A method for manufacturing an optical fiber collimator and an optical fiber collimator

Abstract

The application provides a fiber collimator manufacturing method and a fiber collimator, and comprises the following steps: providing a lens embryo, a glass tube and a capillary of a pigtail fiber; processing an incident end face of the lens embryo to obtain a lens embryo with an incident end face; wherein the angle of the incident end face is determined according to an application scenario; inserting and fixedly connecting the lens embryo with the incident end face into a first end of the glass tube; processing an emergent end face of the lens embryo with the incident end face to obtain a connecting body of the lens and the glass tube; wherein the focal point of the emergent end face of the lens is located on a central axis of the connecting body of the lens and the glass tube; inserting and fixedly connecting the capillary of the pigtail fiber into a second end of the glass tube to obtain the fiber collimator. The gap size error during assembly of the lens embryo and the glass tube is eliminated, the point precision of the fiber collimator is reduced, the fiber collimator can meet the requirements of customers in large quantities, the qualified rate of products is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of optical fiber manufacturing technology, and in particular to a method for manufacturing an optical fiber collimator and the optical fiber collimator itself. Background Technology

[0002] Fiber optic collimators are commonly used passive optical devices. When in use, they can generate nearly parallel light beams with low loss, allowing other optical elements to be inserted into the beam to achieve complex optical structures and performance requirements. Fiber optic collimators have a wide range of applications, including high-power lasers, optical communications, fiber optic sensing, and biomedicine.

[0003] Currently, the typical method for manufacturing collimators involves first designing the dimensions of the lens, glass tube, and capillary of the pigtail, then processing them separately. Next, the lens is bonded to one end of the glass tube, and finally, the capillary end of the pigtail is inserted into the other end of the glass tube to obtain the fiber optic collimator. However, the dot accuracy of products manufactured using this method is easily affected by the mechanical dimensions of the lens parameters (e.g., outer diameter, radius of curvature, length, angle, material), the outer diameter of the capillary, and the inner diameter of the glass tube. Products manufactured using this method with excessively high dot accuracy may not meet customer requirements. Furthermore, as the demand for smaller device sizes and more integrated functions increases, the requirements for the dot accuracy of fiber optic collimators are also increasing. Therefore, it is necessary to optimize current product design and manufacturing methods to further improve the dot accuracy of collimators.

[0004] Existing methods to improve point accuracy generally include: compensation through additional devices, such as adding a wedge or wedge group between the fiber optic cable and the collimating objective or after the collimating objective, or adding an outer sleeve to the collimator to make the outgoing light parallel to the outer sleeve; misaligning the fiber optic cable with the lens axis or changing the incident angle of the fiber optic cable; however, these methods add additional parts or use asymmetrical structures, making assembly more complicated and significantly increasing costs. Summary of the Invention

[0005] This invention proposes a method for manufacturing an optical fiber collimator and an optical fiber collimator, solving the problem that the existing methods for manufacturing optical fiber collimators produce optical fiber collimators with excessively high point accuracy, resulting in a low product qualification rate.

[0006] A method for manufacturing an optical fiber collimator includes the following steps:

[0007] We provide lens blanks, glass tubes, and capillary tubes for fiber optic cables.

[0008] The lens blank is processed to obtain a lens blank with an incident end face; wherein, the angle of the incident end face is determined according to the application scenario.

[0009] inserting the lens blank with the incident end face into the first end of the glass tube and fixedly connecting;

[0010] processing the lens blank with the incident end face to obtain an exit end face, so as to obtain a connecting body of the lens and the glass tube; wherein the focal point of the exit end face of the lens is located on the central axis of the connecting body of the lens and the glass tube;

[0011] inserting the capillary tube of the pigtail into the second end of the glass tube and fixedly connecting, to obtain the fiber collimator.

[0012] In the method for manufacturing the fiber collimator, the lens blank is a cylindrical blank.

[0013] In the method for manufacturing the fiber collimator, the length of the lens blank is 2.7 mm.

[0014] In the method for manufacturing the fiber collimator, the lens blank is a lens blank made of N-SF11 material.

[0015] In the method for manufacturing the fiber collimator, after the lens blank is processed to obtain the lens blank with the incident end face, the incident end face of the lens blank with the incident end face is coated.

[0016] In the method for manufacturing the fiber collimator, the angle between the incident end face and the end face of the lens blank is 0° to 4°, and the angle of the incident end face is determined according to the speed of the node in the optical link.

[0017] In the method for manufacturing the fiber collimator, the lens blank with the incident end face and the glass tube are fixedly bonded by an adhesive.

