A method for detecting relative concentration of microscopic optical point defects in micro-areas of processed surfaces of fused silica optical components

Abstract

The present invention provides a method for detecting the relative concentration of microscopic optical flaws in micro-areas of the processed surface of a fused quartz optical element, which belongs to the field of engineering optics technology. In order to solve the problem that the existing technology for characterizing point defects on the processed surface of a fused quartz element is only suitable for characterizing and distinguishing the types of point defects, and there is no effective method for detecting the relative concentration of point defects. The present invention conducts a photoluminescence detection experiment on the micro-defect area of ​​the processed surface of a fused quartz optical element to obtain the point defect type in the defect area and the peak area of ​​the sub-peak curve corresponding to different point defects, establishes the relationship between the concentration of lone pair electrons contained in the point defect and the peak area of ​​the sub-peak curve, calculates the relative concentration of lone pair electrons contained in different point defects, and calculates the relative concentration of different point defects in the micro-defect area of ​​the processed surface of the fused quartz in combination with the chemical structure and reaction law of the point defect. The present invention fills the technical gap that is currently unable to obtain the relative concentration of point defects on the surface of a material.

Description

Technical Field

[0001] The present invention relates to the field of engineering optics technology, and in particular to a method for detecting relative concentration of microscopic optical point defects in a micro-area on the processed surface of a fused quartz optical element. Background Art

[0002] Fused quartz, due to its high-temperature resistance, extremely low linear expansion coefficient, stable chemical properties, and excellent light transmission performance, has been widely used in high-power laser applications such as extreme ultraviolet lithography, space satellite communications, four-dimensional high-power laser weapons for land, sea, air, and space, and inertial confinement fusion. However, due to the inherent hardness and brittleness of fused quartz, micro-nano defects (size range of 1-100μm) such as pits, scratches, and cracks will inevitably be introduced on the surface during the machining process. These surface micro-defects not only reduce the component surface's resistance to laser damage and shorten its service life, but also limit the increase in the output power of high-power laser systems, thereby posing challenges to the development of fields such as extreme ultraviolet lithography, space satellite communications, high-power laser weapons, and inertial confinement fusion.

[0003] Currently, it is widely accepted both domestically and internationally that point defects in the micro-defect zones of the machined surface of fused silica optical components are the primary cause of strong laser absorption in these micro-defect zones, reducing the component's resistance to laser damage. In numerous reports, point defects on the surface of fused silica optical components are also referred to as "precursors" of laser damage. Therefore, in-depth research into the mechanisms by which point defects on the machined surface of fused silica optical components influence their resistance to laser damage can help fundamentally improve their resistance. It is well known that during the machining process of fused silica optical components, point defects with varying physicochemical properties (such as atomic arrangement, the ability of the nucleus to bind extranuclear electrons, point defect activity, and the ability of the point defects to gain or lose electrons) are introduced onto the machined surface. Under the action of mechanical forces, these point defects typically cluster together in the micro-defect zones of the machined surface. In fact, the combined effect of different point defects on the machined surface of fused silica optical components (i.e., the effect of point defect clusters) is the primary factor affecting the component's resistance to laser damage. However, point defects with different physicochemical properties have varying degrees of influence on the component's resistance to laser damage. Therefore, in order to deeply study the comprehensive influence of different types of point defects on the processing surface of fused silica optical components on the laser damage resistance of the component processing surface, the relative concentration of point defects on the component processing surface must be obtained first.

[0004] During the processing of fused silica (primarily composed of SiO2) optical components, the breaking of Si-O bonds on the surface can generate a variety of point defects with varying physicochemical properties. Under intense laser irradiation, ground-state electrons in micro-defect areas on the surface of fused silica optical components readily absorb photon energy and ionize to form free electrons. When the free electron density reaches a critical free electron density, laser damage occurs on the component surface. Furthermore, because some excited-state electrons generated during this electron transition are extremely unstable, they undergo radiative relaxation and emit fluorescence. Photofluorescence spectroscopy, infrared spectroscopy, and ultraviolet spectroscopy all experimentally characterize point defects on the surface of component components by obtaining their characteristic response signals. Photofluorescence spectroscopy characterizes point defects by detecting the fluorescence emitted by the defects; infrared spectroscopy characterizes point defects by analyzing their absorption characteristics for infrared light; and ultraviolet spectroscopy characterizes point defects by determining their absorption characteristics for ultraviolet light. These three characterization techniques are currently recognized as the most effective means of characterizing point defects. Although these three characterization techniques can determine the type of point defects by obtaining characteristic response signals of point defects, the current point defect characterization theory and technology are still imperfect. At present, it is still impossible to obtain the relative concentration of point defects on the material surface through the existing point defect characterization theory and technology. This brings challenges to the study of surface point defects in fused silica optical components. Summary of the Invention

[0005] The technical problems to be solved by the present invention are:

[0006] Existing technologies for characterizing point defects on the surface of fused quartz components are only suitable for characterizing and distinguishing the types of point defects, and there is no effective method to detect the relative concentration of point defects.

