Preparation method of polishing medium for polishing optical fiber image transmitting element and polishing method

Abstract

The invention relates to a preparation method of a polishing medium for polishing an optical fiber image transmitting element and a polishing method, and the preparation method comprises the following steps: dissolving a rare earth source: dissolving Ce (NO3) 3.6 H2O and polyvinylpyrrolidone in water, carrying out ultrasonic dissolution, stirring for a first preset time, and adjusting the initial pH value of the solution to 7 to obtain a clear mixed solution; high-temperature and high-pressure reaction: transferring the clarified mixed solution into a reaction kettle, heating to a first preset temperature, and reacting for a second preset time; precipitating, separating, washing and drying: after the reaction is finished and the reaction kettle is cooled to room temperature, washing the obtained precipitate with water and ethanol, and drying to obtain a precursor; calcining: calcining the precursor; and ball milling: carrying out ball milling on the calcined precursor on a ball mill to obtain the cerium oxide polishing medium. The optical fiber image transmitting element is polished by adopting the CeO2 polishing medium, so that the pit depth of the optical fiber image transmitting element is reduced, and the surface shape precision of the optical fiber image transmitting element is improved.

Description

Technical Field

[0001] The present invention relates to the field of glass processing, and in particular to a preparation method and a polishing method of a polishing medium for polishing an optical fiber image transmission element. Background Art

[0002] An optical fiber image transmission element is an optical element formed by arranging millions of micron-scale optical fibers regularly, including an optical fiber faceplate, an optical fiber image inverter, a fiber optic taper, etc. The optical fiber image transmission element has characteristics such as a large numerical aperture and an optical zero thickness, and has important applications in the fields of optical image transmission, optical coupling, etc.

[0003] The optical fibers in the optical fiber image transmission element are composed of a core glass with a high refractive index and a cladding glass with a low refractive index. The input light that satisfies the total reflection condition can be transmitted from one end to the other end inside the optical fiber, while the input light that does not satisfy the total reflection condition penetrates the cladding and becomes stray light. Stray light is the most important factor causing poor imaging clarity of the optical fiber image transmission element. To solve the above problems, usually, the method of filling all or part of the light-absorbing glass in the gaps between adjacent optical fibers is adopted.

[0004] The physical and chemical properties of the core glass, cladding glass, and light-absorbing glass that make up the optical fiber image transmission element are different. The hardness of the core glass is greater than that of the cladding glass, but its acid resistance is weaker than that of the cladding glass. Therefore, corrosion and pit defects will appear on the surface during polishing, and these defects have seriously affected the resolution and transmittance of the image inverter and fiber optic taper. At present, there is no polishing medium for polishing the optical fiber image transmission element. Summary of the Invention

[0005] The main purpose of the present invention is to provide a preparation method of a polishing medium for polishing an optical fiber image transmission element, which can reduce the pit depth of the optical fiber image transmission element and improve the surface form accuracy of the optical fiber image transmission element.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A preparation method of a polishing medium for polishing an optical fiber image transmission element includes the following steps:

[0008] 1) Dissolution of rare earth source: Dissolve Ce(NO3)3·6H20 and polyvinylpyrrolidone in water, after ultrasonic dissolution, stir for a first preset time, and adjust the initial pH of the solution to 7 to obtain a clear mixed solution;

[0009] 2) High-temperature and high-pressure reaction: Transfer the clear mixed solution to a reaction kettle, heat it to a first preset temperature, and react for a second preset time;

[0010] 3) Precipitation separation, washing and drying: After the reaction ends, wait for the reaction kettle to cool to room temperature, wash the obtained precipitate with water and ethanol, and dry it to obtain a precursor;

[0011] 4) Calcination: Calcinate the precursor;

[0012] 5) Ball milling: Ball mill the calcined precursor on a ball mill to obtain cerium oxide polishing medium.

[0013] The mass ratio of the amounts of Ce(NO3)3·6H20, polyvinylpyrrolidone and water is (5 - 9):(1 - 6):100.

[0014] The frequency of the ultrasonic wave is 50KHZ - 100KHZ, the power is 300 - 400W, the time for ultrasonic dissolution is 0.5h - 1h, and the first preset time is 30 - 60min; the rotation speed of the stirring is 200 - 500r / min, the first preset temperature is 160°C - 200°C, the second preset time is 20 - 30h, and the reaction pressure of the reaction kettle is 0.5MPa - 1.55MPa.

