High-precision coaxial light collimator and manufacturing method thereof

Abstract

The invention discloses a high-precision coaxial optical collimator and a manufacturing method thereof, and relates to the technical field of coaxial optical collimators, the high-precision coaxial optical collimator comprises a ceramic bushing, a central jack penetrating in the length direction of the ceramic bushing is formed in the center of the ceramic bushing, and an optical fiber assembly is arranged in the central jack. The optical fiber assembly comprises a common optical fiber and a self-focusing optical fiber which are arranged in the central jack in a matched mode, and the common optical fiber and the self-focusing optical fiber are coaxial. The self-focusing optical fiber is used as the collimating lens and is matched with the ceramic ferrule, so that extremely small size is realized, and the self-focusing optical fiber collimator can be applied to the interior of a miniature optical device, such as a miniature probe. The optical-mechanical coaxiality of the collimator is realized through a mechanical precision mode, the structure is simple, a complicated calibration process is not needed, the production efficiency is improved, and the labor cost is reduced at the same time. And the anti-bending sleeve at the rear end of the fixed sleeve can prevent the optical fiber assembly from being broken due to overlarge bending degree at the outlet of the fixed sleeve.

Description

Technical Field

[0001] The present invention relates to the technical field of coaxial light collimators, and in particular to a high-precision coaxial light collimator and a manufacturing method thereof. Background Art

[0002] Coaxial optical collimator is an important device in the field of optical fiber. It uses a self-focusing lens to collimate the light beam emitted by the optical fiber into parallel light, or couples parallel light into the optical fiber. Its characteristic is that the optical axis and the mechanical axis basically coincide, which simplifies the installation and calibration process.

[0003] Commonly used fiber coaxial collimators are usually composed of key components such as self-focusing lenses, precision glass capillaries, and optical fiber pigtails. These components work together to ensure the precise transmission and conversion of optical signals.

[0004] During production, due to the certain angle and off-axis eccentricity between the optical axis and the mechanical axis, the optical and mechanical coaxiality must be adjusted by precision equipment to achieve optical path alignment. After debugging, it needs to be fixed with a specific glue. The entire production process is complicated and time-consuming. In addition, this coaxial collimator is extremely sensitive to angles, and the reliability of the collimator is easily affected when subjected to radial forces. Summary of the invention

[0005] The purpose of the present invention is to provide a high-precision coaxial optical collimator and a manufacturing method thereof, which solves the technical problems that the commonly used optical fiber coaxial collimator is composed of a lens, a glass capillary, and a pigtail, is large in size, has a complex manufacturing process and is time-consuming, and is extremely sensitive to angles, which can easily affect the reliability of the collimator when subjected to radial forces.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A high-precision coaxial optical collimator comprises a ceramic sleeve, wherein a central plug hole is provided at the center of the ceramic sleeve and penetrates the ceramic sleeve along the length direction, an optical fiber assembly is arranged inside the central plug hole, and the optical fiber assembly comprises an ordinary optical fiber arranged at the rear end of the central plug hole and a self-focusing optical fiber arranged at the front end of the central plug hole, and the ordinary optical fiber and the self-focusing optical fiber are arranged coaxially.

[0008] As a further solution of the present invention: the ordinary optical fiber and the self-focusing optical fiber are connected by fusion splicing.

[0009] As a further solution of the present invention: the front end of the common optical fiber is fused with a coreless optical fiber, and the other end of the coreless optical fiber is fused with a self-focusing optical fiber.

[0010] As a further solution of the present invention: the length of the self-focusing optical fiber is L, the pitch of the self-focusing optical fiber is P, and the relationship between L and P is: L=1 / 4×M×P, where M is a positive odd number.

[0011] As a further solution of the present invention: the tail end of the ceramic sleeve is provided with a tapered guide portion for facilitating the insertion of the optical fiber assembly, the inner surface of the central plug hole is a smooth structure, and the diameter of the central plug hole is adapted to the diameter of the self-focusing optical fiber.

[0012] As a further solution of the present invention: the rear end of the ceramic sleeve is fixedly sleeved with a fixed sleeve, and the rear end of the fixed sleeve is fixedly sleeved with an anti-bend sleeve for protecting ordinary optical fiber.

[0013] As a further solution of the present invention: the anti-folding sleeve is made of thermoplastic elastic plastic material, and a slope is arranged on the rear end edge of the anti-folding sleeve.

