Low-refractive high-optical-uniformity light-absorbing glass, preparation method and application thereof

Abstract

The present application relates to special glass material, especially to a kind of low refractive index high optical uniformity light absorption glass and its preparation method and application.Including the following elements by mole fraction:Si 23-25 parts, B 1-3 parts, Al 0.1-0.3 parts, Na 1.5-3 parts, K 0.1-1 part, Ca 0.1-1 part, Ti 0.1-1 part, F 0.5-4 parts, Cl 0-1 part, Fe 0.1-0.8 part, Co 0.15-1 part, Ni 3-4 parts, Mn 0.5-1 part, Cr0.05-0.25 part, V 1-3 parts, Sb 0.3-0.6 parts;The sum of mole fraction of F and Cl is 1.5-4.1 parts, the sum of mole fraction of Fe, Cr and V is ≥1.15 parts.The glass material provided by the present application has lower refractive index and excellent optical uniformity, and good thermal performance and chemical stability.

Description

Technical Field

[0001] This invention relates to special glass materials, and in particular to a low refractive index, high optical uniformity light-absorbing glass, its preparation method, and its applications. Background Technology

[0002] Fiber optic imaging elements are light and image transmission arrays formed by matching fiber optic preforms with tubing, followed by stretching, regular arrangement, vacuum melting, secondary heat treatment, and optical processing. Stray light inevitably occurs during image transmission in fiber optic imaging elements, primarily originating from cross-leakage between fibers. Currently, the main method to reduce cross-leakage between fibers in fiber optic imaging elements is the insertion of light-absorbing glass fibers.

[0003] The optical absorbing glass, which reduces crosstalk between optical fibers, needs to have good material compatibility with the cladding glass, including optical properties such as refractive index and thermal properties such as coefficient of thermal expansion. Furthermore, it must ensure good absorption performance and optical homogeneity in the visible light band. In fiber optics, if the incident angle is too large, total internal reflection cannot be guaranteed at the core-cladding interface; only at a half-cone angle θ... i ≤θ max Only light beams incident inside a cone can propagate in an optical fiber, θ max This is called the critical angle of incidence. The numerical aperture NA of an optical fiber is defined as NA = nsin(θ). max NA is related to the refractive index of the core and cladding. Here, n1 is the refractive index of the fiber core, and n2 is the refractive index of the cladding. A higher refractive index (NA) results in a stronger light-receiving ability, a stronger core confinement of light energy, better bending resistance, and higher coupling efficiency from the light source to the fiber. In recent years, with the continuous expansion and deepening of applications and fields for fiber optic imaging elements, there is a growing demand for cladding glass with lower refractive indices to increase NA without affecting other properties. Therefore, the requirements for light-absorbing glass are correspondingly becoming increasingly stringent. While the addition of coloring ions can enhance the light absorption capacity of the glass, it also increases the refractive index and viscosity, affecting the uniformity of light absorption and hindering the preparation of high-quality light-absorbing glass. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a low-refractive-index, high-optical-uniformity light-absorbing glass, its preparation method, and its applications. The glass material provided by the present invention has a low refractive index, excellent optical uniformity, good thermal properties, and chemical stability, which helps to reduce manufacturing costs.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a low-refractive-index, high-optical-uniformity light-absorbing glass, comprising the following elements in a molar fraction: The composition is as follows: Si 23-25 ​​parts, B 1-3 parts, Al 0.1-0.3 parts, Na 1.5-3 parts, K 0.1-1 parts, Ca 0.1-1 parts, Ti 0.1-1 parts, F 0.5-4 parts, Cl 0-1 parts, Fe 0.1-0.8 parts, Co 0.15-1 parts, Ni 3-4 parts, Mn 0.5-1 parts, Cr 0.05-0.25 parts, V 1-3 parts, Sb 0.3-0.6 parts; wherein the sum of the molar parts of F and Cl is 1.5-4.1 parts.

[0007] In some implementations, the molar fraction of Si is 23.3-25 parts, 23.7-25 parts, 24.3-25 parts, 24.7-25 parts, etc. In the glass structure, Si mainly forms a continuous three-dimensional network framework using silicon-oxygen tetrahedra [SiO4] as the basic unit, which can significantly reduce the coefficient of thermal expansion of the glass and improve its thermal stability, chemical stability, softening point, heat resistance, mechanical strength, hardness, viscosity, and ultraviolet transmittance. However, excessively high Si content can lead to an increase in the glass melting temperature, increase melting energy consumption, and may cause an increased tendency for crystallization, adversely affecting optical uniformity.

