An ultra-small online isolator

Abstract

This application discloses an ultra-miniature online isolator, comprising a first fiber collimator, a second fiber collimator, an isolator core, and an outer sealing glass tube. The first and second fiber collimators are respectively disposed at both ends of the isolator core, serving as the input and output ends of the isolator. The first and second fiber collimators and the isolator core are all sealed and fixed inside the outer sealing glass tube, and are all located on the same optical axis. It has the following advantages: Miniaturization: By integrating the two fiber collimators and the isolator core inside the outer sealing glass tube, and with all components located on the same optical axis, the overall volume of the isolator is greatly reduced, meeting the installation requirements of ultra-miniature optical communication equipment. Sealing: The coreless optical fiber and the inner sealing glass tube are sealed using carbon dioxide laser fusion welding, forming a strong sealed connection that effectively prevents external moisture, dust, etc., from entering the fiber collimator. The components in the isolator core are fixed inside the magnetic tube with adhesive, ensuring the internal structural stability of the isolator core.

Description

Technical Field

[0001] This utility model relates to the field of optical devices, and in particular to an ultra-miniature online isolator. Background Technology

[0002] With the rapid development of technologies such as 5G / 6G communication and data center interconnection, the integration requirements for core optical components in fiber optic communication systems are increasing. Fiber optic in-line isolators, as key components for preventing reflected light interference, generally consist of collimators, isolator cores, and other structures. Existing fiber optic in-line isolators typically use spherical lenses as collimators. Spherical lenses are mostly manufactured by grinding crystals, a process that is difficult and costly to produce when manufacturing small lenses. Alternatively, Green lenses can be used as collimators, which solves the problem of small-size manufacturing, but Green lenses are generally expensive. A patent application with application number CN104656194A proposes a process in which a section of multimode fiber is fused to one end of a single-mode fiber, and the end of the multimode fiber is then melted into a spherical lens with a controllable diameter through electrode tip discharge. The fiber optic lens produced by this process has the advantages of small size and low processing cost. However, there are still some problems in its use: the voltage of the electrode discharge is often relatively large, which makes it difficult to control the accuracy of the spherical lens made by melting the fiber; at the same time, the spherical lens made by melting multimode fiber has uneven material distribution inside, and these factors will seriously affect the performance parameters of the output beam.

[0003] Therefore, how to design and provide an ultra-small online isolator that is simple to manufacture, cost-controllable, and has superior performance is a technical problem to be solved. Utility Model Content

[0004] Based on this, it is necessary to provide an ultra-small online isolator to address the existing problems, including a first fiber collimator (1), a second fiber collimator (2), an isolator core (3), and three outer sealing glass tubes (4).

[0005] The first fiber collimator (1) and the second fiber collimator (2) are respectively disposed at both ends of the isolator core (3) and serve as the input end and output end of the isolator; the first fiber collimator (1), the second fiber collimator (2) and the isolator core (3) are all sealed and fixed inside the outer sealing glass tube (4) and are all located on the same optical axis.

[0006] Preferably, both the first fiber collimator (1) and the second fiber collimator (2) include a fiber lens (11) and an inner glass tube (12) located outside the fiber lens (11).

[0007] Preferably, the fiber optic lens (11) includes a spherical lens (111), a coreless fiber (112), and a single-mode fiber (113).

[0008] Preferably, the coreless optical fiber (112) and the inner sealing glass tube (12) are sealed by carbon dioxide laser melting welding.

[0009] Preferably, the single-mode optical fiber (113) and the inner glass tube (12) are sealed and fixed with glue.

[0010] Preferably, the isolator core (3) includes a first birefringent crystal (31), a second birefringent crystal (32), a Faraday rotator (33), and a magnetic tube (34), wherein the first birefringent crystal (31), the second birefringent crystal (32), and the Faraday rotator (33) are fixed inside the magnetic tube (34) by adhesive.

[0011] Preferably, both the first birefringent crystal (31) and the second birefringent crystal (32) are wedge-shaped birefringent crystals.

[0012] Compared with the prior art, the technical solution disclosed in this utility model has the following beneficial effects:

[0013] (1) Miniaturized design: By integrating the first fiber collimator, the second fiber collimator and the isolator core into the outer glass tube, and with each component located on the same optical axis, the overall volume of the isolator is greatly reduced, which can meet the installation requirements of ultra-miniature optical communication equipment.

[0014] (2) Excellent sealing performance: The coreless optical fiber and the inner sealing glass tube are sealed by carbon dioxide laser melting welding. This welding method can form a strong sealed connection, effectively preventing external moisture, dust and other substances from entering the optical fiber collimator. At the same time, the single-mode optical fiber and the inner sealing glass tube are sealed and fixed with glue, which further enhances the sealing performance of the optical fiber collimator. In addition, the first optical fiber collimator, the second optical fiber collimator and the isolator core are all sealed and fixed in the outer sealing glass tube, so that the entire isolator forms a closed whole, and the sealing performance is greatly improved.