[0015] Furthermore, adjust the initial pH value of the solution with NaOH or HNO3;

[0016] The temperature of the drying is 60°C - 80°C, and the time of the drying is 8 - 12h;

[0017] The rotation speed of the ball milling is 300rpm - 500rpm, and the time of the ball milling is 3 - 5h; the mass ratio of the calcined precursor to the zirconia ball milling beads is 1:(4 - 6).

[0018] The temperature of the calcination is 450°C to 1100°C, and the time of the calcination is 2h - 4h.

[0019] The present invention also provides a polishing method for polishing an optical fiber image transmission element with the cerium oxide polishing medium obtained by the above preparation method, including the following steps:

[0020] (1) Prepare the slurry: Dissolve the cerium oxide polishing medium in water, and adjust the pH value of the slurry to 7 with a NaOH or HNO3 solution to obtain the slurry;

[0021] (2) Polishing: Perform surface polishing treatment on the optical fiber image transmission element with the slurry.

[0022] During the polishing treatment, the polishing pressure is 5 - 15Kg, the main shaft rotation speed is 50 - 60r / min, the pendulum shaft rotation speed is 55 - 65r / min, and the polishing time is 30 - 60min.

[0023] The optical fiber image transmission element includes core glass, cladding glass and light absorption glass;

[0024] The Mohs hardness range of the core glass is 5.6 - 5.8;

[0025] The Mohs hardness range of the skin material glass is 5.3 - 5.5;

[0026] The Mohs hardness range of the light absorption glass is 5.0 - 5.3.

[0027] The mass ratio of the cerium oxide polishing medium to water is 1:(14 - 25);

[0028] The Mohs hardness range of the cerium oxide polishing medium is 5.0 - 6.0;

[0029] The cerium oxide polishing medium is selected from two kinds of cerium oxide polishing media with Mohs hardness or three kinds of cerium oxide polishing media with Mohs hardness;

[0030] When two kinds of Mohs hardness are selected, the hardness of the first kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the core material glass, and the mass percentage of the dosage is A±5%, where A is the area percentage of the core material glass on the surface of the fiber optic image transmission element;

[0031] The hardness of the second kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the skin material glass, and the mass percentage of the dosage is 1-(A±5%);

[0032] When three kinds of Mohs hardness are selected, the hardness of the first kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the core material glass, and the mass percentage of the dosage is A±5%;

[0033] The hardness of the second kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the skin material glass, and the mass percentage of the dosage is B±3%, where B is the area percentage of the skin material glass on the surface of the fiber optic image transmission element;

[0034] The hardness of the third kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the light absorption glass, and the mass percentage of the dosage is Y±1%, where Y is the area percentage of the light absorption glass on the surface of the fiber optic image transmission element.

[0035] The core material glass comprises the following components in weight percentage: SiO2 10 - 20%, Al2O3 0 - 10%, B2O3 20 - 40%, MgO 0 - 5%, CaO 0 - 5%, BaO 0 - 12%, La2O3 20 - 50%, Nb2O5 5 - 20%, Ta2O5 0 - 5%, ZnO 0 - 5%, TiO2 0 - 3%, ZrO2 2 - 6%, Na2O 0 - 2%, K2O 2 - 20%;

[0036] The leather-like glass comprises the following components in weight percentage: SiO2 30-73%, B2O3 10-28%, Al2O3 0-6%, MgO 0-2%, Na2O 0.5-3%, K2O 5-30%, Li2O 0-2%;

[0037] The light absorption glass comprises the following components in weight percentage: SiO2 71-80%, Al2O3 0.5-5%, B2O3 1-5%, Na2O 1-11%, K2O 6-11%, MgO 0.1-2%, CaO 0.1-2%, BaO 0-0.5%, TiO2 0-1%, Co2O3 0.4-1%, NiO 0.1-1%, MnO 1-5%, V2O5 0.1-1%, CeO2 0-0.2%, CuO 0-0.5%.

[0038] The area of the core glass on the surface of the fiber optic image transmission element is 75%-77%; the area of the leather-like glass on the surface of the fiber optic image transmission element is 20%-22%; the area of the light absorption glass on the surface of the fiber optic image transmission element is 2%-5%.

