Chalcogenide optical glass, preparation method thereof and optical element

Abstract

The present invention provides a chalcogenide optical glass and a preparation method thereof and an optical element. In terms of atomic percentage, the chalcogenide optical glass comprises the following components: Ge: 20At% to 35At%; Sb: 0At% to 16At%; Ga: 0At% to 8At%; Se: 55At% to 65At%; Fe: 0.05At% to 0.25At%; Pr: 0At% to 0.25At%. The chalcogenide optical glass of the present invention has a lower transmittance in the band before 3μm and has a good transmittance in the band of 7 to 14μm, so as to alleviate the problem of the current difficulty in coating the chalcogenide optical glass. The thickness of the low-transmittance film required for coating the chalcogenide optical glass of the present invention is low, so as to reduce the coating cost of the chalcogenide optical glass.

Description

Technical Field

[0001] The present invention relates to a chalcogenide optical glass and a preparation method and an optical element, in particular to a 3μm low-transmittance chalcogenide optical glass and a preparation method and an optical element, belonging to the technical field of infrared glass preparation. Background Art

[0002] With the development of infrared detection technology and the emergence of various infrared optical systems, more requirements are placed on the performance of infrared materials. As an infrared optical material, chalcogenide optical glass has attracted much attention due to its unique performance advantages: 1) wide wave transmission range: including three important infrared bands of 1-3μm, 3-5μm and 8-12μm; 2) high refractive index, reducing the volume of the imaging system; 3) can be formed by compression molding, and compared with traditional infrared materials, it has high processing efficiency and low processing cost.

[0003] For some infrared imaging systems that have specific requirements for the working band, it is usually necessary to coat the surface of chalcogenide optical glass with multiple layers of anti-reflection coatings and cut-off coatings to reduce interference from other bands and improve its imaging quality. However, chalcogenide optical glass has low Tg and hardness, and a large thermal expansion coefficient. Usually, due to the mismatch between the thermal expansion coefficients of chalcogenide optical glass and each film layer, film peeling or cracking will occur. Especially with the increasing demand for aspherical lenses today, the difficulty of coating chalcogenide optical glass has increased, so there are higher requirements for the performance of chalcogenide optical glass.

[0004] Therefore, it becomes a technical problem to be solved urgently to study a chalcogenide optical glass that reduces the film thickness required for coating of traditional chalcogenide optical glass and reduces the difficulty of coating of chalcogenide optical glass. Summary of the invention

[0005] Problem that the invention aims to solve

[0006] In view of the technical problems existing in the prior art, the present invention provides a chalcogenide optical glass. The chalcogenide optical glass of the present invention has a low transmittance in the band before 3 μm and a good transmittance in the band of 7 to 14 μm, so as to alleviate the current problem of difficulty in coating chalcogenide optical glass and reduce the coating cost of chalcogenide optical glass.

[0007] The present invention also provides a method for preparing the chalcogenide optical glass. The method is simple and easy to implement, the raw materials are easy to obtain, and the method is suitable for mass production.

[0008] Solutions for solving problems

[0009] The present invention provides a chalcogenide optical glass, which comprises the following components in atomic percentage:

[0010] Ge: 20At% to 35At%, preferably 22At% to 34At%;

[0011] Sb: 0At% to 16At%, preferably 0At% to 15.75At%;

[0012] Ga: 0At% to 8At%, preferably 0At% to 7At%;

[0013] Se: 55At% to 65At%, preferably 58At% to 63At%;

[0014] Fe: 0.05At% to 0.25At%, preferably 0.08At% to 0.2At%;

[0015] Pr: 0At% to 0.25At%, preferably 0At% to 0.2At%.

[0016] According to the chalcogenide optical glass of the present invention, the content of the sum of the atomic percentage of Sb and the atomic percentage of Ga (Sb+Ga) is 1-18At%.

[0017] According to the chalcogenide optical glass of the present invention, the content of the sum of the atomic percentage of Fe and the atomic percentage of Pr (Fe+Pr) is 0.05-0.35At%.

[0018] According to the chalcogenide optical glass of the present invention, the transition temperature of the chalcogenide optical glass is 270-300° C.; and / or the transmittance of the chalcogenide optical glass in the 3 μm band is lower than 15%.

