Optical fiber and method of making same and optical fiber faceplate

Abstract

The application relates to the technical field of optical fiber manufacturing, in particular to an optical fiber and a preparation method and application thereof; the application provides an optical fiber which comprises core material and skin material coated on the outer surface of the core material, a part of the core material close to the skin material is doped with refractive penetration material, and the refractive index of the core material gradually increases from the central axis of the core material to the outer surface of the core material. The provided optical fiber greatly improves the refractive index of the core material, the core material with the gradient refractive index can increase the reflection times of light in the optical fiber, simultaneously optimizes the distribution of the light field on the pixel plane, makes the pixel edge energy more concentrated, is favorable for improving the sharpness of a picture, and thus improves the definition to a certain extent; and the process difficulty is greatly reduced, and the production yield is improved.

Description

Technical Field

[0001] This application belongs to the field of optical fiber manufacturing technology, and in particular relates to an optical fiber, its preparation method, and an optical fiber panel. Background Technology

[0002] Due to their large numerical aperture and small cutoff angle for total internal reflection, fiber optic panels have high light transmission efficiency, low interstage coupling loss, clear and realistic image transmission, and zero optical thickness. As optical input and output windows for micro-image intensifiers, they are widely used in various cathode ray tubes, camera tubes, CCD couplings, and other instruments and equipment that require image transmission.

[0003] In the actual fabrication process of optical fiber materials, the refractive index of the core material depends to a large extent on the core glass material, and the refractive index of ordinary glass is about 1.46, which is relatively low. Current solutions involve adding a certain proportion of heavy metal oxides to ordinary glass to increase the refractive index of the core material. However, heavy metal oxides are expensive, significantly increasing the manufacturing cost and hindering the large-scale commercialization of optical fiber panels.

[0004] Furthermore, each optical fiber in a fiber optic panel is formed from a core and a cladding. However, due to material limitations, the numerical aperture (NA) of the fiber cannot be infinitely large; currently, the NAV of most optical fibers is generally around 1.0 mm. Therefore, the total internal reflection angle cannot be infinitely small, resulting in some light leakage during optical signal propagation. Additionally, because the current requirements for the core diameter of optical fibers are very small, it is difficult to achieve a large aperture ratio, which easily leads to light leakage in the cladding area, causing interference with the signal light. Therefore, to address the problem of light leakage in optical fiber materials, methods such as gap-filling, statistical substitution, and cladding are used to add an absorbing material to the existing optical fiber. However, while the first two methods allow for the insertion of absorbing materials and are simple to implement, they cannot guarantee that all leaked light will be absorbed, potentially resulting in severe light leakage at specific angles, making them less than ideal methods. The cladding method wraps the absorbing material around the cladding, ensuring that leaked light from all angles is absorbed. However, this method requires a three-layer structure per fiber, making the process too difficult and resulting in a low yield, hindering large-scale production. Summary of the Invention

[0005] The purpose of this application is to provide an optical fiber, its fabrication method, and an optical fiber panel, aiming to solve the problems of low refractive index and non-concentrated light field distribution in the pixel plane of optical fiber materials in the prior art, which are not conducive to improving sharpness.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides an optical fiber, comprising a core and a sheath covering the outer surface of the core, wherein the portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core.

[0008] Secondly, this application provides a method for fabricating an optical fiber, comprising the following steps:

[0009] A core tube and a refractive permeation material are provided, and the refractive permeation material is permeated into the core tube to obtain a doped core tube;

[0010] A hollow sheath tube is provided, and the doped core tube is fitted inside the hollow sheath tube and then pressed and drawn to obtain an optical fiber.

[0011] Thirdly, this application provides an optical fiber panel including an array of optical fibers, wherein the optical fibers are selected from optical fibers or optical fibers prepared by optical fiber preparation methods.

[0012] The optical fiber provided in the first aspect of this application includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive infiltrative material, and the refractive index of the core gradually increases from its central axis to its outer surface. Because the core includes the refractive infiltrative material, and the refractive index gradually increases from its central axis to its outer surface to form a gradient refractive index, this gradient refractive index, with the addition of more refractive infiltrative material, gradually increases the refractive index to reach a maximum. This significantly improves the refractive index of the core, and the gradient refractive index increases the number of reflections of light in the optical fiber, while optimizing the distribution of the light field on the pixel plane, making the energy at the pixel edges more concentrated, which is beneficial for improving image sharpness and thus improving clarity to a certain extent. Furthermore, because the refractive index of the core gradually increases from its central axis to its outer surface, the use of refractive infiltrative material can be reduced, lowering manufacturing costs and improving production yield.

[0013] The second aspect of this application provides a method for fabricating optical fibers. The method involves first fabricating a doped core tube, then fitting the doped core tube inside a hollow sheath tube and pressing and drawing it together. This results in a doped core tube that significantly improves the refractive index of the core material. This fabrication method is simple, relatively easy, does not require large-scale equipment, and can be widely applied.

[0014] The fiber optic panel provided in the third aspect of this application includes an array of optical fibers, wherein the optical fibers are selected from optical fibers or optical fibers prepared by optical fiber preparation methods. Since the provided optical fibers have a large refractive index, they can improve the concentration of the light field distribution on the pixel plane to improve sharpness. Therefore, the resulting fiber optic panel has excellent properties, ensuring that the resulting fiber optic panel will not have light leakage and avoiding interference with signal light, which is beneficial for widespread use. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0016] Figure 1 This is a schematic diagram of an optical fiber provided in an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of an optical fiber (including absorbing material) provided in an embodiment of this application.

