Light absorption material glass for optical fiber image transmitting element and preparation method and application of light absorption material glass

Abstract

The invention relates to light absorption material glass for an optical fiber image transmitting element as well as a preparation method and application of the light absorption material glass, and the light absorption material glass for the optical fiber image transmitting element comprises the following components in molar percentage: 68.0 to 78.0 percent of SiO2, 1.0 to 9.0 percent of Al2O3, 2.0 to 10.0 percent of B2O3, 1.0 to 10.0 percent of Na2O, 3.0 to 10.0 percent of K2O, 0.1 to 1.5 percent of MgO, 0.1 to 3.0 percent of CaO, 0.1 to 0.5 percent of SrO, 0.1 to 1.5 percent of NiO, 0.1 to 1.2 percent of Co2O3, 0.1 to 0.8 percent of MnO2 and 0.1 to 0.8 percent of Nd2O3. According to the light absorption material glass for the optical fiber image transmission element, the problem of black and white display compatibility of the optical fiber image transmission element and a low-light image intensifier can be solved, and perfect compatibility with P45 fluorescent powder black and white display is realized.

Description

Technical Field

[0001] The present invention relates to the field of glass material manufacturing, and in particular to a light absorbing glass for an optical fiber image transmission element and a preparation method thereof. Background Art

[0002] With the continuous development of optical imaging technology, low-light-level image intensifiers have found widespread application in military, security, and field detection applications. Fiber optic image transmission components play a crucial role in low-light-level image intensifier systems, ensuring efficient transmission and precise imaging of optical images. Their performance directly impacts the quality of the resulting image.

[0003] Since the low-light-level image intensifier is used in a direct-view optical system, the luminous spectrum of the image intensifier phosphor screen, which is the image output end, should have good adaptability to the human eye. The role of the phosphor in the image intensifier is to convert the electronic image enhanced by the microchannel plate into an optical image. However, the peak wavelength of commonly used phosphors such as P20 and P43 is 540-550nm, emitting yellow-green light. Because green has a moderate absorption coefficient and reflection of light, the human nervous system, cerebral cortex and retinal tissue are more sensitive to green. Although this yellow-green wavelength of light is the most sensitive to the human eye, However, prolonged viewing can lead to irritation and visual fatigue in the human eye. The most comfortable viewing experience for the human eye is achieved with the black and white P45 phosphor, which offers strong visual contrast and sharper details. The wide spectrum of the P45 phosphor also reduces eye fatigue during focusing. However, the P45 phosphor exhibits low screen efficiency and a short afterglow. To achieve this high screen efficiency, a matching fiber optic imaging element must be selected. This requires the optical absorber glass material used in the optical fiber imaging element to be highly compatible with the P45 phosphor in order to produce a clear and stable image. However, existing optical absorber glass materials used in optical fiber imaging elements have significant deficiencies in compatibility with the P45 phosphor. On the one hand, the light absorption characteristics of conventional light-absorbing glass materials cannot precisely match the emission spectrum of the P45 phosphor. This results in color deviation, lack of clarity, reduced contrast, and haloing during image display, severely impacting the clarity and visual quality of low-light-level image intensifiers. On the other hand, the physical and chemical stability of light-absorbing glass materials and their poor compatibility with the core glass materials used to manufacture optical fiber imaging components limit the performance of the entire optical fiber imaging component. This is primarily due to the inability of existing light-absorbing materials to precisely control the optical signal to perfectly match the black-and-white display characteristics of the P45 phosphor.

