High-temperature-resistant airborne optical cable

Abstract

The utility model discloses a high-temperature-resistant airborne optical cable, which belongs to the technical field of special optical cables and realizes buffer protection of optical fibers in the airborne optical cable by arranging an integral buffer layer structure which is hard outside and soft inside and is formed by a soft first buffer layer and a hard second buffer layer in the airborne optical cable. Attenuation loss of the optical fiber caused by external stress is reduced; meanwhile, the first buffer layer is formed in a longitudinal wrapping mode, so that the degree of freedom of the optical fibers in the optical cable and the convenience of subsequent application are improved. The high-temperature-resistant airborne optical cable provided by the utility model is simple in structure and convenient to prepare, can effectively meet the application requirements of the optical cable in an airborne environment, fully guarantees the high-temperature-resistant performance of the optical cable, improves the external acting force influence resistance of the optical fibers in the optical cable, effectively improves the stability and convenience of the airborne optical cable in the actual application process, and is suitable for popularization and application. Attenuation loss of the optical cable caused by external stress is reduced, and reliability of optical cable signal transmission is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of special optical cables, and in particular relates to a high-temperature resistant airborne optical cable. Background Art

[0002] With the rapid development of fiber optic communication technology, its application environment has become increasingly complex, placing higher requirements on the temperature resistance of optical cables, especially in special application fields such as oil well exploration and airborne communications.

[0003] In the field of airborne communications, due to the physical characteristics of airborne optical cables such as thin diameter, small size, and light weight, in terms of signal transmission, optical fiber has low transmission loss and large bandwidth, and optical fiber and optical waveguide devices are mostly dielectric materials, no electromagnetic radiation, and good stealth effect. Therefore, after changing the cable-based airborne transmission system to an optical fiber transmission system, it can not only greatly reduce the cost and weight, but also be well suited for airborne communication environments with strict restrictions on space and load. For this reason, with the rapid development of optical communication technology, the aerospace field has gradually adopted optical cables as signal transmission media. Airborne optical cables are imperative as irreplaceable signal transmission hubs on aircraft.

[0004] At present, the temperature range of airborne optical cables used in many models is usually -55℃~+125℃, and there is a problem that the tight jacket material is easy to deform during the stripping process, resulting in difficulty in stripping. In order to cope with more stringent use environments and optimize the processing process of downstream customers, the current airborne optical cables are in urgent need of product upgrades.

[0005] For existing airborne optical cables, commonly used extrusion materials include ETFE, FEP, PFA, PEEK and other materials, and in order to protect the optical fiber, the tight-fitting buffer layer generally adopts a multi-layer structure design. For example, in the existing patent document CN204556926U, after the PTFE film is wrapped around the periphery of the optical fiber, the PEEK material is used for tight-fitting molding. The above approach can meet the application requirements of airborne optical cables to a certain extent and enhance the buffering effect of the tight-fitting layer on the optical fiber. However, after verification by researchers, it was found that the above-mentioned optical cables have very obvious defects in the process of processing, preparation and actual application, which is mainly reflected in the fact that the optical fiber additional attenuation of the prepared optical cable is high, and the preparation yield of the optical cable is low, which leads to the high application cost of the optical cable; moreover, it is also found in the actual application process that the wrapping film of the optical cable is difficult to remove, and the optical fiber is easily damaged during the removal process, which greatly affects the application of airborne optical cables. Utility Model Content

[0006] In response to one or more of the above defects or improvement needs in the prior art, the utility model provides a high-temperature resistant airborne optical cable, which can effectively meet the application requirements in harsh high-temperature environments, reduce the additional attenuation of the optical cable, and meet the application requirements that the buffer layer can be quickly removed during the use of the optical cable, thereby promoting the application of airborne optical cables.

[0007] To achieve the above object, the utility model provides a high temperature resistant airborne optical cable, comprising an optical fiber located in the middle, the optical fiber is a high temperature resistant optical fiber, and a buffer layer, a reinforcement layer and an outer sheath are sequentially arranged on its periphery from the inside to the outside; the characteristics are:

[0008] The buffer layer includes a first buffer layer located inside and a second buffer layer located outside the first buffer layer;

[0009] The first buffer layer is a soft buffer layer, which is formed by a soft film-like material strip in a longitudinally wrapped manner into a longitudinally continuously extending cylindrical structure;

[0010] The second buffer layer is a hard buffer layer, which is formed by extrusion of an extruded material and is bonded to the first buffer layer to form an integral buffer layer structure.