[0018] Figure 3 This is a curve showing the change in the refractive index distribution of the core material as a function of position, provided in the embodiments of this application.

[0019] Figure 4 These are cross-sectional views of the gradient core material and schematic diagrams of light propagation provided in the embodiments of this application.

[0020] Figure 5 This is a schematic diagram of the phase separation permeation method provided in the embodiments of this application.

[0021] Figure 6 This is a schematic diagram of metal deposition provided in an embodiment of this application.

[0022] The following are the labeling elements in the figure:

[0023] 10-Core material; 11-Core material base glass; 12-Core material base glass doped with refractive and penetrating materials; 12-1-Refractory and penetrating material in molten state; 12-2-Refractory and penetrating material metal target; 13-Sheet material; 14-Penetrating absorbent material; 14-1-Absorbent material in molten state; 14-2-Absorbent material metal target; 15-Sputtering equipment cathode; 16-Magnetic field; 17-Sputtering equipment anode;

[0024] r0 - the central axis of the core material; r1 - the radius of the core material without refractive infiltration material; r2 - the radius of the core material with refractive infiltration material; r3 - the thickness of the outer sheath. Detailed Implementation

[0025] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0026] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0027] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0028] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0029] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0030] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass in the embodiments of this application can be a well-known unit of mass in the chemical industry, such as μg, mg, g, or kg.

[0031] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0032] The first aspect of this application provides an optical fiber, such as... Figure 1 As shown, it includes a core material 10 and a skin material 13 covering the outer surface of the core material. The portion of the core material near the skin material is doped with a refractive infiltrative material, and the refractive index of the core material gradually increases from the central axis of the core material to the outer surface of the core material.

[0033] The optical fiber provided in the first aspect of this application includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive infiltrative material, and the refractive index of the core gradually increases from its central axis to its outer surface. Because the core includes the refractive infiltrative material, and the refractive index gradually increases from its central axis to its outer surface, a gradient refractive index is formed. This gradient refractive index, with the addition of more refractive infiltrative material, gradually increases the refractive index to reach its maximum. On the one hand, this significantly improves the refractive index of the core, and the gradient refractive index increases the number of reflections of light in the optical fiber, while also optimizing the distribution of the light field on the pixel plane, making the energy at the pixel edges more concentrated, which is beneficial for improving image sharpness and thus improving clarity to a certain extent. On the other hand, because the refractive index of the core gradually increases from its central axis to its outer surface, the use of refractive infiltrative material can be reduced, lowering manufacturing costs and improving production yield.

[0034] In some embodiments, such as Figure 3 As shown, the amount of refractive permeable material added gradually increases from the central axis of the core material to the outer surface of the core material, forming a gradient refractive index that gradually increases from the central axis of the core material to the outer surface of the core material; and the part of the core material near the central axis is not permeated with refractive permeable material.

[0035] At the central axis position of the core material (r1-r1), no refractive infiltrating material is used, and there is virtually no heavy metal doping. Therefore, the refractive index of light is relatively low (0-n1). As the core material extends towards its outer surface (r1-r2), the refractive infiltrating material exhibits a gradient increase (n1-n2), and the refractive index gradually increases, reaching its maximum at the outer surface (n2). The provided core material structure with gradient infiltrating can significantly reduce the use of heavy metal elements, thereby reducing costs. Furthermore, since the coating layer does not contain refractive infiltrating material but does contain absorbing material, the refractive index (n3) of the outer layer (r2-r3) is even lower.

[0036] In some embodiments, two total internal reflection surfaces are formed in the optical fiber, and no refractive permeable material is impregnated on either of these surfaces. In some specific embodiments, the portion of the core material near the central axis is not impregnated with refractive permeable material, and the portion of the sheath material near the core material is also not impregnated with refractive permeable material.

[0037] like Figure 4 As shown, in the portion of the core material near the central axis, no refractive permeable material is used. Because the refractive index changes from high to low when the light propagates from the core-sheath interface towards the central axis of the fiber core, total internal reflection still occurs. Since the refractive index of the core material is gradually changing, the location of total internal reflection within the core material varies depending on the angle of light incidence, resulting in a differentiated light distribution. The closer to the sheath, the larger the angle of total internal reflection, and the smaller the required angle of incident light. This allows for adjustment of the light distribution area. Therefore, because the incident light angle is small, the energy is higher; the energy distribution in the fiber is mainly concentrated on the outer surface of the core material, increasing display sharpness and thus improving clarity. Furthermore, the gradual change in structure increases the number of reflections of light within the fiber, further enhancing the upward buoyancy effect.

[0038] In some embodiments, the thickness of the refractive penetrating material in the core is 10% to 90% of the radius length of the core. On the one hand, this ensures that the resulting core forms a material with a gradient refractive index, thereby increasing the refractive index; on the other hand, it also ensures that the refractive penetrating material is not placed along the central axis of the core, so as not to affect the use of the optical fiber material.

[0039] In this process, the refractive infiltrative material penetrates from the outer surface of the core material to the interior of the core material. During the infiltration process, the concentration of heavy metal oxides on the outer surface of the core material is relatively high, resulting in a large refractive index. As the infiltration depth increases, the concentration of infiltrated heavy metals decreases, and the refractive index decreases relative to the outer surface of the core material. However, it will still be higher than that of the part of the core material near the central axis (the part of the core material near the central axis does not have refractive infiltrative material), thus forming a core material with a gradient refractive index.