[0039] The hardness of the CeO2 polishing medium is a macroscopic reflection of its microscopic properties such as chemical bond strength and crystal structure. The hardness of the CeO2 polishing medium is related to the calcination temperature. Selecting an appropriate calcination temperature will cause the CeO2 grains to grow to a suitable particle size for polishing. At this time, the specific surface area is relatively large and the surface activity is strong. The higher the calcination temperature, the greater the hardness of the polishing medium and the increased polishing force, but it is easy to scratch the processed surface. Low-temperature calcination can obtain a polishing medium with low hardness. This type of polishing medium is not easy to scratch the processed surface and is suitable for the processing of high-grade products such as soft glass and photomask substrates that are most afraid of scratches. However, when the calcination temperature is too high, the polishing force decreases instead, which is due to the surface inerting of the particles caused by high temperature and the reduction of the surface area.

[0040] By means of the above technical solutions, the present invention has at least the following advantages:

[0041] The present invention uses a CeO2 polishing medium to polish the fiber optic image transmission element, reducing the pit depth of the fiber optic image transmission element and improving the surface shape accuracy of the fiber optic image transmission element.

[0042] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it in accordance with the content of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a microscopic array structure diagram of the fiber optic image transmission element provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] To further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, detail the specific implementation manners, structures, features, and effects of the present invention as follows. In the following description, different "one embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0045] As Figure 1 shown in the figure, it is the microscopic structure diagram of the fiber optic image transmission element. The area of the core material glass 1 on the surface of the fiber optic image transmission element is approximately 75% - 77%; the area of the cladding material glass 2 on the surface of the fiber optic image transmission element is approximately 20% - 22%; the area of the light absorption glass 3 on the surface of the fiber optic image transmission element is approximately 2% - 5%.

[0046] The following further illustrates the present invention through specific embodiments:

[0047] First, prepare several CeO₂ polishing media with different hardnesses:

[0048] Preparation of the first CeO₂ polishing medium:

[0049] Dissolve 82.4 g of Ce(NO₃)₃·6H₂O and 27.5 g of polyvinyl pyrrolidone PVP (Polyvinyl Pyrrolidone) in 1000 mL of water. After ultrasonic dissolution at a power of 300 W and a frequency of 60 KHZ for 30 min, then stir at a stirring speed of 300 r / min for 30 min. According to the pH value of the solution, select NaOH or HNO₃ to adjust the initial pH of the solution to 7; transfer the obtained clear mixed solution to a reaction kettle, heat it to 160 °C, and react at a reaction pressure of 1 MPa for 25 h. After the reaction ends and the reaction kettle cools to room temperature, perform solid-liquid separation on the obtained precipitate, wash the precipitate with water and ethanol, and dry it at a temperature of 60 °C for 12 h to obtain a precursor. Calcinate the precursor at 450 °C for 4 h. Ball-mill the calcined cerium oxide polishing medium in a ball mill at a rotation speed of 300 rpm for 4 h. The mass ratio of the calcined cerium oxide polishing medium to the zirconia ball milling beads is 1:5 to obtain the cerium oxide polishing medium. After testing, the Mohs hardness of the cerium oxide polishing medium is 5.1.

[0050] Preparation of the second CeO₂ polishing medium:

[0051] Dissolve 75.6 g of Ce(NO3)3·6H20 and 38.2 g of polyvinyl pyrrolidone PVP (Polyvinyl Pyrrolidone) in 1000 mL of water. After dissolving by ultrasonic wave for 40 min at a power of 360 W and a frequency of 50 KHZ, then stir at a stirring speed of 350 r / min for 60 min, and adjust the initial pH of the solution to 7 with NaOH or HNO3; transfer the obtained clear mixed solution to a reaction kettle, heat it to 175 °C, and react at a reaction pressure of 1.25 MPa for 20 h. After the reaction is completed and the reaction kettle is cooled to room temperature, carry out solid-liquid separation on the obtained precipitate, wash the precipitate with water and ethanol, and dry it at a temperature of 65 °C for 10 h to obtain a precursor. Calcinate the precursor at 550 °C for 3 h. Ball-mill the calcined cerium oxide polishing medium in a ball mill at a rotation speed of 380 rpm for 3 h. The mass ratio of the calcined cerium oxide polishing medium to the zirconia ball-milling beads is 1:4 to obtain a cerium oxide polishing medium. After testing, the Mohs hardness of the cerium oxide polishing medium is 5.3.