[0018] In the method for manufacturing the fiber collimator, before the capillary tube of the pigtail is inserted into the second end of the glass tube and fixedly connected, the outer diameter of the capillary tube of the pigtail is polished; wherein the outer diameter tolerance of the polished capillary tube of the pigtail is 1.05 mm+0 / -0.001 mm.

[0019] In the method for manufacturing the fiber collimator, before the outer diameter of the capillary tube of the pigtail is polished, one of the end faces of the capillary tube of the pigtail is processed to form an inclined end face, to obtain a pigtail capillary tube with an inclined end face; wherein the angle of the inclined end face is determined according to the requirements of the insertion loss and the recovery loss of the optical path.

[0020] A fiber collimator comprises:

[0021] The optical fiber collimator manufactured by the optical fiber collimator manufacturing method according to any one of the technical solutions.

[0022] Advantages of the present application:

[0023] The method of the present application processes the exit end face of the lens embryo material by directly clamping the connecting body of the lens and the glass tube, thereby eliminating the gap size error when the lens embryo material is assembled with the glass tube, and using the method can reduce the point precision of the produced optical fiber collimator, thereby being able to mass-produce the products that meet the customer's requirements, improving the product qualification rate, reducing the production cost, and the overall structure is simple to assemble. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The method of the present application is a step flow chart;

[0025] Figure 2 The structure diagram of S100 step of the present application is shown in the figure;

[0026] Figure 3 The structure diagram of S200 step of the present application is shown in the figure;

[0027] Figure 4 The structure diagram of S300 step of the present application is shown in the figure;

[0028] Figure 5 The structure diagram of S400 step of the present application is shown in the figure;

[0029] Figure 6 The structure diagram of S500 step of the present application is shown in the figure.

[0030] Explanation of reference signs:

[0031] 100, lens embryo material; 101, lens embryo material with an entrance end face; 110, entrance end face; 120, exit end face; 200, capillary tube of a pigtail; 300, glass tube; 400, connecting body of the lens and the glass tube; 410, central axis; 500, optical fiber collimator. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and effects of the present application more clear and explicit, the present application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0033] In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0034] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0035] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the first feature is horizontally higher than the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the first feature is horizontally lower than the second feature.

[0037] It is to be noted that when an element is referred to as being "on" or "connected to" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right", and the like are merely used for the purpose of illustration and do not indicate an absolute orientation.

[0038] At present, the commonly used collimator manufacturing method is: first, the size parameters of the lens, the glass tube 300 and the capillary tube 200 of the pigtail are designed, then they are respectively processed, then the lens and one end of the glass tube 300 are bonded, and finally the capillary tube 200 of the pigtail is inserted into the other end of the glass tube 300, to obtain the product of the optical fiber collimator 500. However, in the manufacturing process of the product, the tolerance factors of the mechanical dimensions such as the outer diameter, the radius of curvature, the length, the angle, the material of the lens, the outer diameter of the capillary tube, the inner diameter of the glass tube 300 and the like will affect the point accuracy of the optical fiber collimator 500 after assembly, and the point accuracy of the product manufactured by this method is prone to not meet the customer's demand. With the progress of the times, the point accuracy of the optical fiber collimator 500 is also required to be higher and higher, therefore, the production process needs to be further optimized to improve the point accuracy of the optical fiber collimator 500.

[0039] Based on this, the application provides a kind of optical fiber collimator 500 manufacturing method, comprising the following steps:

[0040] S100, provide lens embryo 100, glass tube 300 and capillary tube 200 of pigtail;

[0041] Referring to Figure 2 As shown in the figure, the lens embryo 100 refers to an unprocessed lens, wherein the lens embryo 100 type selects the C lens (C-lens) commonly used in the optical industry, which has a certain superiority in performance compared with the traditional G lens, with cheap material price and simple curvature processing technology. The glass tube 300 and the capillary tube 200 of the pigtail are made of quartz glass or high borosilicate glass material, which has good chemical stability and electrical insulation performance, and can be penetrated by ultraviolet and infrared, is an excellent ideal glass, and is often used in optical systems.

