Evaluation method for gas release and dust production of continuous laser system structure material

Abstract

The invention discloses an evaluation method for gas release and dust production of a continuous laser system structural material, and belongs to the field of optical system cleaning.The evaluation method comprises the steps that S1, a to-be-tested sample and a reflector sample are prepared; s2, putting the to-be-tested sample and a part of the reflector sample into an outgassing dust production testing device, putting the reflector sample in the front-back direction of the spatial position of the to-be-tested sample, and then carrying out a laser irradiation outgassing dust production experiment; s3, simultaneously putting the polluted reflecting mirror sample and the unpolluted reflecting mirror sample into a temperature rise testing device, and recording temperature rise data of the polluted reflecting mirror sample and the unpolluted reflecting mirror sample; s4, comparing the temperature rise data of the test sample with a temperature threshold value to quantitatively evaluate the gas release and dust production capacity of the laser system structure material. According to the invention, through the change of the temperature rise data of the reflecting mirror, the gas release and dust production capability of the material can be accurately evaluated, and a theoretical support is provided for optimizing material selection and formulating targeted protection measures.

Description

Technical Field

[0001] The invention belongs to the field of optical system cleaning, and in particular relates to an evaluation method for outgassing and dust generation of structural materials in a continuous laser system. Background Art

[0002] Compared to conventional power laser devices, the radiation energy that optical components are subjected to during operation in high-power laser systems increases exponentially, which places revolutionary demands on the damage threshold and environmental adaptability of optical precision devices. It is worth noting that even with the continuous improvement of precision processing technology today, it is still difficult to avoid the dual impact of microstructural defects and manufacturing tolerances on the surface of optical components. Such microscopic defects can lead to diffuse reflection and secondary light interference during beam transmission. This type of derived stray light not only causes more than 4% energy loss in the main optical path, but is also likely to induce system-level resonance damage through multipath propagation. A 2020 research report from the Lawrence Livermore National Laboratory in the United States pointed out that for every 1μJ / cm² increase in coaxial stray light, the risk of thermal stress distortion in the optical component coating layer will increase by 18%.

[0003] Even more serious is that when stray light irradiates the surface of carbon fiber composite materials, a key framework material in the optical path of high-power lasers, for a long time, trace contaminants are generated. As a high-performance material, carbon fiber composite materials play a vital supporting role in the optical path of high-power lasers. However, after prolonged exposure to stray light, their surface undergoes a series of chemical reactions or physical changes, releasing trace contaminants. These contaminants are transported along the optical path and eventually deposited on the surfaces of large-aperture optical components. As core components in high-power laser systems, the surface cleanliness and optical performance of large-aperture optical components are directly related to the performance of the entire system. When contaminants are deposited on their surfaces, they alter the optical properties of the optical components, reducing their transmittance and reflectivity, thereby exposing them to a significant risk of damage. This damage not only degrades the performance of the optical components but can also trigger a series of chain reactions, further affecting the stability and reliability of the entire high-power laser system. For example, the system for simulating the performance degradation of optical components induced by dust pollution under stray light irradiation disclosed in patent application number CN202410164318.7, in which, when studying the outgassing and dust generation of cavity materials under laser irradiation, it is necessary to use equipment such as microscopes and particle counters to observe the number and particle size of pollutants on the surface of the reflector to obtain the material's ability to outgas and generate dust and its impact on the contamination of the reflector surface. However, the reflector is small in size, and when observing with a microscope, it is necessary to divide the reflector surface into multiple areas and examine them one by one, which is very time-consuming and labor-intensive. Given the severity and urgency of the aforementioned issues, there is an urgent need to regulate the clean environment within high-power laser systems and establish a method for evaluating outgassing and dust generation by the structural materials of continuous laser systems. By studying clean environment regulation technologies, it is possible to effectively reduce the level of pollutants within high-power laser systems and the possibility of stray light generating pollutants, thereby providing a cleaner and more stable working environment for optical components. Furthermore, by studying outgassing and dust generation by the structural materials of continuous laser systems, effective protective measures and repair methods can be explored, improving the anti-pollution and damage repair capabilities of optical components, extending their service life, and ensuring the long-term stable operation of high-power laser systems. This is of great significance not only for improving the performance of my country's high-power laser systems, but also for the development of new technologies and new technologies. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] To achieve these objectives and other advantages of the present invention, a method for evaluating outgassing and dust generation of structural materials in a continuous laser system is provided, comprising: S1. Prepare the sample to be tested and the reflector sample; S2. Place the sample to be tested and a portion of the reflector samples into a gas release and dust generation test device, and place the reflector sample in the front and back directions of the spatial position of the sample to be tested, and then conduct a laser irradiation gas release and dust generation experiment; S3. Place the contaminated front and rear reflector samples and the uncontaminated reflector sample into a temperature rise test device at the same time, and record the temperature rise data of both. S4, and compare the temperature rise data in S3 with the set temperature threshold. If the temperature rise data is greater than the temperature threshold, the gas release and dust generation capacity of the test sample is strong; if the temperature rise data is less than the temperature threshold, the gas release and dust generation capacity of the test sample is weak. By comparing the temperature rise data of the test sample with the temperature threshold, the gas release and dust generation capacity of the laser system structural material can be quantitatively evaluated.