[0008] In some implementations, the molar fraction of boron (B) is 1-2.7 parts, 1-2.3 parts, 1-1.7 parts, 1-1.3 parts, 1-1.2 parts, etc. Boron is an important glass network-forming element. In borosilicate glasses, it forms a stable glass framework with boron-oxygen trigonal [BO3] and boron-oxygen tetrahedron [BO4] as structural units, together with the [SiO4] network. The introduction of B can effectively reduce the coefficient of thermal expansion of the glass, improving its thermal stability, chemical stability, and mechanical properties. Simultaneously, it also helps to increase the refractive index of the glass and improve surface gloss. In terms of processing performance, B is unique in that it can significantly regulate the viscosity characteristics of the glass: at high temperatures, it reduces viscosity, acting as a good flux, promoting clarification and inhibiting crystallization; while at low temperatures, it increases viscosity, leading to a narrower forming temperature range for high borosilicate glasses. It is particularly important to note that the content of B needs to be precisely controlled; excessive B, due to the increased proportion of [BO3] units, will actually increase the coefficient of thermal expansion of the glass.

[0009] In some implementations, the sum of the molar parts of Si and B is not less than 25 parts. Specifically, the sum of the molar parts of Si and B is 25-27 parts, and can also be 25-27 parts, 25.5-27.5 parts, etc.

[0010] In some implementations, the molar amounts of Al are 0.1-0.27 parts, 0.1-0.23 parts, 0.1-0.17 parts, 0.1-0.13 parts, 0.1-0.12 parts, etc. As an intermediate element in glass, aluminum (Al), though usually introduced in small amounts, has a crucial impact on glass properties. It effectively suppresses the tendency of glass to crystallize, while improving its mechanical strength, refractive index, hardness, thermal stability, and chemical stability. Furthermore, Al can reduce the erosion of refractory materials by molten glass during the melting process.

[0011] In some implementation schemes, the molar amounts of Na are 1.5-2.8 parts, 1.5-2.6 parts, 1.5-2.3 parts, 1.5-1.9 parts, 1.5-1.7 parts, 1.5-1.6 parts, etc.

[0012] In some implementation schemes, the molar amount of K is 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.4 parts, 0.1-0.3 parts, 0.1-0.2 parts, etc.

[0013] In glass, Na and K are network exogenous elements. They increase the O / Si ratio in the glass structure by providing free oxygen, leading to the breaking of bonds in the silicon-oxygen network and thus significantly reducing the viscosity of the glass melt, making them effective fluxes. However, the amount of these alkali metal oxides introduced must be strictly controlled. Excessive amounts will significantly increase the coefficient of thermal expansion of the glass and weaken its thermal stability, mechanical strength, and chemical stability.

[0014] In some implementations, the molar fraction of Ca is 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.4 parts, 0.1-0.3 parts, 0.1-0.2 parts, etc. As a divalent network exogenous element, Ca mainly acts as a stabilizer in glass, enhancing its mechanical strength and chemical stability. However, it should be noted that excessively high Ca content can increase the glass's tendency to crystallize and lead to increased brittleness. In processing, Ca can reduce glass viscosity at high temperatures, aiding melting and refining; however, at low temperatures, it causes a rapid increase in glass viscosity, thus increasing the difficulty of forming.

[0015] In some implementation schemes, the sum of the molar parts of B, Na, K, and Ca is no more than 6 parts. Specifically, the sum of the molar parts of B, Na, K, and Ca is 2.7-6 parts, and can also be 2.7-5.1 parts, 2.7-4 parts, etc.

[0016] In some implementations, the molar amounts of Ti are 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.6 parts, 0.1-0.4 parts, 0.1-0.3 parts, 0.1-0.2 parts, etc. In glass, Ti acts as an intermediate element, and its structural morphology is related to the glass system: in silicate glasses, it is partially integrated into the network as [TiO4] tetrahedra, and partially located outside the network as octahedrons. In borosilicate glass systems, the introduction of Ti helps to improve the glass's refractive index and chemical stability.

