The necessity for durable optics for higher laser fluences and intensities grows as new technological advancements allow for increased peak powers of laser systems. This has motivated a substantial effort in the last decades to better understand laser induced damage mechanisms and their mitigation. One major damage mechanism limitation to laser systems at high peak intensities is filamentation in fused silica glass, due to Kerr self-focusing of the light [1], that has been motivating an on-going effort for the last few decades [2]. The past studies had led to a set of simplified rules that allows for the operation of laser system below the onset point for this mechanism to take place, namely what is known as the IL rule (intensity times the collapse distance before filamenting equals some empirical constant) and the Bespalov-Talanov (BT) perturbation growth theory [3-6]. The need to increase the laser beam intensities and optimize the throughput, closer to the point where the optical propagation length in the material is comparable to the predicted filamentation distance, requires revisiting and improving our understanding of the current rule set. This is especially emphasized by the shortcomings of these two highly useful yet under-justified models for the relevant situations of large aperture beams where the contrast perturbations on the beam are the seed for the filamentations (i.e., and not whole beam collapse).
{"title":"Revised models for the underlying physics and mitigations of laser induced filamentation damage in large aperture laser optics","authors":"E. Feigenbaum, J. Di Nicola, J. Bude","doi":"10.1117/12.2536688","DOIUrl":"https://doi.org/10.1117/12.2536688","url":null,"abstract":"The necessity for durable optics for higher laser fluences and intensities grows as new technological advancements allow for increased peak powers of laser systems. This has motivated a substantial effort in the last decades to better understand laser induced damage mechanisms and their mitigation. One major damage mechanism limitation to laser systems at high peak intensities is filamentation in fused silica glass, due to Kerr self-focusing of the light [1], that has been motivating an on-going effort for the last few decades [2]. The past studies had led to a set of simplified rules that allows for the operation of laser system below the onset point for this mechanism to take place, namely what is known as the IL rule (intensity times the collapse distance before filamenting equals some empirical constant) and the Bespalov-Talanov (BT) perturbation growth theory [3-6]. The need to increase the laser beam intensities and optimize the throughput, closer to the point where the optical propagation length in the material is comparable to the predicted filamentation distance, requires revisiting and improving our understanding of the current rule set. This is especially emphasized by the shortcomings of these two highly useful yet under-justified models for the relevant situations of large aperture beams where the contrast perturbations on the beam are the seed for the filamentations (i.e., and not whole beam collapse).","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115798686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As a rule of thumb, laser-induced damage threshold (LIDT) is often reported in terms of a single number, without even mentioning the testing details. However, meaning of reported LIDT numbers could be different depending on the testing protocol used. Such differences are not always obvious to practitioners that are designing or building laser systems (users of LIDT numbers). Furthermore, the properties of laser sources used for LIDT testing could also be very different among various testing laboratories. Thus, in order to exemplify possible effects of LIDT testing details on reported values an experimental study is conducted, where direct comparison of the most popular testing protocols, namely 1-on-1, S-on-1, R-on-1, and Raster Scan, is made. Experiments were organized in such a way that all the tests for the wavelength of interest were done on the same sample (conventional high-reflectivity HR mirror) by using both injection-seeded pulses (single longitudinal mode) as well as non-seeded (multimode) pulses with comparable effective pulse duration. Two sufficiently large dielectric mirrors were tested. Experiments were conducted for fundamental- (1064 nm) and third- (355 nm) harmonic wavelengths of Nd:YAG laser. The LIDTs obtained by using distinct testing protocols as well as pertinent damage morphologies are directly compared and discussed.