[0042] S200, process the lens embryo 100 to obtain a lens embryo 101 with an incident end face 110; wherein the angle of the incident end face 110 is determined according to the application scenario;

[0043] Referring to Figure 3As shown, the tooling of the incident end face 110 of the lens blank 100 includes clamping the lens blank 100 by a clamping device, and grinding the incident end face 110 of the lens blank 100 so that the incident end face 110 of the lens blank 100 is changed from a horizontal plane to an inclined plane forming a certain angle with the horizontal plane. The angle of the incident end face 110 is determined by the application scenario, which actually means selecting a suitable angle according to the requirements of the customer. For example, some customers require high point accuracy of the prepared fiber collimator 500, and some customers require low point accuracy of the prepared fiber collimator 500. The angles of the incident end face 110 of the lens blank 100 required by fiber collimators 500 with different point accuracy requirements are different. Only when the appropriate angle is assembled, the influence of reflected light on the communication system can be eliminated to the greatest extent.

[0044] S300, inserting the lens blank 101 with the incident end face into the first end of the glass tube 300 and fixedly connecting;

[0045] Referring to Figure 3 and Figure 4 As shown, the first end refers to the position of the lens blank 100 actually installed after size calculation inside the glass tube 300, that is, the lens blank 101 with the incident end face is installed in the glass tube 300. It is worth noting that the inner diameter of the glass tube 300 is equal to the outer diameter of the lens blank 101 with the incident end face. In addition, in this embodiment, glue can be applied on the lens blank 101 with the incident end face, and fixedly connected in the specified position of the glass tube 300.

[0046] S400, processing the exit end face 120 of the lens blank 101 with the incident end face to obtain the connecting body of the lens and the glass tube 300; wherein the focal point of the exit end face 120 of the lens is located on the central axis 410 of the connecting body of the lens and the glass tube;

[0047] In this embodiment, referring to Figure 5As shown, since the existing lens, glass tube 300 and capillary 200 of the pigtail are separately machined, there will be a certain error in the machining process, and if they are machined separately and then assembled, there will be a certain error gap between the lens and the glass tube 300 during assembly, so that the focal point of the exit end surface 120 of the lens deviates from the central axis 410 of the collimator after the product is formed. The point accuracy of the assembled product is easy to not meet the customer's demand, and the lens is also easy to tilt during installation. Therefore, the method first installs the lens blank 101 with the entrance end surface 110 into the glass tube 300 to obtain the connection body of the lens and the glass tube 300, and finally processes the exit end surface 120 of the lens blank 100 by clamping the outer diameter of the glass tube 300, so that when the lens blank 100 and the glass tube 300 are assembled, the focal point of the exit end surface 120 of the lens blank 100 is ensured to be on the central axis 410 of the connection body of the lens and the glass tube 300, thereby reducing the influence of the machining error size on the point accuracy of the product.

[0048] S500, insert the capillary 200 of the pigtail into the second end of the glass tube 300 and fix it to obtain the optical fiber collimator 500.

[0049] In an embodiment, referring to Figure 6 As shown, the second end refers to the actual position of the glass tube 300 for installing the capillary 200 of the pigtail, but since the glass tube 300 is a cylindrical structure, the second end here actually refers to installing the capillary 200 of the pigtail in the other opening of the glass tube 300, thereby obtaining the optical fiber collimator 500 after forming. It is worth noting that when the capillary 200 of the pigtail is installed in the glass tube 300, the capillary 200 of the pigtail also needs to be fixed, for example, using glue or other fixing methods.

[0050] Specifically, the lens blank 100 is a cylindrical-shaped blank.

[0051] In this embodiment, the lens blank 100 is a cylindrical-shaped blank, so that when the lens blank 100 is processed, the step of processing to a cylindrical shape is omitted, reducing production cost; and when the lens blank 100 is a cylindrical-shaped blank, it can be better adapted to be installed in the glass tube 300.

[0052] Specifically, the length of the lens blank 100 is 2.7mm.

[0053] As a preferred embodiment, the length of the lens blank 100 is set to 2.7 mm, and the width (i.e. the outer diameter) of the lens blank 100 is set to be adapted to the inner diameter of the glass tube 300. Then the length of the glass tube 300 is set to 5.5 mm, the outer diameter of the glass tube 300 is set to 1.4 mm, the inner diameter of the glass tube 300 is set to 1 mm, the inner diameter tolerance of the glass tube 300 is set to 0.005 mm-0.015 mm, the length of the capillary 200 of the pigtail is set to 3.7 mm, the outer diameter of the capillary 200 of the pigtail is set to be the same as the inner diameter of the glass tube 300, i.e. 1 mm, and the outer diameter tolerance of the capillary 200 of the pigtail is set to ±0.005 mm. Finally, the focal length and the wavelength of the lens blank 100 are set, and the set values are input into the Zemax software, so that the maximum deviation is 0.0125 mm, and the theoretical point accuracy range of the model is estimated to be 0°-1.4°.

