High-precision ultra-smooth optical glass and preparation method thereof

Abstract

The invention discloses high-precision ultra-smooth optical glass and a preparation method thereof, and belongs to the technical field of glass manufacturing, and the preparation method of the high-precision ultra-smooth optical glass comprises three steps of founding, forming and polishing. According to the high-precision ultra-smooth optical glass prepared by the preparation method disclosed by the invention, the light transmittance is 93 to 94 percent, the refractive index is 1.92 to 1.96, the abbe number is 40 to 43, and the surface roughness is 0.211 to 0.232 nm.

Description

Technical Field

[0001] The present invention relates to a high-precision and ultra-smooth optical glass and a preparation method thereof, belonging to the technical field of glass manufacturing. Background Art

[0002] High-precision optical glass has high refractive index, high light transmittance, high smoothness and low dispersion coefficient. These performance characteristics conform to the development trend of miniaturization of optical components and play a crucial role in simplifying optical systems. With the development of technology, ordinary optical glass with a refractive index between 1.5 and 1.7 has been difficult to meet the stringent requirements of optical devices. High-precision optical glass with a refractive index above 1.9 has become the development direction of high-performance optical glass.

[0003] Chinese Patent CN119038876A discloses a preparation method of a low-stress and high-precision optical glass, including the following steps: S1, raw material preparation; S2, raw material mixing: putting the prepared glass raw materials into the interior of a mixing device, first adding phosphorus pentoxide into the mixing device, then adding zirconia into it, and finally adding titanium dioxide or nano-silicon powder into it for mixing; S3, melting; S4, forming and annealing; S5, polishing; S6, surface cleaning; S7, coating treatment. The low-stress and high-precision optical glass obtained by this patent has a light transmittance that can only reach 85%, a refractive index that can only reach 1.6 at most, and relatively poor smoothness, making it difficult to meet the requirements of high-precision optical glass.

[0004] Chinese Patent CN118324408A discloses a high-precision and ultra-smooth optical glass, characterized in that the composition includes, in mole percentage: SiO2: 24 - 36%; Nb2O5: 18 - 38%; ZrO2: 0.5 - 10%; RO: 7 - 30%; Na2O: 3 - 16%, Al2O3: 1 - 5%; B2O3: 2 - 8%, where RO / Nb2O5 is 0.2 - 1.5, and the RO is the total content of MgO, CaO, SrO, and BaO. The refractive index of the optical glass is 1.70 - 1.74, and the Abbe number is 32 - 37. The high-precision and ultra-smooth optical glass obtained by this patent has a maximum refractive index of 1.74, and at the same time, the Abbe number is relatively small, and the dispersion is relatively serious, not being an ideal high-precision optical glass.

[0005] It can be seen from the above that there are still prominent problems in current high-precision and ultra-smooth optical glass, such as low refractive index, high dispersion coefficient, and poor smoothness. Therefore, it has very important practical significance to prepare high-precision and ultra-smooth optical glass with high refractive index, low dispersion, and high smoothness. Summary of the Invention

[0006] In view of the deficiencies of the above-mentioned existing technologies, the present invention provides a high-precision ultra-smooth optical glass and a preparation method thereof, achieving the following invention objectives: to prepare a high-precision ultra-smooth optical glass with high refractive index, low dispersion, and high smoothness.