{"title":"Direct comparison of laser-induced damage threshold testing protocols on dielectric mirrors: effect of nanosecond laser pulse shape at NIR and UV wavelengths","authors":"Rūta Pakalnytė, E. Pupka, A. Melninkaitis","doi":"10.1117/12.2536456","DOIUrl":"https://doi.org/10.1117/12.2536456","url":null,"abstract":"As a rule of thumb, laser-induced damage threshold (LIDT) is often reported in terms of a single number, without even mentioning the testing details. However, meaning of reported LIDT numbers could be different depending on the testing protocol used. Such differences are not always obvious to practitioners that are designing or building laser systems (users of LIDT numbers). Furthermore, the properties of laser sources used for LIDT testing could also be very different among various testing laboratories. Thus, in order to exemplify possible effects of LIDT testing details on reported values an experimental study is conducted, where direct comparison of the most popular testing protocols, namely 1-on-1, S-on-1, R-on-1, and Raster Scan, is made. Experiments were organized in such a way that all the tests for the wavelength of interest were done on the same sample (conventional high-reflectivity HR mirror) by using both injection-seeded pulses (single longitudinal mode) as well as non-seeded (multimode) pulses with comparable effective pulse duration. Two sufficiently large dielectric mirrors were tested. Experiments were conducted for fundamental- (1064 nm) and third- (355 nm) harmonic wavelengths of Nd:YAG laser. The LIDTs obtained by using distinct testing protocols as well as pertinent damage morphologies are directly compared and discussed.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131957326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Gischkat, D. Schachtler, Z. Balogh-Michels, R. Botha, André Mocker, B. Eiermann, Sven Günther
Cleaning of substrates prior to optical coating is an important step in the manufacturing of high performance optical components. It is well known that the ultra-sonic frequency used during substrate cleaning has a strong influence on the quality of the cleaning process and the number of remaining particles on the surface. Therefore, we have investigated the influence of ultra-sonic frequency during substrate cleaning on the laser resistance of antireflection coatings. For this purpose, a SiO2 / Ta2O5 AR-coating for a normal angle of incidence at 1064 nm was deposited onto fused silica substrates. Prior to deposition, the substrates were cleaned with cleaning processes. The applied ultra-sonic frequencies were 40, 80, 120 and 500 kHz. After deposition the LIDT was measured using a 1064 nm ns-pulsed laser test bench. It turned out that the different ultra-sonic-cleaning processes have a strong influence on the number of remaining particles on the surface of the cleaned samples. The counted number of particles with sizes greater < 83 nm were between 1320 and 12 particles for the different applied ultra-sonic frequencies. In consequence the different cleaned and AR-coated samples show different laser damage behavior. Nevertheless the measured particle density does not totally explain the differences in laser resistance.
{"title":"Influence of ultra-sonic frequency during substrate cleaning on the laser resistance of antireflection coatings","authors":"T. Gischkat, D. Schachtler, Z. Balogh-Michels, R. Botha, André Mocker, B. Eiermann, Sven Günther","doi":"10.1117/12.2536442","DOIUrl":"https://doi.org/10.1117/12.2536442","url":null,"abstract":"Cleaning of substrates prior to optical coating is an important step in the manufacturing of high performance optical components. It is well known that the ultra-sonic frequency used during substrate cleaning has a strong influence on the quality of the cleaning process and the number of remaining particles on the surface. Therefore, we have investigated the influence of ultra-sonic frequency during substrate cleaning on the laser resistance of antireflection coatings. For this purpose, a SiO2 / Ta2O5 AR-coating for a normal angle of incidence at 1064 nm was deposited onto fused silica substrates. Prior to deposition, the substrates were cleaned with cleaning processes. The applied ultra-sonic frequencies were 40, 80, 120 and 500 kHz. After deposition the LIDT was measured using a 1064 nm ns-pulsed laser test bench. It turned out that the different ultra-sonic-cleaning processes have a strong influence on the number of remaining particles on the surface of the cleaned samples. The counted number of particles with sizes greater < 83 nm were between 1320 and 12 particles for the different applied ultra-sonic frequencies. In consequence the different cleaned and AR-coated samples show different laser damage behavior. Nevertheless the measured particle density does not totally explain the differences in laser resistance.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115456022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amir Khabbazi Oskouei, L. Emmert, M. Steinecke, M. Jupé, D. Ristau, L. Jensen, W. Rudolph
Third harmonic generation (THG) in dielectric films with femtosecond laser pulses is used to study properties of dielectric thin films and stacks thereof below and above the 1-on-1 laser damage threshold. Deviations from the ideal cubic relationship between third-harmonic signal and incident fundamental fluence are a result of several fundamental processes. Their relative contributions are assessed by comparing results from LIDT and conversion efficiency measurements as well as beam profile and pump-probe studies.