[0017] In some implementations, the molar amounts of fluoride (F) are 0.7-4 parts, 1-4 parts, 1.3-4 parts, 1.7-4 parts, 2-4 parts, 2.3-4 parts, 2.5-4 parts, 2.7-4 parts, 3-4 parts, 3.3-4 parts, 3.5-4 parts, and 3.7-4 parts, respectively. F exists in the glass as monovalent F ions. Fluorides act as both clarifying agents and fluxes, accelerating the clarifying process. This is mainly because the addition of fluoride reduces the glass viscosity, accelerates the rate of bubble rise, and simultaneously lowers the liquidus formation temperature, accelerating the silicate formation process. Furthermore, fluoride can react with the iron in the glass to form a colorless complex [FeF6]. 3- This iron complex does not absorb infrared radiation, thus enhancing the penetration of radiant heat into the glass, resulting in a more uniform temperature throughout the glass and making it easier to produce glass with high optical homogeneity. The addition of fluorides also lowers the refractive index of the optical glass, which is beneficial for reducing the glass's refractive index.

[0018] In some implementations, the molar amounts of Cl are 0-0.9 parts, 0-0.5 parts, 0-0.3 parts, 0-0.1 parts, 0.01-0.1 parts, 0.1-1 parts, 0.1-0.9 parts, 0.1-0.5 parts, 0.1-0.3 parts, etc. Cl in glass is mainly in the form of Cl... - It exists in the form of sodium chloride or calcium chloride. Cl - Because chlorine forms weak bonds with surrounding cations, its addition to glass can lower the glass's refractive index. Furthermore, if sodium chloride is added, it can act as a clarifying agent, promoting the removal of air bubbles from the molten glass.

[0019] In some implementations, the sum of the molar amounts of F and Cl can be 1.7-4.1 parts, 2-4.1 parts, 2.1-4.1 parts, 3-4.1 parts, 3.1-4.1 parts, or 4-4.1 parts.

[0020] In some implementations, the molar fraction of Fe is 0.1-0.7 parts, 0.1-0.6 parts, 0.1-0.5 parts, 0.1-0.4 parts, 0.1-0.3 parts, 0.1-0.2 parts, etc. Iron-doped glasses exhibit broad-spectrum absorption capabilities in the ultraviolet, visible, and infrared bands, with their near-infrared absorption peak typically located in the 700-1000 nm range. This characteristic stems from the fact that iron in the glass is distributed as Fe. 2+ with Fe 3+ Coexistence of two valence states: Fe 2+ Dominant infrared absorption, while Fe 3+ It absorbs in the ultraviolet region. The balance between the two is jointly regulated by melting temperature, atmosphere, base glass composition, and total iron content.

[0021] In some implementations, the molar fraction of Cr is 0.05-0.23 parts, 0.05-0.2 parts, 0.05-0.17 parts, 0.05-0.15 parts, 0.05-0.13 parts, 0.05-0.1 parts, 0.05-0.09 parts, 0.05-0.07 parts, etc. Cr generally exists in glass as trivalent chromium ions, with absorption bands around 300-500 nm and 620 nm.

[0022] In some implementations, the molar amounts of V are 1-2.9 parts, 1-2.7 parts, 1-2.3 parts, 1-2 parts, 1-1.7 parts, 1-1.3 parts, 1-1.2 parts, 1-1.1 parts, etc. V in glass is expressed as V0 3+ V 4+ and V 5+ It exists in ionic form. Glass containing this element can be yellow, brown, or green. The yellow coloring is due to V. 5+ This is caused by ions, which produce absorption in the ultraviolet spectral region, with the absorption band extending into the violet region. When V 4+ At higher concentrations, the absorption band extends into the blue region of the spectrum, while the yellow coloration transitions to brown. 3+ Ions cause a green coloration. Overall, its absorption band lies in the 200-600 nm wavelength range.

[0023] In some implementations, the sum of the molar parts of Fe, Cr and V is 1.15-3.25 parts, and can also be 1.15-2.87 parts, 1.15-2.11 parts, 1.15-2.05 parts, 1.15-1.84 parts, etc.

[0024] In some implementations, the molar fraction of Ni is 3-3.9 parts, 3-3.7 parts, 3-3.5 parts, 3-3.3 parts, 3-3.2 parts, 3-3.1 parts, etc. Ni is typically used in glass as Ni 2+It exists, with an absorption range covering 400-650 nm and extending to 650-1000 nm. Its broad-spectrum absorption characteristics allow it to partially replace these ions in cobalt, copper, chromium and other colored glasses when combined with iron, thereby reducing their usage.