[0052] Preparation of the third CeO2 polishing medium:

[0053] Dissolve 72.8 g of Ce(NO3)3·6H20 and 45.3 g of polyvinyl pyrrolidone PVP (Polyvinyl Pyrrolidone) in 1000 mL of water. After dissolving by ultrasonic wave for 60 min at a power of 400 W and a frequency of 93 KHZ, then stir at a stirring speed of 450 r / min for 40 min, and adjust the initial pH of the solution to 7 with NaOH or HNO3; transfer the obtained clear mixed solution to a reaction kettle, heat it to 190 °C, and react at a reaction pressure of 1.55 MPa for 30 h. After the reaction is completed and the reaction kettle is cooled to room temperature, carry out solid-liquid separation on the obtained precipitate, wash the precipitate with water and ethanol, and dry it at a temperature of 73 °C for 9 h to obtain a precursor. Calcinate the precursor at 800 °C for 2 h. Ball-mill the calcined cerium oxide polishing medium in a ball mill at a rotation speed of 500 rpm for 4 h. The mass ratio of the calcined cerium oxide polishing medium to the zirconia ball-milling beads is 1:5 to obtain a cerium oxide polishing medium. After testing, the Mohs hardness of the cerium oxide polishing medium is 5.5.

[0054] Preparation of the fourth CeO2 polishing medium:

[0055] Dissolve 64.3 g of Ce(NO3)3·6H20 and 49.7 g of polyvinyl pyrrolidone PVP (Polyvinyl Pyrrolidone) in 1000 mL of water. After ultrasonic dissolution for 30 min at a power of 400 W and a frequency of 100 KHZ, stir for 30 min at a stirring speed of 500 r / min, and adjust the initial pH of the solution to 7 with NaOH or HNO3. Transfer the obtained clear mixed solution to a reaction kettle, heat it to 200 °C, and react for 20 h at a reaction pressure of 0.5 MPa. After the reaction is completed and the reaction kettle is cooled to room temperature, carry out solid-liquid separation on the obtained precipitate, wash the precipitate with water and ethanol, and dry it at a temperature of 80 °C for 8 h to obtain a precursor. Calcinate the precursor at 1050 °C for 4 h. Ball-mill the calcined cerium oxide polishing medium in a ball mill at a rotation speed of 500 rpm for 4 h. The mass ratio of the calcined cerium oxide polishing medium to the zirconia ball-milling beads is 1:6 to obtain a cerium oxide polishing medium. After testing, the Mohs hardness of the cerium oxide polishing medium is 5.8.

[0056] Preparation of the fifth CeO2 polishing medium:

[0057] Dissolve 58.2 g of Ce(NO3)3·6H20 and 55.2 g of polyvinyl pyrrolidone PVP (Polyvinyl Pyrrolidone) in 1000 mL of water. After ultrasonic dissolution for 50 min at a power of 350 W and a frequency of 80 KHZ, stir for 60 min at a stirring speed of 200 r / min, and adjust the initial pH of the solution to 7 with NaOH or HNO3. Transfer the obtained clear mixed solution to a reaction kettle, heat it to 200 °C, and react for 30 h at a reaction pressure of 0.8 MPa. After the reaction is completed and the reaction kettle is cooled to room temperature, carry out solid-liquid separation on the obtained precipitate, wash the precipitate with water and ethanol, and dry it at a temperature of 80 °C for 8 h to obtain a precursor. Calcinate the precursor at 1100 °C for 2 h. Ball-mill the calcined cerium oxide polishing medium in a ball mill at a rotation speed of 300 rpm for 5 h. The mass ratio of the calcined cerium oxide polishing medium to the zirconia ball-milling beads is 1:5 to obtain a cerium oxide polishing medium. After testing, the Mohs hardness of the cerium oxide polishing medium is 6.

[0058] Example 1

[0059] 1) The selected fiber optic image transmission element includes core glass, cladding glass, and light-absorbing glass;

[0060] The core glass material comprises components with the following weight percentages: SiO2 20%, Al2O3 1%, B2O3 20%, MgO 1%, CaO 2%, BaO 5%, La2O3 20%, Nb2O5 5%, Ta2O5 5%, ZnO 1%, TiO2 3%, ZrO2 3%, Na2O 2%, K2O 12%. The Mohs hardness range of the core glass material is 5.6;

[0061] The cladding glass material comprises components with the following weight percentages: SiO2 30%, B2O3 28%, Al2O3 6%, MgO 2%, Na2O 3%, K2O 30%, Li2O 1%. The Mohs hardness range of the cladding glass material is 5.3;

[0062] The light absorption glass comprises components with the following weight percentages: SiO2 71%, Al2O3 3%, B2O3 5%, Na2O 5.5%, K2O 8%, MgO 1%, CaO 1%, BaO 0.5%, TiO2 0.5%, Co2O3 0.5%, NiO 0.5%, MnO 2%, V2O5 0.8%, CeO2 0.2%, CuO 0.5%. The Mohs hardness range of the light absorption glass is 5.0.

