Ionizing radiation resistant photothermally induced birefringent glass and volume bragg grating and method of making

Abstract

The present application relates to the technical field of optical element manufacturing, in particular to ionizing radiation resistant photo-thermal refractive glass and a body Bragg grating and a preparation method. The photo-thermal refractive glass with ionizing radiation resistance contains high-concentration doped Sb2O3 and Ag2O, the mole percentage of Sb2O3 is 0.3-0.8 mol%, and the mole percentage of Ag2O is 0.1-0.3 mol%. The photo-thermal refractive glass can also contain Eu2O3, and the mole percentage of Eu2O3 is 0.1-3 mol%. The present application greatly improves the concentration of Sb2O3 and Ag2O to improve the radiation resistance of the photo-thermal refractive glass without affecting the photosensitivity of the photo-thermal refractive glass. In addition, the present application improves the radiation resistance of the photo-thermal refractive glass by introducing Eu2O3 and optimizing the concentration of Eu2O3 without affecting the photosensitivity and thermal sensitivity of the photo-thermal refractive glass.

Description

Technical Field

[0001] This invention relates to the field of optical element manufacturing technology, specifically to a photothermal refractive glass with ionizing radiation resistance, its bulk Bragg grating, and its preparation method. Background Technology

[0002] To achieve photothermal sensitivity, photothermal refractive glasses used in bulk Bragg gratings are typically doped with trace amounts of cerium oxide, antimony oxide, tin oxide, and silver oxide, with doping concentrations on the order of a few parts per ten thousand by weight. Cerium ions in cerium oxide and antimony ions in antimony oxide are variable-valence ions, capable of gaining and losing electrons under ultraviolet light irradiation, promoting Ag nucleus growth. However, photothermal refractive glasses are commonly made of fluorosilicate glass. In space irradiation environments, ionizing radiation can generate electron-hole pairs, leading to defects such as color centers. These defects cause fluctuations in refractive index, resulting in variations in the diffraction wavelength of bulk Bragg grating devices based on this glass. Furthermore, the color centers can absorb visible light, potentially causing temperature changes that alter the glass's refractive index, further affecting the diffraction center wavelength. Moreover, these color center defects tend to disappear with increasing temperature, leading to unpredictable wavelength fluctuations. All these phenomena result in uncontrollable wavelength parameters in bulk Bragg grating devices based on this glass under irradiation conditions, potentially rendering such wave-locked pump sources unusable in space environments.

[0003] The fabrication process of bulk Bragg gratings based on photothermal refractive glass consists of two parts: ultraviolet (UV) exposure and thermal development. UV exposure utilizes the absorption of trace amounts of cerium oxide in the glass, and then uses a 325nm laser to write the grating, converting trivalent cerium ions into tetravalent cerium ions. The released electrons are then absorbed by Ag ions or Sb ions. 5+ The process involves absorption, followed by heating where Ag ions accept electrons to become Ag nuclei, inducing sodium fluoride crystallization in the glass and completing the bulk Bragg grating fabrication. Based on this process, and considering the photosensitivity of cerium oxide and the thermosensitivity of antimony oxide, the trace elements in commonly used photothermal refractive glass components are limited to, for example, 0-0.02 mol% Ag₂O, 0-0.02 mol% CeO₂, 0-0.008 mol% SnO₂, and 0-0.1 mol% Sb₂O₃. The low content of variable valence ions in this component results in poor radiation resistance of the glass in a space environment.

[0004] Traditional optical glass typically improves radiation resistance by increasing the content of variable-valence ions, such as cerium oxide. However, in photothermal refractive glass, cerium oxide primarily serves as a photosensitive agent. It is generally etched onto a polished photothermal refractive glass sheet with a thickness of approximately 0.7-10 mm using a 325nm laser. In this process, if the cerium oxide content is too high, it can lead to incomplete or uneven exposure, resulting in an uneven distribution of diffraction efficiency in the final volume Bragg grating.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a photothermal refractive glass with ionizing radiation resistance, its bulk Bragg grating, and its preparation method, in order to solve the problem of poor radiation resistance of existing photothermal refractive glasses.

[0007] In a first aspect, the present invention provides a photothermal refractive glass with resistance to ionizing radiation, wherein the photothermal refractive glass contains Sb2O3 and Ag2O, wherein the molar percentage of Sb2O3 is 0.3-0.8 mol% and the molar percentage of Ag2O is 0.1-0.3 mol%.

[0008] Optionally, the photothermal refractive glass further contains Eu2O3, wherein the molar percentage of Eu2O3 is 0.1-3 mol%.