[0025] In some implementations, the molar amounts of Co are 0.15-0.9 parts, 0.15-0.7 parts, 0.15-0.5 parts, 0.15-0.3 parts, 0.15-0.2 parts, 0.15-0.17 parts, 0.15-0.16 parts, etc. In glass, Co is a colorant with extremely strong coloring power and stable performance, unaffected by the melting atmosphere. In borosilicate glass, Co is the dominant colorant. 2+ The form exhibits strong absorption in the 500-800 nm range.

[0026] In some implementations, the molar fraction of Mn is 0.5-0.9 parts, 0.5-0.8 parts, 0.5-0.7 parts, 0.5-0.6 parts, 0.5-0.55 parts, etc. Mn in glass is expressed as Mn 2+ and Mn 3+ They coexist, and under oxidizing conditions, they mainly form purple Mn. 3+ Furthermore, the stronger the oxidizing atmosphere, the deeper the color. Mn oxides, when used with iron, can be mixed to produce colors ranging from orange-yellow to purple and dark red, and Mn can strongly absorb light in the 450-600 nm range.

[0027] In some implementation schemes, the sum of the molar parts of all the coloring ions (Fe, Cr, V, Ni, Co, Mn) is not less than 4.8 parts. Specifically, the sum of their molar parts is 4.8-8.05 parts, and can also be 4.8-7.55 parts, 4.8-7.25 parts, 4.8-6.71 parts, 4.8-5.6 parts, etc.

[0028] In some implementations, the molar fraction of Sb is 0.3-0.55 parts, 0.3-0.5 parts, 0.3-0.4 parts, 0.3-0.37 parts, 0.3-0.35 parts, 0.3-0.33 parts, etc. The composition of the low-refractive-index, high-optical-uniformity light-absorbing glass also includes a Sb clarifier, which is added in the form of antimony oxide. In the glass industry, antimony oxide, due to its lower toxicity than white arsenic and lower valence transition temperature, is often used as a clarifier in conjunction with nitrates. Its process involves two steps: at low temperature, it combines with oxygen from the decomposition of nitrates to form antimony pentoxide; at high temperature, antimony pentoxide decomposes again to release oxygen. The released oxygen enters bubbles, reducing the internal partial pressure and causing the bubbles to continuously absorb gas, increase in volume, and eventually be expelled from the molten glass, thus efficiently promoting clarification.

[0029] Furthermore, the glass material provided by this invention also contains the necessary oxygen element. O is the core element of the glass network forging body, combining with Si to form silicon-oxygen tetrahedra [SiO4], which constitute the main structure of the glass skeleton, giving the glass mechanical strength and stability. The introduction of different oxides will change the bridging oxygen ratio in the network structure. The oxygen content directly affects the heat resistance, coefficient of thermal expansion, and other properties of the glass.

[0030] By controlling the content of elements such as Si, B, and Al that affect the coefficient of thermal expansion of glass, a glass with a coefficient of thermal expansion of (80-85)×10⁻⁶ at 30-300℃ was prepared. -7 A low-refractive-index, high-optical-uniformity light-absorbing glass with a temperature of / ℃ was obtained. Furthermore, the thermal properties of the glass were improved, facilitating subsequent hot-pressing and wire drawing processes, resulting in a glass transition temperature T0. g 580℃, sag temperature T s 665 ℃, softening point T during wire drawing sp Low transmittance, high strength glass at 750 ℃.

[0031] Improving the optical uniformity of glass helps avoid light leakage and crosstalk caused by insufficient local light absorption in the drawn glass fibers. Controlling the content of F and Cl can result in a lower refractive index and better clarification, thus improving optical uniformity. Controlling the content of elements such as B, Na, K, and Ca can further reduce the molten viscosity of the glass. Controlling the content of Fe, Cr, and V can give the glass excellent light absorption in the 400-800 nm wavelength range. Controlling the total content of coloring elements such as Fe, Cr, V, Co, Ni, and Mn can further improve the light absorption performance of the glass in the 400-800 nm wavelength range. Controlling the content of elements such as Si, B, Al, Ca, and Ti can give the glass good high-temperature stability and chemical stability.