[0007] To achieve the above invention objectives, the present invention adopts the following technical solutions: A high-precision ultra-smooth optical glass and a preparation method thereof, the raw material composition of the high-precision ultra-smooth optical glass is, by weight: Silica 60 - 100 parts, Aluminum oxide 25 - 70 parts, Sodium oxide 15 - 50 parts, Magnesium oxide 10 - 25 parts, Calcium oxide 10 - 40 parts, Lithium oxide 5 - 25 parts, Flux 5 - 9 parts, Compound fining agent 3 - 10 parts, High light transmittance and high refractive index additive 5 - 13 parts; The flux is sodium tetraborate; The compound fining agent is a mixture of cerium dioxide and aluminum borate; The mass ratio of cerium dioxide to aluminum borate is 10 - 57:100; The high light transmittance and high refractive index additive is a mixture of lanthanum disilicide and samarium disilicide; The mass ratio of lanthanum disilicide to samarium disilicide is 25 - 80:13; The following is a further improvement of the above technical solution: Step 1, melting According to the raw material composition of the high-precision ultra-smooth optical glass by weight, after preliminarily mixing silica, aluminum oxide, sodium oxide, magnesium oxide, calcium oxide, lithium oxide, flux, compound fining agent, and high light transmittance and high refractive index additive evenly, put them into a glass melting furnace, and after a heating and constant temperature process, melt them into a high-temperature glass melt; The heating and constant temperature process, the specific operation is: heat at a rate of 2 - 5 °C / min to 1000 - 1200 °C and keep warm for 30 - 50 minutes, then heat at a rate of 1 - 3 °C / min to 1500 - 1680 °C and keep warm for 1 - 4 hours, and then cool down to 1400 - 1480 °C and keep warm for 20 - 40 minutes.

[0008] Step 2, forming Drain the high-temperature glass melt from the glass kiln through a runner to the casting port and continuously cast it on a mold to obtain a glass sheet, and then anneal and cool the glass sheet to obtain a semi-finished high-precision ultra-smooth optical glass; It is cast on the mold, and the temperature of the mold needs to be pre-constant at 600~700°C in advance; For the annealing, the annealing temperature is 550~600°C, and the annealing time is 1~2 hours; For the cooling, the cooling rate is 3~6°C / min.

[0009] Step 3, polishing Use a single-axis grinding and polishing machine and a polyurethane polishing pad to perform chemical mechanical polishing on the semi-finished high-precision ultra-smooth optical glass, control the spindle speed, swing frame speed, polishing liquid droplet acceleration, and polishing time. After polishing, wash with deionized water and dry with clean compressed air to obtain the finished high-precision ultra-smooth optical glass; The specific composition of the polishing liquid is, by weight: 35~65 parts of cerium oxide abrasive, 10~25 parts of tributyl phosphate, 5~15 parts of composite surfactant, 3~8 parts of mixed acid, 50~80 parts of deionized water; The composite surfactant is a mixture of sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2; The mass ratio of sodium lauryl polyoxyethylene ether sulfate to isooctyl polyoxyethylene ether JFC-2 is 30~90:17; The mixed acid is a mixture of mellitic acid and phosphoric acid, and the mass ratio of the two is 10~47:30; The particle size of the cerium oxide abrasive is 50~400nm; The spindle speed is 60~90 revolutions per minute; The swing frame speed is 25~40 revolutions per minute; The polishing liquid droplet acceleration is 0.5~1mL / min; The polishing time is 3~4.5 hours.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, a clarifying agent composed of a compound of cerium dioxide and aluminum borate is used. Among them, cerium dioxide is a commonly used high-efficiency glass clarifying agent and is also very suitable for optical glass, which can improve the refractive index and light transmittance of optical glass. Aluminum borate cooperates with cerium dioxide, which can particularly effectively improve the clarification effect of the glass melt at high temperature. The decomposition temperature of aluminum borate is relatively high, and the gas generated during decomposition can violently stir the glass melt, promoting the coalescence and discharge of microbubbles. In addition, the boric acid and alumina components after the decomposition of aluminum borate, the residual part that is not discharged from the glass melt in time at high temperature, can also become part of the optical glass, and have no negative impact on the refractive index, light transmittance, and Abbe number of the optical glass; 2. The high-transparency and high-refraction additives added in the present invention, namely the mixture of lanthanum disilicide and samarium disilicide, have relatively low melting points and can be fully melted during the glass melting process. More importantly, the lanthanum ions and samarium ions generated after the melting of these two substances will enter the network structure of the glass melt under the induction of silicon anions, reducing the oxygen packing density and crystallization ability of the glass, thereby increasing the composition content of the amorphous glass network, ultimately increasing the refractive index and light transmittance of the optical glass, increasing the Abbe number, and reducing the dispersion degree; 3. The mixed acid composed of mellitic acid and phosphoric acid is added to the polishing liquid used in the present invention. The most important function of the mixed acid is to adjust and maintain the pH value of the polishing liquid at a medium acidity level to prevent excessive precipitation and particle agglomeration of cerium dioxide polishing powder in a non-acidic environment, resulting in a sharp increase in the size of polishing particles and thus a sharp decline in the polishing effect. The main function of mellitic acid is to complex the finer cerium dioxide particles formed during the polishing process and prevent the agglomeration of fine particles. Phosphoric acid can, through the characteristics of its ternary acid, undergo multi-step ionization during the polishing process to form more ionized acid products, thereby maintaining and buffering the pH value fluctuation of the polishing liquid, keeping the pH value of the polishing liquid fluctuating within a relatively small range, and thus avoiding excessive agglomeration of the particle components in the polishing liquid and instability of the chemical polishing environment components on the glass surface; 4. The composite surfactants added to the polishing liquid in the present invention, namely sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2, have characteristics such as dispersion, emulsification, penetration, solubilization, and wetting. While promoting good dispersion of the particulate matter in the system, more importantly, sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2 can cooperate with mellitic acid to adsorb on the particle surface, making the particle surface negatively charged, and preventing the agglomeration of adjacent particles under the action of electrostatic repulsion. In addition, the long organic molecular chains of sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2 play a steric hindrance role at the outer end, further preventing particle agglomeration; 5. The high-precision and ultra-smooth optical glass prepared in the present invention has a light transmittance of 93 - 94%, a refractive index of 1.92 - 1.96, an Abbe number of 40 - 43, and a surface roughness of 0.211 - 0.232 nm. Specific Embodiments

