Low-loss optical connection adapter for hollow optical fiber and solid optical fiber

Abstract

The utility model discloses a hollow optical fiber and solid optical fiber low-loss optical connection adapter, which comprises a solid optical fiber, a hollow optical fiber and a glass tube, the adaptive end of the solid optical fiber inserted into the glass tube is provided with a beam expanding structure, the adaptive end of the solid optical fiber is provided with an APC end face of 8 degrees + / -0.5 degrees, and the adaptive end of the solid optical fiber is coated with an antireflection film. The adaptive end of the hollow fiber inserted into the glass tube is provided with a PC end face. The beneficial effects of the utility model are that the connection loss between the hollow fiber and the common solid fiber is less than 1.2 dB; 1W continuous laser power is tolerated, and the temperature rise is less than 5 DEG C; and the loss change is less than 0.2 dB through a high and low temperature cycle test of-40 DEG C to 85 DEG C.

Description

Technical Field

[0001] This application belongs to the field of optical fiber communication technology, specifically relating to a low-loss optical connection adapter for hollow optical fiber and solid optical fiber. Background Technology

[0002] refer to Figure 1 As shown, this is a conventional fiber optic adapter. Existing fiber optic adapters have the following problems: 1. Hollow-core fibers (such as anti-resonant hollow-core fibers) have significant differences in mode field diameter and mode distribution compared to conventional solid fibers, and direct splicing loss is usually >3dB; 2. Existing fusion splicing technology cannot solve the problem of abrupt changes in refractive index between air cores and solid cores; 3. Commercial fiber optic connectors (such as FC / APC) are not optimized for the special structure of hollow fibers.

[0003] The shortcomings of existing solutions to the above problems are: 1. Gradient index lens (GRIN Lens) solutions are bulky and require excessively high alignment accuracy; 2. Bubbles are prone to form at the weld joints, leading to a decline in long-term reliability. Utility Model Content

[0004] The purpose of this application is to provide a low-loss optical connection adapter for hollow optical fibers and solid optical fibers, which solves the problem of high connection loss of conventional optical fiber adapters.

[0005] The objective of this application is achieved through the following technical solution:

[0006] A low-loss optical connection adapter for hollow and solid optical fibers includes a solid optical fiber, a hollow optical fiber, and a glass tube. The adapter end of the solid optical fiber inserted into the glass tube is provided with a beam expansion structure. The adapter end of the solid optical fiber is provided with an 8°±0.5° APC end face. The adapter end of the solid optical fiber is coated with an anti-reflection film. The adapter end of the hollow optical fiber inserted into the glass tube is provided with a PC end face.

[0007] Furthermore, the solid optical fiber is a single-mode optical fiber.

[0008] Furthermore, the expanded structure of the solid optical fiber has a diameter of 15μm to 20μm.

[0009] Furthermore, the antireflective film is an AR antireflective film.

[0010] Furthermore, the AR antireflection film is a Ta2O5 / SiO2 multilayer antireflection film with a reflectivity ≤0.25%@1250nm~1620nm.

[0011] Furthermore, the PC end face of the hollow optical fiber is an ultra-narrow pitch diamond-cut structure or a femtosecond laser ring scanning cut structure.

[0012] Furthermore, the smoothness Ra of the PC end face of the hollow optical fiber is less than 100 nm.

[0013] Furthermore, the glass tube has an ultrasonic micro-drilled inner hole structure or a laser-induced chemical etching inner hole structure.

[0014] Furthermore, the inner diameter of the glass tube is 0.3 mm ± 1 μm, and the smoothness of the inner wall surface Ra < 0.10 μm.

[0015] Furthermore, the solid optical fiber and the glass tube, as well as the hollow optical fiber and the glass tube, are fixedly connected by adhesive.

[0016] Furthermore, the adhesive is a UV-cured inner layer and a 353ND adhesive-reinforced outer layer.

[0017] The beneficial effects of this application are:

[0018] 1. Achieve a connection loss of <1.2dB between hollow optical fiber and ordinary solid optical fiber.

[0019] 2. Withstands 1W continuous laser power with a temperature rise of <5℃.

[0020] 3. The loss change is <0.2dB after passing the high and low temperature cycle test from -40℃ to 85℃.

[0021] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding this solution, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected in this application, and will not be exhaustively listed here. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a standard fiber optic adapter.

[0023] Figure 2 This is a schematic diagram of the structure of this application.

[0024] In the diagram: 1-Solid optical fiber, 2-Hollow optical fiber, 3-Glass tube, 4-Bundle expansion structure, 5-APC end face, 6-Antireflective coating, 7-PC end face, 8-Adhesive; 01-Conventional connector, 02-Conventional adapter. Detailed Implementation

[0025] The present application will be further described below with reference to specific embodiments and accompanying drawings.

[0026] Example 1

[0027] refer to Figure 2As shown, a low-loss optical connection adapter for hollow and solid optical fibers includes a solid optical fiber 1, a hollow optical fiber 2, and a glass tube 3.