[0011] As a further improvement of the present invention, a gap of 0-0.25 mm is formed between the first buffer layer and the optical fiber.

[0012] As a further improvement of the present invention, the first buffer layer is formed by longitudinally wrapping a PTFE film around the outer periphery of the optical fiber; and / or, the second buffer layer is formed by extruding a PEEK material around the outer periphery of the first buffer layer.

[0013] As a further improvement of the present invention, the optical fiber is a high temperature resistant optical fiber, which is a 9μm / 125μm single-mode optical fiber, a 50μm / 125μm multi-mode optical fiber or a 62.5μm / 125μm multi-mode optical fiber.

[0014] As a further improvement of the present invention, the film-like material tape is one or more film-like material tapes circumferentially wrapped around the outer periphery of the optical fiber.

[0015] As a further improvement of the utility model, at least one film material placement portion is formed in an annular direction on the outer periphery of the optical fiber.

[0016] As a further improvement of the present invention, the overlapping width of the film material overlapping portion is not greater than 0.1 mm; and the width of the film material strip used to form the first buffer layer is 1.6 to 3 times the circumference of the optical fiber.

[0017] As a further improvement of the present invention, the outer diameter of the buffer layer is 0.85-0.95 mm, and the concentricity is less than 40 μm; and the inner diameter of the buffer layer is not less than 0.53 mm.

[0018] As a further improvement of the utility model, the diameter of the airborne optical cable is within 1.9 mm.

[0019] As a further improvement of the present invention, the reinforcing layer is a fiber material woven structure, the outer diameter of which is 1.3±0.1 mm and the total modulus is not less than 7000 dtex;

[0020] and / or

[0021] The outer sheath is formed of fluoroplastics, has an outer diameter of 1.8±0.1 mm, and a wall thickness of 0.2-0.3 mm. The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0022] In general, compared with the prior art, the above technical solutions conceived by the utility model have the following beneficial effects:

[0023] (1) The high temperature resistant airborne optical cable of the utility model can effectively realize the buffer protection of the optical fiber in the airborne optical cable by arranging an integral buffer layer structure composed of a soft first buffer layer and a hard second buffer layer in the airborne optical cable, reduce the direct effect of external force on the surface of the optical fiber, and avoid the attenuation loss of the optical fiber caused by external stress; at the same time, by forming the first buffer layer in a longitudinal wrapping manner, the pressure or damage of the optical fiber caused by the buffer layer molding in the traditional wrapping process is effectively reduced, and the convenience of subsequent use of the optical cable is greatly improved, the comprehensive performance of the airborne optical cable is improved, and the reliability of the application of the airborne optical cable is guaranteed.

[0024] (2) The high-temperature resistant airborne optical cable of the utility model, by optimally setting an integral buffer layer structure composed of a PTFE film and a PEEK material, fully meets the application requirements of the optical cable in the harsh airborne environment and fully guarantees the reliability and stability of the airborne optical cable application; at the same time, by optimizing the corresponding structural dimensions of the optical cable, the optical cable is made to better meet the application requirements of the airborne environment, thereby improving the yield and pass rate of the optical cable preparation.

[0025] (3) The high-temperature resistant airborne optical cable of the utility model has a simple structure and is easy to prepare. It can effectively meet the application requirements of optical cables in airborne environments, fully guarantee the high-temperature resistance of the optical cable, improve the ability of the optical fiber in the optical cable to resist the influence of external forces, effectively improve the stability and convenience of the airborne optical cable in actual application, reduce the attenuation loss of the optical cable caused by external stress, and ensure the reliability of the optical cable signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 , Figure 2 It is a schematic diagram of the structure of the high temperature resistant airborne optical cable in the embodiment of the utility model;

[0028] Figure 3 , Figure 4 Schematic diagram of the longitudinal package of the first buffer layer of the high temperature resistant airborne optical cable in the embodiment of the utility model;