[0011] The following describes the preferred embodiments of the present invention. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0012] Example 1: A method for preparing high-precision and ultra-smooth optical glass Step 1: Melting The raw material composition of the high-precision and ultra-smooth optical glass is as follows, by weight: 90 parts of silica, 60 parts of alumina, 45 parts of sodium oxide, 15 parts of magnesium oxide, 30 parts of calcium oxide, 20 parts of lithium oxide, 8 parts of flux, 9 parts of compound fining agent, 11 parts of high light transmittance and high refractive index additive; The flux is sodium tetraborate; The compound fining agent is a mixture of cerium dioxide and aluminum borate; The mass ratio of cerium dioxide to aluminum borate is 33:100; The high light transmittance and high refractive index additive is a mixture of lanthanum disilicide and samarium disilicide; The mass ratio of lanthanum disilicide to samarium disilicide is 45:13; According to the raw material composition of high-precision ultra-smooth optical glass by weight, silica, alumina, sodium oxide, magnesium oxide, calcium oxide, lithium oxide, flux, compound fining agent, and high light transmittance and high refractive index additive are preliminarily mixed evenly and then put into a glass melting furnace. After a heating and constant temperature process, it is melted into a high-temperature glass melt; The heating and constant temperature process is specifically operated as follows: heating at a rate of 3 °C / min to 1100 °C and holding for 45 minutes, then heating at a rate of 2 °C / min to 1580 °C and holding for 3 hours, and then cooling to 1460 °C and holding for 20 - 40 minutes.

[0013] Step 2, forming The high-temperature glass melt is drained from the glass kiln through a forehearth to a casting port and continuously cast on a mold to obtain a glass sheet. Then, the glass sheet is annealed and cooled to obtain a semi-finished high-precision ultra-smooth optical glass; When casting on the mold, the temperature of the mold needs to be pre-constant at 660 °C; For the annealing, the annealing temperature is 580 °C and the annealing time is 1.6 hours; For the cooling, the cooling rate is 4 °C / min.

