tank group 2, and the gas collection chamber 3 replaces the traditional separate design of the material cabinet and the deposition lathe 61, significantly reducing the overall footprint of the equipment. During operation, there is no need for frequent back-and-forth movement between the material cabinet and the lathe, improving operational convenience and solving the technical problems of large footprint, inconvenient operation, and environmental pollution caused by traditional cabinets.

[0040] In practical applications, the arrangement of the gas collecting chamber 3 also facilitates the installation of a one-way valve to prevent the backflow of vaporized rare earth compounds 51.

[0041] According to one embodiment of this application, such as Figure 3 As shown, the feeding device for rare earth element doping of optical fiber also includes a preheating chamber 4. The air inlet 41 of the preheating chamber is used to introduce carrier gas 52, and the air outlet 42 of the preheating chamber is connected to the air inlet of the sublimation tank group 2. The preheating chamber 4 is configured to preheat the carrier gas 52 that enters the sublimation tank group 2 through the preheating chamber 4.

[0042] The connecting pipes between the preheating chamber 4, the sublimation tank 21, and the gas collecting chamber 3 are placed directly in the insulation box 1 to ensure that the pipes maintain a constant temperature and do not cool down.

[0043] The preheating chamber 4 provides a temperature regulation mechanism before the carrier gas 52 enters the sublimation tank group 2, avoiding local temperature fluctuations caused by the carrier gas 52 absorbing heat directly into the high-temperature sublimation tank group 2 at room temperature. After the carrier gas 52 is heated by the preheating chamber 4, its temperature can be well matched with the ambient temperature inside the sublimation tank group 2, reducing heat exchange losses caused by excessive temperature difference. Combined with the uniform heating environment formed by the first circulating oil pipeline 14 in the insulation box 1, the temperature inside the sublimation tank group 2 can be maintained within a stable range, ensuring that the rare earth compound 51 can undergo the sublimation reaction in a constant thermal environment, which is beneficial to maintaining the consistency of the sublimation rate.

[0044] After preheating, the carrier gas 52 enters the sublimation tank assembly 2, enabling it to more efficiently carry the vaporized rare earth compound 51 into the gas collection chamber 3. Because the temperature difference between the carrier gas 52 and the rare earth gas is reduced, the probability of the rare earth gas condensing into solid particles due to a sudden temperature drop during transport is decreased, reducing the risk of pipeline blockage and ensuring unobstructed gas transport. Simultaneously, the stable temperature of the carrier gas 52 helps maintain a uniform distribution of the rare earth gas in the gas flow, resulting in a more stable concentration of the output rare earth compound 51 gas. This provides a uniform raw material base for subsequent optical fiber doping processes, which is beneficial for improving the doping quality stability of optical fiber products.

[0045] The coordinated design of the preheating chamber 4 with the sublimation tank group 2 and the insulation box 1 can also optimize the overall energy utilization efficiency of the equipment. After preheating, the airflow state of the carrier gas 52 is more stable, reducing airflow disturbances caused by temperature changes. Combined with the centralized output structure of the gas collecting chamber 3, it can reduce the risk of turbulence and leakage during gas transportation. At the same time, the preheating chamber 4 can be integrated into the receiving cavity 13 of the insulation box 1 or set up adjacent to the sublimation tank group 2 without occupying a lot of extra space, maintaining the overall compactness of the equipment and improving the ease of operation.

[0046] In practical applications, gas flow control can still be achieved by the existing carrier gas MFC (mass flow controller).

[0047] In some cases, multiple independent preheating channels can be set up in the preheating chamber 4, with each channel corresponding to a sublimation tank 21 in the sublimation tank group 2, and each preheating channel is equipped with an independent temperature control element. This structural design enables differentiated preheating for different carrier gas 52 paths, meeting the individualized temperature requirements of different rare earth compounds 51 in the sublimation tank group 2. For example, for rare earth compounds 51 with higher sublimation temperatures, the carrier gas 52 can be heated to a higher temperature through the corresponding preheating channel to enhance its carrying capacity; for rare earth compounds 51 with lower sublimation temperatures, the preheating temperature of the carrier gas 52 can be appropriately reduced to avoid energy waste caused by overheating. Simultaneously, a flow regulation device can be added to the air inlet of the preheating chamber 4, combined with temperature control to achieve coordinated regulation of the "temperature-flow" dual parameters of the carrier gas 52, further improving the precise control capability of the feeding process.

[0048] According to one embodiment of this application, such as Figure 3 As shown, the feeding device for rare earth element doping of optical fiber also includes a feeding injection tube 33 with a high-temperature oil jacket connected to the gas outlet 32 ​​of the gas collecting chamber. The high-temperature oil jacket includes a first heating layer disposed outside the feeding injection tube 33 and a second circulating oil pipeline 331 disposed inside the first heating layer to prevent the sublimated rare earth compound 51 gas from condensing.