[0007] The present invention is to solve the above technical problems using the following technical solutions:

[0008] The present invention provides a method for detecting relative concentration of microscopic optical point defects in a micro area on the processed surface of a fused silica optical element, comprising the following steps:

[0009] Step 1: Locate micro-defect areas on the surface of the fused silica optical element and conduct a photoluminescence detection experiment on the located defect areas;

[0010] Step 2: performing peak fitting on the fluorescence emission spectrum obtained from the photoluminescence detection experiment to obtain multiple sub-peak curves, and determining the type of point defects through the sub-peak curves;

[0011] Step 3, calculating the peak area of ​​the sub-peak curve corresponding to different point defects;

[0012] Step 4: Establish a relationship between the lone pair electron concentration of the point defect and the peak area of ​​the sub-peak curve, and determine the relative concentration of the lone pair electrons contained in different point defects based on the peak area of ​​the sub-peak curve corresponding to different point defects;

[0013] Step 5: Determine the number of lone pair electrons contained in different point defects based on the chemical structure and reaction rules of the point defects;

[0014] Step 6: Determine the relative concentration of different point defects in the micro-defect area on the fused quartz processing surface based on the relative concentration of lone pair electrons and the number of lone pair electrons contained in different point defects.

[0015] Furthermore, the step 1 includes performing photoinduced fluorescence detection on any position within the located micro-defect area, determining the position with the highest fluorescence intensity within the defect area, and conducting a photoinduced weak fluorescence detection experiment on the position.

[0016] Furthermore, the point defect types determined in step 2 include: oxygen defect center type II defect, self-trapped exciton defect, color center defect, non-bridging oxygen vacancy center type I defect, non-bridging oxygen vacancy center type II defect, peroxide chain defect and silicon nanocluster defect.

[0017] Furthermore, in step three, the peak area of ​​each sub-peak curve in the fluorescence emission spectrum is calculated using the mathematical software Origin.

[0018] Furthermore, the step 4 includes the following process:

[0019] By formula It can be seen that the fluorescence signal released during the electron transition process at a specific position of a specific defect is often proportional to the excited state electron concentration; where A represents the released fluorescence signal, n e represents the excited state electron concentration, τ r Represents the excited state electron decay relaxation time. For the same position of the same defect, τ r Usually fixed;

[0020] According to existing research, when laser energy is relatively low, meaning only a small fraction of electrons are ionized during electron transitions, the concentration of excited-state electrons is approximately proportional to the concentration of ground-state electrons capable of ionization. Furthermore, the ground-state electrons within a point defect that readily absorb photon energy and undergo ionization are the lone pairs of electrons in the point defect. This leads to the conclusion that, in photoinduced fluorescence detection experiments, the lone-pair electron concentration within a point defect on the surface of a fused silica optical component is directly proportional to the peak area of ​​its corresponding sub-peak curve.

[0021] Therefore, the relative concentrations of lone pair electrons corresponding to different point defects are determined based on the peak areas of the sub-peak curves corresponding to different point defects.

[0022] Furthermore, the relative concentrations of lone pair electrons corresponding to the different point defects determined in step 4 are: oxygen defect center type II defect 7.31%, self-trapped exciton defect 18.33%, color center defect 28.20%, non-bridging oxygen vacancy center type I defect 9.55%, non-bridging oxygen vacancy center type II defect 27.87%, and peroxide chain defect 8.74%.

[0023] Furthermore, according to the chemical structure and reaction rules of point defects, step five targets self-trapped exciton defects, because they contain incompletely broken Si-O bonds generated by mechanical force, and incompletely broken Si-O bonds are extremely easy to break under laser irradiation conditions to generate two lone pairs of electrons; for peroxide chain defects, since they are composed of two non-bridging oxygen vacancy center type I defects, they will be decomposed again under laser irradiation conditions into equal amounts of non-bridging oxygen vacancy center type I defects and non-bridging oxygen vacancy center type II defects. Therefore, the peroxide chain defect can be regarded as containing two lone pairs of electrons.