[0014] Step 3, polishing The semi-finished high-precision ultra-smooth optical glass is chemically mechanically polished using a single-axis grinding and polishing machine and a polyurethane polishing pad. The spindle speed, swing frame speed, polishing liquid droplet acceleration, and polishing time are controlled. After polishing, it is washed with deionized water and dried with clean compressed air to obtain a finished high-precision ultra-smooth optical glass; The specific composition of the polishing liquid is as follows, by weight: 55 parts of cerium oxide abrasive, 20 parts of tributyl phosphate, 10 parts of compound surfactant, 6 parts of mixed acid, and 70 parts of deionized water; The compound surfactant is a mixture of sodium lauryl polyoxyethylene ether sulfate and isooctyl alcohol polyoxyethylene ether JFC-2; The mass ratio of sodium lauryl polyoxyethylene ether sulfate to isooctyl alcohol polyoxyethylene ether JFC-2 is 80:17; The mixed acid is a mixture of mellitic acid and phosphoric acid, and the mass ratio of the two is 37:30; The particle size of the cerium oxide abrasive is 100 nm; The spindle speed is 80 revolutions per minute; The swing frame speed is 30 revolutions per minute; The acceleration rate of the polishing liquid dropping is 0.8 mL / min; The polishing time is 4 hours.

[0015] Example 2: A preparation method of high-precision and ultra-smooth optical glass Step 1, melting The raw material composition of the high-precision and ultra-smooth optical glass is as follows, by weight: Silicon dioxide 60 parts, Aluminum oxide 25 parts, Sodium oxide 15 parts, Magnesium oxide 10 parts, Calcium oxide 10 parts, Lithium oxide 5 parts, Flux 5 parts, Compound fining agent 3 parts, High-transmission and high-refraction additive 5 parts; The flux is sodium tetraborate; The compound fining agent is a mixture of cerium dioxide and aluminum borate; The mass ratio of cerium dioxide to aluminum borate is 10:100; The high-transmission and high-refraction additive is a mixture of lanthanum disilicide and samarium disilicide; The mass ratio of lanthanum disilicide to samarium disilicide is 25:13; According to the raw material composition of the high-precision and ultra-smooth optical glass by weight, after preliminarily mixing silicon dioxide, aluminum oxide, sodium oxide, magnesium oxide, calcium oxide, lithium oxide, flux, compound fining agent, and high-transmission and high-refraction additive evenly, put them into a glass melting furnace, and after the temperature-rising and constant-temperature process, melt them into a high-temperature glass melt; The heating and constant temperature process is specifically operated as follows: heating to 1000°C at a rate of 2°C / min and holding for 30 minutes, then heating to 1500°C at a rate of 1°C / min and holding for 1 hour, and then cooling to 1400°C and holding for 20 minutes.

[0016] Step 2, forming The high-temperature glass melt is drained from the glass furnace through the launder to the casting port and continuously cast on the mold to obtain a glass sheet, and then the glass sheet is annealed and cooled to obtain a high-precision ultra-smooth optical glass semi-finished product; For the casting on the mold, the temperature of the mold needs to be pre-constant at 600°C in advance; For the annealing, the annealing temperature is 550°C and the annealing time is 1 hour; For the cooling, the cooling rate is 3°C / min.

