W-type anti-radiation optical fiber and manufacturing method thereof

Abstract

The invention provides a W-type anti-radiation optical fiber and a manufacturing method thereof, and the W-type anti-radiation optical fiber comprises a core layer, an inner cladding layer, an outer cladding layer and a coating layer. The inner cladding, the outer cladding and the coating layer are sequentially coated outside the core layer from the center of the core layer along the radial direction of the core layer; the core layer, the inner cladding layer and the outer cladding layer are respectively pure silica quartz layers or doped quartz layers; wherein the refractive index of the inner cladding is lower than that of the core layer; the refractive index of the outer cladding is higher than that of the core layer; the refractive index distribution shape of the W-shaped anti-radiation optical fiber is similar to W; and the coating layer is an acrylate layer. According to the W-type radiation-proof optical fiber, aiming at the problem of a doped radiation-proof optical fiber, the W-type radiation-proof optical fiber is correspondingly designed by combining the structural characteristics of the W-type optical fiber, so that the W-type radiation-proof optical fiber has strong radiation-proof capability and low attenuation and can be used in a plurality of wave bands; and the structure is simple, and the corresponding rod manufacturing process difficulty is reduced compared with the prior art, so that the cost can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fibers, and in particular to a W-type radiation-resistant optical fiber and a manufacturing method thereof. Background Art

[0002] High-power lasers, space detectors, and information transmission in space all require radiation-resistant optical fibers. At the same time, radiation-resistant optical fibers can also be used in the detection of pipelines and underground equipment in the nuclear energy field, and in the detection of temperature and pressure, providing solutions for facility monitoring, industrial communications, and structural safety. The particle radiation in these application environments, including charged particles, uncharged particles, and electromagnetic waves, causes fiber damage to varying degrees, significantly reducing fiber performance, especially signal attenuation and service life. Radiation-induced loss of quartz optical fiber is the main effect of particle irradiation. Particle irradiation produces Frank defects and ionization damage, and produces color centers, which are the main mechanisms for destroying the structure of quartz optical fibers. The absorption bands caused by various defects cause the fiber attenuation to increase, the signal or energy transmission capacity to decrease, and the structural damage causes the safety and reliability of optical fiber use to decrease.

[0003] Radiation-resistant optical fiber can effectively avoid the influence of ionizing radiation in radiation environment on optical signal transmission due to its resistance to radiation damage in harsh environments such as nuclear radiation or space radiation. It can operate stably for a long time in radiation environment and withstand extreme environment and temperature fluctuations. At present, the most common radiation-resistant optical fiber mostly uses doped optical fiber core and cladding, which can effectively improve the radiation resistance of optical fiber. However, doping has the following limitations in practical applications: 1. Influence on the refractive index of the core: F doping will reduce the refractive index of the core, while Ge, Ce, and P doping will increase the refractive index of the core. In order to meet the waveguide structure design, the core needs to be co-doped to adjust the overall refractive index. Excessive doping with other elements will increase the defects of the core, increase the loss of the core, and increase the difficulty of viscosity matching and strain point matching design; 2. Increased process requirements and costs: Doping requires higher process precision, and the difficulty lies in the control of doping concentration and doping range, the temperature and pressure setting of the drawing process, and the internal stress caused by fiber defects. For example, the fluorine-doped quartz cladding of the core rod is prone to form volatile silicon fluoride during the high-temperature drawing process, resulting in a large amount of fluorine overflow, which will produce a large number of bubbles and pores on the quartz surface, accompanied by cracks, crystallization, etc., especially in the out-of-tube method, the consumption loss of raw materials is greater, and it is necessary to additionally remove the OH- mixed in during doping.

[0004] Based on this, the present invention proposes a new W-type radiation-resistant optical fiber and a manufacturing method thereof. The W-type optical fiber has a refractive index profile distribution similar to the English letter "W", and the refractive index of the refractive index depression layer (i.e., the inner cladding) is smaller than that of the core and the outer cladding, which affects the waveguide structure therein, and has filtering characteristics of small short-wave loss and large long-wave loss, which increases the effective area, reduces the nonlinear effect, realizes the tuning of the loss curve, and reduces the cost. Summary of the invention

