Preparation method of elliptical cladding optical fiber

Abstract

The invention provides a preparation method of an elliptical cladding optical fiber, and belongs to the technical field of optical fiber preparation. In the preparation process of a normal core rod, after the core rod is machined, a quartz rod is additionally arranged on the peripheral side of the core rod, the quartz rod and the core rod are fused into an optical fiber mother rod through an optical fiber drawing tower heating furnace, then drawing is conducted, and finally the oval core optical fiber or the oval cladding optical fiber is formed. The steps of mechanical outer circle grinding and polishing in the prior art are omitted, the elliptical core optical fiber or the elliptical cladding optical fiber is rapidly formed by controlling different specification ratios and different wire drawing speeds of the core rod and the quartz rod, and the problems that in the prior art, the preform preparation difficulty is high, quantitative machining is difficult, and the elliptical cladding optical fiber is difficult to manufacture are solved. A large boron-doped region exists in the aluminum alloy, and the aluminum alloy is particularly easy to burst in the grinding and polishing process, so that the yield is low.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber preparation, and in particular relates to a method for preparing an elliptical cladding optical fiber. Background Art

[0002] At present, the conventional preparation method of elliptical cladding optical fiber usually adopts grinding of elliptical cladding optical fiber preform rod core rod. Because there is a large boron-doped area in the preform rod core rod, the preform rod core rod is subjected to the vibration of the grinding wheel during the grinding and polishing process, and a large external force acts on the large boron-doped area. This area is particularly easy to burst during the grinding process, which ultimately leads to a low processing yield; at the same time, during the processing process, it is difficult to accurately measure the final size of the inner concave grinding, which causes a gap between the processed core rod and the design value, resulting in the final drawn elliptical cladding optical fiber, which cannot achieve the expected design effect. Summary of the invention

[0003] The embodiment of the present invention provides a method for preparing an elliptical cladding optical fiber, aiming to solve the technical problems in the prior art that the preparation of preform rods is difficult, there is a large boron-doped area inside the preform rods, and the preform rods are particularly prone to cracking during the grinding and polishing process, resulting in a low yield.

[0004] To achieve the above object, the technical solution adopted by the present invention is: to provide a method for preparing an elliptical cladding optical fiber, comprising:

[0005] S1. Prepare a core rod and a quartz rod, wherein the quartz rod is fixed on the outer surface of the core rod to form a preformed rod;

[0006] S2, the assembled preform rod is placed vertically in the high temperature zone of the drawing tower heating furnace for heating, and the quartz rod and the core rod in the high temperature zone are heated and melted into one, forming an optical fiber mother rod;

[0007] S3, drawing the optical fiber mother rod to form an optical fiber.

[0008] In a possible implementation, the core rod in step S1 is a single-mode preform core rod or an elliptical cladding preform core rod, and the optical fiber formed by drawing the optical fiber mother rod in step S3 is an elliptical core optical fiber or an elliptical cladding optical fiber.

[0009] In a possible implementation, in step S1, there are at least two quartz rods.

[0010] In a possible implementation, the quartz rod is a high-purity SiO2 preformed rod.

[0011] In a possible implementation, the wire drawing speed in step S3 is 15-50 m / min.

[0012] In a possible implementation, the diameter of the core rod in step S1 is 10 mm to 35 mm, and the diameter of the quartz rod is 2 mm to 10 mm.

[0013] In a possible implementation, the refractive index n1 of the optical fiber core of the elliptical core optical fiber or the optical fiber core of the elliptical cladding optical fiber is in the range of 1.460 <n1<1.493。

[0014] In a possible implementation, the refractive index value n3 of the stress region of the elliptical cladding optical fiber is in the range of 1.445 <n3<1.459。

[0015] In a possible implementation manner, the refractive index n2 of the silica cladding of the elliptical core optical fiber or the elliptical cladding optical fiber is 1.457.

[0016] In a possible implementation, heating and melting the quartz rod and the core rod comprises the following steps:

[0017] S2.1, the quartz rod collapses on the surface of the core rod due to heat;

[0018] S2.2. Under the action of surface tension, the quartz rod and the core rod are gradually melted into an optical fiber mother rod, thereby reducing the ratio of the fiber core to the optical fiber mother rod.