[0032] Secondly, the present invention provides a method for preparing the low-refractive-index, high-optical-uniformity light-absorbing glass, comprising the following steps: After mixing the components of the glass material in the specified proportions, add the clarifying agent in the specified proportions and mix well. The mixture was melted at 1360-1460℃ and stirred at a speed of 8-13 r / min for 4-8 h. Mechanical stirring can accelerate the homogenization process of molten glass. Stirring can continuously divide the uneven areas and coarse streaks in the molten glass into very fine and short streaks, increasing the contact area and facilitating the mutual dissolution and diffusion between the molten glass and the streaks, thereby causing the streaks to gradually disappear or decrease.

[0033] Then, after high-temperature clarification and molding, glass products are obtained.

[0034] In this invention, the raw materials for introducing fluoride are at least one of potassium hydrogen fluoride, sodium fluorosilicate, and calcium fluoride.

[0035] The raw materials introduced by the chlorine-containing compounds in this invention include chlorides (at least one of sodium chloride, potassium chloride, and calcium chloride) or chlorates (at least one of sodium chlorate, potassium chlorate, and calcium chlorate).

[0036] In some implementations, the melting time is 6-10 hours. This melting time helps to clarify the molten glass.

[0037] In some implementations, the molding temperature is 1250-1350°C and the molding time is 5-10 minutes, thereby reducing the generation of secondary bubbles and impurities by shortening the molding time.

[0038] Thirdly, the present invention provides an application of the above-mentioned low refractive index, high optical uniformity light-absorbing glass in the preparation of light-absorbing glass fibers.

[0039] The beneficial effects of this invention are as follows: Traditional methods of improving the light absorption performance of glass by increasing the content of coloring ions often increase the refractive index and coefficient of thermal expansion, make glass melting more difficult, and are detrimental to the homogenization of glass composition. The glass material provided by this invention exhibits optimized optical and thermal properties and compositional homogeneity, demonstrating a synergistic effect of high coloring ion content, low refractive index, and low melt viscosity. Furthermore, the chemical composition of this material ensures good stability and reliability under a wide range of environmental conditions. Therefore, the glass material of this invention provides the necessary low refractive index performance without sacrificing thermal properties and stability, and reduces costs, making it suitable for imaging elements with high imaging quality requirements.

[0040] The present invention provides a low refractive index, high optical homogeneity, and light-absorbing glass with a refractive index n. D (589 nm) ≤1.50, with a thickness of 0.5 mm, the maximum transmittance in the visible light wavelength range of 400-800 nm is ≤1.0%, indicating that the glass material of the present invention can be perfectly adapted to different tube glass and has excellent absorption performance in the visible light wavelength range, ensuring the effectiveness of crosstalk stray light absorption.

[0041] The low refractive index, high optical homogeneity light-absorbing glass provided by this invention has an optical homogeneity ≤5×10⁻⁶. -4 The coefficient of thermal expansion in the range of 30℃-300℃ is (80-85)×10. -7 / ℃, glass transition temperature T g 530℃, sag temperature T s 620 ℃, fiber softening point T sp At 710 ℃, the glass achieves Class I acid resistance and Class I moisture resistance, making it suitable for image transmission elements with high imaging quality requirements.

[0042] Existing light-absorbing glasses have a high refractive index and low light absorption rate in the 400-800 nm visible light wavelength range, resulting in poor optical uniformity. This invention prepares a low-refractive-index light-absorbing glass with excellent optical performance, good thermal properties, and chemical stability by selecting and adjusting the types and ratios of glass raw materials and colorants. Attached Figure Description

[0043] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0044] Figure 1 This is a comparison chart of the transmittance of Example 1 and Comparative Example 1 in the range of 400-800nm. Detailed Implementation

[0045] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0046] Example 1 The composition, molar fraction of each component, and physical properties of the low refractive index high optical homogeneity light-absorbing glass of this embodiment are shown in Table 1.

[0047] The preparation method of low refractive index, high optical homogeneity, and light-absorbing glass is as follows: Quartz sand, boric acid, aluminum hydroxide, sodium nitrate, potassium carbonate, calcium carbonate, titanium oxide, iron oxide, nickel oxide, cobalt oxide, chromium oxide, vanadium oxide, and manganese dioxide are used as raw materials. Sodium fluorosilicate is used as the fluoride-introducing raw material, and sodium chloride is used as the chloride-introducing raw material. Antimony oxide is added as a clarifying agent, and after thorough mixing, the mixture is melted at 1360℃ for 6 hours, mechanically stirred (8 r / min, 4 hours), and then molded at 1250℃ (forming time 5 minutes) to obtain glass rods.