[0063] The area of the core glass material on the surface of the fiber optic image transmission element is 77%; the area of the cladding glass material on the surface of the fiber optic image transmission element is 21%; the area of the light absorption glass on the surface of the fiber optic image transmission element is 2%.

[0064] 2) Weigh 2 g of the first CeO2 polishing medium, 21 g of the third CeO2 polishing medium, and 77 g of the fourth CeO2 polishing medium. Dissolve these three polishing media in 2000 mL of distilled water to prepare a polishing slurry, and adjust the pH of the slurry to 7 with NaOH or HNO3 solution to obtain the polishing solution for the fiber optic image transmission element. Place the fiber optic image transmission element in the polishing solution for the fiber optic image transmission element, and polish the fiber optic image transmission element for 45 min under the polishing process with a polishing pressure of 15 Kg, a main shaft rotation speed of 52 r / min, and a swing shaft rotation speed of 60 r / min. After polishing, the average surface form accuracy of the fiber optic image transmission element is 0.1643 wave, the surface roughness is 0.369 nm, and the average pit depth is 5.36 nm.

[0065] Example 2

[0066] 1) The selected fiber optic image transmission element includes core glass material, cladding glass material, and light absorption glass;

[0067] The core glass material comprises components with the following weight percentages: SiO2 15%, Al2O3 8%, B2O3 25%, MgO 3%, CaO 2%, BaO 6%, La2O3 14%, Nb2O5 12%, Ta2O5 3%, ZnO 3%, TiO2 1%, ZrO2 4%, Na2O 1%, K2O 3%. The Mohs hardness range of the core glass material is 5.7;

[0068] The cladding glass material comprises components with the following weight percentages: SiO2 56%, B2O3 20%, Al2O3 4%, MgO 2%, Na2O 3%, K2O 13%, Li2O 2%. The Mohs hardness range of the cladding glass material is 5.4;

[0069] The light absorption glass material comprises components with the following weight percentages: SiO2 75%, Al2O3 4.8%, B2O3 2%, Na2O 1%, K2O 9%, MgO 2%, CaO 0.1%, BaO 0.1%, TiO2 0.8%, Co2O3 1%, NiO 1%, MnO 2.5%, V2O5 0.5%, CeO2 0.1%, CuO 0.1%. The Mohs hardness range of the light absorption glass material is 5.3.

[0070] The area of the core glass material on the surface of the fiber optic image transmission element is 75%; the area of the cladding glass material on the surface of the fiber optic image transmission element is 20%; the area of the light absorption glass material on the surface of the fiber optic image transmission element is 5%.

[0071] 2) Weigh 25 g of the third CeO2 polishing medium and 75 g of the fifth CeO2 polishing medium, dissolve them in 2500 mL of distilled water to prepare a polishing slurry, and adjust the pH of the slurry to 7 with NaOH or HNO3 solution to obtain a polishing solution for the fiber optic image transmission element. Place the fiber optic image transmission element in the polishing solution for the fiber optic image transmission element, and polish the fiber optic image transmission element for 60 min under the polishing process with a polishing pressure of 15 Kg, a main shaft rotation speed of 50 r / min, and a pendulum shaft rotation speed of 65 r / min. After polishing, the average surface form accuracy of the fiber optic image transmission element is 0.3323 wave, the surface roughness is 4.160 nm, and the average pit depth is 16.96 nm.