[0019] According to the chalcogenide optical glass of the present invention, the refractive index of the chalcogenide optical glass at a wavelength of 10.6 μm is 2.6 to 2.8; and / or the density of the chalcogenide optical glass is 4.5 to 4.7 g / cm 3 .

[0020] The present invention also provides a method for preparing the chalcogenide optical glass according to the present invention, which comprises weighing each component according to a proportion, mixing the components uniformly, melting the components, and obtaining the optical glass after quenching and annealing.

[0021] According to the preparation method of the present invention, the preparation method comprises the following steps:

[0022] Weighing and mixing the components in proportion, putting them into a quartz ampoule, and sealing the quartz ampoule;

[0023] The sealed quartz ampoule is melted to obtain a melted product;

[0024] The smelted product is subjected to quenching treatment to obtain a glass product;

[0025] The glass product is subjected to annealing treatment to obtain chalcogenide optical glass.

[0026] According to the preparation method of the present invention, the vacuum degree in the quartz ampoule is not higher than 5×10 - 5 mbar.

[0027] According to the preparation method of the present invention, the preparation method has at least one of the following conditions:

[0028] The smelting temperature is not higher than 1200°C;

[0029] The temperature of the quenching treatment is not higher than 100°C;

[0030] The temperature of the annealing treatment is 250-280° C., and the speed of the annealing treatment is -3--5° C. / h.

[0031] The present invention also provides an optical element, comprising the optical glass according to the present invention.

[0032] Effects of the Invention

[0033] The chalcogenide optical glass of the present invention has a lower transmittance in the band before 3 μm and has a good transmittance in the band of 7 to 14 μm, so as to alleviate the problem of the difficulty in coating the current chalcogenide optical glass. The thickness of the low-transmittance film required for coating the chalcogenide optical glass of the present invention is low, so the coating cost of the chalcogenide optical glass is reduced.

[0034] The preparation method of the chalcogenide optical glass of the present invention is simple and easy to implement, the raw materials are easy to obtain, and it is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The transmittance curves of the chalcogenide optical glass materials of Examples 1-4 of the present invention are shown;

[0036] Figure 2 The transmittance curves of the chalcogenide optical glass materials of Comparative Examples 1-2 are shown. DETAILED DESCRIPTION

[0037] Various exemplary embodiments, features and aspects of the present invention will be described in detail below. The word "exemplary" used here means "used as an example, embodiment or illustrative". Any embodiment described here as "exemplary" is not necessarily interpreted as being superior or better than other embodiments.

[0038] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In other examples, methods, means, equipment and steps well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0039] The present invention first provides a chalcogenide optical glass, which comprises the following components in atomic percentage:

[0040] Ge: 20At% to 35At%, preferably 22At% to 34At%;

[0041] Sb: 0At% to 16At%, preferably 0At% to 15.75At%;

[0042] Ga: 0At% to 8At%, preferably 0At% to 7At%;

[0043] Se: 55At% to 65At%, preferably 58At% to 63At%;

[0044] Fe: 0.05At% to 0.25At%, preferably 0.08At% to 0.2At%;

[0045] Pr: 0At% to 0.25At%, preferably 0At% to 0.2At%.

[0046] The chalcogenide optical glass of the present invention uses Ge, Se and optionally Sb and Ga as the glass matrix, and the four elements are all good glass formers, constituting the matrix of the chalcogenide optical glass of the present invention. In addition, Ge-Sb-Ga-Se glass has excellent ion solubility, and Fe and optionally Pr elements are added on this basis to achieve the effect of reducing the transmittance in the 3μm band.

[0047] Ge element has high strength and good infrared transmittance, and is a good infrared material. Adding Ge to chalcogenide optical glass can improve the strength and glass transition temperature of the glass. In the present invention, if the Ge content is lower than 20At% or higher than 35At%, the glass is very easy to crystallize, and it makes the glass difficult to melt. Therefore, in the present invention, the Ge content is 20At% to 35At%, preferably 22At% to 34At%, for example: 21At%, 23At%, 25At%, 27At%, 29At%, 31At%, 33At%, etc.

[0048] Se element is a good ligand of glass and one of the basic components of chalcogenide optical glass. Se and Ge can form a strong Ge-Se bond, giving the glass a higher transition temperature and strength. In the present invention, if the Se content is lower than 55At%, the glass is very easy to crystallize. If the Se content is higher than 65At%, the transition temperature and strength of the glass will decrease sharply, and the glass forming performance of the glass will decrease. Therefore, in the present invention, the Se content is 55At% to 65At%, preferably 58At% to 63At%, for example: 56At%, 57At%, 59At%, 60At%, 61At%, 62At%, 64At%, etc.