[0006] Preferably, in S1, the test sample is one of carbon fiber composite material, epoxy resin glue, Invar, titanium alloy, aluminum alloy, glass-ceramic, quartz fabric, and copper.

[0007] Preferably, the material of the reflector sample is configured as metal or dielectric film; Wherein, the average reflectivity of the reflector sample is greater than 99.9%.

[0008] Preferably, in S1 , all test samples are treated by a combination of ultrasonic cleaning and deionized water rinsing.

[0009] Preferably, in S2, the reflector sample is placed in the front and rear directions of the sample to be tested, the laser irradiation time in the experiment is 30 seconds, and it is left to stand for 24 hours after irradiation.

[0010] Preferably, in S3, the temperature rise data is the difference between the maximum temperature of the reflector sample surface and the ambient temperature.

[0011] Preferably, the temperature rise testing device comprises: a laser for generating laser light to irradiate the reflector sample; Reflector I, Reflector II and Reflector III for preliminary guidance of the laser light path; The light beam transmitted by the reflector III is partially separated to the power meter and the wedge of the beam trap, and the main light path of the light beam is transmitted to the optical beam expander; Wherein, the reflector sample is arranged at the light path output end of the optical beam expander.

[0012] The present invention has at least the following beneficial effects: 1. By using the temperature rise of the reflector, the outgassing and dust generation capacity of the material can be accurately and quickly assessed, providing a scientific basis for the design and operation of the laser system and identifying potential contamination risks in advance, thereby effectively reducing the performance degradation and damage risk of optical components caused by contaminant deposition; 2. This invention deeply studies the outgassing and dust generation patterns of typical structural materials such as carbon fiber composites, and reveals the mechanism of stray light-induced outgassing and dust generation. This provides theoretical support for optimizing material selection and formulating targeted protective measures, helping to improve the anti-pollution and damage repair capabilities of optical components, extend their service life, and ensure the long-term stable operation of high-power laser systems. 3. By analyzing the temperature rise data and surface particle morphology of the reflector before and after contamination, the present invention can quantitatively evaluate the impact of contaminants on the performance of optical components, optimize the clean environment inside the laser system, reduce contaminants generated by stray light, significantly improve the transmittance and reflectivity of optical components, and enhance the performance and reliability of the entire system.

[0013] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the overall structure of the gas release and dust generation testing device of the present invention; Figure 2 This is the microscopic morphology of the surface of the contaminated test mirror I; Figure 3 This is the element content map of the contaminated test mirror I surface; Figure 4 This is the microscopic morphology of the surface of the contaminated test mirror II; Figure 5 This is the element content diagram of the contaminated test mirror II surface; Figure 6 Schematic diagram of the structure of the temperature rise test device in the present invention; Figure 7 This is the test data diagram of the temperature rise on the surface of the contaminated test mirror.