[0040] In some embodiments, the refractive index of the portion of the core material near the central axis that is not permeated with refractive permeable material is 1.6 to 1.7; the refractive index of the portion of the core material permeated with refractive permeable material is 1.7 to 2.0; and the refractive index of the sheath is 1.4 to 1.6.

[0041] In some embodiments, the content of the refractive infiltration material accounts for 5-20% of the total molar amount of the core material. This ensures that the provided refractive infiltration material permeates in a gradient infiltration manner, guaranteeing a high refractive index optical fiber while maintaining low product cost.

[0042] In some embodiments, the core material further includes a core base glass, wherein the softening temperature of the refractive infiltrative material is lower than that of the core base glass. Since the refractive infiltrative material permeates into the core tube via a permeation process, it is required to have a low softening temperature. This is to ensure that the refractive infiltrative material reaches a molten state at a lower temperature, achieving a faster permeation effect. Furthermore, the softening temperature of the core base glass is higher than that of the refractive infiltrative material, which helps maintain the fixed shape of the core base glass during permeation, facilitating the diffusion of molecules within the refractive infiltrative material and ensuring that the core tube prepared from the core base glass maintains a fixed shape at this temperature.

[0043] In some embodiments, the core base glass includes at least one of quartz glass doped with alkali metal oxides, quartz glass doped with alkaline earth metal oxides, quartz glass doped with transition metal oxides, and quartz glass doped with heavy metal oxides.

[0044] In some embodiments, alkali metal oxides include, but are not limited to, Na2O and K2O.

[0045] In some embodiments, alkaline earth metal oxides include, but are not limited to, MgO, CaO, and BaO.

[0046] In some embodiments, the refractive infiltration material includes at least one of PbO, BaO, Y2O3, Nb2O5, and lanthanide metal oxides. In specific embodiments, a mixture of multiple metal oxides is selected as the refractive infiltration material.

[0047] Specifically, optical fibers also include a sheath covering the outer surface of the core material. For example... Figure 2 As shown, in some embodiments, the side of the sheath away from the core is doped with absorbing material 14, while the portion of the sheath close to the core is not doped with absorbing material, ensuring that the total internal reflection requirement of the optical fiber is met. In some embodiments, the interface between the sheath and the core is not doped with absorbing material; if the interface between the sheath and the core is doped with absorbing material, it will cause strong absorption of light to meet the total internal reflection requirement, resulting in significant energy loss.

[0048] In some embodiments, the thickness of the leather material doped with the absorbing material is 10% to 90% of the total thickness of the leather material. Controlling the penetration depth of the absorbing material serves two purposes: firstly, it controls the thickness of the absorbing material to absorb residual light or stray light that does not meet the requirements of total internal reflection, thus avoiding light leakage; secondly, it ensures that the absorbing material does not adhere to the interface between the core material and the leather material, so as not to affect the total internal reflection and avoid significant energy loss.

[0049] In some embodiments, the sheath provided by the optical fiber further includes a base glass, wherein the content of the absorbing material accounts for 10-20% of the total molar amount of the sheath. Controlling the content of the absorbing material is beneficial for the absorbing material to be better incorporated into the base glass, and the resulting sheath can absorb residual light or stray light that does not meet the requirements of total internal reflection, thus avoiding light leakage. If too much absorbing material is added, it is easy for the absorbing material to adhere to the interface between the sheath and the core, resulting in strong absorption of light that meets the requirements of total internal reflection, thus causing a large energy loss. If too little absorbing material is added, it is not conducive to the absorption of residual light or stray light that meets the requirements of total internal reflection, resulting in light leakage, which is not conducive to use.

[0050] In some embodiments, the softening temperature of the absorbent material is lower than that of the base glass; and the softening temperature of the absorbent material is also lower than that of the core glass. This allows the absorbent material to have a higher softening temperature during preparation, reaching a molten state at a lower temperature, thus enabling it to penetrate into the shell tube prepared from the base glass. The base glass and core glass, however, have higher softening temperatures than the absorbent material, allowing them to maintain a fixed shape within the molten absorbent material, facilitating better intermolecular diffusion and slow penetration into the shell tube. Furthermore, the similar softening temperatures and coefficients of thermal expansion of the base glass and core glass are beneficial for preventing deformation at lower temperatures and for doping the base glass with the absorbent material.

[0051] In some embodiments, the base glass of the cladding includes at least one of quartz glass doped with alkali metal oxides, quartz glass doped with alkaline earth metal oxides, and quartz glass doped with transition metal oxides.

[0052] In some embodiments, alkali metal oxides include, but are not limited to, Na2O and K2O.

[0053] In some embodiments, alkaline earth metal oxides include, but are not limited to, MgO, CaO, and BaO.

[0054] In some embodiments, heavy metal oxides include, but are not limited to, lanthanide metal oxides.

[0055] In some embodiments, the absorbing material includes at least one of colored metal ions and their oxides. Using colored metal ions and their oxides as the absorbing material is beneficial for absorbing residual or stray light from total internal reflection; if colorless metal ions and their oxides are used as the absorbing material, the light absorption effect is poor and cannot meet the absorption requirements.

[0056] In some embodiments, the absorbing material is selected from a mixture of various metal oxides to ensure that the absorbing material absorbs light in the visible light band.