[0049] Both Sb and Ga are good ligands for glass. Adding Sb or Ga to Ge-Se glass can improve the ion solubility of glass. The present invention achieves the purpose of improving the ion solubility of glass by adjusting the content and ratio of Sb and Ga. In terms of atomic percentage, if the content of Sb is higher than 16At%, the physical properties such as the strength of the glass will be sharply reduced; in the present invention, the content of Sb is 0At% to 16At%, preferably 0At% to 15.75At%, such as: 1At%, 3At%, 5At%, 7At%, 9At%, 11At%, 13At%, etc.; if the content of Ga is higher than 8At%, the glass-forming properties of the glass will be reduced, and the glass is very easy to crystallize. In the present invention, the content of Ga is 0At% to 8At%, preferably 0At% to 7At%, such as: 1At%, 2At%, 3At%, 4At%, 5At%, 6At%, etc.

[0050] The sum of the atomic percentage of Sb and the atomic percentage of Ga, Sb+Ga, will affect the glass-forming properties of the glass and improve the solubility of glass ions. If the content of Sb+Ga is too high, the glass-forming properties of the glass will be reduced and the glass will be very prone to crystallization; if the content of Sb+Ga is too low, it will lead to the inability to dissolve Fe or Pr and crystallization and devitrification. Therefore, in the present invention, the content of Sb+Ga, the sum of the atomic percentage of Sb and the atomic percentage of Ga, is 1-18At%; for example: 1At%, 3At%, 5At%, 7At%, 9At%, 11At%, 13At%, 15%, 17%, etc.

[0051] The inventors have found that the addition of Fe element to sulfide optical glass will shift the short-wave transmittance of Se-based sulfide optical glass toward the long-wave direction. The present invention reduces the short-wave transmittance of glass by adding Fe element. When the Fe content is lower than 0.05At%, the effect of reducing the short-wave transmittance cannot be achieved. When the Fe content is higher than 0.25At%, the glass is very easy to crystallize, and because of the presence of some incompletely dissolved Fe elements, scattering is caused, which reduces the overall transmittance of the glass. Therefore, in the present invention, the Fe content is 0.05At% to 0.25At%, preferably 0.08At% to 0.2At%, for example: 0.1At%, 0.12At%, 0.14At%, 0.16At%, 0.18At%, 0.22At%, etc.

[0052] Pr is a rare earth element, and Pr has strong absorption of light with a wavelength of 2.5 to 3 μm. The present invention reduces the transmittance near the 3 μm band by adding Pr. When the content of Pr is higher than 0.25 At%, the glass is very easy to crystallize, and because of the presence of some incompletely dissolved Pr elements, scattering occurs, which reduces the overall transmittance of the glass. Therefore, in the present invention, the content of Pr is 0 At% to 0.25 At%, preferably 0 At% to 0.2 At%; for example: 0.02 At%, 0.05 At%, 0.08 At%, 0.1 At%, 0.12 At%, 0.14 At%, 0.16 At%, 0.18 At%, 0.22 At%, etc.

[0053] Furthermore, in the present invention, the sum of the atomic percentage of Fe and the atomic percentage of Ga, Fe+Pr, will affect the glass-forming properties of the glass. When the content of Fe+Pr is too high, the glass-forming properties of the glass will be reduced, and at the same time, the glass will become devitrified due to crystallization inside the glass; when the content of Fe+Pr is too low, it will not have the effect of reducing short-wave transmittance. Therefore, in the present invention, the content of Fe+Pr, which is the sum of the atomic percentage of Fe and the atomic percentage of Ga, is 0.05At-0.35At%; for example: 0.08At%, 0.1At%, 0.15At%, 0.2At%, 0.25At%, 0.3At%, 0.32At%, etc.

[0054] In the present invention, the transmittance of the chalcogenide optical glass at 3 μm is less than 15%. The transition temperature of the chalcogenide optical glass is 270-300° C. The density of the chalcogenide optical glass is 4.5-4.7 g / cm 3 The refractive index of the chalcogenide optical glass at a wavelength of 10.6 μm is 2.6 to 2.8.