[0072] Example 3

[0073] 1) The selected fiber optic image transmission element includes core glass material, cladding glass material, and light absorption glass material;

[0074] The core glass material comprises components with the following weight percentages: SiO2 10%, Al2O3 4%, B2O3 22%, MgO 5%, CaO 5%, BaO 9%, La2O3 13%, Nb2O5 7%, Ta2O5 2%, ZnO 4%, TiO2 1%, ZrO2 6%, Na2O 2%, K2O 10%. The Mohs hardness range of the core glass material is 5.8;

[0075] The cladding glass material comprises components with the following weight percentages: SiO2 71.5%, B2O3 12%, Al2O3 5%, MgO 1%, Na2O 0.5%, K2O 8%, Li2O 2%. The Mohs hardness range of the cladding glass material is 5.5;

[0076] The light absorption glass material comprises components with the following weight percentages: SiO2 80%, Al2O3 0.5%, B2O3 1%, Na2O 3.35%, K2O 6%, MgO 0.15%, CaO 0.8%, BaO 0.3%, TiO2 1%, Co2O3 0.8%, NiO 1%, MnO 4%, V2O5 1%, CeO2 0.05%, CuO 0.05%. The Mohs hardness range of the light absorption glass material is 5.3;

[0077] The area of the core glass material on the surface of the fiber optic image transmission element is 76%; the area of the cladding glass material on the surface of the fiber optic image transmission element is 21%; the area of the light absorption glass material on the surface of the fiber optic image transmission element is 3%.

[0078] 2) Weigh 2 g of the second CeO2 polishing medium, 18 g of the third CeO2 polishing medium, and 80 g of the fifth CeO2 polishing medium. Dissolve the three polishing media in 1500 mL of distilled water to prepare a polishing slurry, and adjust the pH of the slurry to 7 with NaOH or HNO3 solution to obtain a polishing solution for the fiber optic image transmission element. Place the fiber optic image transmission element in the polishing solution for the fiber optic image transmission element. Polish the fiber optic image transmission element for 30 min under the polishing process with a polishing pressure of 5 Kg, a main shaft rotation speed of 60 r / min, and a swing shaft rotation speed of 55 r / min. After polishing, the average surface form accuracy of the fiber optic image transmission element is 0.2230 wave, the surface roughness is 2.238 nm, and the average pit depth is 8.63 nm.

[0079] Example 4

[0080] The fiber optic image transmission element composed of the core glass, cladding glass, and light absorption glass in Example 1 was polished using the third CeO₂ polishing medium, which is also a commonly used polishing method in current processing. Weigh 100 g of the third CeO₂ polishing medium and dissolve it in 2000 mL of distilled water to prepare a polishing slurry, and adjust the pH of the slurry to 7 with NaOH or HNO₃ solution to obtain the polishing solution for the fiber optic image transmission element. Place the fiber optic image transmission element in the polishing solution, and polish the fiber optic image transmission element for 45 minutes under the polishing process with a polishing pressure of 15 Kg, a main shaft rotation speed of 52 r / min, and a wobble shaft rotation speed of 60 r / min. After polishing, the average surface form accuracy of the fiber optic image transmission element is 0.4732 wave, the surface roughness is 10.473 nm, and the average pit depth is 73.42 nm.

[0081] Compared with Example 1 - 3, in Example 1 - 3, polishing was carried out using two or three polishing media with different hardnesses, and the hardness of each polishing medium was slightly higher than or equal to the hardness of the core glass, cladding glass, and light absorption glass. After polishing in Example 1 - 3, the average surface form accuracy, surface roughness, and average pit depth of the fiber optic image transmission element are lower than those in Example 4. Therefore, using the two or three polishing media with different hardnesses of the present invention has the best polishing effect.

[0082] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or decorations to equivalent changes within the scope of the technical solution of the present invention by using the disclosed technical content above. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and decoration made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of a polishing medium for polishing an optical fiber image transmission element, characterized in that: It includes the following steps: 1) Dissolution of rare earth source: Dissolve Ce(NO3)3·6H20 and polyvinylpyrrolidone in water. After ultrasonic dissolution, stir for the first preset time, and adjust the initial pH of the solution to 7 to obtain a clear mixed solution; 2) High-temperature and high-pressure reaction: Transfer the clear mixed solution to a reaction kettle, heat to the first preset temperature, and react for the second preset time; 3) Precipitation separation, washing and drying: After the reaction ends, wait for the reaction kettle to cool to room temperature, wash the obtained precipitate with water and ethanol, and dry to obtain a precursor; 4) Calcination: Calcinate the precursor; 5) Ball milling: Ball mill the calcined precursor on a ball mill to obtain a cerium oxide polishing medium.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the dosages of Ce(NO3)3·6H20, polyvinylpyrrolidone and water is (5-9):(1-6):

100.