[0057] In some embodiments, the absorbing material is selected from at least two of Fe2O3, CoO, MnO2, V2O5, and NiO. By permeating the absorbing material into the base glass, the absorption effect of the absorbing material on the visible light band is improved.

[0058] In some specific embodiments, the absorbent material is selected from a mixture of Fe2O3, CoO, MnO2, and V2O5 in a mass ratio of 2-2.5:1-1.5:2-2.5:1-1.5. Since different metal oxides have different diffusion rates in the molten state, it is necessary to control the ratio between different metal oxides.

[0059] In some specific embodiments, the absorbent material is selected from a mixture of Fe2O3 and CoO in a mass ratio of 4.5 to 6.0:1.0 to 3.5.

[0060] In some specific embodiments, the absorbent material is selected from a mixture of Fe2O3, CoO, and NiO in a mass ratio of 3.5–5.2:1.2–3.8:1.2–4.9.

[0061] In some embodiments, the core material has a radius of 6 micrometers to 10 millimeters; the sheath material has a thickness of 1 micrometer to 500 micrometers.

[0062] The second aspect of this application provides a method for fabricating an optical fiber, comprising the following steps:

[0063] S01. Provide a core tube and a refractive permeation material, and permeate the core tube with the refractive permeation material to obtain a doped core tube;

[0064] S02. Provide a hollow sheath tube, fit the doped core tube inside the hollow sheath tube, and perform compression drawing to obtain optical fiber.

[0065] The second aspect of this application provides a method for fabricating optical fibers. The method involves first fabricating a doped core tube, then fitting the doped core tube inside a hollow sheath tube and pressing and drawing it. The resulting doped core tube significantly improves the refractive index of the core material. This fabrication method is simple, relatively easy, does not require large-scale equipment, and can be widely applied.

[0066] In step S01, a core tube and a refractive permeation material are provided, and a doped core tube is prepared as needed. The core tube and refractive permeation material provided are the same as described above, and will not be repeated here to save space.

[0067] In one implementation, such as Figure 5 As shown, the steps for infiltrating a refractive permeating material into the core tube include:

[0068] The refractive penetrating material and low-melting-point glass are mixed and subjected to a first melting treatment to obtain a molten liquid of the refractive penetrating material.

[0069] The core tube is placed in the molten refractive infiltrate material, allowing the refractive infiltrate material to undergo the first phase separation infiltration into the core tube.

[0070] This method employs a phase-separation infiltration process, where a refractive infiltration material and a low-melting-point glass are melted together. This process allows the refractive infiltration material to form a molten liquid or near-molten state at a lower melting point, thus reducing the temperature of the molten liquid. The core tube is then directly immersed in the molten refractive infiltration material. At this temperature, due to the low softening temperature of the refractive infiltration material, better intermolecular diffusion can be achieved. Under this thermal diffusion, the refractive infiltration material slowly permeates into the core tube, while the core tube maintains a fixed shape at this temperature. This allows for better control of the infiltration depth of the refractive infiltration material. The refractive index of the outer side of the core material is controlled by adjusting the proportion of heavy metal elements in the infiltration material.

[0071] In some embodiments, the temperature of the first melting treatment is 700–800°C; the temperature of the first phase separation infiltration is 650–750°C.

[0072] In some embodiments, the first phase separation infiltration time is 1 to 2.5 hours, wherein the first phase separation infiltration time is related to the infiltration thickness of the refractive infiltration material, and the infiltration depth of the refractive infiltration material is controlled by controlling the first phase separation infiltration time.

[0073] In another embodiment, a metallic element is provided, which is deposited on the outer surface of the core tube, and then subjected to a first heat treatment in an oxygen-rich environment to convert the metallic element into a metal oxide that permeates into the core tube to form a refractive permeable material.

[0074] This method combines vapor deposition with high-temperature infiltration. A layer of elemental metal is uniformly coated on the outer surface of the core tube using vapor deposition, followed by heat treatment in an oxygen-rich environment. The oxygen-rich environment converts the elemental metal into metal oxides, which then diffuse into the core tube at high temperatures to form a refractive infiltration material.

[0075] In some embodiments, such as Figure 6 As shown, the steps for infiltrating a refractive permeating material into the core tube include:

[0076] We provide Pb, Ba, La, Y, Nb, and lanthanide metals as raw materials for permeation and refraction permeation materials.

[0077] The core tube is placed in the sputtering equipment and controlled to rotate at a constant speed around the central axis in the equipment;

[0078] The target material is bombarded using direct sputtering, with a controlled voltage of 1kV-5kV. Before sputtering begins, the cavity environment is first evacuated to a vacuum state: the vacuum level is approximately 10 kV. -5 Argon gas is introduced as a protective gas at a pressure of approximately 0.1 Pa, and the sputtering time is 1–10 hours to deposit a permeating refractive permeating material on the outer surface of the core tube. The sputtering time is determined by the desired sputtering thickness.

[0079] The raw materials for the permeation and refractive materials provided are a mixture of various metals, which ensures that the permeation materials have a high refractive index and thermal properties.

[0080] In some embodiments, the temperature of the first heat treatment is 550–650°C. Controlling the temperature of the first heat treatment to be lower than the glass transition temperature of the material itself can accelerate metal oxidation and penetration, but the temperature must be lower than the softening temperature of the outer material to ensure that the core tube has a fixed shape at high temperatures.

[0081] In some embodiments, the permeation time is 1 to 2.5 hours. The permeation time is related to the thickness of the permeation refractive material, and the permeation time is controlled according to the thickness of the permeation.