[0054] It is worth noting that Zemax is an optical product design and simulation software, which can be used to theoretically calculate the point accuracy of the product model size, reduce design iteration and repeated proofing, speed up the time of pushing the product to the market, and reduce the development cost.

[0055] Specifically, the lens blank 100 is an N-SF11 material lens blank 100.

[0056] In the embodiment, N-SF11 is a kind of optical special glass, the refractive index of N-SF11 is close to 1.8, the refractive index is high, the Abbe number is low, the scattering power is high, and it is very suitable for the application requiring high scattering in the visible light range. It is also the main raw material glass for C-lens in optical communication.

[0057] In an embodiment, the step S200 further comprises:

[0058] After the lens blank 100 is processed to obtain the lens blank 101 with the incident end face 110, the incident end face 110 of the lens blank 101 with the incident end face is coated.

[0059] The coating of the lens is an antireflection coating, also known as a reflection-reducing coating. Its main function is to reduce or eliminate the reflected light on the optical surface of the lens, prism, plane mirror, etc., thereby increasing the light transmission of these components and reducing or eliminating the stray light of the system.

[0060] In an embodiment, the step S200 specifically comprises:

[0061] The included angle between the incident end face 110 and the end face of the lens blank is 0° to 4°, and the angle of the incident end face 110 is determined according to the speed of the node in the optical link.

[0062] In the embodiment, the optical link refers to a line that the high-frequency input of the optical transmitter is photoelectrically converted and output in the optical receiver. By writing each numerical case of the included angle of 0 to 4° into the Zemax software and performing model calculation, the allowable included angle range is obtained.

[0063] In an embodiment, the step S300 specifically includes that the lens blank 101 with the incident end face is fixed by the adhesive bonding with the glass tube 300.

[0064] The adhesive is the guarantee of the bonding strength between the abrasive and the matrix. With the development of the chemical industry, various new adhesives have entered the field of coated abrasives, improving the performance of coated abrasives and promoting the development of the coated abrasive industry. In addition to the glue, the adhesive also includes solvents, curing agents, toughening agents, preservatives, colorants, defoamers and other auxiliary components. In addition to the most commonly used animal glue, the adhesive also includes synthetic resins, rubber and paint. The lens blank 100 is fixedly connected by being sleeved in the glass tube 300 through the adhesive.

[0065] Before the step S500, it further includes:

[0066] Before the step of inserting the capillary 200 of the pigtail into the second end of the glass tube 300 and fixedly connecting, the outer diameter of the capillary 200 of the pigtail is polished; wherein the outer diameter tolerance of the polished capillary 200 of the pigtail is 1.005 mm+0 / -0.001 mm.

[0067] In the scheme, by adjusting the capillary outer diameter tolerance from 1.0±0.005 to 1.005+0 / -0.001 mm, the maximum radial offset of the final product fiber collimator 500 and the central axis 410 of the fiber collimator 500 is reduced from 0.01 mm (capillary offset amount=(1.015-0.995) / 2=0.01) to 0.0055 mm (capillary offset amount optimized=(1.015-1.004) / 2=0.0055), and the total radial offset of the final product fiber collimator 500 and the lens blank 100 optical axis can be reduced by 0.017 mm (total offset amount optimized=0.0125+0.0045=0.017). By reducing the total offset of the lens and the capillary by about 0.017 mm through the above means, the point accuracy A that can be reduced by the Zemax software size model is A≈0.6°. Since the radial offset direction has no specific direction, the low accuracy A direction is completely random.

[0068] It is worth noting that since the grinding angle of the incident end face 110 of the lens is 8°, the direction and size of the fixed point accuracy are generally fixed (the fixed point accuracy refers to the light deviation generated by the light incident on the end face 110 of the lens after the angle is introduced), and the theoretical fixed point accuracy B is calculated by inputting the value of the grinding angle of 8° into the Zemax simulation software, B≈0.6°. The point accuracy A of 0.6°, which is reduced by the total deviation, is random in direction. When the deviation direction of the angle A is the same as that of the angle B, the fixed angle error C affected by other factors except A and B is obtained, C=1.4-A-B=0.2 (random and directionless), wherein the theoretical point accuracy of 1.4° is calculated by inputting the numerical value of the above-mentioned model product into the Zemax software, and the maximum value in the range of point accuracy is obtained. It should be noted that the purpose of this calculation method is to obtain the angle range caused by other errors of the system under the worst filling condition. The fixed point accuracy error caused by other factors except the above two factors is 0.2°. Therefore, when the preset grinding angle is 8°, the point accuracy of the collimator is B±0.2°. Therefore, compared with the original maximum point accuracy of 1.4°, the maximum point accuracy of the optical fiber collimator 500 produced by this method is 0.8°, which effectively reduces the accuracy of the produced optical fiber collimator 500.