[0029] Figure 5 It is a schematic diagram of the buffer layer wrapping of a conventional optical cable in the prior art;

[0030] Figure 6 , Figure 7 It is a schematic diagram of a first buffer layer in an embodiment of the utility model that is longitudinally wrapped with multiple material strips;

[0031] Figure 8 It is a schematic diagram of the dimensions when the first buffer layer is formed by a film-shaped material strip in an embodiment of the utility model;

[0032] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0033] 1. Optical fiber; 2. First buffer layer; 3. Second buffer layer; 4. Reinforcement layer; 5. Outer sheath. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] Example:

[0040] See also Figure 1 The high temperature resistant airborne optical cable in the preferred embodiment of the utility model comprises a high temperature resistant optical fiber 1 located in the middle and a buffer layer, a strengthening layer 4 and an outer sheath 5 arranged in sequence from the inside to the outside on the periphery of the high temperature resistant optical fiber 1.

[0041] Specifically, the optical fiber 1 in the preferred embodiment is a high temperature resistant optical fiber, which includes a glass core layer, a cladding layer and a coating layer arranged in sequence from the inside to the outside.

[0042] The glass core layer is the optical fiber core, which can be either single-mode or multi-mode. For example, in a preferred embodiment, the high temperature resistant optical fiber 1 is a 9μm / 125μm single-mode optical fiber, a 50μm / 125μm multi-mode optical fiber, or a 62.5μm / 125μm multi-mode optical fiber.

[0043] Meanwhile, for the optical fiber 1 in the preferred embodiment, since it needs to meet the requirement of high temperature resistance, its coating layer is prepared by coating with a special coating, for example, by coating with a special polyester material. In the preferred embodiment, the temperature resistance range of the optical fiber 1 is preferably -55°C to +200°C.

[0044] Furthermore, the buffer layer in the preferred embodiment is a double-layer composite structure, which includes a first buffer layer 2 located radially inside the optical cable and a second buffer layer 3 located radially outside, forming a double-layer buffer structure that is hard outside and soft inside.

[0045] The first buffer layer 2 is a soft buffer layer, which is preferably made of a temperature-resistant polymer film strip with a small thermal expansion coefficient and soft quality through a straight longitudinal packaging method.

[0046] When the optical cable is actually manufactured, the first buffer layer 2 in the longitudinal direction of the optical cable is continuously fed by a film-like material strip and longitudinally wrapped in sequence to form a longitudinally continuous cylindrical structure.

[0047] At the same time, in order to ensure that a gap can be formed between the first buffer layer 2 and the optical fiber 1, the thickness of the film tape is optimally designed. If the film width is too small, it will easily fail to completely wrap the outer circumference of the optical fiber 1. If the film width is too large, it will squeeze the internal space and affect the "freedom" of the optical fiber 1.

[0048] In a preferred embodiment, the thickness of the film-like strip is preferably less than 0.1 mm.

[0049] It is further explained that the thickness of the film strip is controlled because, in actual molding, the inner and outer diameters of the second buffer layer 3 are usually determined first, and then the film width L of the film strip of the first buffer layer 2 is determined based on this. Figure 8 It is not difficult to find that the control of the gap between the first buffer layer 2 and the optical fiber 1 is jointly determined by the membrane width L and the thickness d, wherein the membrane width corresponds to the outer diameter and the overlapping width of the first buffer layer 2, and the membrane thickness d determines the inner diameter of the first buffer layer 2 and the size of the gap between it and the optical fiber 1.

[0050] By longitudinally wrapping the outer periphery of the optical fiber 1 with a soft, temperature-resistant polymer film-shaped material tape having a small thermal expansion coefficient, a longitudinally complete and continuous cylindrical cladding is formed on the outer periphery of the optical fiber 1. The wrapping process is as follows: Figure 3 , Figure 4 Compared to Figure 5 Compared with the traditional wrapping method shown in the figure, the above structure has obvious differences:

[0051] On the one hand, the traditional wrapping method will form a "multi-turn" coating structure on the periphery of the optical fiber during the molding process, resulting in poor longitudinal continuity of the first buffer layer. In the subsequent "stripping" process of the optical cable, the coating of the above-mentioned coating structure is extremely difficult, which significantly reduces the subsequent use efficiency of the optical cable; on the other hand, for the existing technology using wrapping molding, it will apply obvious "torsion force" to the optical fiber 1 during the molding process, causing the optical fiber 1 to be subjected to stress, resulting in additional attenuation, affecting the performance of the optical cable. Moreover, the "wrapping" molding method greatly reduces the "freedom" of the optical fiber 1 in the buffer layer. Under environmental and mechanical stress, the release of stress of the optical fiber 1 is hindered and a large additional attenuation is generated; while the longitudinal wrapping structure is a loose structure, and there is a gap between the optical fiber and the film, so it will not cause damage to the optical fiber coating layer, thereby improving the temperature resistance of the optical cable.

[0052] Furthermore, the optical cable in the preferred embodiment is mainly used in airborne environments with strict restrictions on space and load, and its cable size (diameter) is basically within 2 mm, and further preferably within 1.9 mm; therefore, in order to meet the use requirements, the size of the longitudinal wrapping material of the first buffer layer 2 is obviously different from the small-sized longitudinal wrapping of the large-sized longitudinal wrapping structure above 5 mm.

[0053] Different from conventional large-sized wrapping structures such as water-blocking tape and aluminum-steel tape, the object used for longitudinal wrapping in the preferred embodiment is a soft film structure with a smaller width, and its width is usually 0.75~2mm. Moreover, for conventional longitudinal wrapping operations, in order to prevent the edge of the joint from warping, a certain fixing means is usually adopted, such as setting a fixing component such as hot melt adhesive and rolling tape to fix it; for industrial production, this method is difficult to achieve for the smaller optical fiber 1 in the preferred embodiment.

[0054] Therefore, in a preferred embodiment, the material strip forming the first buffer layer 2 is a soft film material with a smaller width, and its molding on the periphery of the optical fiber 1 is mainly achieved by extruding the second buffer layer 3 into a tube and sleeved on the periphery of the first buffer layer 2 to form a double-layer buffer layer structure.

[0055] In a specific preferred embodiment, the first buffer layer 2 is formed by longitudinally wrapping a PTFE film.

[0056] At the same time, a gap of 0-0.25 mm is formed between the first buffer layer 2 and the optical fiber 1, so that after the first buffer layer 2 is set, the optical fiber 1 has sufficient "freedom".

[0057] The reason for controlling the formation of the above-mentioned "gap" is to prevent the optical fiber 1 from generating additional attenuation due to the stress applied by the first buffer layer 2; of course, the above-mentioned gap should not be too large either, because if the gap is too large, the wall thickness of the second buffer layer 3 will be greatly reduced, which is not conducive to the bending resistance of the optical cable on the one hand, and the second buffer layer 3 is easy to break when bending; on the other hand, excessive internal freedom will also cause the optical fiber 1 to generate micro-bends when the second buffer layer 3 shrinks, resulting in large additional attenuation; based on this, the inner diameter of the second buffer layer 3, the width of the film strip of the first buffer layer 2 and the size of the gap need to be coordinated to achieve better temperature resistance of the optical cable.

[0058] Preferably, in actual preparation, the first buffer layer 1 can be formed by a longitudinally continuous material tape that is longitudinally wrapped around the outer periphery of the optical fiber 1 to form a longitudinally continuous cylindrical structure, and the width of the film material tape is preferably 1.5-1.9 mm. Obviously, according to actual production needs, the first buffer layer 1 can also be formed by multiple longitudinally continuous material tapes that are respectively wrapped around the outer periphery of the optical fiber 1 in an annular direction.

[0059] For example, in Figure 6 In the preferred embodiment shown, the material strips on the periphery of the optical fiber 1 are two symmetrically arranged, and the widths of the two material strips are preferably 0.75~1.0 mm, respectively. The two strips extend continuously in the longitudinal direction, and are wrapped around both sides of the periphery of the optical fiber 1 after forming a cylindrical structure in the form of a buckle.

[0060] For example, in Figure 7 In the preferred embodiment shown, the material strips on the periphery of the optical fiber 1 are three strips arranged in sequence in a circumferential direction, and the widths of the three strips are preferably 0.5-0.7 mm, respectively. The three strips extend continuously in the longitudinal direction and wrap different areas of the periphery of the optical fiber 1 in sequence in the circumferential direction.