[0049] As a key channel connecting the gas collecting chamber 3 and subsequent doping processes, the feed injection tube 33, with its outer first heating layer and inner second circulating oil pipeline 331, provides continuous and stable heat supply, effectively maintaining the high-temperature environment inside the feed injection tube 33. Through heat transfer via the circulating oil, the second circulating oil pipeline 331 keeps the temperature of the feed injection tube 33 within a range suitable for the rare earth compound 51 gas, preventing phase changes due to sudden temperature drops during transport, fundamentally reducing the probability of pipeline blockage, and ensuring unobstructed gas transport path.

[0050] The heating method of the second circulating oil pipeline 331 features uniform temperature distribution. Compared with traditional electric heating, which is prone to temperature differences due to localized heating, the circulating oil can achieve uniform heat coverage around the outer periphery of the feed injection tube 33 through its flow, ensuring consistent temperature across different sections of the feed injection tube 33 (including straight sections and joint sections), further reducing the risk of condensation caused by localized low temperatures. Simultaneously, the circulating oil heating exhibits strong stability, maintaining the set temperature for extended periods and avoiding temperature fluctuations due to heating element malfunctions. This ensures that the rare earth compound 51 gas is delivered to subsequent processes in a stable state, guaranteeing the consistency of rare earth element doping concentration in optical fibers. A stable gas supply avoids uneven doping caused by gas flow interruptions or concentration fluctuations, improving the quality stability of optical fiber products.

[0051] The first heating layer is equipped with a second circulating oil pipeline 331, which can reduce the heat loss from the feed injection pipe 33 to the external environment and reduce energy consumption. At the same time, for the feed injection pipe 33 joint, a traditional high-failure area, the first heating layer can provide enveloping heating, which can make up for the deficiencies of traditional joint insulation design, prevent the joint from becoming a weak point due to heat loss, further improve the reliability of the entire conveying system, reduce the number of downtimes for cleaning due to pipe blockage, and ensure the continuity of production, which is in line with the overall high-efficiency and stable design goals of the feeding device.

[0052] The second circulating oil line 331 is similar to the first circulating oil line 14, which can make the temperature control more uniform and make temperature control more convenient and easier.

[0053] In some cases, a temperature sensor can be added inside the first heating layer. This sensor is electrically connected to the temperature control system of the second circulating oil pipeline 331 to monitor the outer wall temperature of the feed injection tube 33 in real time and feed the temperature data back to the temperature control system. When the local temperature of the feed injection tube 33 is detected to be lower than a set threshold, the temperature control system can automatically adjust the circulation rate or oil temperature of the second circulating oil pipeline 331 to achieve dynamic and precise temperature control of the feed injection tube 33, adapting to the differentiated temperature requirements of different types of rare earth compound 51 gases. Simultaneously, an auxiliary heating ring can be separately installed on the outside of the joint of the feed injection tube 33. This auxiliary heating ring shares the temperature control system with the second circulating oil pipeline 331, further enhancing the heat supply to the joint and preventing heat loss due to structural connection at the joint. This forms a dual guarantee of "overall heating + local enhancement," improving the comprehensiveness of the temperature control of the feed injection tube 33.

[0054] According to one embodiment of this application, such as Figure 3 As shown, the sublimation tank assembly 2 includes sublimation tanks 21. The number of sublimation tanks 21 can be set from 1 to 6 depending on the type of rare earth doped compound, for example, it can be 3, 4 or 5. Sublimation tank assembly 2 serves as the sublimation zone for rare earth compound 51 and adopts a modular and miniaturized design. Each type of rare earth compound 51 can use one sublimation tank 21, and the number can be increased or decreased as needed, making it highly practical.

[0055] The sublimation tank 21, serving as the vaporization chamber for rare earth compounds 51, meets three basic requirements: first, maintaining a sufficient temperature; second, a special structural design to ensure the solid material is fully exposed to the temperature field and undergoes complete sublimation; and third, separate design for the gas and solid phases. The cylindrical sublimation tank 21 can have dimensions (internal cavity) of 20-200 mm in diameter and 50-300 mm in height. The sublimation tank 21, equipped with a high-temperature circulating oil jacket, has an outermost insulation layer 16. The thickness of the insulation layer 16 is determined based on the internal temperature control and the external ambient temperature; a typical material is high-temperature insulation cotton, with a thickness of 5-50 mm.