[0004] Fiber optic imaging components include optical fiber panels, fiber optic image inverters, fiber optic light cones, etc. The image transmission mechanism of fiber optic imaging components is realized by the total internal reflection principle of optical fibers. The optical fibers that constitute the fiber optic imaging components are made of a low-refractive-index skin glass tube, a high-refractive-index core glass rod, and light-absorbing glass fibers, which are prepared by hot melting and pressing through a rod-tube combination and vacuum drawing process. Because the optical fibers are completely tightly fused together by the skin glass, the adjacent optical fibers are close to each other, resulting in crosstalk between adjacent optical fibers. For example, due to uneven temperature fields or uneven drawing forces during the preparation process, the uneven wall thickness of the skin glass tube may cause the input light to penetrate the skin during total internal reflection, resulting in light leakage. Alternatively, the contact interface between the glass or skin glass of the optical fiber may have defects or contaminants, which destroys the total internal reflection conditions of the light, causing light scattering. These scattered lights enter adjacent optical fibers and also cause crosstalk. Crosstalk is an important factor directly affecting the imaging quality of the fiber optic imaging component, such as contrast and clarity. To address issues such as crosstalk and light leakage between optical fibers in fiber-optic image sensors, light-absorbing glass filaments are typically inserted into the gaps between adjacent optical fibers to absorb stray light and reduce crosstalk. This approach effectively eliminates stray light. By drawing the absorber glass into filaments and inserting them into the gaps between aligned optical fibers, the absorber glass absorbs crosstalk and light leakage. However, this approach does not completely isolate the optical fiber. The key issue lies in the transmittance of the absorber glass. The absorber glass absorbs stray light that penetrates the fiber cortex, achieving optical insulation and improving image contrast. Absorber glass is an important type of optical glass, primarily designed to absorb interfering stray light and enhance the clarity and contrast of fiber-optic image sensors. With the widespread application of black-and-white image intensifiers, the requirements for fiber-optic image sensors are becoming increasingly stringent. Consequently, the absorber glass material must be able to precisely control the optical signal to match the display characteristics of the P45 phosphor used in black-and-white displays.

[0005] Therefore, developing a light-absorbing glass material for optical fiber imaging elements that is perfectly compatible with the black-and-white display of P45 phosphor can solve the compatibility problem between optical fiber imaging elements and the black-and-white display of low-light-level image intensifiers and improve the quality of low-light-level imaging, which has important practical significance and application value. Summary of the Invention

[0006] In response to the above-mentioned problems in the prior art, the present invention provides a light-absorbing glass for optical fiber imaging elements. The light-absorbing glass can solve the compatibility problem between optical fiber imaging elements and low-light-level image intensifier black and white displays, and achieve perfect compatibility with P45 phosphor black and white displays.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A light absorbing glass composition for optical fiber image transmission elements comprises the following components in molar percentages:

[0009]

[0010] The present invention also provides a preferred technical solution, a composition of light absorbing glass for optical fiber imaging elements, comprising the following components in molar percentages:

[0011]

[0012] The present invention also provides a more preferred technical solution, a composition of light absorbing glass for optical fiber imaging elements, comprising the following components in molar percentages:

[0013]

[0014]

[0015] The total content of the colorants NiO, Co2O3, MnO2 and Nd2O3 in the light absorbing glass is no more than 2.0 mol%. The total content of the light absorbing colorants of the present invention does not exceed 2.0 mol%, which can effectively improve the transmittance in the ultraviolet band and reduce the transmittance in the visible light band.

[0016] The present invention further provides a method for preparing a light absorbing glass for an optical fiber imaging element using the composition, comprising the following steps:

[0017] (1) Raw material preparation: the raw materials are mixed uniformly according to proportion to obtain a raw material mixture;

[0018] (2) Glass melting: Add the raw material mixture into a crucible and melt it at a temperature of 1500-1560°C for 4-8 hours. After the raw material mixture is melted, stir it 2-3 times, with the rotation speed of each stirring being 150-180 rpm and the stirring time being 0.5-1 hour, to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. Then, discharge the material at a temperature of 1420-1480°C and cast it into the required glass in a mold to form a preliminary glass structure. After the glass is cooled and solidified, annealing treatment is performed to obtain a light absorbing material glass blank for optical fiber imaging elements; the annealing temperature is 560-600°C and the annealing time is 24-36 hours.

[0019] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0020] The present invention further provides a light-absorbing glass for an optical fiber image transmission element, which is prepared according to the preparation method. The light-absorbing glass for an optical fiber image transmission element has a spectral transmittance of >70% in the ultraviolet wavelength range of 300-400 nm and a spectral transmittance of <2.0% in the visible light wavelength range of 580-670 nm at a thickness of 0.30±0.01 mm; a thermal expansion coefficient of (77±2)×10 －7 / ℃; no crystallization occurs when kept at 850℃ for 6 hours.

[0021] The present invention also provides an application of light absorbing material glass for optical fiber image transmission elements in a low-light-level image intensifier.

[0022] The present invention provides a light-absorbing glass material for an optical fiber imaging element, which is suitable for use as a light-absorbing glass material for glass fibers when preparing optical fiber imaging elements. The optical fiber imaging elements include an optical fiber panel, an optical fiber image inverter, an optical fiber light cone, etc. The optical fiber imaging element is used in a low-light-level image intensifier.