[0014] As a further solution of the present invention: the fixed sleeve is provided with a protective sleeve for protecting the ceramic sleeve port, the length of the protective sleeve is greater than the ceramic sleeve, the front end of the fixed sleeve is surrounded by a surrounding protrusion, the protective sleeve includes a protective sleeve that slides with the surrounding protrusion, the rear end of the protective sleeve is fixedly provided with a limiting sleeve that slides with the rear end of the fixed sleeve, and the inner diameter of the limiting sleeve is smaller than the inner diameter of the protective sleeve.

[0015] As a further solution of the present invention: a limiting groove is arranged around the surrounding protrusion, and a limiting strip matching the limiting groove is fixedly arranged inside the protective sleeve. The limiting strip is made of elastic rubber material, and the rear end cross-sectional size is larger than the front end cross-sectional size.

[0016] A method for manufacturing a high-precision coaxial light collimator comprises the following steps:

[0017] S1: A common optical fiber and a self-focusing optical fiber are fused to form an optical fiber assembly, or a common optical fiber is fused to one end of a coreless optical fiber and the other end is fused to the self-focusing optical fiber to form an optical fiber assembly;

[0018] S2: insert the end of the fused optical fiber assembly close to the self-focusing optical fiber into the protective sleeve, the anti-bend sleeve, the fixed sleeve and the ceramic sleeve in sequence;

[0019] S3: Fixing and connecting the front end of the anti-bend sleeve and the rear end of the fixed sleeve;

[0020] S4: Fix the optical fiber assembly and the ceramic sleeve by glue, and then fix the fixed sleeve and the ceramic sleeve.

[0021] Beneficial effects of the present invention:

[0022] 1. In the use of the present invention, a self-focusing optical fiber is used as a collimating lens, and a ceramic ferrule is used to achieve an extremely small volume, which can be used inside a micro optical device, such as a micro probe. The optical-mechanical coaxiality of the collimator is achieved by mechanical precision, the structure is simple, and no complicated calibration process is required, which improves production efficiency and reduces labor costs.

[0023] 2. When the present invention is stored, the protective sleeve can be pushed to the ceramic sleeve, and the limit bar will be embedded in the limit groove. As the protective sleeve moves forward, the rear end of the limit bar with a larger cross-sectional size will enter the limit groove. The limit bar is limited by the limit groove to fix the protective sleeve, thereby protecting the ceramic sleeve and reducing the possibility of damage to the self-focusing optical fiber.

[0024] 3. When the present invention is in use, the anti-folding sleeve at the rear end of the fixed sleeve can prevent the optical fiber component from being broken due to excessive bending at the outlet of the fixed sleeve. A slope is provided at the rear end of the anti-folding sleeve. The setting of the slope can produce a continuously weakened guiding protection on the optical fiber component near the output port of the anti-folding sleeve, thereby preventing the optical fiber component from being broken due to excessive bending at the port of the anti-folding sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 It is a schematic diagram of the longitudinal section structure of the ceramic sleeve of the present invention;

[0027] Figure 2 It is a schematic diagram of the motion structure of light in ordinary optical fiber and self-focusing optical fiber of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the present invention after installing the coreless optical fiber;

[0029] Figure 4 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure after the protective sleeve of the present invention is removed;

[0031] Figure 6 It is a schematic diagram of the longitudinal section structure of the protective sleeve of the present invention.

[0032] In the figure: 1. Ceramic sleeve; 2. Center jack; 3. Conical guide; 4. Ordinary optical fiber; 5. Self-focusing optical fiber; 6. Coreless optical fiber; 7. Fixed sleeve; 701. Limiting groove; 702. Surrounding protrusion; 8. Anti-bending sleeve; 9. Protective sleeve; 901. Protective sleeve; 902. Limiting strip; 903. Limiting sleeve. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0034] See also Figure 1-6 As shown, the present invention is a high-precision coaxial optical collimator. The technical solution of the present invention provides a high-precision coaxial optical collimator, including a ceramic sleeve 1 and an optical fiber assembly inserted into the ceramic sleeve 1. A central plug hole 2 is provided at the center of the ceramic sleeve 1 and along the length direction of the ceramic sleeve 1. The optical fiber assembly is inserted into the central plug hole 2, and the inner surface of the central plug hole 2 is a smooth structure. The inner diameter of the central plug hole 2 in the ceramic sleeve 1 and the outer diameter of the ceramic sleeve 1 have extremely high roundness and coaxiality. The ceramic material is used, the material stability is good, the accuracy can reach the micron level, and the mechanical error is reduced. The optical fiber assembly is inserted into the ceramic central plug hole 2. The ultra-high precision and extremely small gap between the central plug hole 2 and the optical fiber assembly ensures the coaxiality of the optical fiber assembly and the ceramic sleeve 1, thereby achieving an optical-mechanical coaxial effect.