[0082] In step S02, a hollow sheath tube is provided, and a doped core tube is fitted inside the hollow sheath tube and pressed and drawn to obtain an optical fiber.

[0083] In some embodiments, the hollow tube is selected from hollow doped tubes doped with absorbent materials, and the preparation steps of the hollow doped tube include: providing a hollow tube, infiltrating absorbent material into the outer surface of the hollow tube, and obtaining a hollow doped tube.

[0084] In some embodiments, the step of preparing a hollow doped shell tube as needed includes: providing a base glass to prepare a hollow shell tube, and infiltrating an absorbent material into the hollow shell tube to obtain a hollow doped shell tube.

[0085] In one implementation, such as Figure 5 As shown, the steps for infiltrating absorbent material into the hollow plastic tube include:

[0086] The hollow ends of the hollow tube are sealed to obtain a prefabricated hollow tube.

[0087] The absorbent material and low-melting-point glass are mixed and subjected to a second melting process to obtain a melt of the absorbent material.

[0088] The prefabricated hollow tube is placed in the molten absorbent material, allowing the absorbent material to undergo a second phase separation penetration into the prefabricated hollow tube.

[0089] This method employs a phase-separation permeation technique, where the absorbent material and low-melting-point glass are mixed and melted to form a molten liquid at a lower melting point, thus reducing the temperature of the molten liquid. The casing is then directly immersed in the molten or near-molten absorbent material. At this temperature, due to the low softening temperature of the absorbent material, better intermolecular diffusion can be achieved. Under thermal diffusion, the absorbent material slowly permeates into the casing, while the casing maintains a fixed shape at this temperature, thereby better controlling the penetration depth of the absorbent material.

[0090] In some embodiments, the absorbent material and low-melting-point glass are mixed and subjected to a second melting treatment to obtain a melt of the absorbent material. The melting treatment time and temperature are determined according to the different components of the provided absorbent material. The temperature of the second melting treatment is 600-700°C. By controlling the temperature of the second melting treatment, the obtained melt of the absorbent material is kept in a molten state, which is beneficial for the molten absorbent material to penetrate into the leather.

[0091] In some embodiments, the temperature for the second phase infiltration is 550–650°C. This ensures that the absorbent material slowly permeates into the sheath tube under thermal diffusion, while the sheath tube maintains a fixed shape at this temperature, thereby better controlling the penetration depth of the absorbent material and ensuring the formation of optical fiber.

[0092] In some embodiments, the second phase infiltration time is 1 to 5 hours, wherein the thickness of the infiltration is controlled according to the infiltration time.

[0093] In another embodiment, the step of permeating the absorbent material into the leather tube includes:

[0094] A metallic element is provided and deposited on the outer surface of a hollow tube. Then, a second heat treatment is performed in an oxygen-rich environment to convert the metallic element into a metal oxide, which then diffuses into the hollow tube to form an absorbent material.

[0095] This method combines vapor deposition with high-temperature infiltration. A layer of absorbent metal is uniformly coated on the outside of the leather tube by vapor deposition. Then, it is placed in a high-temperature environment for oxidation and infiltration of the absorbent material. The elemental metal is oxidized under oxygen-rich conditions to form metal oxides. The diffusion effect of the metal oxides at high temperature allows it to penetrate into the leather tube to obtain the leather.

[0096] In some embodiments, such as Figure 6 As shown, in the step of depositing absorbent material on the outer surface of the hollow tube, ion sputtering is used to provide a sputtering target so that the absorbent material is uniformly sputtered on the entire surface of the tube.

[0097] In some specific embodiments, an absorbing material is deposited on the outer surface of the tubing using ion sputtering, including: providing a sputtering target; placing the tubing with the core material deposited in it into a sputtering apparatus and ensuring that the tubing rotates uniformly around a central axis within the apparatus; bombarding the target using direct sputtering with a controlled voltage of 1kV-5kV; and before sputtering begins, evacuating the chamber environment to a vacuum state with a vacuum level of approximately 10 kV. -5 Argon gas is introduced as a protective gas at a pressure of approximately 0.1 Pa, and the sputtering time is 1–10 hours to deposit absorbent material on the outer surface of the tubing. The sputtering time is determined by the desired sputtering thickness.

[0098] Further, a heat treatment is performed to allow the heat-treated absorbent material to permeate into the leather tube.

[0099] In some embodiments, a second heat treatment is performed in an oxygen-rich environment to accelerate the oxidation of the absorbent material and improve the permeation efficiency.

[0100] In some embodiments, the temperature of the second heat treatment is 400–500°C. Controlling the temperature of the second heat treatment to be lower than the glass transition temperature of the material itself can accelerate metal oxidation and penetration, but the temperature must be lower than the softening temperature of the leather to ensure that the leather maintains a fixed shape at high temperatures.

[0101] In some embodiments, the second infiltration time is 1 to 5 hours, and the thickness of the infiltration is controlled according to the infiltration time.

[0102] The doped core tube is fitted inside the hollow sheath tube and then pressed and drawn to form a sheath, thus obtaining an optical fiber.

[0103] In some embodiments, the pressing and drawing step includes: heating treatment with an oxyhydrogen flame at a temperature of 1200–1250°C.

[0104] A third aspect of this application provides an optical fiber panel including an array of optical fibers, wherein the optical fibers are selected from optical fibers or optical fibers prepared by optical fiber preparation methods.