[0028] The adapter end of the solid optical fiber 1 inserted into the glass tube 3 is equipped with a beam expander structure 4 to facilitate a transition fit between the smaller diameter solid optical fiber 1 and the larger diameter hollow optical fiber 2. The adapter end of the solid optical fiber 1 has an 8°±0.5° APC end face to reduce Fresnel reflection. The adapter end of the solid optical fiber 1 is coated with an antireflection film 6 to reduce reflection and improve transmission. The adapter end of the hollow optical fiber 2 inserted into the glass tube 3 has a PC end face 7 to eliminate air gaps.

[0029] The expander structure 4 of the solid optical fiber 1 has a diameter of 15μm to 20μm, preferably expanded to a diameter of 20μm. The antireflection coating 6 is an AR antireflection coating, which is a Ta2O5 / SiO2 multilayer antireflection coating with a reflectivity ≤0.25%@1250nm to 1620nm.

[0030] The PC end face 7 of the hollow optical fiber 2 has an ultra-narrow pitch diamond-cut structure, or a femtosecond laser (1030nm, 500fs) ring scanning cut structure can be used as a backup, with the radius of curvature controlled by a Z-axis piezoelectric platform. The smoothness Ra of the PC end face 7 of the hollow optical fiber 2 is <100nm.

[0031] Glass tube 3 has an ultrasonically micro-drilled inner hole structure, but a laser-induced chemical etching (LICE) inner hole structure can also be used as a backup. The inner hole diameter of glass tube 3 is 0.3 mm ± 1 μm, and the inner hole wall smoothness Ra < 0.10 μm ensures low scattering loss.

[0032] Solid optical fiber 1 and glass tube 3, as well as hollow optical fiber 2 and glass tube 3, are fixedly connected by adhesive 8. Adhesive 8 consists of a UV-cured inner layer and an ND-reinforced outer layer, which are automatically coupled and positioned. First, the UV-cured adhesive is used, and then it is reinforced with 353ND adhesive.

[0033] The measured average insertion loss of this adapter is <1.2dB.

[0034] Example 2

[0035] refer to Figure 2 As shown, a low-loss optical connection adapter for hollow and solid optical fibers is implemented based on Embodiment 1, including a solid optical fiber 1, a hollow optical fiber 2, and a glass tube 3.

[0036] Solid fiber 1 uses ordinary solid fiber, and its end face is processed in batches using a fully automatic laser cutting machine (Fujikura LZM-100). Hollow fiber 2's end face is processed with a DISCO DFD6360 diamond dicing tool, with a yield rate >98%. Glass tube 3 uses a molding process, reducing the unit cost by 60%. The standard deviation of insertion loss for batch products is <0.1dB.

[0037] Solid fiber 1 is a single-mode fiber with a MFD of 8.8±0.4μm@1310nm, specifically G657A1 / G657A2 fiber. The mode length diameter of the hollow fiber is 20~50um.

[0038] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0039] 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. A low-loss optical connection adapter of a hollow optical fiber and a solid optical fiber, comprising a solid optical fiber (1), a hollow optical fiber (2) and a glass tube (3), characterized in that: The solid optical fiber (1) is inserted into the glass tube (3) and has an expansion structure (4) at the adapter end. The solid optical fiber (1) is also provided with an APC end face of 8°±0.5° at the adapter end. The solid optical fiber (1) is coated with an anti-reflection film (6). The hollow optical fiber (2) is inserted into the glass tube (3) and has a PC end face (7) at the adapter end.

2. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1, characterized in that: The solid optical fiber (1) is a single-mode optical fiber.

3. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1, characterized in that: The expansion structure (4) of the solid optical fiber (1) has a diameter of 15μm to 20μm.

4. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1 or 3, characterized in that: The antireflective membrane (6) is an AR antireflective membrane.

5. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 4, characterized in that: The AR antireflection film is a Ta2O5 / SiO2 multilayer antireflection film with a reflectivity of ≤0.25%@1250nm~1620nm.

6. The low-loss optical connection adapter for hollow and solid optical fibers according to claim 1, characterized in that: The PC end face (7) of the hollow optical fiber (2) is an ultra-narrow pitch diamond cutting structure or a femtosecond laser ring scanning cutting structure.

7. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1 or 6, characterized in that: The smoothness Ra of the PC end face (7) of the hollow optical fiber (2) is less than 100 nm.

8. The low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1, characterized by: The glass tube (3) is an ultrasonic micro-drilled inner hole structure or a laser-induced chemical etching inner hole structure.

9. A low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1 or 8, characterized in that: The inner diameter of the glass tube (3) is 0.3 mm ± 1 μm, and the smoothness of the inner wall surface Ra < 0.10 μm.

10. The low-loss optical connection adapter for a hollow optical fiber and a solid optical fiber according to claim 1, characterized by: The solid optical fiber (1) and the glass tube (3) and the hollow optical fiber (2) and the glass tube (3) are fixedly connected by adhesive (8); the adhesive (8) is a UV-cured inner layer and a 353ND adhesive reinforced outer layer.

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