[0056] The number of sublimation tanks 21 is set to 1 to 6, which can adapt to the production needs of rare earth element doping of optical fibers of different scales. For small-batch trial production or single rare earth element doping scenarios, only 1 to 2 sublimation tanks 21 need to be used, which can avoid idle equipment resources and energy waste. For medium-batch production or scenarios that require mixed doping of two or more rare earth elements, 3 to 6 sublimation tanks 21 can be used, and different types of rare earth compounds 51 can be placed in different sublimation tanks 21. Then, the gas is mixed through the subsequent gas collection chamber 3, without the need to add an additional independent feeding device, which simplifies the equipment configuration for mixed doping.

[0057] To adapt to the requirements of different optical fiber products for doping with various rare earth elements, multiple independent sublimation tanks 21 can be installed in the containment cavity 13 of the insulation box 1. Each sublimation tank 21 corresponds to a different type of rare earth compound 51, and the outlet of each sublimation tank 21 is connected to the inlet 31 of the gas collection chamber through a pipe with a control valve. By controlling the opening of each valve, the proportion of different rare earth compound 51 gases entering the gas collection chamber 3 can be adjusted to achieve mixed doping of multiple rare earth elements and improve the adaptability of the device to different production needs. At the same time, a temperature sensor can be added in the hollow jacket of the insulation box 1. The temperature sensor is electrically connected to the temperature control system of the first circulating oil pipeline 14. The temperature sensor monitors the temperature in the containment cavity 13 in real time, and the temperature control system adjusts the temperature of the first circulating oil in real time according to the monitoring data to maintain the temperature in the containment cavity 13 within the set range, further improving the accuracy of temperature control, ensuring the stability of the sublimation rate of rare earth compound 51, and thus more accurately controlling the amount of rare earth compound 51 gas generated.

[0058] Multiple sublimation tanks 21 can be freely combined and placed into a high-temperature chamber as a whole, or each sublimation tank 21 can be heated, kept warm and controlled individually, and used flexibly as needed.

[0059] According to one embodiment of this application, when the sublimation tank is a one-time feeding type, the sublimation tank 21 includes: a tank body 211, provided with a carrier gas inlet 52, a gas phase mixture outlet, and a material inlet, the carrier gas inlet 52 forming the air inlet of the sublimation tank group 2, and the gas phase mixture outlet forming the air outlet of the sublimation tank group 2; as Figure 4 As shown, when the sublimation tank is a continuously feeding type, in addition to the aforementioned tank body 211, the sublimation tank also includes: a metering tube 212, the lower end of which is connected to the material inlet; and a hopper 213, which contains rare earth compound 51, with the lower opening of the hopper 213 connected to the upper end of the metering tube 212.

[0060] The carrier gas inlet 52 of tank 211 provides a channel for the carrier gas 52 to enter, and the gas phase mixture outlet realizes the mixed output of rare earth compound 51 gas and carrier gas 52. The material inlet is connected to the silo 213 through the metering pipe 212, forming a material conveying path of "silo 213-metering pipe 212-tank 211". This path can realize continuous feeding of rare earth compound 51, avoiding heat loss and environmental interference caused by directly opening tank 211 for feeding. Traditional sublimation tank 21 requires interrupting heating and opening tank 211 for feeding, which can easily damage the high temperature environment inside the tank and affect sublimation stability. In this solution, the silo 213 can pre-store rare earth compound 51 and deliver the material to tank 211 through metering pipe 212, reducing the number of times tank 211 is opened, maintaining the temperature inside the tank is stable, and ensuring the consistency of the sublimation rate of rare earth compound 51.

[0061] The metering tube 212 can regulate the amount of rare earth compound 51 entering the tank 211, preventing excessive material from entering at once, which could lead to accumulation inside the tank, uneven heating, or insufficient material causing supply interruption. Through the buffering and metering function of the metering tube 212, the amount of rare earth compound 51 inside the tank 211 can always be kept within a suitable sublimation dosage range. Combined with the uniform heating of the first circulating oil pipeline 14 in the insulation box 1, the uniformity of rare earth compound 51 sublimation is further improved, ensuring the stability of the concentration of rare earth compound 51 in the gas phase mixture. This provides a stable raw material basis for the subsequent optical fiber doping process and reduces the difference in doping quality caused by fluctuations in material dosage.

[0062] The design of the hopper 213, which houses the rare earth compound 51, extends the duration of a single feeding cycle, reducing the workload of frequent refills by operators. Simultaneously, the combination of the hopper 213 and the metering tube 212 creates a relatively sealed material storage and conveying space, preventing the rare earth compound 51 from coming into contact with the external environment during refilling and thus avoiding deliquescence or contamination. This ensures the purity of the rare earth compound 51 and reduces the impact of impurities on the doping quality of the optical fiber. Furthermore, this structural layout allows the material refilling and gas output processes of the sublimation tank 21 to be independent yet coordinated, improving the ease of operation and the reliability of the feeding process.