[0005] Based on the above description, the present invention provides a W-type radiation-resistant optical fiber and a method for manufacturing the same to solve the technical problems in the prior art of radiation-resistant optical fiber, such as reduced core refractive index, high process requirements and costs, that is, the limitations of the existing fluorine-doped radiation-resistant optical fiber manufacturing method.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: In a first aspect, the present invention provides a W-type radiation-resistant optical fiber, comprising: a core layer, an inner cladding layer, an outer cladding layer and a coating layer; The inner cladding layer, the outer cladding layer and the coating layer are sequentially coated outside the core layer along the radial direction from the center of the core layer; The core layer, the inner cladding layer and the outer cladding layer are respectively pure silica quartz layers or doped quartz layers; wherein the refractive index of the inner cladding layer is lower than the refractive index of the core layer; the refractive index of the outer cladding layer is higher than the refractive index of the core layer; the refractive index distribution shape of the W-type radiation-resistant optical fiber is W-shaped The coating layer is an acrylate layer.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, when the core layer is a doped quartz layer, the core layer is a fluorine-doped quartz layer, a fluorine-germanium co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

[0009] Furthermore, in the case where the core layer is a fluorine-doped quartz layer, the doping amount of fluorine in the core layer is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a fluorine-germanium co-doped quartz layer, the doping amount of fluorine in the core layer is 0.01-1wt%, the doping amount of germanium is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a cerium-phosphorus co-doped quartz layer, the doping amount of cerium in the core layer is 0.01-1wt%, the doping amount of phosphorus is 10-15wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the core layer is 1-3wt%, the doping amount of germanium is 3-5wt%, and the rest is silicon dioxide.

[0010] Furthermore, when the inner cladding is a doped quartz layer, the inner cladding is a fluorine-doped quartz layer or a fluorine-germanium co-doped quartz layer.

[0011] Furthermore, in the case where the inner cladding is a fluorine-doped quartz layer, the fluorine doping amount in the inner cladding is 1-5wt%, and the rest is silicon dioxide; Or, when the inner cladding is a germanium-fluorine co-doped quartz layer, the doping amount of fluorine in the inner cladding is 0.01-1wt%, the doping amount of germanium is 1-3wt%, and the rest is silicon dioxide.

[0012] Furthermore, when the outer cladding layer is a doped quartz layer, the outer cladding layer is a germanium-fluorine co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

[0013] Furthermore, in the case where the outer cladding is a germanium-fluorine co-doped quartz layer, the doping amount of germanium in the outer cladding is 1-3wt%, the doping amount of fluorine is 0.01-1wt%, and the rest is silicon dioxide; Or, in the case where the outer cladding is a cerium-phosphorus co-doped quartz layer, the doping amount of cerium in the outer cladding is 0.01-3wt%, the doping amount of phosphorus is 10-15wt%, and the rest is silicon dioxide; Or, in the case where the outer cladding is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the outer cladding is 1-3wt%, the doping amount of germanium is 3-5wt%, and the rest is silicon dioxide.

[0014] In a second aspect, the present invention provides a method for fabricating a W-shaped radiation-resistant optical fiber for deposition as described in the first aspect, comprising the following steps: The optical fiber preform is obtained by using a PCVD deposition method, wherein inner cladding and outer cladding glass are deposited in a quartz liner using oxygen, silicon tetrachloride and F-containing gas, and core layer glass is deposited outside the inner cladding and outer cladding glass to obtain a preform; S2: Melting and shrinking the preform rod by a rod shrinking process, and then sequentially performing annealing and rod drawing processes; S3: Drawing the processed preform rod to obtain a drawn optical fiber, and coating the outer wall of the drawn optical fiber with a low refractive index coating to obtain the W-type radiation-resistant optical fiber.

[0015] Based on the above technical solution, the present invention can also be improved as follows.

[0016] Further, in step S1, the mass flow rates of oxygen, silicon tetrachloride and F-containing gas are 100-3000 sccm; In step S2, the melting furnace temperature is 2000-2500°C. In step S3, the wire drawing speed is 100-150 m / min, and the coating material has a viscosity of 950-1050 cp during operation.

[0017] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The W-type radiation-resistant optical fiber provided by the present invention comprises: a core layer, an inner cladding layer, an outer cladding layer and a coating layer; the inner cladding layer, the outer cladding layer and the coating layer are sequentially coated on the outside of the core layer along the radial direction from the center of the core layer; the core layer, the inner cladding layer and the outer cladding layer are pure silica quartz layers or doped quartz layers respectively; wherein the refractive index of the inner cladding layer is lower than the refractive index of the core layer; the refractive index of the outer cladding layer is higher than the refractive index of the core layer; the refractive index distribution shape of the W-type radiation-resistant optical fiber is W-shaped; the coating layer is an acrylate layer. Compared with the existing method, this scheme has the following advantages: This W-type radiation-resistant optical fiber is designed to solve the problems of doped radiation-resistant optical fiber and combines the structural characteristics of W-type optical fiber to make it have strong radiation resistance and low attenuation and can be used in multiple bands. It also has a simple structure and the corresponding rod making process is less difficult than the existing technology, thereby ensuring the cost.