[0017] Step 3, polishing The high-precision ultra-smooth optical glass semi-finished product is chemically mechanically polished using a single-axis grinding and polishing machine and a polyurethane polishing pad, controlling the spindle speed, swing frame speed, polishing liquid droplet acceleration, and polishing time. After polishing, it is washed with deionized water and dried with clean compressed air to obtain a high-precision ultra-smooth optical glass finished product; The specific composition of the polishing liquid is, by weight: 35 parts of cerium oxide abrasive, 10 parts of tributyl phosphate, 5 parts of composite surfactant, 3 parts of mixed acid, and 50 parts of deionized water; The composite surfactant is a mixture of sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2; The mass ratio of sodium lauryl polyoxyethylene ether sulfate to isooctyl polyoxyethylene ether JFC-2 is 30:17; The mixed acid is a mixture of mellitic acid and phosphoric acid, and the mass ratio of the two is 10:30; The particle size of the cerium oxide abrasive is 50 nm; The spindle speed is 60 revolutions per minute; The swing frame speed is 25 revolutions per minute; The polishing liquid droplet acceleration is 0.5 mL / min; The polishing time is 3 hours.

[0018] Example 3: A method for preparing a high-precision ultra-smooth optical glass Step 1, melting The raw material composition of the high-precision ultra-smooth optical glass is, by weight: Silica 100 parts, Aluminum oxide 70 parts, Sodium oxide 50 parts, Magnesium oxide 25 parts, 40 parts of calcium oxide, 25 parts of lithium oxide, 9 parts of flux, 10 parts of compound fining agent, 13 parts of high light transmittance and high refractive index additive; The flux is sodium tetraborate; The compound fining agent is a mixture of cerium dioxide and aluminum borate; The mass ratio of cerium dioxide to aluminum borate is 57:100; The high light transmittance and high refractive index additive is a mixture of lanthanum disilicide and samarium disilicide; The mass ratio of lanthanum disilicide to samarium disilicide is 80:13; According to the raw material composition of high-precision ultra-smooth optical glass by weight, after preliminarily mixing silica, alumina, sodium oxide, magnesium oxide, calcium oxide, lithium oxide, flux, compound fining agent, and high light transmittance and high refractive index additive evenly, put them into a glass melting furnace, and after the temperature-rising and constant-temperature process, melt them into a high-temperature glass melt; For the temperature-rising and constant-temperature process, the specific operation is: heat up at a rate of 5 °C / min to 1200 °C and hold for 50 minutes, then heat up at a rate of 3 °C / min to 1680 °C and hold for 4 hours, and then cool down to 1480 °C and hold for 40 minutes.

[0019] Step 2, forming Drain the high-temperature glass melt from the glass kiln to the casting port through the runner and continuously cast it on the mold to obtain a glass sheet, and then anneal and cool the glass sheet to obtain a high-precision ultra-smooth optical glass semi-finished product; For the casting on the mold, the temperature of the mold needs to be pre-constant at 700 °C in advance; For the annealing, the annealing temperature is 600 °C and the annealing time is 2 hours; For the cooling, the cooling rate is 6 °C / min.

[0020] Step 3, polishing Use a single-axis grinding and polishing machine and a polyurethane polishing pad to chemically mechanically polish the high-precision ultra-smooth optical glass semi-finished product, control the spindle speed, swing frame speed, polishing liquid droplet acceleration, and polishing time. After polishing, wash it with deionized water and dry it with clean compressed air to obtain a high-precision ultra-smooth optical glass finished product; The specific composition of the polishing liquid is, by weight: 65 parts of cerium oxide abrasive, 25 parts of tributyl phosphate, 15 parts of compound surfactant, 8 parts of mixed acid, and 80 parts of deionized water; The compound surfactant is a mixture of sodium lauryl polyoxyethylene sulfate and isooctyl polyoxyethylene ether JFC-2; The mass ratio of the sodium lauryl polyoxyethylene ether sulfate to the isooctyl alcohol polyoxyethylene ether JFC-2 is 90:17; The mixed acid is a mixture of mellitic acid and phosphoric acid, and the mass ratio of the two is 47:30; The particle size of the cerium oxide abrasive is 400 nm; The spindle speed is 90 revolutions per minute; The swing frame speed is 40 revolutions per minute; The acceleration rate of the polishing liquid drop is 1 mL / min; The polishing time is 4.5 hours.