[0024] Furthermore, in step five, based on the chemical structure of the point defect, it is determined that the oxygen defect center type II defect contains 2 lone pairs of electrons, the color center defect contains 1 lone pair of electrons, the non-bridging oxygen vacancy center type I defect contains 1 lone pair of electrons, and the non-bridging oxygen vacancy center type II defect contains 2 lone pairs of electrons.

[0025] Furthermore, the step 6 determines the relative concentration of different point defects in the micro-defect area on the fused quartz processing surface by the following formula:

[0026]

[0027] Among them, n i Indicates the relative concentration of different point defects, i is a different point defect; n ei is the relative concentration of lone pair electrons corresponding to the i-th type point defect, m i is the number of lone pair electrons of the i-th type point defect.

[0028] Furthermore, in step six, the relative concentrations of different point defects in the micro-defect area on the processed surface of fused quartz are determined as follows: oxygen defect center type II defect 5.31%, self-trapped exciton defect 13.31%, color center defect 40.90%, non-bridging oxygen vacancy center type I defect 13.87%, non-bridging oxygen vacancy center type II defect 20.23%, and peroxide chain defect 6.38%.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a method for detecting the relative concentration of microscopic optical point defects in micro-areas of the machined surface of fused silica optical components. By conducting a photoluminescence detection experiment on the micro-defect areas of the machined surface of the fused silica optical component, the method determines the point defect type in the defect area and the sub-peak curve peak area corresponding to different point defects. A relationship is established between the lone pair electron concentration contained in the point defect and the sub-peak curve peak area. Combining the chemical structure and reaction patterns of the point defects, the relative concentration of different point defects in the micro-defect areas of the machined surface of the fused silica is calculated. This method improves current point defect characterization theory and technology, filling the current technical gap in determining the relative concentration of point defects on material surfaces.

[0031] The present invention helps to understand, at the atomic scale, the generation and evolution mechanism of point defects in fused silica materials during mechanical processing (under the action of mechanical forces). Point defects are considered to be "damage precursors" that cause laser damage to the surface of fused silica optical components. Therefore, the present invention helps to fundamentally reveal the comprehensive influence of point defects in the micro-defect areas on the processed surface of fused silica optical components on the laser damage resistance of the component processed surface, providing a theoretical basis and technical support for solving the problem of laser damage caused by point defects on the processed surface of such components.

[0032] The present invention can provide experimental verification for research on atomic-level structural theoretical simulations of fused quartz and other glass materials (such as molecular dynamics simulations and first principles), and help promote the development of these fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of a method for detecting relative concentration of microscopic optical point defects in a micro-area on the processed surface of a fused silica optical element according to an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of the surface morphology of pit-like defects on the machined surface of a fused silica optical element and the locations of defect detection points in an embodiment of the present invention;

[0035] Figure 3 This is a light path diagram of a continuous excitation light-induced weak fluorescence detection system in an embodiment of the present invention;

[0036] Figure 4 The fluorescence emission spectrum of the micro-defect area on the surface of the fused silica optical element processed by peak fitting in the embodiment of the present invention, wherein the wavelength range of a is 350-700 nm, and the wavelength range of b is 680-1100 nm;

[0037] Figure 5 is the peak area of ​​the sub-peak curve corresponding to different point defects in the embodiment of the present invention;

[0038] Figure 6 is the relative concentration of lone pair electrons corresponding to different point defects in the embodiment of the present invention;

[0039] Figure 7 Schematic diagram of the chemical structure of various point defects on the machined surface of a fused silica optical element according to an embodiment of the present invention;

[0040] Figure 8 is the relative concentration of defects at various points on the processed surface of the fused silica optical element in the embodiment of the present invention. DETAILED DESCRIPTION

[0041] In the description of the present invention, it should be noted that the terms "first," "second," and "third" mentioned in the embodiments of the present invention are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0043] The present invention provides a method for detecting relative concentration of microscopic optical point defects in micro-areas of processed surfaces of fused silica optical elements. Figure 1 As shown, the following steps are included:

[0044] Step 1: Locate the micro-defect area on the processed surface of the fused silica optical element and perform a photoluminescence detection experiment on the located defect area.

[0045] like Figure 2 As shown in the figure, the ultra-depth-of-field three-dimensional imaging system (VHX-1000) is used to inspect the processed surface of the fused silica optical element, locate a pit-like defect with a circumscribed circle diameter of 31 μm, and obtain its surface morphology.