[0018] Since the method for manufacturing the W-type radiation-resistant optical fiber adopts the above-mentioned W-type radiation-resistant optical fiber, the manufacturing method at least has all the beneficial effects brought by the W-type radiation-resistant optical fiber, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of a W-shaped radiation-resistant optical fiber provided in an embodiment of the present invention; Figure 2 A schematic diagram of the refractive index profile of a W-type radiation-resistant optical fiber provided in an embodiment of the present invention; Figure 3 A schematic diagram of an enlarged refractive index of the core layer of a W-type radiation-resistant optical fiber provided in an embodiment of the present invention; Figure 4 A flow chart of a method for manufacturing a W-shaped radiation-resistant optical fiber provided by an embodiment of the present invention; In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Core layer; 2. Inner cladding; 3. Outer cladding; 4. Coating layer. DETAILED DESCRIPTION

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" 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, an indirect connection through an intermediate medium, or the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The following is combined with Figures 1 to 4 The embodiments of the present invention are further described in detail with examples. The following examples are used to illustrate the present invention but cannot be used to limit the scope of the present invention.

[0024] At present, fluorine ion doping in conventional radiation-resistant optical fibers reduces the refractive index of the fiber core, so other elements are doped to compensate for the decrease in refractive index caused by F doping. However, excessive doping will increase optical fiber loss, and the doping concentration and range are difficult to control, thus affecting the performance of the radiation-resistant optical fiber.

[0025] The present invention provides a W-type radiation-resistant optical fiber, which is mainly used to overcome the limitations of the manufacturing technology of fluorine-doped radiation-resistant optical fiber, such as Figure 1 As shown, it includes: a core layer, an inner cladding layer, an outer cladding layer and a coating layer.

[0026] The inner cladding, the outer cladding and the coating layer are sequentially coated on the outside of the core layer along the radial direction from the center of the core layer.

[0027] The core layer, inner cladding layer and outer cladding layer are pure silica quartz layers or doped quartz layers respectively; wherein the refractive index of the inner cladding layer is lower than the refractive index of the core layer; and the refractive index of the outer cladding layer is higher than the refractive index of the core layer.

[0028] The coating layer is an acrylate layer.

[0029] The refractive index distribution of W-type radiation-resistant optical fiber is W-shaped.

[0030] Figure 2 FIG. 1 is a schematic diagram of a refractive index profile of a W-type radiation-resistant optical fiber provided in an embodiment of the present invention. Figure 3 The figure shows an enlarged schematic diagram of the refractive index of the core layer 1 of the W-type radiation-resistant optical fiber. It can be seen that the core layer 1 has a W-shaped shape as a whole.

[0031] It should be noted that W-type optical fiber is an optical fiber with a refractive index distribution shape similar to W. It can form a low refractive index layer (also called a depressed refractive index layer) around the core of the optical fiber by doping fluorine ions. The refractive index of this layer is lower than that of the core and cladding. It has the characteristics of large long-wave loss and small short-wave loss, that is, the long-wave cut-off characteristic.

[0032] In an optional embodiment, when the core layer is a doped quartz layer, the core layer is a fluorine-doped quartz layer, a fluorine-germanium co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

[0033] Specifically, when the core layer is a fluorine-doped quartz layer, the doping amount of fluorine in the core layer is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a fluorine-germanium co-doped quartz layer, the doping amount of fluorine in the core layer is 0.01-1wt%, the doping amount of germanium is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a cerium-phosphorus co-doped quartz layer, the doping amount of cerium in the core layer is 0.01-1 wt %, the doping amount of phosphorus is 10-15 wt %, and the rest is silicon dioxide; Alternatively, when the core layer is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the core layer is 1-3 wt %, the doping amount of germanium is 3-5 wt %, and the rest is silicon dioxide.

[0034] In an optional embodiment, when the inner cladding is a doped quartz layer, the inner cladding is a fluorine-doped quartz layer or a fluorine-germanium co-doped quartz layer.