[0021] Comparative Example 1: On the basis of Example 1, in Step 1, melting, without adding the high-transmittance and high-refractive-index additive, replacing 11 parts of the high-transmittance and high-refractive-index additive with 11 parts of silicon dioxide in equal amount, the specific operation is as follows: Step 1, melting Replacing 11 parts of the high-transmittance and high-refractive-index additive with 11 parts of silicon dioxide in equal amount, and other operations are the same as those in Example 1; The operations in Steps 2 and 3 are the same as those in Example 1.

[0022] Comparative Example 2: On the basis of Example 1, in Step 1, melting, in the compound clarifying agent, without adding aluminum borate, replacing 9 parts of the compound clarifying agent with 9 parts of cerium oxide in equal amount, the specific operation is as follows: Step 1, melting Without adding aluminum borate, replacing 9 parts of the compound clarifying agent with 9 parts of cerium oxide in equal amount, and other operations are the same as those in Example 1; The operations in Steps 2 and 3 are the same as those in Example 1.

[0023] Comparative Example 3: On the basis of Example 1, in Step 3, polishing, in the polishing liquid, without adding the mixed acid, replacing 6 parts of the mixed acid with 6 parts of deionized water in equal amount, the specific operation is as follows: The operations in Steps 1 and 2 are the same as those in Example 1; Step 3, polishing In the polishing liquid, replacing 6 parts of the mixed acid with 6 parts of deionized water in equal amount, and other operations are the same as those in Example 1.

[0024] Comparative Example 4: On the basis of Example 1, in Step 3, polishing, in the polishing liquid, without adding the composite surfactant, replacing 10 parts of the composite surfactant with 10 parts of deionized water in equal amount, the specific operation is as follows: The operations in Steps 1 and 2 are the same as those in Example 1; Step 3, polishing In the polishing liquid, replacing 10 parts of the composite surfactant with 10 parts of deionized water in equal amount, and other operations are the same as those in Example 1.

[0025] Performance test: For the high-precision ultra-smooth optical glass obtained in Examples 1, 2, 3 and Comparative Examples 1, 2, 3, 4, tests were conducted on indicators such as light transmittance, refractive index, Abbe number, and surface roughness: 1. Light transmittance: The average light transmittance in the visible light band was measured using a UV-visible spectrophotometer (UV-6100); 2. Refractive index: The measurement was carried out according to the test method specified in "GB / T7962.1-2010 Test Methods for Colorless Optical Glass - Part 1: Refractive Index and Dispersion Coefficient"; 3. Abbe number: The measurement was carried out according to the test method specified in "GB / T7962.1-2010 Test Methods for Colorless Optical Glass - Part 1: Refractive Index and Dispersion Coefficient"; 4. Surface roughness: The surface roughness was detected using a Dimention-3100 type atomic force microscope (AFM); The results are shown in Table 1: Table 1

[0026] As can be seen from the data in Table 1, the light transmittance of Examples 1-3 is greater than 93%, the refractive indices are all 1.92 or above, the Abbe numbers are 40 or above, and the surface roughness is less than 0.24 nm. This indicates that the optical glass obtained by the present invention has excellent characteristics of high refractive index, low dispersion, and high smoothness; in Comparative Example 1, without adding a high-light-transmittance and high-refractive-index additive, the light transmittance of Comparative Example 1 decreased to 81%, the refractive index also decreased significantly to 1.64, the Abbe number decreased to 33, and the surface roughness remained unchanged. This shows that the high-light-transmittance and high-refractive-index additive can effectively improve the light transmittance and refractive index of the optical glass and reduce dispersion; in the compound clarifying agent of Comparative Example 2, without adding aluminum borate, the light transmittance of Comparative Example 2 decreased, the refractive index also decreased significantly, the Abbe number also decreased correspondingly a lot, and the surface roughness hardly changed. This shows that aluminum borate plays a crucial role in ensuring the efficient clarification of the optical glass; in the polishing liquid of Comparative Example 3, without adding a mixed acid, the light transmittance and refractive index of Comparative Example 3 both decreased, the Abbe number changed little, and the surface roughness increased significantly. This shows that the mixed acid has a very significant effect on promoting the smoothness of the optical glass polishing process, and the decrease in smoothness also has a negative effect on the light transmittance, refractive index, and dispersion to a certain extent; in the polishing liquid of Comparative Example 4, without adding a composite surfactant, the light transmittance of Comparative Example 4 decreased to 89%, the refractive index also decreased significantly, the Abbe number decreased slightly, and the surface roughness increased to 0.776 nm. This shows that the composite surfactant plays a very important role in promoting the efficient polishing of the polishing liquid and improving the surface smoothness of the glass.