[0009] Optionally, the photothermal refractive glass comprises the following components in molar percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO,

[0010] 2-5moL%NaF, 1-4moL%KBr, 0.02-0.04moL%CeO2, 0.02-0.05moL%SnO2, 0.1-0.3moL%Ag2O, 0.3-0.8moL%Sb2O3, 0.1-3moL%Eu2O3.

[0011] Optionally, the photothermal refractive glass is composed of the following components in molar percentage: 65 mol% SiO2, 9.43 mol% Al2O3, 15 mol% Na2O, 5 mol% ZnO, 3 mol% NaF, 2 mol% KBr, 0.02% CeO2, 0.05 mol% SnO2, 0.1 mol% Ag2O, 0.3 mol% Sb2O3, and 0.1 mol% Eu2O3.

[0012] Optionally, the photothermal refractive glass is composed of the following components in molar percentage: 67 mol% SiO2, 7.45 mol% Al2O3, 12 mol% Na2O, 7 mol% ZnO, 3 mol% NaF, 2 mol% KBr, 0.03% CeO2, 0.02 mol% SnO2, 0.15 mol% Ag2O, 0.35 mol% Sb2O3, and 1 mol% Eu2O3.

[0013] Optionally, the photothermal refractive glass is composed of the following components in molar percentage: 70 mol% SiO2, 4 mol% Al2O3, 14.69 mol% Na2O, 3 mol% ZnO, 3 mol% NaF, 3 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.25 mol% Ag2O, 0.5 mol% Sb2O3, and 1.5 mol% Eu2O3.

[0014] Optionally, the photothermal refractive glass is composed of the following components in molar percentage: 69.04 mol% SiO2, 3 mol% Al2O3, 8 mol% Na2O, 8 mol% ZnO, 5 mol% NaF, 4 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.3 mol% Ag2O, 0.6 mol% Sb2O3, and 2 mol% Eu2O3.

[0015] Optionally, the photothermal refractive glass is composed of the following components in molar percentage: 70.84 mol% SiO2, 2 mol% Al2O3, 10 mol% Na2O, 10 mol% ZnO, 2 mol% NaF, 1 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.3 mol% Ag2O, 0.8 mol% Sb2O3, and 3 mol% Eu2O3.

[0016] In a second aspect, the present invention provides a method for preparing a volume Bragg grating, wherein the photothermal refractive glass with ionization-resistant properties described in the present invention is subjected to ultraviolet exposure treatment and thermal development treatment in sequence to obtain the volume Bragg grating.

[0017] In a third aspect, the present invention provides a volume Bragg grating, wherein the volume Bragg grating is prepared by the method for preparing a volume Bragg grating according to the present invention.

[0018] Beneficial effects: This invention significantly increases the concentration of Sb2O3 and Ag2O in the photothermal refractive glass without affecting its photosensitivity, thereby improving the radiation resistance of the photothermal refractive glass. In addition, without affecting the photosensitivity and thermosensitivity of the photothermal refractive glass, the radiation resistance of the photothermal refractive glass is improved by introducing Eu2O3 (Eu2O3) and optimizing the Eu2O3 concentration. Attached Figure Description

[0019] Figure 1 The transmittance spectrum of the photothermal refractive glass in Example 1 is shown.

[0020] Figure 2 This is a comparison diagram of the electron paramagnetic resonance (EPR) spectrum of the photothermal refractive glass after irradiation in Example 1 and the EPR spectrum of the conventional photothermal refractive glass after irradiation in Comparative Example 1.

[0021] Figure 3 This is a comparison of the pyroelectric spectra of the photothermal refractive glass of Example 1 before and after irradiation with the pyroelectric spectra of the conventional photothermal refractive glass of Comparative Example 1 before and after irradiation. Detailed Implementation

[0022] This invention provides a photothermal refractive glass with resistance to ionizing radiation, its bulk Bragg grating, and a method for its preparation. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] This invention provides a photothermal refractive glass with resistance to ionizing radiation, wherein the photothermal refractive glass contains Sb2O3 and Ag2O, wherein the molar percentage of Sb2O3 is 0.3-0.8 mol% and the molar percentage of Ag2O is 0.1-0.3 mol%.

[0024] The photothermal refractive glass of this invention significantly increases the concentrations of Sb₂O₃ and Ag₂O without affecting the photosensitivity of the photothermal refractive glass, thereby improving the radiation resistance of the photothermal refractive glass.

[0025] In one embodiment, the photothermal refractive glass further contains Eu2O3, wherein the molar percentage of Eu2O3 is 0.1-3 mol%.