[0019] Compared with the prior art, the present invention, in the normal process of preparing the core rod, after the core rod is processed, by adding a quartz rod on the outer peripheral side of the core rod, melting the quartz rod and the core rod into an optical fiber mother rod through a drawing tower heating furnace, and then drawing to finally form an elliptical core optical fiber or an elliptical cladding optical fiber. The present invention adopts a stacking melting molding technology, omitting the steps of mechanical outer circle grinding and polishing in the prior art, and quickly forms an elliptical core optical fiber or an elliptical cladding optical fiber by controlling the different specification ratios of the core rod and the quartz rod and different drawing speeds, thereby solving the technical problems in the prior art that the preform rod preparation is difficult, there is a large boron-doped area inside, and the grinding and polishing process is particularly prone to cracking, resulting in a low yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the melting process of an elliptical cladding preform core rod and a quartz rod provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the melting process of a single-mode preform core rod and a quartz rod provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the three-dimensional structure of a single-mode preform core rod and a quartz rod provided in an embodiment of the present invention;

[0023] Description of reference numerals:

[0024] 1. Core rod; 2. Quartz rod; 3. Optical fiber mother rod. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention 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 present invention and are not used to limit the present invention.

[0026] It should be further explained that the drawings and implementation modes of the present invention mainly describe the concept of the present invention. On the basis of this concept, the specific forms and settings of some connection relationships, positional relationships, power mechanisms, power supply systems, hydraulic systems and control systems may not be fully described. However, on the premise that those skilled in the art understand the concept of the present invention, those skilled in the art can implement the above-mentioned specific forms and settings in a well-known manner.

[0027] When an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element.

[0028] The directions or positional relationships indicated by terms such as “length”, “width”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0029] 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 one or more of the features. In the description of the present invention, "multiple" means two or more, and "several" means one or more, unless otherwise clearly and specifically defined.

[0030] See also Figure 1 Now, a method for preparing an elliptical cladding optical fiber provided by the present invention is described.

[0031] A method for preparing an elliptical cladding optical fiber comprises:

[0032] S1, preparing a core rod 1 and a quartz rod 2, wherein the quartz rod 2 is fixedly arranged on the outer surface of the core rod 1 to form a preformed rod;

[0033] S2, the assembled preform rod is placed vertically in a drawing tower heating furnace for high-temperature heating, and the heated quartz rod 2 and the core rod 1 are melted into one body and sintered to form an optical fiber mother rod 3;

[0034] S3, drawing the optical fiber mother rod 3 to form an optical fiber.

[0035] Compared with the prior art, the present invention provides a method for preparing an elliptical cladding optical fiber. In the normal preparation process of a core rod 1, after the core rod 1 is processed, a quartz rod 2 is added to the outer peripheral side of the core rod 1, the quartz rod 2 and the core rod 1 are melted into an optical fiber mother rod 3 through a drawing tower heating furnace, and then drawing is performed to finally form an elliptical core optical fiber or an elliptical cladding optical fiber. The present invention adopts a stacking melting molding technology, omitting the steps of mechanical outer circle grinding and polishing in the prior art, and quickly forms an elliptical cladding optical fiber by controlling the different specification ratios of the core rod 1 and the quartz rod 2 and different drawing speeds, thereby solving the technical problems in the prior art that the preform is difficult to prepare, a large boron-doped area exists inside the preform, and the grinding and polishing process is particularly prone to cracking, resulting in a low yield.

[0036] For details, please refer to Figures 1 to 3 The core rod 1 in step S1 is a single-mode preform core rod 1 or an elliptical cladding preform core rod 1, and the optical fiber in step S3 is an elliptical core optical fiber or an elliptical cladding optical fiber.

[0037] Specifically, in step S1, there are at least two quartz rods 2.

[0038] The two quartz rods 2 are symmetrically arranged on both sides of the core rod 1 , and the quartz rods 2 and the core rod 1 are arranged in parallel.

[0039] A plurality of quartz rods 2 are arranged at equal intervals on the outer peripheral side of the core rod 1 , and the quartz rods 2 and the core rod 1 are arranged in parallel.

[0040] Specifically, the wire drawing speed in step S3 is 15-50 m / min.