[0023] In the light-absorbing glass used in optical fiber image transmission elements of the present invention, SiO2 forms the main component of the glass skeleton and plays a major role in the glass framework. It also enhances chemical resistance. The molar percentage of SiO2 is 68-78 mol%, preferably 70-76 mol%. A SiO2 content below 68.0 mol% makes it difficult to achieve a thermal expansion coefficient similar to that of the veneer glass and reduces the glass's chemical resistance. A SiO2 content above 78.0 mol% increases the glass's high-temperature viscosity, resulting in excessively high melting temperatures.

[0024] B2O3 is a glass-forming oxide and a component of the glass skeleton. It is also a flux that reduces the viscosity of the glass. Boron oxide triangles [BO3] and boron oxide tetrahedrons [BO4] are structural components. Boron may exist in the form of triangles [BO3] or boron oxide tetrahedrons [BO4] under different conditions. Under high-temperature melting conditions, it is generally difficult to form boron oxide tetrahedrons and can only exist in the form of trihedrons. However, at low temperatures, under certain conditions, B 3+B2O3 tends to capture free oxygen to form tetrahedra, compacting the structure and increasing the low-temperature viscosity of the glass. However, due to its characteristic of decreasing glass viscosity at high temperatures and increasing it at low temperatures, its content range is relatively limited. However, an appropriate amount of B2O3 can effectively remove bubbles from the molten glass during the glass melting process, significantly improving the optical uniformity of the melted glass. This characteristic is crucial for ensuring stable transmission of optical signals within the material, avoiding light scattering and signal distortion caused by internal defects, thereby maintaining high image quality compatible with black and white displays. The molar percentage of B2O3 is 2.0-10 mol%, preferably 3.5-8.0 mol%. A B2O3 content below 2.0 mol% will not act as a solubilizing agent and will reduce the chemical stability of the glass. A B2O3 content greater than 10.0 mol% will increase the glass's tendency to phase separate.

[0025] Al2O3 is an intermediate oxide of glass. 3+ There are two coordination states: located in tetrahedra or octahedra. When there is sufficient oxygen in the glass, aluminum oxide tetrahedra [AlO4] form, forming a continuous network with silicon oxide tetrahedra. When there is insufficient oxygen in the glass, aluminum oxide octahedra [AlO6] form, which are external to the network and located within the cavities of the silicon oxide network. Therefore, within a certain content range, it can form the main component of the glass network with SiO2. The molar percentage of Al2O3 is 1.0-9.0 mol%, preferably 1.5-8.0 mol%. Al2O3 content below 1.0 mol% increases the thermal expansion coefficient of the glass. Al2O3 content above 9.0 mol% significantly increases the high-temperature viscosity of the glass, causing the glass to melt at a higher temperature and reducing the crystallization performance of the glass.

[0026] Na2O is an oxide external to the glass structure network. It also acts as a flux, significantly lowering the glass's melting temperature and promoting uniform mixing of components during the glass melting process, thereby improving production efficiency. Na2O can also fine-tune the glass's optical properties, further optimizing the compatibility of the light-absorbing glass material with other glass materials in the fiber optic imaging element, ensuring performance matching across the entire fiber optic imaging element. The molar percentage of Na2O is 1.0-10 mol%, preferably 3.5-8 mol%. A Na2O content greater than 10 mol% increases the glass's thermal expansion coefficient and increases its tendency to crystallize.

[0027] K2O is an oxide outside the glass structure network. The molar percentage of K2O is 3.0-10 mol%, preferably 4.5-9 mol%. When the K2O content is greater than 10 mol%, the thermal expansion coefficient of the glass increases and the crystallization tendency of the glass increases.

[0028] MgO is an oxide outside the glass structure network and is used to adjust the crystallization temperature of the glass. The molar percentage of MgO is 0.1-1.5 mol%, preferably 0.1-0.9 mol%. When the MgO content is greater than 1.5 mol%, the thermal expansion coefficient and crystallization tendency of the glass will increase.

[0029] CaO is an oxide outside the glass structure network, and the molar percentage of CaO is 0.1-3.0 mol%, preferably 0.5-2.5 mol%. If the CaO content is greater than 3.0 mol%, the chemical resistance of the glass will be reduced.