[0015] (3) Stable structure: The connections between the components are firm and reliable. The first fiber collimator, the second fiber collimator, and the isolator core are all located on the same optical axis, effectively avoiding the problem of optical axis misalignment. The first birefringent crystal, the second birefringent crystal, and the Faraday rotator in the isolator core are fixed inside the magnetic tube with glue, ensuring the stability of the internal structure of the isolator core. This stable structural design allows the isolator to maintain good optical performance when affected by external factors such as vibration and impact.

[0016] (4) Excellent optical performance: The combination of wedge-shaped birefringent crystal and Faraday rotator can effectively improve the isolation of the isolator and reduce the insertion loss. At the same time, due to the stable structure and small optical axis offset, the optical performance of the isolator has good consistency and stability. Attached Figure Description

[0017] The exemplary embodiments of this utility model can be more fully understood by referring to the following accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain the utility model and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0018] Figure 1 This is a schematic diagram of the structure of an ultra-miniature online isolator provided according to an exemplary embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of a first fiber collimator provided according to an exemplary embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the structure of an optical fiber lens provided according to an exemplary embodiment of this application;

[0021] Figure 4 This is a schematic diagram of the structure of another ultra-miniature online isolator provided according to an exemplary embodiment of this application.

[0022] Figure Labels

[0023] 1-First fiber collimator, 2-Second fiber collimator, 3-Isolator core, 4-Outer sealing glass tube, 11-Fiber lens, 12-Inner sealing glass tube, 13-Glue, 111-Spherical lens, 112-Coreless fiber, 113-Single-mode fiber, 31-First birefringent crystal, 32-Second birefringent crystal, 33-Faraday rotator, 34-Magnetic tube. Detailed Implementation

[0024] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] Reference Figure 1 This application provides an ultra-miniature online isolator, including a first fiber collimator 1, a second fiber collimator 2, an isolator core 3, and an outer sealing glass tube 4; the first fiber collimator 1 and the second fiber collimator 2 are respectively disposed at both ends of the isolator core 3, and serve as the input end and output end of the isolator; the first fiber collimator 1, the second fiber collimator 2, and the isolator core 3 are all sealed and fixed inside the outer sealing glass tube 4, and are all located on the same optical axis.

[0029] Reference Figure 2 The structure of the first fiber optic collimator 1 is shown, which includes a fiber optic lens 11 and an inner sealing glass tube 12 located outside the fiber optic lens 11. The fiber optic lens 11 and the inner sealing glass tube are sealed and fixed together by adhesive 13. The structure of the second fiber optic collimator 2 is similar.

[0030] Reference Figure 3The fiber optic lens 11 includes a spherical lens 111, a coreless fiber 112, and a single-mode fiber 113. The coreless fiber 112 is sealed to the inner glass tube 12 by carbon dioxide laser fusion welding. During welding, the laser power and welding time are controlled to ensure a strong sealing structure is formed at the weld. In a preferred embodiment, the coreless fiber can be replaced with a pure quartz rod. The specific fabrication process for the fiber optic lens can be as follows: a 0.4mm diameter coreless fiber or pure quartz rod is fused to one end of a single-mode fiber. At the other end of the fused coreless fiber or pure quartz rod, a multi-channel carbon dioxide laser is used to focus and fuse it into a spherical lens. During the melting process, the fiber needs to rotate around its axis to ensure that the center of the spherical lens is on the axis of the fiber, while also preventing the molten fiber from dripping or deforming. The output beam waist size of this fiber optic lens can reach 0.1mm or even smaller. In this embodiment, the spherical lens made of coreless optical fiber or pure quartz rod has the advantages of uniform lens material and good output beam performance compared to the spherical lens made of multimode optical fiber; and the fiber lens made of laser-fused coreless optical fiber or pure quartz rod has the advantages of high precision and controllability compared to the spherical lens made by electrode discharge.

[0031] Specifically, the single-mode optical fiber 113 is sealed and fixed to the inner glass tube 12 with adhesive. The adhesive used is a high-temperature resistant and low-shrinkage epoxy adhesive to ensure sealing performance and connection strength, and to prevent the optical fiber from breaking due to bending.

[0032] Specifically, the isolator core 3 includes a first birefringent crystal 31, a second birefringent crystal 32, a Faraday rotator 33, and a magnetic tube 34. The first birefringent crystal 31, the second birefringent crystal 32, and the Faraday rotator 33 are fixed inside the magnetic tube 34 with adhesive. The adhesive used is a low-volatility, high-bonding-strength silicone rubber adhesive, which can withstand temperature changes from -40℃ to 85℃ after curing. Both the first birefringent crystal 31 and the second birefringent crystal 32 are wedge-shaped birefringent crystals, which can effectively achieve polarization separation and recombination of light. The Faraday rotator 33 is made of yttrium iron garnet (YIG) material, which can rotate the polarization direction of light by 45 degrees under the action of the magnetic field provided by the magnetic tube 34.