[0061] In actual operation, for the longitudinal wrapping of a single film-like material strip, it is preferably guided by a single variable-diameter needle tube; while for the longitudinal wrapping of multiple film-like material strips, it is usually necessary to add a corresponding number of guide grooves at the film inlet end on the basis of the variable-diameter needle tube to position each film unit, so that the multiple film-like material strips can be longitudinally wrapped into a tubular form when entering the variable-diameter needle tube.

[0062] At the same time, whether it is a single-film longitudinal package or a multi-film longitudinal package, it is necessary to ensure that the film material completely wraps the optical fiber 1 to prevent the optical fiber 1 from being burned when the second buffer layer 3 is extruded. For this reason, the first buffer layer 1 in the preferred embodiment is formed with at least one film material lap position in the annular direction. However, considering that the first buffer layer 2 needs to be completely wrapped by the second buffer layer 3 and does not affect the appearance size, the width of the film material lap position should be strictly controlled. In the preferred embodiment, the width of each film material lap position should not be greater than 0.1mm (setting this width on the one hand prevents the lap width from being too wide, causing the film to shrink inward and exert stress on the optical fiber, and not lapped may cause the optical fiber to be burned during extrusion).

[0063] In addition, the width of the film material used to form the first buffer layer 2 should not be too large, which mainly affects the gap between the first buffer layer 2 and the optical fiber 1. In a preferred embodiment, the width of the film material strip is 1.6 to 3.0 times the circumferential length of the optical fiber 1. Within this range, the internal gap structure can be ensured without causing the thickness of the second buffer layer 3 to be too thin, and after the second buffer layer 3 wraps the first buffer layer 2, no serious wrinkles will be formed on the inner side of the buffer layer, thereby reducing the stress exerted by the first buffer layer 2 on the optical fiber and reducing the attenuation loss of the optical cable.

[0064] Furthermore, in the preferred embodiment, the second buffer layer 3 is a hard buffer layer, which is used to provide buffering protection for the internal optical fiber 1 to prevent external stress from acting on the optical fiber 1 and affecting the performance of the optical fiber 1. It is preferably formed by extruding an extruded material on the periphery of the first buffer layer 2.

[0065] Considering the high temperature resistance requirement of the optical cable, in a preferred embodiment, the second buffer layer 3 is preferably extruded from a material with high hardness and good temperature resistance. On the one hand, the high hardness can resist part of the stress caused by the shrinkage of the outer sheath during service, and on the other hand, the wide temperature resistance range can reduce the impact of its own shrinkage on its internal optical fiber.

[0066] For example, in a specific preferred embodiment, the second buffer layer 3 is preferably formed by extrusion of PEEK material, which has the characteristics of high hardness and high temperature resistance, and the glass transition temperature is 143°C.

[0067] In actual operation, the second buffer layer 3 is formed by extruding the first buffer layer 2 from an extruded material, and the two form an integral buffer layer structure to provide sufficient buffer protection for the optical fiber 1 located inside.

[0068] In a preferred embodiment, the outer diameter of the buffer layer is preferably 0.85-0.95 mm, and the concentricity is less than 40 μm; and to ensure the wrapping property of the first buffer layer 2, the inner diameter is preferably not less than 0.50 mm.

[0069] More specifically, a reinforcement layer 4 is disposed on the outer periphery of the second buffer layer 3. In a preferred embodiment, the reinforcement layer 4 may adopt a braided structure of fiber materials with different strands to adjust and optimize the tensile performance of the optical cable.

[0070] Further preferably, the reinforcing layer 4 is preferably a fiber material woven structure, and is further preferably woven from materials such as aramid fibers and PI fibers; in addition, in actual settings, the number of fiber strands corresponding to the reinforcing layer 4 can be optimized as needed, such as 8 strands or 16 strands.

[0071] In a specific preferred embodiment, the outer diameter of the reinforcement layer 4 is preferably 1.3±0.1 mm, and the total modulus thereof is not less than 7000 dtex.

[0072] By providing the reinforcement layer 4 , the optical fiber 1 inside the optical cable has a certain tensile strength, thereby preventing the optical fiber 1 from attenuating and losing due to external stress.