[0026] The photothermal refractive glass of this invention improves the radiation resistance of the photothermal refractive glass by introducing Eu2O3 and optimizing the Eu2O3 concentration without affecting the photosensitivity and thermosensitivity of the photothermal refractive glass. At the same time, since europium in europium oxide is a rare earth element, its absorption peak is mainly narrow absorption around 400nm, which does not affect the application of near-infrared volume Bragg gratings.

[0027] In one embodiment, the photothermal refractive glass comprises the following components in molar percentages: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, and 0.1-3 mol% Eu2O3.

[0028] The photothermal refractive glass of this invention is an improvement on conventional photothermal refractive glass. The main improvement is that the concentrations of Sb2O3 and Ag2O are significantly increased based on the composition of conventional photothermal refractive glass, thereby improving the radiation resistance of the photothermal refractive glass. In addition, Eu2O3 is introduced and its concentration is optimized to further improve the radiation resistance of the photothermal refractive glass.

[0029] Conventional photothermal refractive glass is a silicate glass co-doped with Si, Al, Na, K, and Zn, and also doped with Sn, Sb, Ce, and Ag. The composition of conventional photothermal refractive glass is: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0-0.02 mol% Ag2O, 0-0.02 mol% CeO2, 0-0.008 mol% SnO2, and 0-0.01 mol% Sb2O3.

[0030] The method for preparing photothermal refractive glass with ionizing radiation resistance according to this invention is basically the same as the existing conventional method for preparing photothermal refractive glass, except that the formulation of the photothermal refractive glass is different. This will not be further described in detail in this embodiment.

[0031] This invention also provides a method for preparing a volume Bragg grating, wherein the photothermal refractive glass with ionizing radiation resistance described in this invention is subjected to ultraviolet exposure treatment and thermal development treatment in sequence to obtain the volume Bragg grating.

[0032] This invention also provides a volume Bragg grating, wherein the volume Bragg grating is prepared by the volume Bragg grating preparation method described in this invention.

[0033] The present invention relates to a radiation-resistant photothermal refractive glass. Without significantly affecting the photothermal sensitivity of the photothermal refractive glass, the radiation resistance of the photothermal refractive glass is greatly improved by increasing the valence of variable ions such as Sb and Eu ions and optimizing their concentration. At the same time, a volume Bragg grating is fabricated to meet its application in the space environment.

[0034] The present invention will be further described below through specific embodiments.

[0035] Example 1

[0036] The photothermal refractive glass of this embodiment is composed of the following components in molar percentage: 65 mol% SiO2, 9.43 mol% Al2O3, 15 mol% Na2O, 5 mol% ZnO, 3 mol% NaF, 2 mol% KBr, 0.02% CeO2, 0.05 mol% SnO2, 0.1 mol% Ag2O, 0.3 mol% Sb2O3, and 0.1 mol% Eu2O3.

[0037] Example 2

[0038] The photothermal refractive glass of this embodiment is composed of the following components in molar percentage: 67 mol% SiO2, 7.45 mol% Al2O3, 12 mol% Na2O, 7 mol% ZnO, 3 mol% NaF, 2 mol% KBr, 0.03% CeO2, 0.02 mol% SnO2, 0.15 mol% Ag2O, 0.35 mol% Sb2O3, and 1 mol% Eu2O3.

[0039] Example 3

[0040] The photothermal refractive glass of this embodiment is composed of the following components in molar percentage: 70 mol% SiO2, 4 mol% Al2O3, 14.69 mol% Na2O, 3 mol% ZnO, 3 mol% NaF, 3 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.25 mol% Ag2O, 0.5 mol% Sb2O3, and 1.5 mol% Eu2O3.

[0041] Example 4

[0042] The photothermal refractive glass of this embodiment is composed of the following components in molar percentage: 69.04 mol% SiO2, 3 mol% Al2O3, 8 mol% Na2O, 8 mol% ZnO, 5 mol% NaF, 4 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.3 mol% Ag2O, 0.6 mol% Sb2O3, and 2 mol% Eu2O3.

[0043] Example 5

[0044] The photothermal refractive glass of this embodiment is composed of the following components in molar percentage: 70.84 mol% SiO2, 2 mol% Al2O3, 10 mol% Na2O, 10 mol% ZnO, 2 mol% NaF, 1 mol% KBr, 0.04% CeO2, 0.02 mol% SnO2, 0.3 mol% Ag2O, 0.8 mol% Sb2O3, and 3 mol% Eu2O3.