[0105] The fiber optic panel provided in the third aspect of this application includes an array of optical fibers. The optical fibers are selected from optical fibers or optical fibers prepared by optical fiber preparation methods. Since the provided optical fibers not only meet the interface requirements for total internal reflection of optical fibers, but can also absorb residual light or stray light that does not meet the requirements for total internal reflection, the resulting fiber optic panel has excellent properties, ensuring that the resulting fiber optic panel will not have light leakage, avoiding interference with signal light, and is conducive to widespread use.

[0106] The following description is based on specific embodiments.

[0107] Example 1

[0108] An optical fiber and its fabrication method

[0109] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0110] The thickness of the refractive permeable material is 10% of the radius of the core material.

[0111] The content of the refractive infiltrative material accounts for 5% of the total molar amount of the core material;

[0112] The content of absorbent material accounts for 10% of the total molar weight of the leather;

[0113] The leather is 50 micrometers thick;

[0114] The thickness of the absorbent material in the leather is 10% of the total thickness of the leather.

[0115] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0116] The base glass is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3, CoO, MnO2, and V2O5 in a mass ratio of 2-2.5:1-1.5:2-2.5:1-1.5.

[0117] The method for fabricating optical fibers includes the following steps:

[0118] (1) Provide a core material base glass and a refractive permeable material. As needed, a doped core material tube is prepared by a phase separation permeation method. Specifically, the refractive permeable material and a low melting point glass are mixed and subjected to a first melting treatment to obtain a refractive permeable material melt. The core material tube is placed in the refractive permeable material melt, so that the refractive permeable material undergoes a first phase separation permeation into the core material tube.

[0119] (2) Provide the base glass and absorbent material, and prepare a hollow doped tube by phase separation infiltration method as needed; specifically, seal the hollow positions at both ends of the hollow tube to obtain a pre-made hollow tube; mix the absorbent material and low melting point glass for a second melting treatment to obtain the absorbent material melt; place the pre-made hollow tube in the absorbent material melt to allow the absorbent material to undergo a second phase separation infiltration into the pre-made hollow tube;

[0120] (3) The doped core tube is fitted inside the hollow doped sheath tube and pressed and drawn to form a sheath, thus obtaining an optical fiber.

[0121] Example 2

[0122] An optical fiber and its fabrication method

[0123] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0124] The thickness of the refractive permeable material is 20% of the radius of the core material.

[0125] The content of refractive infiltrative material accounts for 8% of the total molar amount of the core material;

[0126] The content of absorbent material accounts for 11% of the total molar weight of the leather;

[0127] The leather is 50 micrometers thick;

[0128] The thickness of the absorbent material in the leather is 10% of the total thickness of the leather.

[0129] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0130] The base glass is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3, CoO, MnO2, and V2O5 in a mass ratio of 2-2.5:1-1.5:2-2.5:1-1.5.

[0131] The method for fabricating optical fibers includes the following steps:

[0132] (1) Provide the core material base glass and refractive infiltration material. As needed, prepare the doped core material tube using ion sputtering combined with high-temperature infiltration. Specifically: provide the sputtering target, place the core material tube in the sputtering equipment, and ensure that the core material tube rotates uniformly around the central axis in the equipment; bombard the target material using direct sputtering, controlling the voltage at 1kV-5kV; before sputtering begins, first evacuate the cavity environment to a vacuum state: the vacuum degree is approximately 10. -5 Argon gas was introduced as a protective gas at a pressure of approximately 0.1 Pa, and the sputtering time was 1 hour to deposit a refractive infiltrative material on the outer surface of the core tube; and the material was infiltrated at 450°C for 1 hour under oxygen-rich conditions.

[0133] (2) Provide the base glass and absorbent material for the shell. As needed, prepare a hollow doped shell tube using ion sputtering combined with high-temperature infiltration. Specifically: provide the sputtering target, place the shell tube in the sputtering equipment, and ensure the shell tube rotates uniformly around the central axis within the equipment; bombard the target using direct sputtering, controlling the voltage at 1kV-5kV; before sputtering begins, first evacuate the cavity to a vacuum state: the vacuum degree is approximately 10... -5 Argon gas was introduced as a protective gas at a pressure of approximately 0.1 Pa, and the sputtering time was 1 hour to deposit absorbent material on the outer surface of the tubing; and the material was then permeated at 450°C for 1 hour under oxygen-rich conditions.

[0134] (3) The doped core tube is fitted inside the hollow doped sheath tube and pressed and drawn to form a sheath, thus obtaining an optical fiber.

[0135] Example 3

[0136] An optical fiber and its fabrication method

[0137] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0138] The thickness of the refractive permeable material is 30% of the radius of the core material.

[0139] The content of the refractive infiltrative material accounts for 10% of the total molar amount of the core material;

[0140] The content of absorbent material accounts for 12% of the total molar weight of the leather;

[0141] The leather is 100 micrometers thick;

[0142] The thickness of the absorbent material in the leather is 20% of the total thickness of the leather.

[0143] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0144] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3 and CoO in a mass ratio of 4.5 to 6.0:1.0 to 3.5.

[0145] The method for preparing the optical fiber is the same as that provided in Example 1.

[0146] Example 4

[0147] An optical fiber and its fabrication method

[0148] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0149] The thickness of the refractive permeable material is 40% of the radius of the core material.