[0046] like Figure 3 As shown, a supercontinuum photoexcitation weak fluorescence detection system was used to conduct a photofluorescence detection experiment on the located micro-defect area. The effective spot diameter of the incident excitation light of the supercontinuum photoexcitation weak fluorescence detection system was 3μm. Photofluorescence detection was performed at any position within the defect area, and it was determined that the center of the pit-type defect often has the highest fluorescence intensity. Therefore, the photofluorescence detection experiment was conducted at the center of the pit-type defect.

[0047] Step 2: Perform peak fitting on the fluorescence emission spectrum obtained from the photoluminescence detection experiment to obtain multiple sub-peak curves, and determine the point defect type through the sub-peak curves.

[0048] like Figure 4As shown, since the continuous excitation light-induced weak fluorescence detection system used in the present invention includes two spectrometers with different detection bands, the obtained fluorescence emission spectrum contains two parts. The obtained fluorescence emission spectrum is subjected to peak fitting to obtain multiple sub-peak curves. By analyzing the peak positions of different sub-peak curves, the point defect types corresponding to the different sub-peak curves are determined, which are: oxygen defect center type II defect (ODCII), self-trapped exciton defect (STE), color center defect (E'Center), non-bridging oxygen vacancy center type I defect (NBOHCI), non-bridging oxygen vacancy center type II defect (NBOHCII), peroxide chain defect (POL) and silicon nanocluster defect (Silicon nanocluster). Among them, existing research at home and abroad generally believes that silicon nanocluster defects are impurity point defects introduced during the preparation of fused silica optical components, rather than point defects introduced by mechanical forces during the component processing. Due to the randomness of silicon nanocluster defects (the introduction of impurities is random) and their small proportion, this type of point defect is not considered.

[0049] Step 3: Calculate the peak area of ​​the sub-peak curve corresponding to different point defects.

[0050] like Figure 5 As shown, the mathematical software Origin was used to calculate the peak area of ​​each sub-peak curve in the fluorescence emission spectrum, and the peak areas of the sub-peak curves corresponding to oxygen defect center type II defect (ODCII), self-trapped exciton defect (STE), color center defect (E'Center), non-bridging oxygen vacancy center type I defect (NBOHCI), non-bridging oxygen vacancy center type II defect (NBOHCII), and peroxide chain defect (POL) were 9622, 24135, 37133, 12574, 36700, and 11500, respectively.

[0051] Step 4: Establish a relationship between the lone pair electron concentration of the point defect and the peak area of ​​the sub-peak curve, and determine the relative concentration of the lone pair electrons contained in different point defects based on the peak area of ​​the sub-peak curve corresponding to different point defects.

[0052] Currently, domestic and international research generally believes that point defects in micro-defect areas on the surface of fused silica optical components can introduce defect energy levels. Ground-state electrons in the defect area can absorb photon energy and first transition to the defect energy level, becoming excited electrons before ultimately transitioning to the conduction band and becoming free electrons. Electrons in the excited state are generally unstable and will undergo radiative relaxation, releasing fluorescence signals. The relationship between the released fluorescence signal and the excited-state electron concentration is shown below:

[0053]

[0054] Where: A represents the released fluorescence signal, ne represents the excited state electron concentration, τ r Represents the excited state electron decay relaxation time. For the same position of the same defect, τ r It is usually fixed, so the fluorescence signal released during the electronic transition at a specific position of a specific defect is often proportional to the excited state electron concentration.

[0055] According to existing research, when the laser energy is relatively low, that is, when only a small number of electrons are ionized during the electron transition process, the concentration of excited state electrons is approximately proportional to the concentration of ground state electrons that can undergo ionization (some ground state electrons easily absorb photon energy to become ionized, while some ground state electrons are relatively stable and not easily ionized). According to existing research, the ground state electrons within a point defect are the lone pair electrons of the point defect.

[0056] Since the excitation light energy of the photoluminescence detection experiment is very low, and the intensity of the fluorescence signal released by a point defect during the electron ionization process can be represented by the peak area of ​​the sub-peak curve corresponding to the point defect. In summary, in the photoluminescence detection experiment, the peak area of ​​the sub-peak curve corresponding to a point defect on the surface of the fused silica optical element is approximately proportional to the lone pair electron density of the point defect. Figure 6 As shown in the figure, the relative concentrations of lone pair electrons corresponding to different point defects are determined based on the peak areas of the sub-peak curves corresponding to the point defects on the surface of the fused silica optical element. Specifically, the relative concentrations of lone pair electrons corresponding to different point defects are 7.31% for type II defects at oxygen defect centers, 18.33% for self-trapped exciton defects, 28.20% for color center defects, 9.55% for type I defects at non-bridging oxygen vacancy centers, 27.87% for type II defects at non-bridging oxygen vacancy centers, and 8.74% for peroxide chain defects.