{"title":"Third harmonic (TH) generation: a tool to study dielectric material properties near the laser induced damage threshold (LIDT)","authors":"Amir Khabbazi Oskouei, L. Emmert, M. Steinecke, M. Jupé, D. Ristau, L. Jensen, W. Rudolph","doi":"10.1117/12.2536440","DOIUrl":"https://doi.org/10.1117/12.2536440","url":null,"abstract":"Third harmonic generation (THG) in dielectric films with femtosecond laser pulses is used to study properties of dielectric thin films and stacks thereof below and above the 1-on-1 laser damage threshold. Deviations from the ideal cubic relationship between third-harmonic signal and incident fundamental fluence are a result of several fundamental processes. Their relative contributions are assessed by comparing results from LIDT and conversion efficiency measurements as well as beam profile and pump-probe studies.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115261416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The typical measurement error reported for laser damage tests is the fluence uncertainty due to inaccuracies in measuring the laser beam energy and its diameter. However, the inherent uncertainty of the testing protocol should also be included in the reported laser damage threshold error bars. Underestimating measurement errors can lead to false conclusions about the impact of process changes on laser damage resistance. In this study, four different laser damage precursor fluence distributions were created from randomly generated numbers and then evaluated using the ISO and raster scan laser damage test protocols to determine a laser damage threshold. Measurement errors are determined for flat top test beams for multiple cases. To add real world relevance, the impact of Gaussian test beams with beam pointing instability was modeled for the lowest accuracy laser damage precursor distribution. The impact of damage test area compared to optic dimension is also examined. The measurement error for the raster scan test ranged from 8% to 24% depending on the test beam spatial profile (flat top or Gaussian) and beam pointing stability. ISO measurement errors ranged from 4% to 250% for a simulated 10 J/cm2 test and was much more sensitive to the laser damage precursor distribution as well as the spatial profile and pointing of the test beam. Both testing protocols poorly predicted the laser damage resistance of large areas with Gaussian precursor laser damage distributions.
{"title":"Monte Carlo analysis of ISO and raster scan laser damage protocols","authors":"C. Stolz, R. Negres, J. Arenberg","doi":"10.1117/12.2536443","DOIUrl":"https://doi.org/10.1117/12.2536443","url":null,"abstract":"The typical measurement error reported for laser damage tests is the fluence uncertainty due to inaccuracies in measuring the laser beam energy and its diameter. However, the inherent uncertainty of the testing protocol should also be included in the reported laser damage threshold error bars. Underestimating measurement errors can lead to false conclusions about the impact of process changes on laser damage resistance. In this study, four different laser damage precursor fluence distributions were created from randomly generated numbers and then evaluated using the ISO and raster scan laser damage test protocols to determine a laser damage threshold. Measurement errors are determined for flat top test beams for multiple cases. To add real world relevance, the impact of Gaussian test beams with beam pointing instability was modeled for the lowest accuracy laser damage precursor distribution. The impact of damage test area compared to optic dimension is also examined. The measurement error for the raster scan test ranged from 8% to 24% depending on the test beam spatial profile (flat top or Gaussian) and beam pointing stability. ISO measurement errors ranged from 4% to 250% for a simulated 10 J/cm2 test and was much more sensitive to the laser damage precursor distribution as well as the spatial profile and pointing of the test beam. Both testing protocols poorly predicted the laser damage resistance of large areas with Gaussian precursor laser damage distributions.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121533007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The absorption of fused silica, CaF2, MgF2, and sapphire at VUV region (193.4 nm) and IR region (1070 nm) were measured. For this measurement, LID (Laser Induced Deflection) method was used because of its high sensitivity. We report the degradation behavior of materials by comparison of absorption before and after ArF laser irradiation, and also the ultra-minute absorption at IR wavelength. At each wavelength, the absorption of low OH fused silica before the laser irradiation showed the smallest. At ArF wavelength, sapphire and CaF2 showed higher laser durability than MgF2 and fused silica. At IR wavelength, VUV-transmissive sapphire showed a lower absorption compared to general sapphire.