[0015] Figure numerals: 1. Laser, 2. Reflector I, 3. Reflector II, 4. Reflector III, 5. Power meter, 6. Beam trap, 7. Optical wedge, 8. Optical beam expander, 9. Continuous laser, 10. Reflector IV, 11. Reflector V, 12. Reflector VI, 13. Beam splitter wedge, 14. Beam collector, 15. Test power meter, 16. Beam expander, 17. Test sample, 18. Test reflector I, 19. Test reflector II, 20. Sealed box. DETAILED DESCRIPTION

[0016] The present invention will be described in further detail below with reference to the accompanying drawings, so that those skilled in the art can implement the invention with reference to the description. It should be understood that terms such as "having," "comprising," and "including" as used herein do not exclude the presence or addition of one or more other elements or combinations thereof. It should be noted that in the description of the present invention, the orientations or positional relationships indicated by terms are based on the orientations or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed or operate in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance. In the description of the present invention, unless otherwise expressly specified or limited, the terms "installed," "provided with," "sleeved / connected," and "connected" should be understood broadly. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or internal communication between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances. Furthermore, in the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0017] The present invention provides a method for evaluating outgassing and dust generation of a continuous laser system structural material, comprising: S1, preparing the sample to be tested 17 and the reflector sample; S2. Place the sample to be tested 17 and a portion of the reflector samples into a gas release and dust generation test device, and place the reflector samples in the front and back directions of the spatial position of the sample to be tested 17, and then perform a laser irradiation gas release and dust generation test; S3. Place the contaminated reflector sample and the uncontaminated reflector sample into a temperature rise test device at the same time, and record the temperature rise data of both. S4, and compare the temperature rise data in S3 with the set temperature threshold. If the temperature rise data is greater than the temperature threshold, the gas release and dust generation capacity of the test sample 17 is strong; if the temperature rise data is less than the temperature threshold, the gas release and dust generation capacity of the test sample 17 is weak. By comparing the temperature rise data of the test sample 17 with the temperature threshold, the gas release and dust generation capacity of the laser system structural material can be quantitatively evaluated.

[0018] Working principle: Step 1: Prepare the sample 17 to be tested and the reflector sample. Select typical structural materials commonly used in high-power laser systems, such as metals, ceramics, or composite materials, process them into standard-sized sample blocks, and clean them to remove surface impurities. At the same time, select the same reflector material as that used in the actual laser system and ensure its surface is clean and free of contamination after cleaning. Through these steps, the sample 17 to be tested and the reflector sample are prepared, providing high-quality experimental objects for subsequent experiments. In actual operation, the test samples 17 were made of carbon fiber composite materials, epoxy resin glue, Invar steel, titanium alloy, aluminum alloy, microcrystalline glass, quartz fabric, and copper. High-reflectivity metal or dielectric film reflectors were selected as the experimental reflector materials. The average reflectivity of the reflector samples was greater than 99.9%. All test samples 17 underwent a strict cleaning process before the experiment. A combination of ultrasonic cleaning and deionized water rinsing was used to effectively remove impurities and contaminants on the sample surface. Step 2: Build a gas release and dust generation test system for typical structural materials in a high-intensity laser system. Perform a laser irradiation gas release and dust generation experiment on the sample to be tested 17 to simulate the gas release and dust generation process of the material irradiated by stray light in the laser system. Place a reflector in the system to simulate the situation where dust pollution generated by the stray light irradiation material is deposited on the reflector surface. In actual operation, all experiments were conducted in a Class 1000 cleanroom. Laser 1 was a 1064nm continuous laser 9 with a laser spot diameter of 1.68mm. The laser irradiation time was 30s. The reflector sample was placed before and after the sample to be tested 17. After laser irradiation, it was necessary to let it stand for 24 hours for the contaminants to settle.

[0019] Step 3: Test the contaminated reflector and the uncontaminated reflector to characterize the surface contaminants. After the laser irradiation experiment, remove the contaminated reflector and the uncontaminated control reflector and perform characterization tests on them separately. Use equipment such as atomic force microscopy (AFM), scanning electron microscopy (SEM), particle counter, and X-ray photoelectron spectroscopy (XPS) to analyze changes in the microscopic morphology, optical properties, and chemical composition of the reflector surface. Compare the test results of the reflector before and after contamination to evaluate the impact of contaminants on the reflector performance and provide a scientific basis for subsequent evaluation. During the actual operation, the pollutant tests include the morphology of the reflector pollutants, the elemental composition of the reflector pollutants, the number and size of the particles released and produced by dust. The atomic force microscope (AFM) is used to analyze the nano-scale micromorphology of the reflector surface, and the scanning electron microscope (SEM) is used to observe the microstructure and pollutant distribution of the reflector surface.

