A method for preparing thin-diameter C-Lens

Abstract

The present invention discloses a method for preparing a thin-diameter C-Lens, comprising the following preparation steps: (1) processing N-SF11 glass into a glass mother rod with a diameter of 50 mm and a length of 500 mm; (2) placing the obtained glass mother rod on an optical glass drawing machine for drawing; (3) etching the obtained drawn wire in a glass fiber etching solution to a designed size; (4) arranging the etched glass fiber blank on a wire arrangement plate; (5) cutting the glass blank array along the cross section of the wire arrangement array on a multi-wire cutting machine into a glass blank array of required length; (6) cleaning and degumming to obtain a thin-diameter C-Lens glass cylindrical lens blank; (7) machining a spherical end face and a flat end at the other end according to a designed curvature to finally obtain a C-Lens product of specified specifications; through the above-mentioned method, the present invention can not only achieve a disposable cylindrical blank length of more than 300 mm and a product diameter of less than 0.5 mm, but also have higher processing accuracy and product consistency; but also is convenient to prepare and has a low production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of optical communication lenses, and in particular to a method for preparing a thin-diameter C-Lens. Background Art

[0002] C-Lens is a cylindrical spherical lens with a flat surface at one end and a spherical surface at the other end. It is widely used in the production of fiber collimators. The glass material used in its production is SF11 heavy flint glass or other optical glasses with the same refractive index parameters, and it is processed using traditional optical cold working technology. The optical cold working methods are as follows:

[0003] The first step is to cut the glass block into quadrilaterals of a certain specification, process the quadrilaterals into octagons, further process them into hexagons, and finally process them into cylinders to obtain cylindrical glass blanks. The cylindrical diameter tolerance requirement is -10 microns to +5 microns, and the processing specifications include Φ1.0mm, Φ1.4mm, Φ1.8mm, Φ3.0mm, etc.

[0004] The second step is to process the ball end surface according to a certain curvature. The processing specifications include R0.7mm, R1.0mm, R1.2mm, R1.5mm, R2.0mm, R4.5mm, etc.

[0005] The third step is to process the plane end and control the axis length from the plane end to the spherical end with the vertex of the spherical end as the center to meet the design requirements.

[0006] However, with the increase in optical communication transmission rate, optical communication devices are developing towards miniaturization and integration, requiring the diameter of C-Lens used for optical fiber collimation to be less than 0.5mm, and higher requirements for product processing accuracy and product consistency. In particular, in response to batch processing, the length of disposable cylindrical blanks is required to be greater than 300mm. However, traditional processing methods make it difficult to meet the use requirements because the wire diameter is too thin and the glass wire is easily broken, which seriously restricts the development of optical communication collimator devices.

[0007] Based on the above research, a new preparation method for thin-diameter C-Lens needs to be developed to make up for the above technical drawbacks. Summary of the Invention

[0008] The main technical problem solved by the present invention is to provide a new method for preparing thin-diameter C-Lens, which can not only achieve a disposable cylindrical blank length of more than 300 mm and a product diameter of less than 0.5 mm, but also have higher processing accuracy and product consistency; it is also easy to prepare and has low production costs, while the product has good stability and reliability.

[0009] To solve the above technical problems, the present invention adopts a technical solution: providing a method for preparing a thin-diameter C-Lens, comprising the following preparation steps:

[0010] (1) Process N-SF11 glass into a glass mother rod with a diameter of 50 mm and a length of 500 mm;

[0011] (2) placing the glass mother rod obtained in step (1) on an optical glass drawing machine for drawing;

[0012] (3) etching the drawn wire obtained in step (2) in a glass fiber etching solution to a designed size;

[0013] (4) Arranging the glass fiber blank after etching in step (3) on a wire arrangement plate;

[0014] (5) Cutting the glass blank array into a desired length along the cross section of the wire array on a multi-wire cutting machine;

[0015] (6) Cleaning and degumming to obtain a thin-diameter C-Lens glass cylindrical lens blank;

[0016] (7) Process the ball end surface according to the designed curvature, and the processing specifications are but not limited to R0.7mm, R1.0mm, R1.2mm, R1.5mm, R2.0mm, and R4.5mm;

[0017] (8) Process the plane end of the other end, with the vertex of the spherical end as the center, and control the axis length from the plane end to the spherical end to meet the design requirements, and finally obtain the C-Lens product of the specified specifications;

[0018] (9) Test the relevant performance of the C-Lens product obtained in step (8).