[0063] To increase the sublimation rate of solid particles, the material added to the tank 211 of the sublimation tank 21 can be laid in multiple layers or suspended in a fluidized bed.

[0064] Of course, in addition to the "metering and feeding" method described above, tank 211 can also adopt a one-time feeding method and a corresponding tank 211 structure, such as... Figure 5 As shown, after the one-time feeding is completed, ensure that there is enough rare earth in tank 211 to sustain the entire doping process.

[0065] According to one embodiment of this application, such as Figure 4 As shown, the sublimation tank 21 also includes: a metering screw 214, installed in the hopper 213, and partially located in the metering tube 212; the metering screw 214 is configured to: restrict the rare earth compound 51 in the hopper 213 from falling into the tank body 211 when stationary, and drive a portion of the rare earth compound 51 in the hopper 213 to fall into the tank body 211 when rotating; and a drive motor 215 to drive the metering screw 214 to rotate.

[0066] Compared to single-time feeding, the working method of metering screw 214 and drive motor 215 can continuously feed at a set time, reducing the heat required for sublimation, creating conditions for space reduction, and at the same time, it can accurately control the amount of rare earth compounds used, reducing material costs.

[0067] The combination of the metering screw 214 and the drive motor 215 provides a precise and controllable delivery method for replenishing rare earth compounds 51 in the sublimation tank 21. Driven by the drive motor 215, the metering screw 214 can precisely control the amount of rare earth compounds 51 falling into the tank 211 each time by adjusting the rotation speed or the number of rotations, so that the tank always maintains an appropriate material level. Combined with the uniform high-temperature environment formed by the first circulating oil pipeline 14 in the insulation box 1, it ensures the continuous and stable sublimation of rare earth compounds 51, thereby ensuring the consistency of the concentration of rare earth compounds 51 in the gas phase mixture and providing a stable raw material supply for the subsequent optical fiber doping process.

[0068] When stationary, the metering screw 214 prevents rare earth compounds 51 from falling into the tank 211 from the hopper 213. This structural feature prevents materials from accidentally leaking into the tank 211 due to seal failure or gravity during non-replenishment stages, reducing the risk of excessive material accumulation inside the tank. Simultaneously, it eliminates the need for frequent opening of the tank 211 or hopper 213 to control material replenishment, effectively maintaining a relatively sealed environment between the hopper 213 and the tank 211. This reduces the risk of moisture or contamination of rare earth compounds 51 caused by external air intrusion, ensuring material purity. It also prevents the high-temperature environment inside the tank from being disrupted when the tank 211 is opened, reducing the impact of temperature fluctuations on sublimation efficiency and further improving supply stability.

[0069] The drive motor 215 enables automated control of the material conveying process, eliminating the need for manual adjustment of material replenishment and reducing operator workload and human error. Operators can remotely or automatically adjust the motor parameters to adapt to material demands under different production rhythms. Especially in collaborative scenarios involving multiple sublimation tank groups 2, unified control of motor parameters can achieve synchronization of material conveying across multiple tanks, improving overall equipment operating efficiency and production coordination.

[0070] In some cases, a frequency converter can be added to the drive motor 215, and the frequency converter is electrically connected to the material level sensor inside the tank 211. The material level sensor monitors the amount of rare earth compound 51 in the tank 211 in real time. When the amount is lower than a set threshold, the frequency converter automatically adjusts the speed of the drive motor 215 to increase the rotation speed of the metering screw 214 and increase the material conveying capacity. When the amount is close to the set upper limit, the motor speed is reduced to decrease the conveying capacity, forming a closed-loop control of "inventory monitoring - speed adjustment - precise replenishment", which further improves the accuracy of material conveying and avoids over- or under-material conveying. At the same time, a wear-resistant coating can be added to the surface of the metering screw 214. A high-temperature and corrosion-resistant coating material can be selected to extend the service life of the metering screw 214 in high-temperature environments, reduce the decrease in material conveying accuracy caused by screw wear, and reduce equipment maintenance costs.

[0071] According to one embodiment of this application, such as Figure 5 As shown, the sublimation tank 21 is covered with a second heating layer, and a third circulating oil pipeline 22 is provided inside the second heating layer. The third circulating oil pipeline 22 is used to heat the rare earth compound 51 inside the sublimation tank 21 to sublimate it. In this case, the number and density of the first circulating oil pipelines 14 in the hollow jacket of the insulation box 1 can be appropriately reduced, so that the first circulating oil pipelines 14 mainly maintain the temperature of the gas collecting chamber 3 and the preheating chamber 4 inside the insulation box 1, thereby reducing the heating requirements of the first circulating oil pipelines 14.