[0020] Step 4: Build a reflector temperature rise test setup, including a continuous laser 9, a fixture for securing the reflector sample, a temperature sensor, and a thermal imager. Secure the contaminated and uncontaminated reflectors to the experimental target area, then activate the continuous laser 9 to conduct a temperature rise test. The temperature sensor and thermal imager monitor the temperature changes and distribution on the reflector surface in real time, recording the temperature rise data. Combining these temperature rise results with the previous characterization test data, a comprehensive evaluation of the outgassing and dust generation capabilities of the laser system's structural materials and their impact on reflector performance is conducted.

[0021] Example: The temperature rise test device used in the evaluation method of gas release and dust generation of continuous laser system structural materials in the present invention is as follows: Figure 1 The device shown includes: a laser 1 for generating laser light to irradiate the reflector sample; Reflector I2, reflector II3 and reflector III4 for preliminary guidance of the laser light path; The light beam transmitted by the reflector III 4 is partially separated to the power meter 5 and the optical wedge 7 of the beam trap 6, and the main optical path of the light beam is transmitted to the optical beam expander 8; The reflector sample is arranged at the light path output end of the optical beam expander 8 .

[0022] Preparation of the test sample 17 and the reflector sample: The samples to be processed are immersed in acetone, ethanol and ultrapure water in turn, and ultrasonic cleaning is performed separately. Ultrasonic cleaning is an efficient cleaning method that uses the cavitation effect generated by high-frequency sound waves to remove tiny particles, organic matter and stains attached to the surface of the sample. In this experiment, the ultrasonic cleaning time of each solvent was set to 10 minutes. This time length has been verified by preliminary experiments to be able to effectively remove pollutants on the surface of the sample while avoiding potential damage to the sample itself. After the ultrasonic cleaning is completed, the sample is removed from the cleaning liquid. In order to prevent the residual solvent on the surface of the sample from re-adsorbing impurities in the air during the natural drying process, this experiment uses clean air for drying. Clean air is filtered and purified to ensure that it does not contain particulate matter or chemical components that may contaminate the sample, thereby ensuring the purity and performance stability of the sample in subsequent experiments.

[0023] Laser irradiation outgassing and dust generation experiments were carried out on carbon fiber composite materials using a typical structural material outgassing and dust generation test system in a high-intensity laser system to simulate the outgassing and dust generation process of materials irradiated by stray light in the laser system. All experiments were carried out in a Class 1000 clean room. Continuous laser 9 was a 1064nm continuous laser with a laser spot diameter of 1.68mm. The laser irradiation time in the experiment was 30s, and a reflector was placed in the system to simulate the situation where dust pollution caused by stray light irradiation materials is deposited on the surface of the reflector. The reflector was placed before and after the irradiated sample. The laser irradiation outgassing and dust generation experiment needed to be left still for 24 hours after laser irradiation for the contaminants to settle. Continuous laser light 9 passes through reflector IV 10, reflector V 11, reflector VI 12, beam splitter wedge 13, beam dump 14, and test power meter 15, and then through beam expander 16 (5x beam expansion) before irradiating test sample 17. Test reflector 18I and test reflector II 19 are placed directly below test sample 17, respectively. Test sample 17 is secured within a sealed box 20. When the laser beam passes through beam splitter wedge 13, a laser beam is reflected from each of its upper and lower surfaces. Beam dump 14 collects one of these beams, and test power meter 15 collects the other beam to monitor real-time laser power.