[0035] Specifically, when the inner cladding is a fluorine-doped quartz layer, the fluorine doping amount in the inner cladding is 1-5wt%, and the rest is silicon dioxide; Alternatively, when the inner cladding is a germanium-fluorine co-doped quartz layer, the doping amount of fluorine in the inner cladding is 0.01-1 wt %, the doping amount of germanium is 1-3 wt %, and the rest is silicon dioxide.

[0036] In an optional embodiment, when the outer cladding layer is a doped quartz layer, the outer cladding layer is a germanium-fluorine co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

[0037] Specifically, when the outer cladding is a germanium-fluorine co-doped quartz layer, the doping amount of germanium in the outer cladding is 1-3wt%, the doping amount of fluorine is 0.01-1wt%, and the rest is silicon dioxide; Or, in the case where the outer cladding is a cerium-phosphorus co-doped quartz layer, the cerium doping amount in the outer cladding is 0.01-3wt%, the phosphorus doping amount is 10-15wt%, and the rest is silicon dioxide; Alternatively, when the outer cladding is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the outer cladding is 1-3 wt %, the doping amount of germanium is 3-5 wt %, and the rest is silicon dioxide.

[0038] In an optional embodiment, the cladding ratio of the inner cladding layer to the core layer is 1.0-5.0; The cladding ratio of the outer cladding layer to the core layer is 5.0-13.0.

[0039] The following is further detailed description in conjunction with specific embodiments: Example 1 This embodiment provides a W-type radiation-resistant optical fiber, which includes: a core layer, an inner cladding layer, an outer cladding layer and a coating layer.

[0040] The inner cladding, outer cladding and coating layer are sequentially coated outside the core layer along the radial direction from the center of the core layer; the core layer, inner cladding and outer cladding are pure silica quartz layers or doped quartz layers respectively; the refractive index of the inner cladding is lower than that of the core layer; the refractive index of the outer cladding is higher than that of the core layer.

[0041] The coating layer is an acrylate layer.

[0042] The refractive index distribution of W-type radiation-resistant optical fiber is W-shaped.

[0043] In this embodiment, the core layer, the inner cladding layer and the outer cladding layer are all pure silica quartz layers.

[0044] Example 2 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that the core layer is a silica quartz layer doped with 1-3% F, the inner cladding is a silica quartz layer doped with 3-5% F, and the outer cladding is a pure silica quartz layer.

[0045] Example 3 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that the core layer is a silica quartz layer doped with F1-3%, the inner cladding is a silica quartz layer doped with F 3-5%, and the outer cladding is a fluorine-germanium co-doped quartz layer, wherein Ge is doped with 1-3% and F is doped with 0.01-1%.

[0046] Example 4 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that the core layer is a pure silica quartz layer, the inner cladding is a silica quartz layer doped with 1-3% F, and the outer cladding is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped with 0.01-1% and P is doped with 10-15%.

[0047] Example 5 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a fluorine-germanium co-doped quartz layer, wherein Ge is doped 1-3% and F is doped 0.01-1%; the inner cladding is a silica quartz layer doped with F1-3%; and the outer cladding is a cerium-germanium co-doped quartz layer, wherein Ce is doped 1-3% and Ge is doped 3-5%.

[0048] Example 6 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a fluorine-germanium co-doped quartz layer, wherein Ge is doped 1-3% and F is doped 0.01-1%; the inner cladding is a silica quartz layer doped with F 1-3%; and the outer cladding is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped 0.01-1% and P is doped 10-15%.

[0049] Example 7 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped at 0.01-1% and P is doped at 10-15%; the inner cladding is a pure silica quartz layer; and the outer cladding is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped at 1-3% and P is doped at 10-15%.

[0050] Example 8 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped 0.01-1% and P is doped 10-15%; the inner cladding is a fluorine-germanium co-doped quartz layer, wherein Ge is doped 1-3% and F is doped 0.01-1%; the outer cladding is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped 1-3% and P is doped 10-15%.

[0051] Example 9 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a cerium-germanium co-doped quartz layer, wherein Ce is doped 1-3% and Ge is doped 3-5%; the inner cladding is a pure silica quartz layer; and the outer cladding is a cerium-phosphorus co-doped quartz layer, wherein Ce is doped 1-3% and P is doped 10-15%.

[0052] Example 10 The W-type radiation-resistant optical fiber provided in this embodiment is different from the optical fiber provided in Example 1 in that: the core layer is a cerium-germanium co-doped quartz layer, wherein Ce is doped 1-3% and Ge is doped 3-5%; the inner cladding is a fluorine-germanium co-doped quartz layer, wherein Ge is doped 1-3% and F is doped 0.01-1%; the outer cladding is a cerium-germanium co-doped quartz layer, wherein Ce is doped 3-5% and Ge is doped 3-5%.