[0035] The optical fiber assembly and the center plug 2 are bonded by 353nd glue, the main components of which are epoxy resin and curing agent. Epoxy resin is a polymer compound with excellent bonding properties and chemical corrosion resistance, while the curing agent can harden the epoxy resin under specific conditions to achieve the fixation of the optical fiber assembly and the center plug 2.

[0036] In some specific embodiments, such as Figure 1 As shown, the optical fiber assembly includes a common optical fiber 4 and a self-focusing optical fiber 5 connected to the common optical fiber 4, and the common optical fiber 4 and the self-focusing optical fiber 5 are coaxially arranged. The common optical fiber 4 and the self-focusing optical fiber 5 are connected by fusion splicing. The diameter of the central plug hole 2 is adapted to the diameter of the self-focusing optical fiber 5.

[0037] In other specific embodiments, the optical fiber assembly can also be Figure 3 In the structure shown, the common optical fiber 4 is fused with one end of the coreless optical fiber 6 of calculated length, and the other end of the coreless optical fiber 6 is fused with the self-focusing optical fiber 5 of specific length. The coreless optical fiber 6 is a special optical fiber with uniform refractive index. The addition of the coreless optical fiber 6 can improve the focusing performance of the light beam by expanding the beam.

[0038] The rear end of the ceramic sleeve 1 is provided with a tapered guide portion 3 for facilitating the insertion of the optical fiber component, thereby guiding the optical fiber component and facilitating the insertion of the optical fiber component into the central plug hole 2 .

[0039] like Figure 2As shown, based on the above optical fiber assembly structure, the length of the self-focusing optical fiber 5 is fixed, and the light beam propagates along a sinusoidal trajectory in the self-focusing optical fiber 5. The length of a sine wave cycle is called a pitch P. The relationship between the length L of the self-focusing optical fiber 5 and the pitch P in the coaxial collimator is L=1 / 4×M×P (where M is a positive odd number). For a self-focusing optical fiber 5 of a specific length L, when the light beam is input from one end of the self-focusing lens optical fiber, it will be transformed into parallel light after passing through the self-focusing optical fiber 5.

[0040] The collimator of the above solution uses a self-focusing optical fiber 5 as a collimating lens, and is matched with a ceramic ferrule to achieve an extremely small volume, and can be used inside a micro optical device, such as a micro probe, etc. The optical-mechanical coaxiality of the collimator is achieved by mechanical precision, the structure is simple, and no complicated calibration process is required, which improves production efficiency and reduces labor costs.

[0041] In some specific implementation schemes, the rear end of the ceramic sleeve 1 is fixedly sleeved with a fixed sleeve 7, and the rear end of the fixed sleeve 7 is fixedly sleeved with an anti-folding sleeve 8 for protecting the ordinary optical fiber 4, and the anti-folding sleeve 8 is used to prevent the optical fiber component from being broken due to excessive bending at the outlet of the fixed sleeve 7. The anti-folding sleeve 8 is made of thermoplastic elastic plastic material, has a certain degree of flexibility, can resist the impact and extrusion of external forces, and protect the internal wires from damage. At the same time, the thermoplastic elastic plastic material also has a certain degree of hardness, which can prevent the optical fiber from being excessively bent. A slope is set at the rear end edge of the anti-folding sleeve 8, and the setting of the slope can produce a continuously weakened guiding protection on the optical fiber component near the output port of the anti-folding sleeve 8, to prevent the optical fiber component from being broken due to excessive bending at the port of the anti-folding sleeve 8.

[0042] The fixed sleeve 7 is provided with a protective sleeve 9 for protecting the port of the ceramic sleeve 1. The length of the protective sleeve 9 is greater than that of the ceramic sleeve 1. A surrounding protrusion 702 is provided around the front end of the fixed sleeve 7. The protective sleeve 9 includes a protective sleeve 901 that is slidably matched with the surrounding protrusion 702. A limiting sleeve 903 that is slidably matched with the rear end of the fixed sleeve 7 is fixedly provided at the rear end of the protective sleeve 901. The inner diameter of the limiting sleeve 903 is smaller than that of the protective sleeve 9. By limiting the limiting sleeve 903 by the surrounding protrusion 702, and then limiting the protective sleeve 9, the protective sleeve 9 can be prevented from being separated from the ceramic sleeve 1 and the fixed sleeve 7.