[0072] In other words, the temperature of the sublimation tank 21 can be controlled by heat transfer from the insulation box 1, or each sublimation tank 21 can be equipped with an oil bath heating jacket or heating cylinder (with a third circulating oil pipeline 22), and a temperature sensor can be used to control the individual temperature of the sublimation tank 21.

[0073] The combination of the second heating layer and the third circulating oil pipeline 22 provides a targeted local heating path for the sublimation tank 21, enabling direct heat application to the rare earth compound 51 within the sublimation tank 21. Compared to the overall heating mode relying on the first circulating oil pipeline 14 in the hollow jacket of the insulation box 1, local heating provides more direct and efficient heat transfer, quickly heating the rare earth compound 51 to its sublimation temperature while reducing heat loss to other areas of the insulation box 1, thus improving energy utilization efficiency. Simultaneously, this local heating method allows for precise temperature control of the sublimation tank 21, avoiding temperature fluctuations caused by overall heating, ensuring the rare earth compound 51 remains in a stable sublimation state, guaranteeing the consistency of the rare earth compound 51 concentration in the gas mixture, and providing stable raw materials for subsequent fiber optic doping processes.

[0074] Reducing the number and density of the first circulating oil pipeline 14 in the hollow jacket of the insulation box 1 lowers the heating requirements for the first circulating oil pipeline 14. The first circulating oil pipeline 14 only needs to focus on maintaining the temperature of the gas collecting chamber 3 and the preheating chamber 4—the gas collecting chamber 3 needs to stabilize its temperature to prevent the gas mixture from condensing, and the preheating chamber 4 needs to maintain the preheating effect of the carrier gas 52. The temperature requirements of both are relatively mild and stable. After the load on the first circulating oil pipeline 14 is reduced, the temperature control accuracy is easier to ensure, and the equipment maintenance cost is reduced.

[0075] The independent heating functions of the second heating layer and the third circulating oil pipeline 22 complement the heat preservation function of the first circulating oil pipeline 14. The heating requirement of the sublimation tank 21 is specifically met by the third circulating oil pipeline 22, while the temperature requirements of the gas collecting chamber 3 and the preheating chamber 4 are specifically guaranteed by the first circulating oil pipeline 14, avoiding mutual interference caused by differences in temperature requirements in different areas. For example, there is no need to excessively increase the temperature of the first circulating oil pipeline 14 to meet the high temperature requirement of the sublimation tank 21, thereby affecting the gas stability of the gas collecting chamber 3; nor is there need to limit the heating intensity of the sublimation tank 21 to maintain a mild temperature in the gas collecting chamber 3, effectively balancing the temperature requirements of each area and improving the operational stability of the entire feeding device.

[0076] According to one embodiment of this application, such as Figure 6 and Figure 7 As shown, the insulated box 1 is a cuboid or cylinder to achieve miniaturization.

[0077] The insulation box 1 can adopt a cuboid shape. Its regular planar structure facilitates its arrangement, stacking, or docking with other equipment (such as the deposition lathe 61) in the production workshop, making full use of the workshop's floor space and reducing the equipment's footprint. At the same time, the internal space of the cuboid has a regular linear distribution, which is conducive to the modular layout of components such as the sublimation tank group 2, the gas collection chamber 3, and the preheating chamber 4 according to the preset functional zones. For example, the sublimation tank group 2 can be evenly arranged along the length of the cuboid, with the gas collection chamber 3 located at one end and the preheating chamber 4 located at the other end, forming a clear material and gas flow path. It also facilitates the laying of the first circulating oil pipeline 14 in a straight or right-angled path within the hollow jacket, reducing the resistance and heat loss caused by pipeline bends and ensuring heating uniformity.

[0078] The insulation box 1 can also adopt a cylindrical shape. Its arc-shaped sidewall structure results in a more uniform stress distribution when heated, which can reduce local deformation caused by thermal expansion and contraction of the box due to the heating of the first circulating oil pipeline 14, and extend the service life of the insulation box 1. At the same time, the annular hollow sandwich space of the cylinder makes it easier for the first circulating oil pipeline 14 to be spirally and uniformly wound, so that the pipeline can fully cover the inside of the box, further improving the uniformity of temperature distribution in the containment cavity 13, avoiding the problem of low temperature in the corner areas that may exist in the cuboid shape, and better maintaining a stable temperature environment for the sublimation tank group 2, the gas collecting chamber 3, and the preheating chamber 4, ensuring the stability of the sublimation of rare earth compound 51 and gas transportation.