[0069] Since 0° to 4° are all feasible solutions, as a preferred solution, the grinding angle of the incident end face 110 is adjusted to 4°, the fixed point accuracy B is about 0.25°, and the point accuracy of the collimator is 0.25±0.2°.

[0070] As a more preferred solution, the grinding angle of the incident end face 110 is adjusted to 0°, the fixed point accuracy B is about 0°, and the point accuracy of the collimator is 0±0.2°, and the actual output is 0 to 0.2°.

[0071] It can be understood that the above-mentioned numerical values are calculated by theoretically inputting the size values into the Zemax optical simulation software model in advance.

[0072] Referring to Figure 6 Before polishing the outer diameter of the capillary 200 of the pigtail fiber, one end face of the capillary 200 of the pigtail fiber is machined to form an inclined end face, so as to obtain a pigtail fiber capillary with an inclined end face. The angle of the inclined end face is determined according to the requirements of the insertion loss and the recovery loss of the optical path.

[0073] In this embodiment, by forming the end face of the capillary 200 of the pigtail fiber into an inclined end face, the reflection of the optical path in the glass tube 300 is reduced in cooperation with the incident end face 110 of the lens.

[0074] A kind of optical fiber collimator 500, comprising:

[0075] The optical fiber collimator 500 manufactured by the manufacturing method of the optical fiber collimator 500 described in any one of the above technical solutions.

[0076] In this embodiment, the present application relates to an optical fiber collimator 500, which is manufactured by the manufacturing method of the optical fiber collimator 500 described in any one of the above technical solutions. Since the effects have been discussed above, they will not be repeated here.

[0077] In summary, the point accuracy of the optical fiber collimator 500 manufactured by the method is reduced from the original 1° to 0.2° or less. Using the method of the present application to manufacture the optical fiber collimator 500 can reduce the point accuracy of the optical fiber collimator 500, significantly reduce the impact of error gap size and other errors, thereby enabling mass production, improving product yield and processing efficiency.

[0078] Of course, the present application can also have other various embodiments. Based on the present embodiment, other embodiments obtained by those of ordinary skill in the art without any creative labor fall within the scope of the present application.

Claims

1. A method of making a fiber collimator, comprising: The method comprises the following steps: providing a lens blank, a glass tube, and a capillary of a pigtail fiber; processing an incident end face of the lens blank to obtain a lens blank with an incident end face; wherein the angle of the incident end face is determined according to an application scenario; inserting the lens blank with the incident end face into a first end of the glass tube and fixedly connecting the same; processing an emergent end face of the lens blank with the incident end face to obtain a connecting body of the lens and the glass tube; wherein a focal point of the emergent end face of the lens is located on a central axis of the connecting body of the lens and the glass tube; inserting the capillary of the pigtail fiber into a second end of the glass tube and fixedly connecting the same to obtain the fiber collimator.

2. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: The lens blank is a cylindrical blank.

3. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: The length of the lens blank is 2.7 mm.

4. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: The lens blank is made of N-SF11 material.

5. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: After processing the incident end face of the lens blank to obtain the lens blank with the incident end face, the incident end face of the lens blank with the incident end face is coated. ​ 6. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: The angle between the incident end face and the end face of the lens blank is 0° to 4°.

7. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: The lens blank with the incident end face is fixedly connected to the glass tube through an adhesive. ​ 8. The method of claim 1, wherein the step of forming the optical fiber collimator is performed by a process comprising: Before inserting the capillary of the pigtail fiber into the second end of the glass tube and fixedly connecting the same, the outer diameter of the capillary of the pigtail fiber is polished; wherein the outer diameter tolerance of the polished capillary of the pigtail fiber is 1.005 mm+0 / -0.001 mm.

9. The method of claim 8, wherein the step of forming the optical fiber collimator is performed by a process comprising: Before polishing the outer diameter of the capillary of the pigtail fiber, one of the end faces of the capillary of the pigtail fiber is processed to form an inclined end face to obtain a capillary of the pigtail fiber with the inclined end face; wherein the angle of the inclined end face is determined according to the requirements of insertion loss and recovery loss of an optical path.

10. An optical fiber collimator characterized by, The method comprises the following steps: The fiber collimator manufactured by the method for manufacturing the fiber collimator according to any one of claims 1 to 9.

Images