[0019] Preferably, the drawing process in step (2) above requires vibration isolation of the ground and the drawing machine motor, while controlling the air flow disturbance during the drawing furnace heating the glass mother rod.

[0020] Preferably, the diameter of the wire drawing process in the above step (2) is 1.0 mm, the wire drawing tolerance is controlled at ±5 μm, and the wire drawing cutting length is 500 mm.

[0021] Preferably, the glass fiber etching solution used in step (3) above is composed of the following components: hydrofluoric acid, phosphoric acid, nitric acid, sulfuric acid, percarbonic acid and stearic acid, and the concentration of each component is 100% pure, and water is combined to adjust the etching speed.

[0022] Preferably, the volume ratio of the above components is: 1.0-10 parts of hydrofluoric acid, 1.0-10 parts of phosphoric acid, 0.5-5.0 parts of nitric acid, 0-5.0 parts of sulfuric acid, 0.5-3.0 parts of percarbonic acid, 0.5-5.0 parts of stearic acid, and 3-20 parts of water.

[0023] Preferably, the high carbonic acid is C17-C20 high carbonic acid.

[0024] Preferably, the wire arrangement plate in the above step (4) comprises a flat float glass substrate, on which a photoresist V-groove array is evenly arranged, and the etched glass fiber blanks are arranged along the photoresist V-groove array.

[0025] Preferably, the photoresist V-groove array is obtained by coating photoresist on a flat float glass substrate, etching uniformly distributed V-shaped positioning grooves by laser lithography, and arranging the etched glass fiber blanks in the V-shaped positioning grooves accordingly, with adjacent ones being circumscribed and fitted.

[0026] The beneficial effects of the present invention are:

[0027] In response to the development trend of existing optical communication devices towards miniaturization / integration, the present invention proposes higher requirements for C-Lens for optical fiber alignment with a diameter less than 0.5mm, and higher requirements for product processing accuracy and product consistency. In particular, in order to cope with batch processing, the length of a disposable cylindrical blank is required to be greater than 300mm. However, the existing public technology is difficult to meet the above requirements, which seriously restricts the technical drawbacks of the development of optical communication collimation devices. A new method for preparing thin-diameter C-Lens is pioneered. Through the selection of glass mother rods, control of the wire drawing process, a new formula of glass fiber etching liquid, a new design of the wire arrangement mode, and subsequent degumming and curvature processing, the thin-diameter C-Lens product finally prepared has a length that is not limited to 300mm in the existing technology and can be obtained according to actual needs, effectively improving product production capacity and reducing product costs. At the same time, it can ensure product quality and long-term stability and reliability. It has very good technology promotion value and fills the technical gap in the existing market. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of a wire arrangement plate used in a method for preparing a thin-diameter C-Lens of the present invention;

[0029] Figure 2 This is a schematic diagram of the cross-sectional effect of a glass fiber blank arranged in a photoresist V-groove array in a method for preparing a thin-diameter C-Lens of the present invention;

[0030] Figure 3 This is a comparison photo of the surface quality of products obtained by the preparation method of a thin-diameter C-Lens of the present invention;

[0031] The markings of the components in the accompanying drawings are as follows:

[0032] 1. Flat float glass substrate; 2. Photoresist V-groove arrangement; 3. Glass fiber blank. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0034] Example:

[0035] A method for preparing a thin-diameter C-Lens comprises the following steps:

[0036] The first step is to process N-SF11 glass into a glass mother rod with a diameter of 50 mm and a length of 500 mm;

[0037] In the second step, the glass mother rod obtained in the first step is placed on an optical glass drawing machine for drawing. The drawing process requires vibration isolation between the ground and the drawing machine motor, and the air flow disturbance during the heating of the glass mother rod by the drawing furnace is controlled. In this step, the diameter of the drawn wire is 1.0 mm, the drawing tolerance is controlled within ±5 μm, and the drawn wire length is 500 mm.