[0024] In order to deeply analyze the dust pollution characteristics of carbon fiber composite materials under laser irradiation, a systematic characterization test was carried out on the contaminated reflector. The morphology and element distribution of the pollutants on the reflector surface were tested and analyzed in detail using a scanning electron microscope (SEM). Figure 2-Figure 5As shown, the test results show that after the stray light irradiated the carbon fiber composite material, particulate pollutants and molecular pollutants were deposited on the surface of the test reflector Ⅰ18 in the front, while only diffused molecular pollutants were deposited on the surface of the test reflector Ⅱ19 in the rear. Further analysis showed that these pollutants were all carbon pollutants, and their sources were closely related to the thermal decomposition and chemical reactions of the carbon fiber composite material under laser irradiation. The high-resolution imaging function of the SEM can clearly observe the microscopic morphology of the pollutants, and combined with energy dispersive X-ray spectroscopy (EDS) analysis, the elemental composition of the pollutants can be quantitatively analyzed. This comprehensive characterization method not only provides an important basis for understanding the contamination mechanism of carbon fiber composites in a laser environment, but also lays the foundation for the subsequent material optimization and formulation of pollution control strategies; The contaminated reflector and the uncontaminated reflector are tested using a temperature rise testing device, wherein the temperature rise testing device comprises: a laser for generating laser light to irradiate the reflector sample; Reflector I2, reflector II3 and reflector III4 for preliminary guidance of the laser light path; The light beam transmitted by the reflector III is partially separated and sent to the power meter and the optical wedge 7 of the beam trap 6, and the main optical path of the light beam is transmitted to the optical beam expander 8; The reflector sample is set at the optical output end of the optical beam expander 8. The reflector is fixed in the temperature rise test target area (located at the optical output end of the beam expander) and a reflector temperature rise test is performed to simulate the reflector load condition during strong laser operation after dust pollution. The test results of the microstructure and element content of the test reflector I18 and the test reflector II19 are as follows: Figure 2-Figure 5 As shown. According to the reflector temperature rise data (such as Figure 7 The outgassing and dust generation capabilities of laser system structural materials are evaluated using the test results (microstructure and elemental content) and the test results (microstructure and elemental content). Contamination increases the reflector surface's thermal absorption of intense laser light. The contaminated surfaces of test mirrors I18 and II19 exhibit varying degrees of temperature rise, which is essentially linear with the laser power density. The temperature rise on the reflector surface is relatively large, primarily due to the presence of both layered molecular contaminants and dispersed particulate contaminants. The higher the reflector surface temperature rise, the greater the impact of the test sample's dust generation on the laser system, and the greater its dust generation capacity. In this example, the reflector surface temperature rise is required to be less than 3°C. The test sample also requires additional cleaning treatment to control dust generation.

[0025] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for evaluating outgassing and dust generation of structural materials in a continuous laser system, characterized in that: include: S1. Prepare the sample to be tested and the reflector sample; S2. Place the sample to be tested and a portion of the reflector samples into a gas release and dust generation test device, and place the reflector sample in the front and back directions of the spatial position of the sample to be tested, and then conduct a laser irradiation gas release and dust generation experiment; S3. Place the contaminated reflector sample and the uncontaminated reflector sample into a temperature rise test device at the same time, and record the temperature rise data of both. S4, and compare the temperature rise data in S3 with the set temperature threshold. If the temperature rise data is greater than the temperature threshold, the gas release and dust generation capacity of the test sample is strong; if the temperature rise data is less than the temperature threshold, the gas release and dust generation capacity of the test sample is weak. By comparing the temperature rise data of the test sample with the temperature threshold, the gas release and dust generation capacity of the laser system structural material can be quantitatively evaluated.

2. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: In S1, the test sample is one of carbon fiber composite material, epoxy resin glue, Invar, titanium alloy, aluminum alloy, microcrystalline glass, quartz fabric, and copper.

3. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: The material configuration of the reflector sample is metal or dielectric film; Wherein, the average reflectivity of the reflector sample is greater than 99.9%.

4. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: In S1, all test samples were processed by a combination of ultrasonic cleaning and deionized water rinsing.

5. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: In S2, the reflector sample is placed in the front and rear directions of the sample to be tested. The laser irradiation time in the experiment is 30 seconds, and it is left to stand for 24 hours after irradiation.

6. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: In S3, the temperature rise data is the difference between the maximum temperature of the reflector sample surface and the ambient temperature.

7. The method for evaluating outgassing and dust generation of structural materials in a continuous laser system according to claim 1, wherein: The temperature rise testing device comprises: a laser for generating laser light to irradiate the reflector sample; Reflector I, Reflector II and Reflector III for preliminary guidance of the laser light path; The light beam transmitted by the reflector III is partially separated to the power meter and the wedge of the beam trap, and the main light path of the light beam is transmitted to the optical beam expander; Wherein, the reflector sample is arranged at the light path output end of the optical beam expander.

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