[0030] SrO is an oxide outside the glass structure network and is used to adjust the crystallization temperature of the glass. The molar percentage of SrO is 0.1-0.5 mol%, preferably 0.1-0.2 mol%. If the SrO content is greater than 0.5 mol%, the chemical stability of the glass will be reduced.

[0031] NiO is a light-absorbing colorant in light-absorbing glass. It can significantly enhance the glass's ability to absorb light of a specific wavelength. Within a range that matches the commonly used display band (300-400nm) for black and white displays, it can effectively increase light transmittance and reduce light reflection and scattering, thereby significantly improving image contrast and making the outlines of objects in the image more clearly discernible. The molar percentage of NiO is 0.1-1.5 mol.%, preferably 0.2-0.8 mol.%. Ni 2+ It has a good absorption effect in the visible light region. A NiO content greater than 1.5 mol% will reduce the transmittance of the glass in the ultraviolet band and increase the crystallization tendency of the glass.

[0032] Co2O3 is a light-absorbing colorant in absorbent glass, playing a significant role in enhancing ultraviolet transmittance and visible light absorption. Co2O3 is a key light-absorbing colorant, capable of precisely regulating the glass's absorption of different wavelengths. By precisely controlling its content, the absorption spectrum of the absorbent glass can be aligned with the optimal response spectrum for black-and-white displays, enabling precise light absorption control. This control mechanism ensures that the color reproduction and grayscale representation of images on black-and-white displays are consistent with human visual habits, significantly improving viewing comfort and reducing visual fatigue caused by prolonged viewing. Co2O3 synergistically with NiO enhances ultraviolet transmittance and optimizes visible light absorption efficiency, resulting in images from the fabricated optical fiber imaging element displayed on a black-and-white display with greater detail and improved image clarity and legibility. The molar percentage of Co2O3 is 0.1-1.2 mol%, preferably 0.3-0.9 mol%. Co2O3 combines with other coloring ions to form a stable form within the glass, thereby enhancing the stability of the light-absorbing coloring properties. When the content of Co2O3 is greater than 1.2 mol%, the transmittance of the glass in the ultraviolet band will be reduced and the crystallization tendency of the glass will be increased.

[0033] MnO2 is a light absorbing colorant in light absorbing glass, and Mn 4+ This material exhibits stable light absorption and filtering properties in the visible light wavelength range, creating a stable coloration within the glass. MnO2 solidifies the coloration, further stabilizing the light absorption, coloration, and light transmission properties. The molar percentage of MnO2 is 0.1-0.8 mol%, preferably 0.1-0.5 mol%. A MnO2 content greater than 0.8 mol% reduces the glass's transmittance in the ultraviolet range and increases its tendency to crystallize.

[0034] Nd2O3 is a light absorbing colorant for light absorbing glass. Rare earth ion Nd 3+ The spectral characteristics and light absorption capacity of Nd in glass are very stable. 3+ There are strong absorption peaks at 548nm, 568nm, and 588nm. A small amount of Nd 3+ It creates a composite absorption effect in glass, eliminating a distinct transmission peak in the visible light region. The molar percentage of Nd2O3 is 0.1-0.8 mol%, preferably 0.2-0.8 mol%. A Nd2O3 content greater than 0.8 mol% reduces the glass's transmittance in the ultraviolet range and increases the glass's tendency to crystallize.

[0035] Compared with the prior art, the light absorbing glass for optical fiber image transmission element of the present invention has the following beneficial effects:

[0036] (1) The light-absorbing glass of the present invention has good light transmittance. At a thickness of 0.3±0.01 mm, the spectral transmittance is greater than 70% in the wavelength range of the ultraviolet band of 300-400 nm, which is highly matched with the optimal response spectrum of black and white display. It can accurately control the light signal to ensure that the image output by the optical fiber imaging element is perfectly compatible with the black and white display, avoiding problems such as image distortion, reflection, insufficient clarity, decreased contrast, and halo, and providing users with a stable and clear observation experience.

[0037] (2) The light-absorbing glass of the present invention can efficiently absorb light in the wavelength range of 580-670 nm. At a glass thickness of 0.3±0.01 mm, the spectral transmittance of the glass in the wavelength range of 580-670 nm is less than 2.0%, effectively reducing reflection, scattering and fluorescence interference, and greatly improving the contrast, clarity and color accuracy of the image.