[0079] The insulated box 1 can be made of heat-resistant (>300℃) metal materials, such as stainless steel. A hollow sandwich layer is formed between two stainless steel plates (i.e., outer shell 11 and inner shell 12) to house the first circulating oil channel. The spacing between the first circulating oil channels is 3~20mm. The outermost layer is the insulation layer 16, the thickness of which is determined according to the internal temperature control and external ambient temperature of the insulated box. A typical material is high-temperature insulation cotton, with a thickness of 5~100mm. Rectangular dimensions (internal cavity): length 200~1000mm; width 200~1000mm; height 300~1000mm. Cylindrical dimensions (internal cavity): diameter 100~800mm; height 300~1000mm.

[0080] According to an embodiment of the second aspect of this application, a rare earth element doping device for optical fibers is provided, such as... Figure 8 As shown, the fiber optic rare earth element doping device includes: a deposition lathe 61; a deposition liner 62, mounted on the deposition lathe 61; a rare earth compound inlet, a main feed inlet, and a tail gas outlet; and a feeding device, wherein the gas outlet 32 ​​of the gas collecting chamber is connected to the inlet of the deposition liner 62 through a feed injection pipe 33.

[0081] The feeding device can be mounted on a movable feeding cart 612, which moves along the guide rail 611 on the deposition lathe 61 to approach or move away from the deposition liner 62. The feeding device mounted on the feeding cart 612 is located near the MCVD equipment. The temperature and gas flow control of the high-temperature doping cabinet (i.e., the feeding device) are designed separately, and can be integrated into the existing deposition platform control system or controlled independently.

[0082] The deposition lathe 61 provides stable support for the reaction carrier of the deposition liner 62 during the fiber doping process by fixing it in place. During the deposition and doping processes, the deposition liner 62 needs to maintain a specific position and orientation to ensure uniform deposition of the raw materials. The deposition lathe 61, through its stable clamping and positioning structure, avoids uneven deposition caused by vibration or displacement of the deposition liner 62, ensuring the consistency of the thickness and concentration of the subsequent doped layer. This solves the problem of product quality fluctuations caused by unstable fixing of traditional liners.

[0083] The rare earth compound inlet of the deposition liner 62 is directly connected to the gas outlet of the gas collecting chamber 3 of the feeding device via a feeding injection pipe with a high-temperature oil jacket. Compared with existing rare earth doping devices, this shortens the transport path of the rare earth compound 51 gas, reduces the risk of the sublimated rare earth compound gas condensing into solid particles due to temperature drop during long-distance transport, and also reduces the probability of supply interruption caused by pipeline blockage. The main feed inlet can separately introduce the main raw materials required for the optical fiber matrix, achieving precise mixing of the rare earth compound 51 gas and the main raw materials in the liner. Combined with the timely discharge of waste gas generated by the reaction at the tail gas outlet, this avoids the accumulation of waste gas in the liner, which could affect reaction efficiency or contaminate the product, further improving the stability of the doping process and the purity of the product.

[0084] The structural synergy of the entire device enhances production continuity and operational convenience. The stable rare-earth doping gas supplied by the feeding device enters the liner through a dedicated inlet, eliminating the need to share a conveying channel with the main raw material and reducing interference between different raw materials. The modular installation of the deposition lathe 61 and the deposition liner 62 facilitates liner replacement and maintenance. Combined with the automated feeding capability of the feeding device, it reduces manual intervention and operational errors. The independent exhaust outlet simplifies the waste gas treatment process, eliminating the need for complex separation of mixed gases, improving overall production efficiency, and adapting to the needs of large-scale optical fiber doping production.

[0085] According to one embodiment of this application, such as Figure 9 As shown, the fiber optic rare earth element doping device also includes a high-temperature circulating oil system 63, which is connected to the first circulating oil pipeline 14, the second circulating oil pipeline 331, and the third circulating oil pipeline 22, respectively, to provide high-temperature circulating oil and maintain the gas phase state after the rare earth compound sublimates; the high-temperature circulating oil system 63 is set separately from the heat preservation box 1 to shorten the distance between the heat preservation box 1 and the deposition liner 62.

[0086] The feed injection pipe 33 with a high-temperature oil jacket is set outside the insulation box 1, connecting the gas from the gas outlet 32 ​​of the gas collecting chamber to the MCVD deposition liner 62; the high-temperature circulating oil system 63 is set separately outside the insulation box 1. The high-temperature circulating oil system 63 provides a constant temperature heating circulating medium for the insulation box 1, the sublimation tank group 2 and the jacket of the feed injection pipe 33, etc., to ensure that the sublimation gas remains in the gas phase state.