[0038] The third step is to etch the drawn wire obtained in the second step to a diameter of 0.5 mm in a glass fiber etching solution. The etching solution used will be described separately below.

[0039] The fourth step is to arrange the glass fiber blank after the etching in the third step on the wire arrangement plate. The structure of the wire arrangement plate is as follows: Figure 1 and Figure 2 As shown, it includes a flat float glass substrate 1, a photoresist V-groove array 2 is evenly arranged on the flat float glass substrate 1, and etched glass fiber blanks 3 are arranged along the photoresist V-groove array 2; wherein the photoresist V-groove array is obtained by coating photoresist on the flat float glass substrate 1, etching evenly distributed V-shaped positioning grooves by laser lithography, and the etched glass fiber blanks are arranged correspondingly in the V-shaped positioning grooves. The depth and spacing of the V-shaped positioning grooves are related to the diameter of the C-Lens glass fiber blanks, ensuring that adjacent glass fiber blanks are circumscribed and fitted;

[0040] Step 5: Cutting the glass blank array into the required length along the cross section of the wire array on a multi-wire cutting machine;

[0041] The sixth step is cleaning and degumming to obtain a thin-diameter C-Lens glass cylindrical lens blank;

[0042] The seventh step is to process the ball end surface according to the designed curvature. The processing specification is R1.5mm, and can also be R0.7mm, R1.0mm, R1.2mm, R2.0mm, R4.5mm, depending on actual needs;

[0043] The eighth step is to process the flat end of the other end. With the vertex of the spherical end as the center, the axis length from the flat end to the spherical end is controlled to meet the design requirements, and finally a C-Lens product with the specified specifications is obtained.

[0044] In the third step, since N-SF11 glass is an environmentally friendly optical glass, the drawing process is a high-temperature operation, which is prone to surface crystallization, affecting the performance of the glass filaments. Therefore, it cannot be directly drawn to the specified blank size according to conventional technology. Based on the second step, it is necessary to use a glass filament etching solution to further etch the glass filaments to the set size. The present invention innovatively proposes a new glass filament etching solution, which is composed of the following components:

[0045] 1 part of hydrofluoric acid, 5 parts of phosphoric acid, 0.5 parts of nitric acid, 2 parts of sulfuric acid, 0.5 parts of heptadecanoic acid, and 0.5 parts of stearic acid are diluted with 3 to 5 parts of water. The water content requirement is: while ensuring the surface corrosion quality of the glass wool, the corrosion rate is adjusted by adjusting the water content in the etching solution. As the water content increases, the corrosion rate decreases, and as the water content decreases, the corrosion rate accelerates. The actual water content in this embodiment is 4 parts. The glass wool etching solution is prepared at room temperature and normal pressure according to the volume ratio of the above-mentioned glass wool etching solution. The prepared glass wool etching solution is stirred with a ceramic stirrer to mix evenly to form a stable mixed acid solution.

[0046] In the above-mentioned etching solution formula system, hydrofluoric acid reacts chemically with silicon dioxide in glass filaments to generate SiF4 and H2O, so that the surface silicon dioxide is separated from the main body of glass filaments. The main component of optical communication cylindrical lenses is SiO2, and its content is 45% to 65%. Therefore, the main component of this glass filament etching solution is hydrofluoric acid; further, nitric acid reacts chemically with alkaline metal oxides such as aluminum oxide and titanium dioxide in glass to generate various phosphates. As cylindrical lenses for optical communication also contain a large amount of TiO2, phosphoric acid needs to be combined as the main component of glass etching solution; further, nitric acid reacts chemically with monovalent alkalis such as calcium oxide, magnesium oxide, barium oxide, thallium oxide, cesium oxide, and lithium oxide in glass Metal oxides react chemically with divalent alkaline earth metal oxides to generate various nitrates, and sulfuric acid reacts chemically with metal nitrates generated on the surface of glass fibers to generate metal sulfate powder. Furthermore, high carbonic acid is combined to enhance the ion movement activity on the surface of glass fibers, promote the uniform removal of nitrate, phosphate and sulfate compounds from the glass surface, avoid the adhesion of corrosive substances during hydrofluoric acid corrosion alone, thereby preventing the glass surface from becoming hairy and ultimately keeping the surface of glass fibers bright. Furthermore, stearic acid is combined to enhance the sulfurization characteristics of the exfoliated substances on the surface of glass fibers, so that the glass surface is uniformly corroded. Finally, while ensuring the corrosion quality of the glass fibers, the corrosion rate is adjusted by adjusting the water content in the etching solution.