[0055] The present invention also provides a method for preparing the chalcogenide optical glass according to the present invention, which is characterized by comprising weighing the components according to a proportion, mixing them uniformly, then melting them, and obtaining the optical glass after quenching and annealing.

[0056] In some specific embodiments, the preparation method comprises the following steps:

[0057] Weighing and mixing the components in proportion, putting them into a quartz ampoule, and sealing the quartz ampoule;

[0058] The sealed quartz ampoule is melted to obtain a melted product;

[0059] The smelted product is subjected to quenching treatment to obtain a glass product;

[0060] The glass product is subjected to annealing treatment to obtain chalcogenide optical glass.

[0061] In the present invention, in order to obtain chalcogenide optical glass with excellent performance, the raw materials of the present invention are prepared using Ge, Sb, Ga, Se, Fe and Pr single substances.

[0062] Specifically, the components are weighed and mixed in proportion and then placed in a quartz ampoule, and then the quartz ampoule is sealed by oxyhydrogen flame welding after evacuation. Preferably, the vacuum degree in the quartz ampoule is not higher than 5×10 - 5 mbar.

[0063] Further, the sealed quartz ampoule is melted to obtain a smelted product; specifically, the sealed quartz ampoule can be placed in a rocking furnace for high-temperature melting, and then cooled to 600-800°C to obtain a smelted product; preferably, the melting temperature is not higher than 1200°C.

[0064] Further, the smelted product is quenched to obtain a glass product; specifically, the smelted quartz ampoule can be put into hot water for quenching and solidification to obtain a glass product. Generally speaking, the quenching temperature is not higher than 100°C, that is, the temperature of the hot water is not higher than 100°C.

[0065] Further, the glass product is annealed to obtain chalcogenide optical glass. Specifically, the quenched quartz ampoule can be placed in an annealing furnace for annealing to obtain chalcogenide optical glass. Preferably, the annealing temperature is 250 to 280°C, and the annealing speed is -3 to -5°C / h.

[0066] Furthermore, the present invention also provides an optical element, which comprises the optical glass according to the present invention.

[0067] Example

[0068] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0069] Examples 1-4

[0070] 1) Raw material preparation: According to the raw material preparation ratios of Examples 1 to 4 in Table 1, Ge, Sb, Ga and Se single-substance raw materials with a purity of 5N or above, and Fe and Pr single-substance raw materials with a purity of 3N or above were weighed, placed in a quartz ampoule, and evacuated to 1×10 -5 mbar, using hydrogen-oxygen flame to seal the ampoule containing the raw material;

[0071] 2) High temperature smelting: The sealed ampoule is placed in a rocking furnace for high temperature smelting at 1000°C for 10 hours, and then cooled to 700°C to obtain a smelting product;

[0072] 3) Quenching: Take the molten ampoule out of the swing and put it into 40°C hot water for quenching for 3 minutes to obtain a glass product;

[0073] 4) Annealing: Place the glass product in an annealing furnace for annealing at 280°C for 5 hours at an annealing rate of -3°C / h. After cooling to 80°C, a chalcogenide optical glass is obtained.

[0074] Comparative Examples 1 to 5

[0075] According to the raw material ratios of Comparative Examples 1 to 5 in Table 2, Ge, Sb, Ga and Se raw materials with a purity of 5N or above, and Fe and Pr raw materials with a purity of 3N or above were weighed, and the chalcogenide optical glasses of Comparative Examples 1 to 5 were prepared according to the preparation methods of the chalcogenide optical glasses of Examples 1 to 4.

[0076] Performance Testing

[0077] In the examples and comparative examples, the glass transition temperature (Tg), volume density, refractive index n of the optical glasses prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were tested by the following test methods. 10.6μm And infrared transmittance, the results are shown in Table 1-2 and Figure 1-2 middle.

[0078] 1. Glass transition temperature (Tg)

[0079] The glass transition temperature Tg of the obtained chalcogenide optical glass was measured according to the test method of GB / T 7962.16-2010, and the test was performed using a TMA tester from PE Company of the United States.

[0080] 2. Bulk density (ρ)

[0081] The bulk density of the glass was tested by the water displacement method using an electronic balance from METTLER TOLEDO.

[0082] 3. Refractive index (n 10.6μm )

[0083] The refractive index of the glass at 10.6μm was tested by the minimum deviation angle method using the SpectroMaster high-precision refractive index tester from the German company TransEurope.