[0038] (3) The light absorbing glass of the present invention has a thermal expansion coefficient and viscosity characteristics similar to those of the skin glass in the optical fiber imaging element. The thermal performance meets the requirements of the optical fiber imaging element preparation process and has good matching with the core glass material. The thermal expansion coefficient at 30-300°C is (77±2)×10 －7 / ℃.

[0039] (4) The optical fiber image transmission element prepared by the present invention has the advantages of no stones or bubbles inside the glass after melting. It does not produce crystallization when kept at 850°C for 6 hours, and has good anti-crystallization performance.

[0040] (5) The light-absorbing glass of the present invention is applied to optical fiber image transmission elements. As light-absorbing glass, it can effectively improve the imaging contrast and clarity of optical fiber image transmission elements. By precisely adjusting the degree of absorption of light of different wavelengths by the light-absorbing glass material, the color reproduction and grayscale performance of the image on the black and white display are consistent with the visual habits of the human eye, effectively reducing visual fatigue during viewing, improving the viewing comfort of the human eye, and helping users maintain a good visual state during long-term observation.

[0041] (6) The light-absorbing glass of the present invention has excellent physical and chemical stability, maintaining stable performance under various environmental conditions and being unaffected by factors such as temperature and humidity. This ensures that the compatibility and synergistic performance of the light-absorbing glass with the P45 phosphor and other materials of the optical fiber imaging element will not deteriorate over time, thus ensuring the long-term stable operation of the entire system and reducing maintenance costs.

[0042] (7) The preparation method of the light-absorbing glass provided by the present invention is simple. The preparation method adopts common raw materials and mature glass preparation technology. The operation process is concise. The parameters of each step are clear and easy to control. The cost is low. The total content of the light-absorbing colorant used does not exceed 2.0 mol.%, which is suitable for large-scale industrial production. It can ensure the consistency and reliability of product quality, provide solid technical support for the widespread application of the light-absorbing glass, and is conducive to promoting the industrialization development of related optical imaging products.

[0043] (8) The low-light-level image intensifier made of this light-absorbing glass presents images with rich details, clear outlines, and accurate color reproduction in the relevant display system, which effectively improves the imaging quality of the low-light-level image intensifier system used with P45 phosphor, and meets the needs of military, security, scientific research and other fields that have strict requirements for high-precision imaging.

[0044] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The transmittance curve of the light-absorbing glass used in an optical fiber imaging element provided in an embodiment of the present invention at 300-900nm;

[0046] Figure 2 The transmittance curve of the light-absorbing glass used in an optical fiber imaging element provided in an embodiment of the present invention at 300-400nm;

[0047] Figure 3 This is a transmittance curve of a light-absorbing glass material used in an optical fiber imaging element provided by an embodiment of the present invention in the wavelength range of 580-670nm. DETAILED DESCRIPTION

[0048] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with preferred embodiments. However, this description is not intended to limit the present invention. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0049] See also Figure 1 、 Figure 2 and Figure 3, is the transmittance curve of the light-absorbing glass. It can be seen from the figure that at a thickness of 0.3±0.01mm, it has strong light absorption ability and filtering effect in the wavelength range of 580-670nm visible light band, and the spectral transmittance is less than 2.0%. It can be seen that the light absorption effect on visible light is very obvious; and at a thickness of 0.3±0.01mm, it has a higher transmittance in the wavelength range of 300-400nm ultraviolet band, and the spectral transmittance is greater than 70%. It can be seen that the light transmittance effect on the ultraviolet band is very obvious.

[0050] Herein, all "mol. %" are based on the total molar amount of the final glass composition. The glass chemical composition (mol. %) of the examples is detailed in Table 1.

[0051] The parameters, measuring methods and instruments for the light absorbing glass of the present invention are as follows:

[0052] (1) The transmittance of the light absorbing glass is measured using a transmittance tester;

[0053] (2) Average linear thermal expansion coefficient α at 30-300℃ 30 / 300 [×10 -7 / ℃] was measured using a horizontal dilatometer and the method specified in GB / T 16920-2015.