[0043] A limiting groove 701 is arranged around the surrounding protrusion 702, and a limiting strip 902 matching the limiting groove 701 is fixedly arranged inside the protective sleeve 901. Figure 4As shown, the limiting strip 902 and the limiting groove 701 are both surrounded by three groups, and the limiting strip 902 is made of elastic rubber material, and the cross-sectional size of the rear end is larger than the cross-sectional size of the front end. When the protective sleeve 9 is pushed to the ceramic sleeve 1, the limiting strip 902 will be embedded in the limiting groove 701, and as the protective sleeve 9 moves forward, the rear end of the limiting strip 902 with a larger cross-sectional size will enter the limiting groove 701, and the limiting strip 902 is limited by the limiting groove 701 to fix the protective sleeve 9.

[0044] A method for manufacturing a high-precision coaxial light collimator comprises the following steps:

[0045] S1: The common optical fiber 4 and the self-focusing optical fiber 5 are fused to form an optical fiber assembly, such as Figure 2 As shown, the light beam propagates along a sinusoidal trajectory and is emitted parallel to the end of the self-focusing optical fiber 5. Or the common optical fiber 4 is fused with one end of the coreless optical fiber 6, and the other end is fused with the self-focusing optical fiber 5 to form an optical fiber assembly, such as Figure 3 As shown, the light beam enters the coreless fiber 6 to achieve beam expansion, and then changes the propagation direction of the light beam through the self-focusing fiber 5, so that the light beam can be emitted in parallel when it reaches the end of the self-focusing fiber 5. The coreless fiber 6 is a special optical fiber with a uniform refractive index. Adding the coreless fiber 6 can improve the focusing performance of the light beam by beam expansion.

[0046] S2: insert the end of the fused optical fiber assembly close to the self-focusing optical fiber 5 into the protective sleeve 9, the anti-bend sleeve 8, the fixed sleeve 7 and the ceramic sleeve 1 in sequence, ensuring that the front end of the common optical fiber 4 and the self-focusing optical fiber 5 are located in the ceramic sleeve 1, and the front end of the optical fiber, the coreless optical fiber 6 and the self-focusing optical fiber 5 are all located in the ceramic sleeve 1;

[0047] S3: The front end of the anti-bend sleeve 8 and the rear end of the fixed sleeve 7 are fixedly connected. The anti-bend sleeve 8 at the rear end of the fixed sleeve 7 can prevent the optical fiber assembly from being broken due to excessive bending at the outlet of the fixed sleeve 7, thereby ensuring the service life of the optical fiber;

[0048] S4: Fix the optical fiber assembly and the ceramic sleeve 1 by glue. The glue needs to be 353nd glue. Then, fix the fixing sleeve 7 and the ceramic sleeve 1 together.

[0049] The working principle of the present invention is as follows: when storing, the protective sleeve 9 is pushed to the ceramic sleeve 1, and the limiting strip 902 will be embedded in the limiting groove 701. As the protective sleeve 9 moves forward, the rear end of the limiting strip 902 with a larger cross-sectional size will enter the limiting groove 701. The limiting strip 902 is limited by the limiting groove 701 to fix the protective sleeve 9, thereby protecting the ceramic sleeve 1 and reducing the possibility of damage to the self-focusing optical fiber 5. By limiting the limiting sleeve 903 around the protrusion 702, and then limiting the protective sleeve 9, the protective sleeve 9 can be prevented from being separated from the ceramic sleeve 1 and the fixed sleeve 7;

[0050] When in use, the protective sleeve 9 is pushed to the rear of the fixed sleeve 7, so as to expose the ceramic sleeve 1, so as to facilitate the docking of the ceramic sleeve 1 with the interface. The anti-bending sleeve 8 at the rear end of the fixed sleeve 7 can prevent the optical fiber component from being broken due to excessive bending at the outlet of the fixed sleeve 7. The rear end of the anti-bending sleeve 8 is provided with a slope, and the setting of the slope can produce a continuously weakened guiding protection on the optical fiber component near the output port of the anti-bending sleeve 8, so as to prevent the optical fiber component from being broken due to excessive bending at the port of the anti-bending sleeve 8.