[0084] 4. Infrared transmittance

[0085] The infrared transmittance of the chalcogenide optical glasses of Examples 1-4 and Comparative Examples 1-2 was tested using a Nicolet 380 Fourier transform infrared spectrometer from Thermo Fisher, USA. The results are as follows: Figure 1 and Figure 2 shown.

[0086] Table 1

[0087]

[0088] Table 2

[0089]

[0090] From Table 1-2 and Figure 1-2 It can be seen from the above that the transmittance of the chalcogenide optical glass of the present invention is less than 15% before the 3 μm band, and the transmittance in the 7 μm to 14 μm band is higher than 40%. It can be seen from Examples 1 to 4 that as the content of Ge and Ga increases, the transition temperature of the glass gradually increases. Figure 1 It can be seen from the figure that when Fe is contained, there is a Ge-O absorption peak at 12-13 μm. Comparing Example 3 with Comparative Example 1, it can be seen that when excessive Fe is contained, the overall transmittance of the glass drops sharply. It can be seen from Comparative Example 2 that in the optical glass without Fe, the transmittance at 3 μm is still very high.

[0091] In addition, it can be seen from Comparative Example 3 that when excessive Pr is added, the glass will be devitrified due to crystallization. Comparison of Comparative Examples 4 and 5 shows that the addition of Sb or Ga can significantly improve the ion solubility of the glass, and Comparative Examples 4 and 5 are devitrified due to crystallization because Fe or Pr cannot be dissolved.

[0092] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0093] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A chalcogenide optical glass, characterized in that: In terms of atomic percentage, it includes the following components: Ge: 24 At%~35 At%; Sb: 1 At%~16 At%; Ga: 1 At%~7 At%; Se: 55 At%~65 At%; Fe: 0.05 At%~0.25 At%; Pr: 0At%~0.25At%.

2. The chalcogenide optical glass according to claim 1, characterized in that: In terms of atomic percentage, it includes the following components: Ge: 24 At%~34 At%; Sb: 1At%~15.75At%; Ga: 1 At%~6 At%; Se: 58 At%~63 At%; Fe: 0.08 At%~0.2 At%; Pr: 0At%~0.2At%.

3. The chalcogenide optical glass according to claim 1 or 2, characterized in that: The content of Sb+Ga, which is the sum of the atomic percentage of Sb and the atomic percentage of Ga, is 3 At-18 At%.

4. The chalcogenide optical glass according to claim 1, characterized in that: The content of Fe+Pr, which is the sum of the atomic percentage of Fe and the atomic percentage of Pr, is 0.05 At-0.35 At%.

5. The chalcogenide optical glass according to claim 1 or 2, characterized in that: The transition temperature of the chalcogenide optical glass is 270-300° C.; and / or the transmittance of the chalcogenide optical glass at 3 μm waveband is lower than 15%.

6. The chalcogenide optical glass according to claim 1 or 2, characterized in that: The refractive index of the chalcogenide optical glass at a wavelength of 10.6 μm is 2.6-2.8; and / or the density of the chalcogenide optical glass is 4.5-4.7 g / cm 3 .

7. A method for preparing chalcogenide optical glass according to claim 1 or 2, characterized in that: The process includes weighing each component according to a proportion, mixing the components uniformly, melting the components, and obtaining the optical glass after quenching and annealing.

8. The preparation method according to claim 7, characterized in that: The preparation method comprises the following steps: Weigh each component according to a proportion, mix them evenly, put them into a quartz ampoule, and seal the quartz ampoule; The sealed quartz ampoule is melted to obtain a melted product; The smelted product is subjected to quenching treatment to obtain a glass product; The glass product is subjected to annealing treatment to obtain chalcogenide optical glass.

9. The preparation method according to claim 8, characterized in that: The vacuum degree in the quartz ampoule is not higher than 5×10 -5 mbar.

10. The preparation method according to claim 8 or 9, characterized in that: The preparation method has at least one of the following conditions: The smelting temperature is not higher than 1200°C; The temperature of the quenching treatment is not higher than 100°C; The temperature of the annealing treatment is 250-280°C, and the speed of the annealing treatment is -3-5°C / h.

11. An optical element, characterized in that: The invention comprises the chalcogenide optical glass according to any one of claims 1 to 6.

Images