[0048] The refractive index at 589.29 nm was measured using a V-prism refractometer.

[0049] Transmittance was tested using a UV-Vis-IR spectrophotometer.

[0050] The optical uniformity of the glass was tested by China National Testing & Inspection Group Co., Ltd. The test employed a holographic interferometer optical path, and the interference order m of the transmitted interference fringes was measured. t The interference order m of the reflected interference fringes r Given the emission wavelength λ of the light source, the sample thickness h, and the refractive index n of the sample, the refractive index difference Δn is calculated using the following formula (1). (GB / T7962.3-2010) (1) The coefficient of thermal expansion of glass samples was tested using a Netzsch DIL 402 thermal expansion meter. Sample preparation involved grinding and polishing the glass sample into a cylindrical strip with a diameter of 6 × 50 mm, ensuring both ends were parallel. The heating rate was set to 5 °C / min, and the data acquisition period was 20 ms. The data were plotted as a temperature versus linear expansion curve, and the glass transition temperature and sag temperature were obtained using the tangent method. (GB / T 7962.16~2010) The softening point of the glass sample was tested using a plate viscometer. The sample was processed into a cylindrical glass strip with a diameter of 6×6 mm and parallel end faces.

[0051] The acid resistance stability test of glass was conducted by Chengdu Guangming Optoelectronic Co., Ltd. Polished glass samples were eroded by test media with acidities of pH 2.9, pH 4.6, and pH 6.0. The time it took for the glass surface to exhibit violet-blue interference colors, surface discoloration, or peeling under incandescent light was observed. Based on the duration of this time, the acid resistance stability of colorless optical glass was classified in descending order. (GB / T 7962.14~2010) The moisture resistance stability test of the glass was conducted by Chengdu Guangming Optoelectronics Co., Ltd. The turbidity H0 and H1 of the tested sample and standard samples (BaK7 glass and ZK9 glass) before and after etching were measured respectively. The turbidity value H was calculated using H = H1 - H0. Based on the comparison with the turbidity value of the standard sample, the moisture resistance stability grade of the optical glass was obtained from a table. (GB / T 7962.15~2010) Example 2 The composition, molar fraction of each component, and physical properties of the low refractive index high optical homogeneity light-absorbing glass of this embodiment are shown in Table 1.

[0052] In the preparation method of low refractive index high optical homogeneity light-absorbing glass, the melting temperature is 1460 ℃ and the melting time is 10 h; mechanical stirring (13 r / min, 8 h), the forming temperature is 1350 ℃ and the forming time is 10 min. Other preparation steps, parameters and testing procedures are the same as in Example 1.

[0053] Example 3 The composition, molar fraction of each component, and physical properties of the resulting glass with low refractive index and high optical homogeneity are shown in Table 1.

[0054] In this embodiment, the preparation method of the low refractive index high optical uniformity light-absorbing glass is as follows: the melting temperature is 1450℃ and the melting time is 8 h; mechanical stirring (12 r / min, 7 h) is used; the forming temperature is 1340℃ and the forming time is 6 min; other preparation steps, parameters and testing processes are the same as in Example 1.

[0055] Example 4 The composition, molar fraction of each component, and physical properties of the resulting glass with low refractive index and high optical homogeneity are shown in Table 1.

[0056] In this embodiment, the preparation method of low refractive index high optical homogeneity light-absorbing glass is as follows: the melting temperature is 1370℃ and the melting time is 7 h; mechanical stirring (9 r / min, 5 h) is performed; the forming temperature is 1270℃ and the forming time is 9 min; other preparation steps, parameters and testing processes are the same as in Example 1.

[0057] Example 5 The composition, molar fraction of each component, and physical properties of the resulting glass with low refractive index and high optical homogeneity are shown in Table 1.

[0058] In this embodiment, the preparation method of low refractive index high optical homogeneity light-absorbing glass is as follows: the melting temperature is 1430℃ and the melting time is 9 h; mechanical stirring (12 r / min, 7 h) is performed; the forming temperature is 1320℃ and the forming time is 7 min; other preparation steps, parameters and testing processes are the same as in Example 1.

[0059] Example 6 The composition, molar fraction of each component, and physical properties of the resulting glass with low refractive index and high optical homogeneity are shown in Table 1.