[0054] Table 1 Chemical composition (mol.%) and properties of light absorbing glass examples

[0055]

[0056] Example 1

[0057] Select raw materials according to the glass composition of Example 1 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the light absorbing material glass according to the following steps:

[0058] (1) Raw material preparation: weigh raw materials quartz sand, boric acid, aluminum oxide, sodium carbonate, potassium carbonate, basic magnesium carbonate, calcium carbonate, strontium carbonate, nickel oxide, cobalt oxide, manganese dioxide and neodymium oxide according to a molar ratio, mix them uniformly, and obtain a raw material mixture;

[0059] (2) Glass melting: The raw material mixture is added to a crucible and melted at 1500°C for 8 hours. After the raw material mixture is melted, it is stirred twice, each stirring speed is 150 rpm, and the stirring time is 1 hour to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. The material is then discharged at 1420°C and cast into the required glass in a mold to form a preliminary glass structure. After the glass cools and solidifies, it is annealed at 600°C for 24 hours. Thus, a light absorbing material glass blank for optical fiber imaging elements is obtained.

[0060] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0061] The glass sheet (thickness 0.30±0.01 mm) made from the raw materials of Example 1 was tested to have a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670 nm and a spectral transmittance of greater than 70% in the ultraviolet wavelength range of 300-400 nm. No crystallization occurred after being kept at 850° C. for 6 hours.

[0062] Example 2

[0063] Select raw materials according to the glass composition of Example 2 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the light absorbing material glass according to the following steps:

[0064] (1) Raw material preparation: weigh raw materials quartz sand, boric acid, aluminum oxide, sodium carbonate, potassium carbonate, basic magnesium carbonate, calcium carbonate, strontium carbonate, nickel oxide, cobalt oxide, manganese dioxide and neodymium oxide according to a molar ratio, mix them uniformly, and obtain a raw material mixture;

[0065] (2) Glass melting: The raw material mixture is added to a crucible and melted at 1560°C for 4 hours. After the raw material mixture is melted, it is stirred three times, each stirring speed is 180 rpm, and the stirring time is 0.5 hours to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. The material is then discharged at 1480°C and cast into the required glass in a mold to form a preliminary glass structure. After the glass is cooled and solidified, it is annealed at 560°C for 36 hours. Thus, a light absorbing material glass blank for optical fiber imaging elements is obtained.

[0066] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0067] The glass sheet (thickness 0.30±0.01 mm) made from the raw materials of Example 2 was tested to have a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670 nm and a spectral transmittance of greater than 70% in the ultraviolet wavelength range of 300-400 nm. No crystallization occurred after being kept at 850° C. for 6 hours.

[0068] Example 3

[0069] Select raw materials according to the glass composition of Example 3 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the light absorbing material glass according to the following steps:

[0070] (1) Raw material preparation: weigh raw materials quartz sand, boric acid, aluminum oxide, sodium carbonate, potassium carbonate, basic magnesium carbonate, calcium carbonate, strontium carbonate, nickel oxide, cobalt oxide, manganese dioxide and neodymium oxide according to a molar ratio, mix them uniformly, and obtain a raw material mixture;

[0071] (2) Glass melting: The raw material mixture is added to a crucible and melted at 1550°C for 6 hours. After the raw material mixture is melted, it is stirred twice, each stirring speed is 160 rpm, and the stirring time is 0.5 hours to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. The material is then discharged at 1430°C and cast into the required glass in a mold to form a preliminary glass structure. After the glass cools and solidifies, it is annealed at 580°C for 28 hours. Thus, a light absorbing material glass blank for optical fiber imaging elements is obtained.

[0072] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0073] The glass sheet (thickness 0.30±0.01 mm) made from the raw materials of Example 3 was tested to have a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670 nm and a spectral transmittance of greater than 70% in the ultraviolet wavelength range of 300-400 nm. No crystallization occurred after being kept at 850° C. for 6 hours.

[0074] Example 4

[0075] Select raw materials according to the glass composition of Example 4 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the light absorbing material glass according to the following steps:

[0076] (1) Raw material preparation: weigh raw materials quartz sand, boric acid, aluminum oxide, sodium carbonate, potassium carbonate, basic magnesium carbonate, calcium carbonate, strontium carbonate, nickel oxide, cobalt oxide, manganese dioxide and neodymium oxide according to a molar ratio, mix them uniformly, and obtain a raw material mixture;

[0077] (2) Glass melting: The raw material mixture is added to a crucible and melted at 1540°C for 7 hours. After the raw material mixture is melted, it is stirred three times, each stirring speed is 150 rpm, and the stirring time is 1 hour to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. The material is then discharged at 1450°C and cast into the required glass in a mold to form a preliminary glass structure. After the glass cools and solidifies, it is annealed at 570°C for 26 hours. Thus, a light absorbing material glass blank for optical fiber imaging elements is obtained.