[0150] The content of refractive infiltrative material accounts for 12% of the total molar amount of the core material;

[0151] The content of absorbent material accounts for 13% of the total molar weight of the leather;

[0152] The leather is 150 micrometers thick;

[0153] The thickness of the absorbent material in the leather is 30% of the total thickness of the leather.

[0154] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0155] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3, CoO and NiO in a mass ratio of 3.5-5.2:1.2-3.8:1.2-4.9.

[0156] The method for preparing the optical fiber is the same as that provided in Example 1.

[0157] Example 5

[0158] An optical fiber and its fabrication method

[0159] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0160] The thickness of the refractive permeable material is 40% of the radius of the core material.

[0161] The content of refractive infiltrative material accounts for 14% of the total molar amount of the core material;

[0162] The content of absorbent material accounts for 14% of the total molar weight of the leather;

[0163] The leather is 200 micrometers thick;

[0164] The thickness of the absorbent material in the leather is 40% of the total thickness of the leather.

[0165] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0166] The base glass is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3, CoO, MnO2, and V2O5 in a mass ratio of 2-2.5:1-1.5:2-2.5:1-1.5.

[0167] The method for preparing the optical fiber is the same as that provided in Example 1.

[0168] Example 6

[0169] An optical fiber and its fabrication method

[0170] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0171] In this process, the thickness of the refractive permeable material is 50% of the radius of the core material.

[0172] The content of refractive infiltrative material accounts for 16% of the total molar amount of the core material;

[0173] The content of absorbent material accounts for 15% of the total molar weight of the leather;

[0174] The leather is 300 micrometers thick;

[0175] The thickness of the absorbent material in the leather is 50% of the total thickness of the leather.

[0176] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0177] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3 and CoO in a mass ratio of 4.5 to 6.0:1.0 to 3.5.

[0178] The method for preparing the optical fiber is the same as that provided in Example 2.

[0179] Example 7

[0180] An optical fiber and its fabrication method

[0181] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0182] The thickness of the refractive permeable material is 60% of the radius of the core material.

[0183] The content of refractive infiltrative material accounts for 18% of the total molar amount of the core material;

[0184] The content of absorbent material accounts for 16% of the total molar weight of the leather;

[0185] The leather is 400 micrometers thick;

[0186] The thickness of the absorbent material in the leather is 60% of the total thickness of the leather.

[0187] The core material base glass is selected from quartz glass doped with alkali metal oxides;

[0188] The base glass is selected from quartz glass doped with transition metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0189] The absorbent material is selected from a mixture of Fe2O3, CoO and NiO in a mass ratio of 3.5–5.2:1.2–3.8:1.2–4.9.

[0190] The method for preparing the optical fiber is the same as that provided in Example 2.

[0191] Example 8

[0192] An optical fiber and its fabrication method

[0193] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0194] In this process, the thickness of the refractive permeable material is 70% of the radius of the core material.

[0195] The content of refractive infiltrative material accounts for 20% of the total molar amount of the core material;

[0196] The content of absorbent material accounts for 17% of the total molar weight of the leather;

[0197] The leather is 350 micrometers thick;

[0198] The thickness of the absorbent material in the leather is 70% of the total thickness of the leather.

[0199] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0200] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3 and CoO in a mass ratio of 4.5 to 6.0:1.0 to 3.5.

[0201] The method for preparing the optical fiber is the same as that provided in Example 2.

[0202] Example 9

[0203] An optical fiber and its fabrication method

[0204] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0205] In this process, the thickness of the refractive permeable material is 80% of the radius of the core material.

[0206] The content of refractive infiltrative material accounts for 20% of the total molar amount of the core material;

[0207] The content of absorbent material accounts for 18% of the total molar weight of the leather;

[0208] The leather is 350 micrometers thick;

[0209] The thickness of the absorbent material in the leather is 80% of the total thickness of the leather.

[0210] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0211] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3, CoO and NiO in a mass ratio of 3.5-5.2:1.2-3.8:1.2-4.9.

[0212] The method for preparing the optical fiber is the same as that provided in Example 2.

[0213] Example 10

[0214] An optical fiber and its fabrication method

[0215] Optical fiber includes a core and a sheath covering the outer surface of the core. The portion of the core near the sheath is doped with a refractive penetrating material, and the refractive index of the core gradually increases from the central axis of the core to the outer surface of the core. Furthermore, the sheath is doped with an absorbing material, but the interface between the sheath and the core is not doped with an absorbing material.

[0216] In this process, the thickness of the refractive permeable material is 90% of the radius of the core material.

[0217] The content of refractive infiltrative material accounts for 20% of the total molar amount of the core material;

[0218] The content of absorbent material accounts for 19% of the total molar weight of the leather;

[0219] The leather is 350 micrometers thick;

[0220] The thickness of the absorbent material in the leather is 90% of the total thickness of the leather.

[0221] The core material base glass is selected from quartz glass doped with alkali metal oxides; the refractive and penetrating materials are selected from a mixture of PbO, BaO, La2O3 and Y2O3 in a mass ratio of 1:2.5:1:1.5.

[0222] The base glass for the leather is selected from quartz glass doped with transition metal oxides; the absorbent material is selected from a mixture of Fe2O3 and CoO in a mass ratio of 4.5 to 6.0:1.0 to 3.5.

[0223] The method for preparing the optical fiber is the same as that provided in Example 2.