[0060] In this embodiment, the preparation method of the low refractive index high optical homogeneity light-absorbing glass is as follows: the melting temperature is 1390℃ and the melting time is 8 h; mechanical stirring (10 r / min, 6 h) is performed, the forming temperature is 1290℃ and the forming time is 9 min. Other preparation steps, parameters and testing processes are the same as in Example 1.

[0061] Comparative Examples 1-7 The composition of the glass materials and the physical properties of the glass obtained in Comparative Examples 1-7 are shown in Table 2. The introduction of each component, the glass preparation steps, parameters and testing procedures are the same as in Example 1.

[0062] Table 1. Composition and physical properties of the shielding glass in Examples 1-6 of the present invention

[0063] Table 2. Composition and physical properties of light-absorbing glasses in Comparative Examples 1-6

[0064] Examples 1-6, by rationally adding appropriate components and controlling the proportions of each component in the raw materials, achieved better optical homogeneity of the glass while maintaining a low refractive index, without sacrificing the glass's light absorption performance. Table 1 shows that the optical properties of the low refractive index, high optical homogeneity, and light-absorbing glass prepared from the glass components of Examples 1-6 of this invention are as follows: In the range of 400-800 nm, the maximum transmittance is ≤1.0%, and the refractive index n... D ≤1.50, optical uniformity ≤5×10 -4 Its overall performance is superior to that of Comparative Examples 1-3 and the glass involved in the prior art.

[0065] Figure 1 This is a comparison chart of the transmittance of Example 1 and Comparative Example 1 in the range of 400-800nm.

[0066] As can be seen from the above, the low-refractive-index, high-optical-uniformity light-absorbing glass provided in Examples 1-6 of the present invention achieves better optical uniformity while maintaining a low refractive index, without sacrificing light absorption performance, and also possesses good chemical stability. This is because Examples 1-6 of the present invention added F, Cl, Fe, Cr, and V during the preparation of the low-refractive-index, high-optical-uniformity light-absorbing glass, and also maintained the content and proportion of some components in the raw materials, while setting appropriate melting and forming temperatures and stirring processes. Therefore, the low-refractive-index, high-optical-uniformity light-absorbing glass of the present invention has excellent optical performance and has great potential for application in fiber optic imaging elements with high imaging quality requirements.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A light-absorbing glass with low refractive index and high optical homogeneity, characterized in that, The molar count includes the following elements: The composition is as follows: Si 23-25 ​​parts, B 1-3 parts, Al 0.1-0.3 parts, Na 1.5-3 parts, K 0.1-1 parts, Ca 0.1-1 parts, Ti 0.1-1 parts, F 0.5-4 parts, Cl 0-1 parts, Fe 0.1-0.8 parts, Co 0.15-1 parts, Ni 3-4 parts, Mn 0.5-1 parts, Cr 0.05-0.25 parts, V 1-3 parts, Sb 0.3-0.6 parts; wherein the sum of the molar parts of F and Cl is 1.5-4.1 parts.