[0047] The diameter and surface corrosion quality of the C-Lens products obtained by the above treatment were measured by microscope, such as Figure 3 As shown, it can be clearly seen that the surface finish of the glass fiber of the final C-Lens product is good, which is not much different from the surface finish of the original glass fiber, and is significantly better than the surface quality of the glass fiber etched by conventional hydrofluoric acid; at the same time, the diameter of the product is 0.48 mm, which also meets the use requirements of existing miniaturized optical communication devices; finally, the glass fiber after etching in this embodiment is subjected to a stability test, and its surface condition is observed under a microscope every 10 days. There is basically no change, indicating that the thin-diameter C-Lens product prepared by this solution is very stable.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a thin-diameter C-Lens, characterized in that: The method comprises the following preparation steps: (1) Process N-SF11 glass into a glass mother rod with a diameter of 50 mm and a length of 500 mm; (2) placing the glass mother rod obtained in step (1) on an optical glass drawing machine for drawing; (3) etching the drawn wire obtained in step (2) in a glass fiber etching solution to a designed size; (4) Arranging the glass fiber blank after etching in step (3) on a wire arrangement plate; (5) Cutting the glass blank array into a desired length along the cross section of the wire array on a multi-wire cutting machine; (6) Cleaning and degumming to obtain a thin-diameter C-Lens glass cylindrical lens blank; (7) Process the ball end surface according to the designed curvature, and the processing specifications are but not limited to R0.7mm, R1.0mm, R1.2mm, R1.5mm, R2.0mm, and R4.5mm; (8) Process the plane end of the other end, with the vertex of the spherical end as the center, and control the axis length from the plane end to the spherical end to meet the design requirements, and finally obtain the C-Lens product of the specified specifications; (9) Testing the relevant performance of the C-Lens product obtained in step (8); The glass fiber etching solution used in the above-mentioned step (3) has the following components: hydrofluoric acid, phosphoric acid, nitric acid, sulfuric acid, percarbonate and stearic acid. The concentration of the above-mentioned components is 100% purity, and the etching rate is adjusted in combination with water. The volume ratio of the above-mentioned components is: 1.0-10 parts of hydrofluoric acid, 1.0-10 parts of phosphoric acid, 0.5-5.0 parts of nitric acid, 0-5.0 parts of sulfuric acid, 0.5-3.0 parts of percarbonate, 0.5-5.0 parts of stearic acid, and 3-20 parts of water. The percarbonate is selected from C17-C20 percarbonate.

2. The method for preparing a thin-diameter C-Lens according to claim 1, characterized in that: The drawing process in step (2) above requires vibration isolation of the ground and the drawing machine motor operation, while controlling the air flow disturbance during the drawing furnace heating the glass mother rod.

3. The method for preparing a thin-diameter C-Lens according to claim 2, characterized in that: The diameter of the wire drawing process in the above step (2) is 1.0 mm, the wire drawing tolerance is controlled at ±5 μm, and the wire drawing length is 500 mm.

4. The method for preparing a thin-diameter C-Lens according to claim 1, characterized in that: The wire arrangement plate in the above step (4) comprises a flat float glass substrate, on which a photoresist V-groove array is evenly arranged, and the etched glass fiber blanks are arranged along the photoresist V-groove array.

5. The method for preparing a thin-diameter C-Lens according to claim 4, characterized in that: The photoresist V-groove array is obtained by coating photoresist on a flat float glass substrate, etching uniformly distributed V-shaped positioning grooves by laser lithography, and arranging the etched glass fiber blanks in the V-shaped positioning grooves accordingly, with adjacent glass fiber blanks being circumscribed and fitted.

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