[0027] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for preparing a high-precision and ultra-smooth optical glass, characterized in that: The method for preparing the high-precision and ultra-smooth optical glass includes three steps: melting, forming, and polishing; For the melting, according to the raw material composition of the high-precision and ultra-smooth optical glass by weight, after initially mixing silicon dioxide, aluminum oxide, sodium oxide, magnesium oxide, calcium oxide, lithium oxide, a flux, a compound clarifying agent, and a high-transmittance and high-refractive-index additive evenly, put them into a glass melting furnace, and after a temperature-raising and constant-temperature process, melt them into a high-temperature glass melt; The compound clarifying agent is a mixture of cerium dioxide and aluminum borate; The high-transmittance and high-refractive-index additive is a mixture of lanthanum disilicide and samarium disilicide; For the polishing, use a single-axis grinding and polishing machine and a polyurethane polishing pad to perform chemical mechanical polishing on the semi-finished high-precision and ultra-smooth optical glass, control the spindle speed, swing frame speed, polishing liquid droplet acceleration, and polishing time. After polishing, wash it with deionized water and dry it with clean compressed air to obtain the finished high-precision and ultra-smooth optical glass; The polishing liquid is composed of cerium oxide abrasive, tributyl phosphate, a compound surfactant, a mixed acid, and deionized water; The compound surfactant is a mixture of sodium lauryl polyoxyethylene ether sulfate and isooctyl polyoxyethylene ether JFC-2; The mixed acid is a mixture of mellitic acid and phosphoric acid.

2. The method for preparing a high-precision and ultra-smooth optical glass according to claim 1, characterized in that: The raw material composition of the high-precision and ultra-smooth optical glass by weight is specifically 60-100 parts of silicon dioxide, 25-70 parts of aluminum oxide, 15-50 parts of sodium oxide, 10-25 parts of magnesium oxide, 10-40 parts of calcium oxide, 5-25 parts of lithium oxide, 5-9 parts of a flux, 3-10 parts of a compound clarifying agent, and 5-13 parts of a high-transmittance and high-refractive-index additive.

3. The method for preparing a high-precision and ultra-smooth optical glass according to claim 1, characterized in that: The flux is sodium tetraborate; The mass ratio of cerium dioxide to aluminum borate is 10-57:100; The mass ratio of lanthanum disilicide to samarium disilicide is 25-80:

13.

4. The method for preparing a high-precision and ultra-smooth optical glass according to claim 1, characterized in that: The mass ratio of sodium lauryl polyoxyethylene ether sulfate to isooctyl polyoxyethylene ether JFC-2 is 30-90:17; The mass ratio of mellitic acid to phosphoric acid in the mixed acid is 10-47:30; The particle size of the cerium oxide abrasive is 50-400 nm.

5. The high-precision and ultra-smooth optical glass prepared by the preparation method according to any one of claims 1-4, characterized in that: The high-precision and ultra-smooth optical glass has a light transmittance of 93-94%, a refractive index of 1.92-1.96, an Abbe number of 40-43, and a surface roughness of 0.211-0.232 nm.

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