[0078] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0079] The glass sheet (thickness 0.30±0.01 mm) made from the raw materials of Example 4 was tested to have a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670 nm and a spectral transmittance of greater than 70% in the ultraviolet wavelength range of 300-400 nm. No crystallization occurred after being kept at 850° C. for 6 hours.

[0080] Example 5

[0081] Select raw materials according to the glass composition of Example 5 in Table 1 so that the ingredients meet the glass chemical composition of Table 1, and then prepare the light absorbing material glass according to the following steps:

[0082] (1) Raw material preparation: weigh raw materials quartz sand, boric acid, aluminum oxide, sodium carbonate, potassium carbonate, basic magnesium carbonate, calcium carbonate, strontium carbonate, nickel oxide, cobalt oxide, manganese dioxide and neodymium oxide according to a molar ratio, mix them uniformly, and obtain a raw material mixture;

[0083] (2) Glass melting: The raw material mixture is added to a crucible and melted at 1530°C for 8 hours. After the raw material mixture is melted, it is stirred twice, each stirring speed is 170 rpm, and the stirring time is 0.5 hours to ensure that all components are fully and evenly melted until a clear and homogenized glass liquid is formed. The material is then discharged at 1460°C and cast into the required glass in a mold to form a preliminary glass structure. After the glass cools and solidifies, it is annealed at 590°C for 27 hours. Thus, a light absorbing material glass blank for optical fiber imaging elements is obtained.

[0084] (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

[0085] The glass sheet (thickness 0.30±0.01 mm) made from the raw materials of Example 5 was tested to have a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670 nm and a spectral transmittance of greater than 70% in the ultraviolet wavelength range of 300-400 nm. No crystallization occurred after being kept at 850° C. for 6 hours.

[0086] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A composition of light absorbing glass for optical fiber imaging element, characterized in that: The following components are included in mole percentage:

2. The composition according to claim 1, characterized in that The following components are included in mole percentage:

3. The composition according to claim 2, characterized in that The following components are included in mole percentage:

4. The composition according to any one of claims 1 to 3, characterized in that The total content of the colorants NiO, Co2O3, MnO2 and Nd2O3 in the light absorbing glass is not greater than 2.0 mol%.

5. A method for preparing a light absorbing glass for an optical fiber imaging element using the composition according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Raw material preparation: the raw materials are mixed uniformly according to proportion to obtain a raw material mixture; (2) Glass melting: adding the raw material mixture into a crucible and melting it at a first preset temperature. After the raw material mixture is melted, stirring is performed to make the components fully and evenly melt until a clear and homogenized glass liquid is formed. Then, the raw material mixture is discharged at a second preset temperature and cast into the required glass in a mold to form a preliminary glass structure. After the glass is cooled and solidified, annealing is performed to obtain a light absorbing material glass blank for an optical fiber imaging element. (3) Blank processing: The annealed and cooled light-absorbing glass blank is cut, ground, and polished to ensure that the dimensional accuracy and surface finish of the glass meet the assembly requirements for the preparation of optical fiber imaging components and the optical matching requirements with the P45 phosphor.

6. The preparation method according to claim 5, characterized in that The first preset temperature is 1500-1560° C., and the melting time is 4-8 hours.

7. The preparation method according to claim 6, characterized in that The stirring is performed 2-3 times, the rotation speed of each stirring is 150-180 rpm, and the stirring time is 0.5-1 hour.

8. The preparation method according to claim 7, characterized in that The second preset temperature is 1420-1480° C.; the annealing temperature is 560-600° C., and the annealing time is 24-36 hours.

9. A light absorbing glass for optical fiber image transmission element, characterized in that: Prepared according to the preparation method of any one of claims 5 to 8; the light absorbing glass has a spectral transmittance of more than 70% in the ultraviolet wavelength range of 300-400nm and a spectral transmittance of less than 2.0% in the visible light wavelength range of 580-670nm at a thickness of 0.30±0.01mm; and a thermal expansion coefficient of (77±2)×10 －7 / ℃; no crystallization occurs when kept at 850℃ for 6 hours.

10. Use of the light absorbing glass for optical fiber image transmission element according to claim 9 in a low-light-level image intensifier.

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