[0045] The compositions of the photothermal refractive glasses of Examples 1-5 are shown in Table 1 below:

[0046] Table 1. Composition of the photothermal refractive glass in Examples 1-5

[0047] Example <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Na2O]]> ZnO NaF KBr <![CDATA[SnO2]]> <![CDATA[CeO2]]> <![CDATA[Ag2O]]> <![CDATA[Sb2O3]]> <![CDATA[Eu2O3]]> 1 65 9.43 15 5 3 2 0.05 0.02 0.1 0.3 0.1 2 67 7.45 12 7 3 2 0.02 0.03 0.15 0.35 1.0 3 70 4 14.69 3 3 3 0.02 0.04 0.25 0.5 1.5 4 69.04 3 8 8 5 4 0.02 0.04 0.3 0.6 2 5 70.84 2 10 10 2 1 0.02 0.04 0.3 0.8 3

[0048] Comparative Example 1

[0049] The conventional photothermal refractive glass of this comparative example is composed of the following components in molar percentage: 68.5 mol% SiO2, 4.85 mol% Al2O3, 12.9 mol% Na2O, 6.6 mol% ZnO, 4.3 mol% NaF, 2.8 mol% KBr, 0.02 mol% Ag2O, 0.02 mol% CeO2, 0.005 mol% SnO2, and 0.005 mol% Sb2O3.

[0050] The following performance tests were performed on the photothermal refractive glasses of Examples 1-5 and the conventional photothermal refractive glass of Comparative Example 1:

[0051] like Figure 1 As shown, the photothermal refractive glass of Example 1 has high transmittance characteristics in the 470-1200nm spectral range.

[0052] Figure 2The images show the electron paramagnetic resonance (EPR) spectra of the conventional photothermal refractive glass of Comparative Example 1 and the photothermal refractive glass of Example 1 after irradiation with 500 kGy of Gamma rays. For the conventional photothermal refractive glass, the electron-hole trapping centers generated after Gamma irradiation result in a significant superposition signal at g = 2.011. For the photothermal refractive glass of Example 1, the intensity of the EPR signal significantly decreases after Gamma irradiation. Since the concentration of the color centers is proportional to the double integral of the EPR signal, the concentration of irradiated color centers in the photothermal refractive glass of Example 1 is significantly reduced after irradiation.

[0053] like Figure 3 As shown, the thermoluminescence curves of the photothermal refractive glass of Example 1 and the conventional photothermal refractive glass of Comparative Example 1 before and after irradiation with 500 kGy of Gamma rays are displayed, with a radiation dose rate of 100 Gy / h. For the unirradiated photothermal refractive glass of Example 1 and the conventional photothermal refractive glass of Comparative Example 1, it can be seen that neither exhibits a thermoluminescence effect. This indicates that the number of trapping centers in the matrix of both is low before irradiation; simultaneously, Eu... 3+ Ion doping did not introduce additional carrier trapping centers.

[0054] Table 2 shows a comparison of the parameters of the 976nm bulk Bragg gratings prepared based on the photothermal refractive glass of Examples 1-5 before and after irradiation.

[0055] Table 2. Comparison of parameters of 976nm bulk Bragg gratings prepared from photothermal refractive glass in Examples 1-5 and Comparative Example 1 before and after irradiation.

[0056]

[0057] As shown in Table 2, compared with conventional volume gratings, the wavelength fluctuation under irradiation is greater than 0.16 nm, while the volume grating improved by this invention has a minimum wavelength fluctuation of only 0.02 nm under irradiation, which greatly improves its reliability in the irradiation environment.

[0058] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A photothermal poling glass having ionizing radiation resistance, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

2. The photothermal poling glass with ionizing radiation resistance according to claim 1, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

3. The photothermal poling glass with ionizing radiation resistance according to claim 1, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

4. The photothermal poling glass with ionizing radiation resistance according to claim 1, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

5. The photothermal poling glass with ionizing radiation resistance according to claim 1, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

6. The photothermal poling glass with ionizing radiation resistance according to claim 1, characterized in that, The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3.

7. A method of fabricating a volume Bragg grating, characterized by The photo-thermally induced birefringent glass comprises the following components in mole percentage: 65-75 mol% SiO2, 2-10 mol% Al2O3, 10-15 mol% Na2O, 3-10 mol% ZnO, 2-5 mol% NaF, 1-4 mol% KBr, 0.02-0.04 mol% CeO2, 0.02-0.05 mol% SnO2, 0.1-0.3 mol% Ag2O, 0.3-0.8 mol% Sb2O3, 0.1-3 mol% Eu2O3. The photo-thermally induced birefringent glass with ionizing radiation resistance performance according to any one of claims 1-6 is subjected to ultraviolet exposure treatment and heat development treatment in sequence to obtain a volume Bragg grating.

8. A volume Bragg grating, characterized in that The volume Bragg grating is prepared by the method of claim 7. The volume Bragg grating is prepared by the method of claim 7.

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