[0053] It should be noted that the above embodiments are only for explanation of the present invention and do not limit the protection scope provided by the present invention. Other embodiments not described may also fall within the protection scope of this application.

[0054] Taking the W-type radiation-resistant optical fiber provided in the above-mentioned embodiment 1 as the most preferred example, further introduction is given: The core-cladding ratio (CCDR) of the outer cladding 3 to the core layer 1 of the W-type radiation-resistant optical fiber is 13.0±0.5. The diameter of the outer cladding 3 is 25.0±5.0 mm.

[0055] The numerical aperture of the W-type radiation-resistant optical fiber preform is 0.145~0.150 and the length is 750~1000mm.

[0056] The relevant design parameters of W-type radiation-resistant optical fiber are shown in the following table: W-type radiation-resistant optical fiber parameter table

[0057] In the W-type radiation-resistant optical fiber of this example, the composition and content of the fluorine-doped zone of the core layer 1 are 98.5wt% of silicon dioxide (SiO2) and 1.5wt% of fluorine (F); the composition and content of the fluorine-doped quartz layer of the inner cladding 2 are 96.0wt% of silicon dioxide (SiO2) and 4.0wt% of fluorine (F).

[0058] Its cut-off wavelength is 1162nm, and the fiber loss is the OTDR measurement loss: @1310mn: 0.594dB / km; @1550nm: 0.588dB / km. Correspondingly, its total irradiation dose is the fiber additional attenuation @1310mn: 0.594dB / km; @1550nm: 0.588dB / km under 1500 rad.

[0059] In summary, the W-type radiation-resistant optical fiber proposed in Example 1 of the present invention utilizes the special structure of the W-type optical fiber, adopts a light-doping method, and combines the actual regulation of its numerical aperture and cut-off wavelength to obtain a specific waveguide structure. Experiments show that the optical fiber has good radiation resistance in the 850nm, 1300nm and 1310nm windows.

[0060] Embodiment 11 In order to better explain the W-type radiation-resistant optical fiber, this embodiment provides a method for manufacturing the W-type radiation-resistant optical fiber corresponding to Embodiment 1: like Figure 4 As shown, the production steps are as follows: Step S1: Obtaining an optical fiber preform by PCVD deposition method, using oxygen, silicon tetrachloride and F-containing gas to deposit inner cladding and outer cladding glass in a quartz liner tube, and then depositing core glass outside the inner cladding and outer cladding glass to obtain a preform; Step S2: melt and shrink the preform rod by using the rod shrinking process, and then perform annealing and rod drawing treatment in sequence; Step S3: Drawing the processed preform rod to obtain a drawn optical fiber, and coating the outer wall of the drawn optical fiber with a low refractive index coating to obtain a W-type radiation-resistant optical fiber.

[0061] Wherein, in step S1, the mass flow rates of oxygen, silicon tetrachloride and F-containing gas are 100-3000 sccm; In step S2, the melting furnace temperature is 2000-2500°C; In step S3, the wire drawing speed is 100-150 m / min, and the coating material has a working viscosity of 950-1050 cp.

[0062] Comparative Example This comparative example provides a radiation-resistant optical fiber, which is different from Example 1 in that the third cladding (the outer cladding in Example 1) is fluorine-doped quartz, the fourth layer (the coating layer in Example 1) is quartz, and the corresponding total irradiation dose of the optical fiber is 1500rad, and the additional attenuation of the optical fiber @1310nm: 0.748dB / km; @1550nm: 0.718dB / km, and its attenuation is significantly higher than the attenuation of the W-type radiation-resistant optical fiber in Example 1, and the performance is not as good as Example 1.

[0063] In summary, compared with the prior art and comparative examples, the W-type radiation-resistant optical fiber and its manufacturing method provided by the embodiments of the present invention can achieve the following technical effects: the W-type radiation-resistant optical fiber is designed accordingly to address the problems of doped radiation-resistant optical fiber, combined with the structural characteristics of the W-type optical fiber, so that it has strong radiation resistance and low attenuation, and can be used in multiple bands; and the structure is simple, and the corresponding rod making process difficulty is reduced compared with the prior art, thereby ensuring the cost.