[0033] Specifically, the outer sealing glass tube 4 is made of high borosilicate glass, which has good light transmittance and mechanical strength. Its inner diameter matches the outer diameter of the first fiber collimator 1, the second fiber collimator 2, and the isolator core 3. The first fiber collimator 1, the second fiber collimator 2, and the isolator core 3 are sealed and fixed inside the outer sealing glass tube 4 with adhesive. The outer sealing glass tube 4 and the inner sealing glass tube 12 are sealed together by carbon dioxide laser melting welding, ensuring that the isolator has good sealing performance and forming a complete ultra-miniature online isolator. Compared with adhesive sealing, glass welding encapsulation has better sealing performance and can also prevent the possibility of stress changing the lens position under high temperature due to adhesive sealing.

[0034] In a preferred embodiment, reference is made to Figure 4 In order to increase the light transmission area of ​​the isolator core and improve the isolation, the magnetic tube (34) can be sleeved on the outside of the outer sealing glass tube (4).

[0035] In the manufacturing process of the ultra-miniature online isolator in this embodiment, it is necessary to strictly ensure the optical axis alignment of each component. Adjustments are made using precision optical alignment equipment to ensure that the optical axis deviations of the first fiber collimator 1, the second fiber collimator 2, and the isolator core 3 are within a preset reasonable range.

[0036] The technical solution disclosed in this utility model has the following beneficial effects:

[0037] (1) Miniaturized design: By integrating the first fiber collimator, the second fiber collimator and the isolator core into the outer glass tube, and with each component located on the same optical axis, the overall volume of the isolator is greatly reduced, which can meet the installation requirements of ultra-miniature optical communication equipment.

[0038] (2) Excellent sealing performance: The coreless optical fiber and the inner sealing glass tube are sealed by carbon dioxide laser melting welding. This welding method can form a strong sealed connection, effectively preventing external moisture, dust and other substances from entering the optical fiber collimator. At the same time, the single-mode optical fiber and the inner sealing glass tube are sealed and fixed with glue, which further enhances the sealing performance of the optical fiber collimator. In addition, the first optical fiber collimator, the second optical fiber collimator and the isolator core are all sealed and fixed in the outer sealing glass tube, so that the entire isolator forms a closed whole, and the sealing performance is greatly improved.

[0039] (3) Stable structure: The connections between the components are firm and reliable. The first fiber collimator, the second fiber collimator, and the isolator core are all located on the same optical axis, effectively avoiding the problem of optical axis misalignment. The first birefringent crystal, the second birefringent crystal, and the Faraday rotator in the isolator core are fixed inside the magnetic tube with glue, ensuring the stability of the internal structure of the isolator core. This stable structural design allows the isolator to maintain good optical performance when affected by external factors such as vibration and impact.

[0040] (4) Excellent optical performance: The combination of wedge-shaped birefringent crystal and Faraday rotator can effectively improve the isolation of the isolator and reduce the insertion loss. At the same time, due to the stable structure and small optical axis offset, the optical performance of the isolator has good consistency and stability.

[0041] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0042] It should be noted that in the description of this utility model, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means at least two.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An ultra-miniature online isolator, characterized in that, It includes a first fiber collimator (1), a second fiber collimator (2), an isolator core (3), and an outer sealing glass tube (4); The first fiber collimator (1) and the second fiber collimator (2) are respectively disposed at both ends of the isolator core (3) and serve as the input end and output end of the isolator; the first fiber collimator (1), the second fiber collimator (2) and the isolator core (3) are all sealed and fixed inside the outer sealing glass tube (4) and are all located on the same optical axis.

2. The ultra-miniature online isolator according to claim 1, characterized in that, Both the first fiber collimator (1) and the second fiber collimator (2) include a fiber lens (11) and an inner glass tube (12) located outside the fiber lens (11).

3. The ultra-miniature online isolator according to claim 2, characterized in that, The fiber optic lens (11) includes a spherical lens (111), a coreless fiber (112), and a single-mode fiber (113).

4. The ultra-miniature online isolator according to claim 3, characterized in that, The coreless optical fiber (112) and the inner glass tube (12) are sealed together by carbon dioxide laser melting welding.

5. The ultra-miniature online isolator according to claim 3, characterized in that, The single-mode optical fiber (113) and the inner glass tube (12) are sealed and fixed with glue.

6. The ultra-miniature online isolator according to claim 3, characterized in that, The outer sealing glass tube (4) and the inner sealing glass tube (12) are sealed together by carbon dioxide laser melting welding.

7. The ultra-miniature online isolator according to claim 1, characterized in that, The isolator core (3) includes a first birefringent crystal (31), a second birefringent crystal (32), a Faraday rotator (33), and a magnetic tube (34). The first birefringent crystal (31), the second birefringent crystal (32), and the Faraday rotator (33) are fixed inside the magnetic tube (34) with glue.

8. The ultra-miniature online isolator according to claim 7, characterized in that, Both the first birefringent crystal (31) and the second birefringent crystal (32) are wedge-shaped birefringent crystals.

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