[0087] The high-temperature circulating oil system 63 includes: a circulating oil return port 631, a circulating pump 632, a heat exchanger 633, a throttle valve 634, a condenser 635, a compressor 636, a second thermocouple 637, a circulating oil output port 638, and a filling port 639. The high-temperature circulating oil system 63 delivers high-temperature circulating oil that meets the required temperature to the first circulating oil pipeline 14, the second circulating oil pipeline 331, and the third circulating oil pipeline 22 via the circulating oil output port 638. For example, the circulating oil output port 638 can be connected to the circulating oil inlet 141 of the first circulating oil pipeline 14, and the circulating oil outlet 142 of the first circulating oil pipeline 14 can be connected to the circulating oil return port 631 of the high-temperature circulating oil system 63. The circulating oil entering the high-temperature circulating oil system 63 through the circulating oil return port 631 first passes through the circulating pump 632 to obtain the power to flow to the subsequent pipeline, then passes through the heat exchanger 633 to be heated, then passes through the throttle valve 634, and then passes through the condenser 635 to adjust the temperature (e.g., to appropriately cool down the circulating oil that is too hot after passing through the heat exchanger 633 so that the temperature of the circulating oil is within the required range), and then passes through the compressor 636 and the second thermocouple 637 before being output to the circulating oil pipeline through the circulating oil output port 638.

[0088] The high-temperature circulating oil system 63 can be a high-temperature oil-type mold temperature controller, with a maximum temperature of 360℃, configured according to the sublimation temperature of the dopant. Its high-temperature oil output can be single or multiple, with each output allowing independent control of the circulating oil inlet and outlet temperatures. Safety features can be added to the high-temperature oil-type mold temperature controller if necessary.

[0089] The high-temperature circulating oil system 63 provides a unified high-temperature circulating oil for the first circulating oil pipeline 14, the second circulating oil pipeline 331, and the third circulating oil pipeline 22. This ensures the basic temperature consistency of the heating medium in the three circulating oil pipelines, avoiding temperature deviations caused by independent power supply from different heating sources. The first circulating oil pipeline 14 needs to maintain the temperature of the gas collecting chamber 3 and the preheating chamber 4 in the insulation box 1. The second circulating oil pipeline 331 needs to prevent the condensation of rare earth compound 51 in the feed injection pipe 33. The third circulating oil pipeline 22 needs to heat the rare earth compound 51 in the sublimation tank 21 to sublimate it. Although the temperature requirements of the three are different, the unified power supply can be precisely matched through subsequent branch control (such as valve flow regulation), reducing the instability of sublimation rate or pipeline blockage caused by temperature fluctuations, and ensuring the continuity of the entire feeding and doping process. The coordinated operation of multiple circulating oil pipelines enables continuous and precise temperature control in different zones.

[0090] The high-temperature circulating oil system 63 is separated from the insulation box 1, which significantly reduces the overall volume of the insulation box 1 and eliminates the restriction imposed by the high-temperature circulating oil system 63 on the installation location of the insulation box 1, thereby shortening the distance between the insulation box 1 and the deposition liner 62. With the distance shortened, the length of the feed injection pipe 33 connecting the gas collecting chamber 3 and the rare earth compound inlet of the deposition liner 62 is correspondingly reduced. This reduces the risk of condensation due to heat loss during long-distance gas transport, further reducing the probability of pipe blockage. Furthermore, the shortened path of the feed injection pipe 33 reduces gas transport resistance, improving the rate stability of rare earth compound 51 gas reaching the deposition liner 62 and avoiding fluctuations in doping concentration due to transport delays. Simultaneously, the separate setup facilitates independent maintenance of the high-temperature circulating oil system 63 and the insulation box 1. For example, when repairing the heating device, it is not necessary to disassemble the insulation box 1, reducing the impact on the overall operation of the feeding system and improving the convenience of equipment maintenance.

[0091] The doping device can also be configured with separate cold and hot zones: in the feeding device, the insulation box 1 only encloses the sublimation tank group 2, the gas collection chamber 3, the preheating chamber 4, and part of the high-temperature feeding injection pipeline, while the related solenoid valves, MFCs, etc. can operate at room temperature (cold zone), improving operational reliability and service life. The control system can be designed independently to adapt to various deposition equipment and processes.

[0092] Compared to multiple independent heating sources, the unified high-temperature circulating oil system 63 reduces the overall failure points of the equipment and lowers operation and maintenance costs. Its centralized power supply mode also optimizes energy utilization efficiency, avoids energy waste caused by the heat dissipation of independent heating sources, and, together with the space layout optimization brought about by the separate setting, makes the workshop space occupied by the entire optical fiber rare earth element doping device more reasonable, adapting to the equipment layout requirements of large-scale production.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should be covered within the scope of the claims of this application.