[0041] Specifically, the quartz rod 2 is of F300ES type or F300HQ type.

[0042] As a specific embodiment of the present application, the diameter of the core rod 1 in step S1 is 10 mm to 35 mm, and the diameter of the quartz rod 2 is 2 mm to 10 mm.

[0043]

[0044] Specifically, the refractive index n1 of the optical fiber core of the elliptical core optical fiber or the optical fiber core of the elliptical cladding optical fiber is in the range of 1.460 <n1<1.493。

[0045] Specifically, the refractive index value n3 of the stress zone of the elliptical cladding optical fiber ranges from 1.445 to <n3<1.459。

[0046] Furthermore, the refractive index n3 of the stress region of the elliptical cladding optical fiber (whose composition is boron or high stress doped silica glass such as boron germanium co-doped) is in the range of 1.445 <n3<1.459。

[0047] Specifically, the refractive index n2 of the silica cladding of the elliptical core optical fiber or the elliptical cladding optical fiber is 1.457.

[0048] Furthermore, the refractive index n2 of the quartz cladding (which may contain phosphorus, fluorine or pure quartz) of the elliptical core optical fiber or the elliptical cladding optical fiber is 1.457.

[0049] Specifically, the heating and melting of the quartz rod 2 and the core rod 1 includes the following steps:

[0050] S2.1, the quartz rod 2 collapses on the surface of the core rod 1 due to heat;

[0051] S2.2. Under the action of surface tension, the quartz rod 2 and the core rod 1 are gradually melted into an optical fiber mother rod 3, thereby reducing the ratio of the fiber core to the optical fiber mother rod 3.

[0052] 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 method for preparing an elliptical cladding optical fiber, characterized in that: include: S1. Prepare a core rod and a quartz rod, wherein the quartz rod is fixed on the outer surface of the core rod to form a preformed rod; S2, the assembled preform rod is placed vertically in the high temperature zone of the drawing tower heating furnace for heating, and the quartz rod and the core rod in the high temperature zone are heated and melted into one, forming an optical fiber mother rod; S3, drawing the optical fiber mother rod to form an optical fiber.

2. The method for preparing an elliptical cladding optical fiber according to claim 1, characterized in that: The core rod in step S1 is a single-mode preform core rod or an elliptical cladding preform core rod, and the optical fiber formed by drawing the optical fiber mother rod in step S3 is an elliptical core optical fiber or an elliptical cladding optical fiber.

3. The method for preparing an elliptical cladding optical fiber according to claim 1, characterized in that: In step S1, there are at least two quartz rods.

4. The method for preparing an elliptical cladding optical fiber according to claim 3, characterized in that: The quartz rod is a high-purity SiO2 preformed rod.

5. The method for preparing an elliptical cladding optical fiber according to claim 4, characterized in that: The wire drawing speed in step S3 is 15 to 50 m / min.

6. The method for preparing an elliptical cladding optical fiber according to claim 1, characterized in that: The diameter of the core rod in step S1 is 10 mm to 35 mm, and the diameter of the quartz rod is 2 mm to 10 mm.

7. The method for preparing an elliptical cladding optical fiber according to claim 2, characterized in that: The refractive index value n1 of the optical fiber core of the elliptical core optical fiber or the optical fiber core of the elliptical cladding optical fiber is in the range of 1.460 <n1<1.493。 8. The method for preparing an elliptical cladding optical fiber according to claim 7, characterized in that: The refractive index value n3 of the stress zone of the elliptical cladding optical fiber ranges from 1.445 <n3<1.459。 9. The method for preparing an elliptical cladding optical fiber according to claim 8, characterized in that: The refractive index n2 of the silica cladding of the elliptical core optical fiber or the elliptical cladding optical fiber is 1.

457.

10. The method for preparing an elliptical cladding optical fiber according to any one of claims 1 to 9, characterized in that: The heating and melting of the quartz rod and the core rod comprises the following steps: S2.1, the quartz rod collapses on the surface of the core rod due to heat; S2.

2. Under the action of surface tension, the quartz rod and the core rod are gradually melted into an optical fiber mother rod, thereby reducing the ratio of the fiber core to the optical fiber mother rod.

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