[0057] Step 5: Determine the number of lone pair electrons contained in different point defects based on the chemical structure and reaction rules of the point defects;

[0058] like Figure 7 As shown in formulas (2) to (5), under the action of mechanical force, the Si-O bond will be broken on the fused quartz processing surface, generating equal amounts of color center defects and non-bridging oxygen vacancy center type I defects (formula (2)); non-bridging oxygen vacancy center type I defects will polymerize to generate peroxide chain defects (formula (3)); peroxide chain defects are unstable under the conditions of excitation light irradiation and will decompose to generate non-bridging oxygen vacancy center type II defects and non-bridging oxygen vacancy center type I defects (formula (4)); color center defects will further cause the Si-O bond to break under the action of mechanical force, generating oxygen defect center type II defects and non-bridging oxygen vacancy center type I defects (formula (5)).

[0059] ≡Si-O-Si≡→≡Si·+·O-Si≡(2)

[0060] ≡Si-O·+·O-Si≡→≡Si-OO-Si≡(3)

[0061] ≡Si-OO-Si≡→≡Si-O·+:O-Si≡(4)

[0062] ≡Si·→=Si:+·O-Si≡(5)

[0063] Existing studies have shown that self-trapped exciton defects contain incompletely broken Si-O bonds generated by mechanical forces, and incompletely broken Si-O bonds are easily broken under laser irradiation to generate two lone pairs of electrons. As shown in formula (4), the peroxide chain defect is formed by the aggregation of two non-bridging oxygen vacancy center type I defects, but it will decompose again under laser irradiation into equal amounts of non-bridging oxygen vacancy center type I defects and non-bridging oxygen vacancy center type II defects. Therefore, the peroxide chain defect can be regarded as containing two lone pairs of electrons.

[0064] In summary, the number of lone pair electrons in different point defects is as follows: oxygen defect center type II defect contains 2 lone pair electrons, self-trapped exciton defect contains 2 lone pair electrons, color center defect contains 1 lone pair electron, non-bridging oxygen vacancy center type I defect contains 1 lone pair electron, non-bridging oxygen vacancy center type II defect contains 2 lone pair electrons, and peroxide chain defect contains 2 lone pair electrons.

[0065] Step 6: Determine the relative concentration of different point defects in the micro-defect area on the fused quartz processing surface based on the relative concentration of lone pair electrons and the number of lone pair electrons contained in different point defects.

[0066] The relative concentration of lone pair electrons corresponding to a certain point defect on the surface of fused quartz processing is shown in formula (6):

[0067]

[0068] Among them, n i Indicates the relative concentration of different point defects, i is a different point defect; n ei is the relative concentration of lone pair electrons corresponding to the i-th type point defect, m i is the number of lone pair electrons of the i-th type point defect.

[0069] like Figure 8As shown, combining the lone pair electron counts of different point defects in the micro-defect area of ​​the fused silica surface obtained in step 5 with the relative lone pair electron concentrations corresponding to different point defects obtained in step 4, the relative concentrations of different point defects in the micro-defect area of ​​the component surface were obtained: oxygen vacancy center type II defects (5.31%), self-trapped exciton defects (13.31%), color center defects (40.90%), non-bridging oxygen vacancy center type I defects (13.87%), non-bridging oxygen vacancy center type II defects (20.23%), and peroxide chain defects (6.38%).

[0070] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art of the present invention may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for detecting relative concentration of microscopic optical point defects in micro-areas on the processed surface of fused silica optical elements, characterized in that The steps include: Step 1: Locate the micro-defect area on the surface of the fused silica optical element and perform a photoluminescence detection experiment on the located defect area; Step 2: performing peak fitting on the fluorescence emission spectrum obtained from the photoluminescence detection experiment to obtain multiple sub-peak curves, and determining the type of point defects through the sub-peak curves; Step 3, calculating the peak area of ​​the sub-peak curve corresponding to different point defects; Step 4: Establish a relationship between the lone pair electron concentration of the point defect and the peak area of ​​the sub-peak curve, and determine the relative concentration of the lone pair electrons contained in different point defects based on the peak area of ​​the sub-peak curve corresponding to different point defects; Step 5: Determine the number of lone pair electrons contained in different point defects based on the chemical structure and reaction rules of the point defects; Step 6: Determine the relative concentration of different point defects in the micro-defect area on the fused quartz processing surface based on the relative concentration of lone pair electrons and the number of lone pair electrons contained in different point defects.