Claims

1. A supply device for optical fiber rare earth dopants, characterized in that, The application relates to a heat preservation box (1) and a sublimation tank group (2) and a gas collecting chamber (3) and a preheating chamber (4) and a feed injection pipe (33) with a high-temperature oil jacket. The heat preservation box (1) comprises an outer shell (11) and an inner shell (12), a containing cavity (13) is formed in the inner shell (12), a hollow interlayer is formed between the outer shell (11) and the inner shell (12), a first circulating oil pipeline (14) is arranged in the hollow interlayer, and the first circulating oil pipeline (14) is used for maintaining the temperature in the containing cavity (13); the sublimation tank group (2) is arranged in the containing cavity (13) and is used for placing and heating a rare earth compound (51); and the gas collecting chamber (3) is arranged in the containing cavity (13), an air inlet (31) of the gas collecting chamber is communicated with an air outlet of the sublimation tank group (2), and an air outlet (32) of the gas collecting chamber is used for outputting the required rare earth compound (51) gas. The preheating chamber (4) is further arranged, an air outlet (42) of the preheating chamber (4) is communicated with an air inlet of the sublimation tank group (2), and the preheating chamber (4) is arranged to preheat carrier gas (52) entering the sublimation tank group (2) through the preheating chamber (4). The feed injection pipe (33) with the high-temperature oil jacket is further arranged and communicated with the air outlet (32) of the gas collecting chamber, the high-temperature oil jacket comprises a first heating layer arranged outside the feed injection pipe (33) and a second circulating oil pipeline (331) arranged in the first heating layer.

2. A supply for optical fiber rare earth dopants according to claim 1, characterized in that, The sublimation tank group (2) comprises sublimation tanks (21), and the number of the sublimation tanks (21) is arranged to be 1-6.

3. A device for supplying optical fiber rare earth dopant according to claim 2, characterized in that, When the sublimation tank (21) is in a one-time feeding form, the sublimation tank (21) comprises a tank body (211) provided with a carrier gas (52) inlet, a gas phase mixture outlet and a material inlet, the carrier gas (52) inlet forms the air inlet of the sublimation tank group (2), and the gas phase mixture outlet forms the air outlet of the sublimation tank group (2).

4. A supply for optical fiber rare earth dopants according to claim 3, characterized in that, When the sublimation tank (21) is in a continuous feeding form, the sublimation tank (21) further comprises:

5. A supply for optical fiber rare earth dopants according to claim 4, characterized in that, A metering pipe (212) in communication with the material inlet at a lower end; A bin (213) internally provided with the rare earth compound (51), and a lower end opening of the bin (213) is in communication with an upper end of the metering pipe (212). The sublimation tank (21) further comprises: A metering screw (214) installed in the bin (213) and partially located in the metering pipe (212), and the metering screw (214) is arranged to limit the rare earth compound (51) in the bin (213) from falling into the tank body (211) when being static and to drive part of the rare earth compound (51) in the bin (213) to fall into the tank body (211) when rotating; 6. A supply for optical fiber rare earth dopants according to claim 5, characterized in that, A driving motor (215) driving the metering screw (214) to rotate. The outer side of the sublimation tank (21) is covered with a second heating layer, a third circulating oil pipeline (22) is arranged in the second heating layer, and the third circulating oil pipeline (22) is used for heating the rare earth compound (51) in the sublimation tank (21) to sublimate. The heat preservation box (1) is a rectangular parallelepiped or a cylinder.

7. The apparatus for supplying a rare earth dopant for an optical fiber according to claim 4, wherein The application further relates to a deposition lathe (61).

8. A supply device for optical fiber rare earth dopants according to any of claims 1 to 7, characterized in that, ​ 9. An optical fiber rare earth dopant apparatus, comprising: ​ ​ A deposition liner (62) is installed on the deposition lathe (61); The rare earth compound inlet, the main feeding inlet and the tail gas outlet are arranged; The gas outlet (32) of the gas collection chamber is communicated with the rare earth compound inlet of the deposition liner (62) through a feeding injection pipe (33) with a high-temperature oil jacket.

10. The optical fiber rare earth dopant apparatus of claim 9, wherein, The feeding device for the optical fiber rare earth element doping is the feeding device for the optical fiber rare earth element doping as claimed in claim 7. The optical fiber rare earth element doping device further comprises a high-temperature circulating oil system (63) which is communicated with the first circulating oil pipeline (14), the second circulating oil pipeline (331) and the third circulating oil pipeline (22) respectively, so as to provide high-temperature circulating oil and maintain the gaseous state of the sublimed rare earth compound. The high-temperature circulating oil system (63) is arranged separately from the heat preservation box (1), so as to shorten the distance between the heat preservation box (1) and the deposition liner (62).

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