[0224] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An optical fiber, characterized in that, The device includes a core material and a sheath covering the outer surface of the core material. The portion of the core material near the sheath is doped with a refractive infiltrative material, which permeates and distributes from the outer surface of the core material into the core material. The portion of the core material near the central axis is not permeated by the refractive infiltrative material, causing the refractive index of the core material to gradually increase from the central axis to the outer surface. The refractive infiltrative material permeates into the core material tube by a permeation process. The core material also includes a core material base glass, wherein the softening temperature of the refractive and penetrating material is lower than the softening temperature of the core material base glass; Two total reflection surfaces are formed in the optical fiber. No refractive permeable material is impregnated in either of these two total reflection surfaces. One of these surfaces is the part of the core material near the central axis, where no refractive permeable material is impregnated. The other surface is the part of the sheath material near the core material, where no refractive permeable material is impregnated. The core material base glass includes at least one of quartz glass doped with alkali metal oxides, quartz glass doped with alkaline earth metal oxides, quartz glass doped with transition metal oxides, and quartz glass doped with heavy metal oxides. The refractive permeable material includes at least one of PbO, BaO, Y2O3, Nb2O5, and lanthanide metal oxides.

2. The optical fiber according to claim 1, characterized in that, In the core material, the thickness of the refractive permeable material is 10% to 90% of the radius length of the core material.

3. The optical fiber according to claim 1, characterized in that, The content of the refractive permeable material accounts for 5-20% of the total molar amount of the core material.

4. The optical fiber according to claim 1, characterized in that, The side of the leather material away from the core material is doped with absorbent material, while the portion of the leather material close to the core material is not doped with absorbent material.

5. The optical fiber according to claim 4, characterized in that, The thickness of the leather material doped with absorbent material is 10% to 90% of the total thickness of the leather material.

6. The optical fiber according to claim 4, characterized in that, The absorbent material accounts for 10-20% of the total molar amount of the leather.

7. The optical fiber according to claim 4, characterized in that, The leather material also includes a leather base glass, and the softening temperature of the absorbent material is lower than that of the leather base glass.

8. The optical fiber according to claim 7, characterized in that, The base glass of the skin comprises at least one of quartz glass doped with alkali metal oxides, quartz glass doped with alkaline earth metal oxides, and quartz glass doped with transition metal oxides; and / or, The absorbent material includes at least one of colored metal ions and their oxides.

9. The optical fiber according to claim 1, characterized in that, The core material has a radius of 6 micrometers to 10 millimeters; the outer layer has a thickness of 1 micrometer to 500 micrometers.

10. A method for fabricating an optical fiber according to any one of claims 1 to 9, characterized in that, Includes the following steps: A core tube and a refractive infiltration material are provided. The refractive infiltration material is infiltrated into the core tube to obtain a doped core tube. The refractive infiltration material is distributed from the outer surface of the core material to the interior of the core material, and the portion of the core material near the central axis is not infiltrated by the refractive infiltration material, so that the refractive index of the core material gradually increases from the central axis of the core material to the outer surface of the core material. A hollow sheath tube is provided, and the doped core tube is fitted inside the hollow sheath tube and then pressed and drawn to obtain an optical fiber.

11. The method for fabricating optical fiber according to claim 10, characterized in that, The step of infiltrating the core tube with a refractive permeable material includes: The refractive penetrating material and low-melting-point glass are mixed and subjected to a first melting treatment to obtain a molten liquid of the refractive penetrating material. The core tube is placed in the molten refractive permeable material, allowing the refractive permeable material to undergo a first phase separation permeation into the core tube; or, A metallic element is provided, deposited on the outer surface of the core tube, and then subjected to a first heat treatment in an oxygen-rich environment to convert the metallic element into a metal oxide that permeates into the core tube to form a refractive permeable material.

12. The method for preparing optical fiber according to claim 11, characterized in that, The temperature of the first melting treatment is 700~800℃; The temperature of the first phase separation permeation is 650~750℃; or, The temperature of the first heat treatment is 550~650℃.

13. The method for preparing optical fiber according to claim 10, characterized in that, The hollow tube is selected from hollow doped tubes containing doped absorbent materials, and the preparation steps of the hollow doped tube include: providing a hollow tube, infiltrating the hollow tube with absorbent material, and obtaining a hollow doped tube.

14. The method for preparing optical fiber according to claim 13, characterized in that, The step of infiltrating the hollow plastic tube with absorbent material includes: The hollow ends of the hollow tube are sealed to obtain a prefabricated hollow tube. The absorbent material and low-melting-point glass are mixed and subjected to a second melting process to obtain a melt of the absorbent material. The prefabricated hollow tube is placed in the molten absorbent material, allowing the absorbent material to undergo a second phase separation permeation into the prefabricated hollow tube. or, A metallic element is provided, deposited on the outer surface of the hollow tube, and then subjected to a second heat treatment in an oxygen-rich environment to convert the metallic element into a metal oxide that diffuses into the hollow tube to form an absorbent material.

15. The method for preparing optical fiber according to claim 14, characterized in that, The temperature of the second melting treatment is 600~700℃; The temperature of the second phase separation permeation is 550~650℃; or, The temperature of the second heat treatment is 400~500℃.

16. The method for preparing optical fiber according to claim 10, characterized in that, The pressing and drawing step includes: heating treatment with an oxyhydrogen flame at a temperature of 1200~1250℃.

17. An optical fiber panel comprising an array of optical fibers, characterized in that, The optical fiber is selected from the optical fiber according to any one of claims 1 to 9 or the optical fiber prepared by the optical fiber preparation method according to any one of claims 10 to 16.

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