[0064] In the description of this specification, the description with reference to the terms "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A W-type radiation-resistant optical fiber, characterized in that: include: Core layer, inner cladding, outer cladding and coating layer; The inner cladding layer, the outer cladding layer and the coating layer are sequentially coated outside the core layer along the radial direction from the center of the core layer; The core layer, the inner cladding layer and the outer cladding layer are pure silica quartz layers or doped quartz layers respectively; wherein the refractive index of the inner cladding layer is lower than the refractive index of the core layer; the refractive index of the outer cladding layer is higher than the refractive index of the core layer; the refractive index distribution shape of the W-type radiation-resistant optical fiber is W-shaped; The coating layer is an acrylate layer.

2. The W-type radiation-resistant optical fiber according to claim 1, characterized in that: When the core layer is a doped quartz layer, the core layer is a fluorine-doped quartz layer, a fluorine-germanium co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

3. The W-type radiation-resistant optical fiber according to claim 2, characterized in that: In the case where the core layer is a fluorine-doped quartz layer, the doping amount of fluorine in the core layer is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a fluorine-germanium co-doped quartz layer, the doping amount of fluorine in the core layer is 0.01-1wt%, the doping amount of germanium is 1-3wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a cerium-phosphorus co-doped quartz layer, the doping amount of cerium in the core layer is 0.01-1wt%, the doping amount of phosphorus is 10-15wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the core layer is 1-3wt%, the doping amount of germanium is 3-5wt%, and the rest is silicon dioxide.

4. The W-type radiation-resistant optical fiber according to claim 1, characterized in that: When the inner cladding layer is a doped quartz layer, the inner cladding layer is a fluorine-doped quartz layer or a fluorine-germanium co-doped quartz layer.

5. The W-type radiation-resistant optical fiber according to claim 4, characterized in that: In the case where the inner cladding is a fluorine-doped quartz layer, the fluorine doping amount in the inner cladding is 1-5wt%, and the rest is silicon dioxide; Or, in the case where the core layer is a germanium-fluorine co-doped quartz layer, the doping amount of fluorine in the inner cladding is 0.01-1wt%, the doping amount of germanium is 1-3wt%, and the rest is silicon dioxide.

6. The W-type radiation-resistant optical fiber according to claim 1, characterized in that: When the outer cladding layer is a doped quartz layer, the outer cladding layer is a germanium-fluorine co-doped quartz layer, a cerium-phosphorus co-doped quartz layer, or a cerium-germanium co-doped quartz layer.

7. The W-type radiation-resistant optical fiber according to claim 6, characterized in that: In the case where the outer cladding is a germanium-fluorine co-doped quartz layer, the doping amount of germanium in the outer cladding is 1-3wt%, the doping amount of fluorine is 0.01-1wt%, and the rest is silicon dioxide; Or, in the case where the outer cladding is a cerium-phosphorus co-doped quartz layer, the doping amount of cerium in the outer cladding is 0.01-3wt%, the doping amount of phosphorus is 10-15wt%, and the rest is silicon dioxide; Or, in the case where the outer cladding is a cerium-germanium co-doped quartz layer, the doping amount of cerium in the outer cladding is 1-3wt%, the doping amount of germanium is 3-5wt%, and the rest is silicon dioxide.

8. The W-type radiation-resistant optical fiber according to claim 1, characterized in that: The core ratio of the inner cladding layer to the core layer is 1.0-5.0; The cladding ratio of the outer cladding layer to the core layer is 5.0-13.

0.

9. A method for manufacturing a W-type radiation-resistant optical fiber according to any one of claims 1 to 8, characterized in that: The steps include: S1: Obtaining an optical fiber preform by PCVD deposition method, depositing inner cladding and outer cladding glass in a quartz liner by using oxygen, silicon tetrachloride and F-containing gas, and then depositing core glass outside the inner cladding and outer cladding glass to obtain a preform; S2: Melting and shrinking the preform rod by a rod shrinking process, and then sequentially performing annealing and rod drawing processes; S3: Drawing the processed preform rod to obtain a drawn optical fiber, and coating the outer wall of the drawn optical fiber with a low refractive index coating to obtain the W-type radiation-resistant optical fiber.

10. The manufacturing method according to claim 9, characterized in that: In step S1, the mass flow rates of the oxygen, silicon tetrachloride and F-containing gas are 100-3000 sccm; In step S2, the melting and shrinking furnace temperature is 2000-2500°C; In step S3, the wire drawing speed is 100-150 m / min, and the coating material has a viscosity of 950-1050 cp during operation.

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