[0073] In more detail, the outer periphery of the reinforcement layer 4 is also covered with an outer protective layer 5, which is preferably formed of fluoroplastics that are highly resistant to strong acids, strong bases, and strong oxidants, and whose corrosion resistance even exceeds that of glass, ceramics, stainless steel, etc. In a preferred embodiment, the fluoroplastics are preferably ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene propylene copolymer (FEP), polytetrafluoroethylene (PFA), etc.

[0074] In a preferred embodiment, the outer sheath 5 uses ETFE as the outer sheath material.

[0075] Meanwhile, in a specific preferred embodiment, the outer diameter of the outer protective layer 5 is preferably 1.8±0.1 mm, and the wall thickness is between 0.2 and 0.3 mm.

[0076] The high-temperature resistant airborne optical cable in the utility model has a simple structure and is easy to prepare. It can effectively meet the application requirements of optical cables in airborne environments, fully guarantee the high-temperature resistance of the optical cable, improve the ability of the optical fiber in the optical cable to resist the influence of external forces, effectively improve the stability and convenience of the airborne optical cable in actual application, reduce the attenuation loss of the optical cable caused by external stress, and ensure the reliability of optical cable signal transmission.

[0077] It is easy for those skilled in the art to understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high temperature resistant airborne optical cable, comprising an optical fiber located in the middle, the optical fiber is a high temperature resistant optical fiber, and a buffer layer, a reinforcement layer and an outer sheath are sequentially arranged on the periphery thereof from the inside to the outside; characterized in that: The buffer layer includes a first buffer layer located inside and a second buffer layer located outside the first buffer layer; The first buffer layer is a soft buffer layer, which is formed by a soft film-like material strip in a longitudinally wrapped manner into a longitudinally continuously extending cylindrical structure; The second buffer layer is a hard buffer layer, which is formed by extrusion of an extruded material and is bonded to the first buffer layer to form an integral buffer layer structure.

2. The high temperature resistant airborne optical cable according to claim 1, characterized in that: A gap of 0-0.25 mm is formed between the first buffer layer and the optical fiber.

3. The high temperature resistant airborne optical cable according to claim 1 or 2, characterized in that: The first buffer layer is formed by longitudinally wrapping a PTFE film around the outer periphery of the optical fiber; and / or the second buffer layer is formed by extruding a PEEK material around the outer periphery of the first buffer layer.

4. The high temperature resistant airborne optical cable according to claim 1 or 2, characterized in that: The film-like material tape is one or more tapes circumferentially wrapped around the outer periphery of the optical fiber.

5. The high temperature resistant airborne optical cable according to claim 4, characterized in that: At least one film material placement portion is formed in an annular direction around the outer periphery of the optical fiber.

6. The high temperature resistant airborne optical cable according to claim 5, characterized in that: The overlapping width of the film material overlapping portion is not greater than 0.1 mm; and the width of the film material tape used to form the first buffer layer is 1.6 to 3 times the circumference of the optical fiber.

7. The high temperature resistant airborne optical cable according to claim 1 or 2 or 5 or 6, characterized in that: The outer diameter of the buffer layer is 0.85-0.95 mm, and the concentricity is less than 40 μm; and the inner diameter of the buffer layer is not less than 0.53 mm.

8. The high temperature resistant airborne optical cable according to claim 1 or 2 or 5 or 6, characterized in that: The optical fiber is a 9μm / 125μm single-mode optical fiber, a 50μm / 125μm multi-mode optical fiber or a 62.5μm / 125μm multi-mode optical fiber.

9. The high temperature resistant airborne optical cable according to claim 1 or 2 or 5 or 6, characterized in that: The diameter of the airborne optical cable is within 1.9 mm.

10. The high temperature resistant airborne optical cable according to claim 1 or 2 or 5 or 6, characterized in that: The reinforcing layer is a fiber material woven structure with an outer diameter of 1.3±0.1mm and a total modulus of not less than 7000dtex; and / or The outer protective layer is formed by fluoroplastics, has an outer diameter of 1.8±0.1 mm, and a wall thickness of 0.2-0.3 mm.

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