2. The method according to claim 1, characterized in that The step 1 includes performing photoinduced fluorescence detection on any position within the located micro-defect area, determining the position with the highest fluorescence intensity within the defect area, and conducting a photoinduced weak fluorescence detection experiment on the position.

3. The method according to claim 1, characterized in that The point defect types determined in step 2 include: oxygen defect center type II defect, self-trapped exciton defect, color center defect, non-bridging oxygen vacancy center type I defect, non-bridging oxygen vacancy center type II defect, peroxide chain defect and silicon nanocluster defect.

4. The method according to claim 1, characterized in that The step three is to calculate the peak area of ​​each sub-peak curve in the fluorescence emission spectrum by using the mathematical software Origin.

5. The method according to claim 1, characterized in that The step 4 includes the following process: By formula It can be seen that the fluorescence signal released during the electron transition process at a specific position of a specific defect is often The excited state electron concentration is proportional to the released fluorescence signal. e represents the excited state electron concentration, τ r Represents the excited state electron decay relaxation time. For the same position of the same defect, τ r Usually fixed; According to existing research, when laser energy is relatively low, meaning only a small fraction of electrons are ionized during electron transitions, the concentration of excited-state electrons is approximately proportional to the concentration of ground-state electrons capable of ionization. Furthermore, the ground-state electrons within a point defect that readily absorb photon energy and undergo ionization are the lone pairs of electrons in the point defect. This leads to the conclusion that, in photoinduced fluorescence detection experiments, the lone-pair electron concentration within a point defect on the surface of a fused silica optical component is directly proportional to the peak area of ​​its corresponding sub-peak curve. Therefore, the relative concentrations of lone pair electrons corresponding to different point defects are determined based on the peak areas of the sub-peak curves corresponding to different point defects.

6. The method according to claim 5, characterized in that The relative concentrations of lone pair electrons corresponding to the different point defects determined in step 4 are: oxygen defect center type II defect 7.31%, self-trapped exciton defect 18.33%, color center defect 28.20%, non-bridging oxygen vacancy center type I defect 9.55%, non-bridging oxygen vacancy center type II defect 27.87%, and peroxide chain defect 8.74%.

7. The method according to claim 1, characterized in that According to the chemical structure and reaction rules of point defects, step five targets self-trapped exciton defects, because they contain incompletely broken Si-O bonds generated by mechanical force, and incompletely broken Si-O bonds are extremely easy to break under laser irradiation conditions to generate two lone pairs of electrons; and targets peroxide chain defects, because they are formed by the polymerization of two non-bridging oxygen vacancy center type I defects, they will be decomposed again under laser irradiation conditions into equal amounts of non-bridging oxygen vacancy center type I defects and non-bridging oxygen vacancy center type II defects. Therefore, the peroxide chain defect can be regarded as containing two lone pairs of electrons.

8. The method according to claim 1, characterized in that In step 5, based on the chemical structure of the point defect, it is determined that the oxygen defect center type II defect contains 2 lone pairs of electrons, the color center defect contains 1 lone pair of electrons, the non-bridging oxygen vacancy center type I defect contains 1 lone pair of electrons, and the non-bridging oxygen vacancy center type II defect contains 2 lone pairs of electrons.

9. The method according to claim 1, characterized in that In step 6, the relative concentration of defects at different points in the micro-defect area on the fused quartz processing surface is determined by the following formula: Among them, n i Indicates the relative concentration of different point defects, i is a different point defect; n ei is the relative concentration of lone pair electrons corresponding to the i-th type point defect, m i is the number of lone pair electrons of the i-th type point defect.

10. The method according to claim 9, characterized in that Step 6: Determine the relative concentrations of different point defects in the micro-defect area of ​​the fused quartz processing surface: oxygen defect center type II defect 5.31%, self-trapped exciton defect 13.31%, color center defect 40.90%, non-bridging oxygen vacancy center type I defect 13.87%, non-bridging oxygen vacancy center type II defect 20.23%, and peroxide chain defect 6.38%.

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