[0051] When the light beam is input from one end of the self-focusing lens fiber, it will be transformed into parallel light after passing through the self-focusing fiber 5. The collimator of this solution uses the self-focusing fiber 5 as a collimating lens, and is matched with a ceramic ferrule to achieve an extremely small volume, and can be used inside micro-optical devices, such as micro-probes. The optical-mechanical coaxiality of the collimator is achieved by mechanical precision, the structure is simple, and no complicated calibration process is required. The production efficiency is improved while reducing labor costs.

[0052] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A high-precision coaxial light collimator, characterized in that: The invention comprises a ceramic sleeve (1), wherein a central plug hole (2) is provided at the center of the ceramic sleeve (1) and penetrates along the length direction of the ceramic sleeve (1), and an optical fiber assembly is arranged inside the central plug hole (2), and the optical fiber assembly comprises a self-focusing optical fiber (5) arranged inside the central plug hole (2) and an ordinary optical fiber (4) for introducing a light beam into the self-focusing optical fiber (5), and the ordinary optical fiber (4) is coaxially arranged with the self-focusing optical fiber (5).

2. A high-precision coaxial light collimator according to claim 1, characterized in that: The common optical fiber (4) and the self-focusing optical fiber (5) are connected by fusion splicing.

3. A high-precision coaxial light collimator according to claim 1, characterized in that: The front end of the common optical fiber (4) is fused with a coreless optical fiber (6), and the other end of the coreless optical fiber (6) is fused with a self-focusing optical fiber (5).

4. A high-precision coaxial light collimator according to claim 2 or 3, characterized in that: The length of the self-focusing optical fiber (5) is L, the pitch of the self-focusing optical fiber (5) is P, and the relationship between L and P is: L=1 / 4×M×P, wherein M is a positive odd number.

5. A high-precision coaxial light collimator according to claim 4, characterized in that: The tail end of the ceramic sleeve (1) is provided with a tapered guide portion (3) for facilitating the insertion of the optical fiber assembly, the inner surface of the central plug hole (2) is a smooth structure, and the diameter of the central plug hole (2) is adapted to the diameter of the self-focusing optical fiber (5).

6. The high-precision coaxial light collimator according to claim 1, characterized in that: The ceramic sleeve (1) has a fixed sleeve (7) fixedly sleeved at the rear end, and the fixed sleeve (7) has an anti-bend sleeve (8) for protecting a common optical fiber (4) fixedly sleeved at the rear end.

7. A high-precision coaxial light collimator according to claim 6, characterized in that: The anti-folding sleeve (8) is made of thermoplastic elastic plastic material, and a slope is arranged on the rear edge of the anti-folding sleeve (8).

8. The high-precision coaxial light collimator according to claim 6, characterized in that: The fixed sleeve (7) is provided with a protective sleeve (9) for protecting the port of the ceramic sleeve (1); the length of the protective sleeve (9) is greater than that of the ceramic sleeve (1); a surrounding protrusion (702) is provided around the front end of the fixed sleeve (7); the protective sleeve (9) comprises a protective sleeve (901) that is slidably matched with the surrounding protrusion (702); a limiting sleeve (903) that is slidably matched with the rear end of the fixed sleeve (7) is fixedly provided at the rear end of the protective sleeve (901); the inner diameter of the limiting sleeve (903) is smaller than the inner diameter of the protective sleeve (9).

9. A high-precision coaxial light collimator according to claim 8, characterized in that: A limiting groove (701) is arranged around the surrounding protrusion (702), and a limiting strip (902) matching the limiting groove (701) is fixedly arranged inside the protective sleeve (901). The limiting strip (902) is made of elastic rubber material, and the cross-sectional dimension of the rear end is larger than the cross-sectional dimension of the front end.

10. A method for manufacturing a high-precision coaxial light collimator according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: fusing the common optical fiber (4) and the self-focusing optical fiber (5) to form an optical fiber assembly, or fusing the common optical fiber (4) with one end of the coreless optical fiber (6) and fusing the other end with the self-focusing optical fiber (5) to form an optical fiber assembly; S2: inserting the end of the fused optical fiber assembly close to the self-focusing optical fiber (5) into the protective sleeve (9), the anti-bend sleeve (8), the fixed sleeve (7) and the ceramic sleeve (1) in sequence; S3: fixedly connecting the front end of the anti-bend sleeve (8) and the rear end of the fixed sleeve (7); S4: fix the optical fiber assembly and the ceramic sleeve (1) by glue, and then fix the fixing sleeve (7) and the ceramic sleeve (1) together.

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