2. The low refractive index, high optical homogeneity light-absorbing glass as described in claim 1, characterized in that, The molar fractions of Si are 23.3-25 parts, 23.7-25 parts, 24.3-25 parts, or 24.7-25 parts; Alternatively, the molar amounts of B are 1-2.7 parts, 1-2.3 parts, 1-1.7 parts, 1-1.3 parts, or 1-1.2 parts; Alternatively, the molar amounts of Al are 0.1-0.27 parts, 0.1-0.23 parts, 0.1-0.17 parts, 0.1-0.13 parts, or 0.1-0.12 parts; Alternatively, the molar amounts of Na are 1.5-2.8 parts, 1.5-2.6 parts, 1.5-2.3 parts, 1.5-1.9 parts, 1.5-1.7 parts, or 1.5-1.6 parts; Alternatively, the molar amounts of K are 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.4 parts, 0.1-0.3 parts, or 0.1-0.2 parts; Alternatively, the molar amounts of Ca are 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.4 parts, 0.1-0.3 parts, or 0.1-0.2 parts; Alternatively, the molar amounts of Ti are 0.1-0.9 parts, 0.1-0.7 parts, 0.1-0.6 parts, 0.1-0.4 parts, 0.1-0.3 parts, or 0.1-0.2 parts; Alternatively, the molar amounts of F are 0.7-4 parts, 1-4 parts, 1.3-4 parts, 1.7-4 parts, 2-4 parts, 2.3-4 parts, 2.5-4 parts, 2.7-4 parts, 3-4 parts, 3.3-4 parts, 3.5-4 parts, or 3.7-4 parts; Alternatively, the molar amounts of Cl are 0-0.9 parts, 0-0.5 parts, 0-0.3 parts, 0-0.1 parts, 0.01-0.1 parts, 0.1-1 parts, 0.1-0.9 parts, 0.1-0.5 parts, or 0.1-0.3 parts; Alternatively, the molar fraction of Fe is 0.1-0.7 parts, 0.1-0.6 parts, 0.1-0.5 parts, 0.1-0.4 parts, 0.1-0.3 parts, or 0.1-0.2 parts; Alternatively, the molar amounts of Cr are 0.05-0.23 parts, 0.05-0.2 parts, 0.05-0.17 parts, 0.05-0.15 parts, 0.05-0.13 parts, 0.05-0.1 parts, 0.05-0.09 parts, or 0.05-0.07 parts; Alternatively, the molar amounts of V are 1-2.9 parts, 1-2.7 parts, 1-2.3 parts, 1-2 parts, 1-1.7 parts, 1-1.3 parts, 1-1.2 parts, or 1-1.1 parts; Alternatively, the molar amounts of Ni are 3-3.9 parts, 3-3.7 parts, 3-3.5 parts, 3-3.3 parts, 3-3.2 parts, or 3-3.1 parts; Alternatively, the molar amounts of Co are 0.15-0.9 parts, 0.15-0.7 parts, 0.15-0.5 parts, 0.15-0.3 parts, 0.15-0.2 parts, 0.15-0.17 parts, or 0.15-0.16 parts; Alternatively, the molar amounts of Mn are 0.5-0.9 parts, 0.5-0.8 parts, 0.5-0.7 parts, 0.5-0.6 parts, or 0.5-0.55 parts; Alternatively, the molar amounts of Sb are 0.3-0.55 parts, 0.3-0.5 parts, 0.3-0.4 parts, 0.3-0.37 parts, 0.3-0.35 parts, or 0.3-0.33 parts.

3. The low refractive index, high optical homogeneity light-absorbing glass as described in claim 1, characterized in that, The sum of the molar amounts of Si and B is not less than 25 parts; preferably, the sum of the molar amounts of Si and B is 25-27 parts, 25-27 parts, or 25.5-27.5 parts.

4. The low refractive index, high optical homogeneity light-absorbing glass as described in claim 1, characterized in that, The sum of the molar amounts of B, Na, K, and Ca is no more than 6 parts; preferably, the sum of the molar amounts of B, Na, K, and Ca is 2.7-6 parts, 2.7-5.1 parts, or 2.7-4 parts.

5. The low refractive index, high optical homogeneity light-absorbing glass as described in claim 1, characterized in that, The sum of the molar amounts of F and Cl is 1.7-4.1 parts, 2-4.1 parts, 2.1-4.1 parts, 3-4.1 parts, 3.1-4.1 parts, or 4-4.1 parts.

6. The low refractive index, high optical homogeneity light-absorbing glass as described in claim 1, characterized in that, The sum of the molar parts of Fe, Cr and V is 1.15-3.25 parts, 1.15-2.87 parts, 1.15-2.11 parts, 1.15-2.05 parts or 1.15-1.84 parts; Alternatively, the sum of the molar parts of Fe, Cr, V, Ni, Co, and Mn shall not be less than 4.8 parts; preferably, the sum of the molar parts is 4.8-8.05 parts, 4.8-7.55 parts, 4.8-7.25 parts, 4.8-6.71 parts, or 4.8-5.6 parts.

7. A method for preparing a low-refractive-index, high-optical-uniformity light-absorbing glass according to any one of claims 1 to 6, characterized in that, Includes the following steps: After mixing the components of the glass material in the specified proportions, add the clarifying agent in the specified proportions and mix well. The mixture was melted at 1360-1460℃ and stirred at a speed of 8-13 r / min for 4-8 h. Then, after high-temperature clarification and molding, glass products are obtained.

8. The preparation method according to claim 7, characterized in that, The melting time is 6-10 hours.

9. The preparation method according to claim 7, characterized in that, The molding temperature is 1250-1350 ℃, and the molding time is 5-10 min.

10. The application of the low refractive index, high optical homogeneity light-absorbing glass according to any one of claims 1 to 6 in the preparation of light-absorbing glass fibers.

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