3. The preparation method according to claim 2, characterized in that, The frequency of the ultrasonic wave is 50KHZ-100KHZ, the power is 300-400W, the ultrasonic dissolution time is 0.5h-1h, and the first preset time is 30-60min; the stirring speed is 200-500r / min, the first preset temperature is 160℃-200℃, the second preset time is 20-30h, and the reaction pressure of the reaction kettle is 0.5MPa-1.55MPa.

4. The preparation method according to claim 3, wherein, Adjust the initial pH value of the solution with NaOH or HNO3; The drying temperature is 60℃-80℃, and the drying time is 8-12h; The rotation speed of the ball milling is 300rpm-500rpm, and the ball milling time is 3-5h; the mass ratio of the calcined precursor to the zirconia ball milling beads is 1:(4-6).

5. The preparation method according to any one of claims 1-4, characterized in that, The calcination temperature is 450℃~1100℃, and the calcination time is 2h-4h.

6. A polishing method for polishing an optical fiber image transmission element with the cerium oxide polishing medium obtained by the preparation method according to any one of 1-5, characterized in that, It includes the following steps: (1) Prepare a slurry: Dissolve the cerium oxide polishing medium in water, and adjust the pH value of the slurry to 7 with a NaOH or HNO3 solution to obtain a slurry; (2) Polishing: Perform surface polishing treatment on the fiber optic image transmission element with the slurry.

7. The polishing method according to claim 6, wherein During the polishing treatment, the polishing pressure is 5-15Kg, the main shaft rotation speed is 50-60r / min, the swing shaft rotation speed is 55-65r / min, and the polishing time is 30-60min.

8. The polishing method according to claim 7, wherein The fiber optic image transmission element includes core glass, cladding glass and light absorption glass; The Mohs hardness range of the core glass is 5.6-5.8; The Mohs hardness range of the cladding glass is 5.3-5.5; The Mohs hardness range of the light absorption glass is 5.0-5.

3.

9. The polishing method according to claim 8, wherein The mass ratio of the cerium oxide polishing medium to water is 1:(14-25); The Mohs hardness range of the cerium oxide polishing medium is 5.0-6.0; The cerium oxide polishing medium selects two kinds of cerium oxide polishing media with Mohs hardness or three kinds of cerium oxide polishing media with Mohs hardness; When two kinds of Mohs hardness are selected, the hardness of the first kind of cerium oxide polishing medium is higher than or equal to the Mohs hardness of the core glass, and the mass percentage of the dosage is A±5%, where A is the area percentage of the core glass on the surface of the fiber optic image transmission element; The hardness of the cerium oxide polishing medium with the second Mohs hardness is higher than or equal to the Mohs hardness of the leather glass, and the mass percentage of the dosage is 1-(A±5%); When three Mohs hardnesses are selected, the mass percentage of the dosage of the cerium oxide polishing medium with the second Mohs hardness is B±3%, and B is the area percentage of the leather glass on the surface of the fiber optic image transmission element; The hardness of the cerium oxide polishing medium with the third Mohs hardness is higher than or equal to the Mohs hardness of the light absorption glass, and the mass percentage of the dosage is Y±1%, where Y is the area percentage of the light absorption glass on the surface of the fiber optic image transmission element.

10. The polishing method according to claim 9, characterized in that, The core glass comprises the following components in weight percentage: SiO2 10-20%, Al2O3 0-10%, B2O3 20-40%, MgO 0-5%, CaO 0-5%, BaO 0-12%, La2O3 20-50%, Nb2O5 5-20%, Ta2O5 0-5%, ZnO 0-5%, TiO2 0-3%, ZrO2 2-6%, Na2O 0-2%, K2O 2-20%; The leather glass comprises the following components in weight percentage: SiO2 30-73%, B2O3 10-28%, Al2O3 0-6%, MgO 0-2%, Na2O 0.5-3%, K2O 5-30%, Li2O 0-2%; The light absorption glass comprises the following components in weight percentage: SiO2 71-80%, Al2O3 0.5-5%, B2O3 1-5%, Na2O 1-11%, K2O 6-11%, MgO 0.1-2%, CaO 0.1-2%, BaO 0-0.5%, TiO2 0-1%, Co2O3 0.4-1%, NiO 0.1-1%, MnO 1-5%, V2O5 0.1-1%, CeO2 0-0.2%, CuO 0-0.5%; The area of the core glass on the surface of the fiber optic image transmission element is 75%-77%; The area of the leather glass on the surface of the fiber optic image transmission element is 20%-22%; The area of the light absorption glass on the surface of the fiber optic image transmission element is 2%-5%.

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