{"title":"The direct absorption measurement of fused silica, CaF2, MgF2, and sapphire at VUV and IR region","authors":"K. Kato, C. Higashimura, S. Niisaka","doi":"10.1117/12.2536388","DOIUrl":"https://doi.org/10.1117/12.2536388","url":null,"abstract":"The absorption of fused silica, CaF2, MgF2, and sapphire at VUV region (193.4 nm) and IR region (1070 nm) were measured. For this measurement, LID (Laser Induced Deflection) method was used because of its high sensitivity. We report the degradation behavior of materials by comparison of absorption before and after ArF laser irradiation, and also the ultra-minute absorption at IR wavelength. At each wavelength, the absorption of low OH fused silica before the laser irradiation showed the smallest. At ArF wavelength, sapphire and CaF2 showed higher laser durability than MgF2 and fused silica. At IR wavelength, VUV-transmissive sapphire showed a lower absorption compared to general sapphire.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128513158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Liao, C. Carr, D. Cross, C. Miller, P. Miller, M. Monticelli, B. Olejniczak, R. Raman, D. VanBlarcom, B. Welday, P. Whitman, L. Wong, T. Suratwala
The final optics in the National Ignition Facility (NIF) are protected from target debris by sacrificial (disposable) debris shields (DDS) comprised of 3-mm thick Borofloat. While relatively inexpensive, Borofloat has been found to have bulk inclusions which, under UV illumination, damage, grow, and occasional erupt though the surface of the DDS. We have shown previously that debris generated from Input Surface Bulk Eruptions (ISBE) are a significant source of damage on NIF. Inclusion-free fused silica debris shield (FSDS) have been installed in between the DDS and the final optics on some NIF beam lines to test their efficacy in mitigating damage initiation. We will show results of the damage performance of the FSDS and its role in protecting the final optics. These results will help in our economic analysis of the potential benefits of using FSDS to protect NIF final optics.
{"title":"Damage performance of fused silica debris shield at the National Ignition Facility","authors":"Z. Liao, C. Carr, D. Cross, C. Miller, P. Miller, M. Monticelli, B. Olejniczak, R. Raman, D. VanBlarcom, B. Welday, P. Whitman, L. Wong, T. Suratwala","doi":"10.1117/12.2536452","DOIUrl":"https://doi.org/10.1117/12.2536452","url":null,"abstract":"The final optics in the National Ignition Facility (NIF) are protected from target debris by sacrificial (disposable) debris shields (DDS) comprised of 3-mm thick Borofloat. While relatively inexpensive, Borofloat has been found to have bulk inclusions which, under UV illumination, damage, grow, and occasional erupt though the surface of the DDS. We have shown previously that debris generated from Input Surface Bulk Eruptions (ISBE) are a significant source of damage on NIF. Inclusion-free fused silica debris shield (FSDS) have been installed in between the DDS and the final optics on some NIF beam lines to test their efficacy in mitigating damage initiation. We will show results of the damage performance of the FSDS and its role in protecting the final optics. These results will help in our economic analysis of the potential benefits of using FSDS to protect NIF final optics.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122532765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This year’s competition aimed to survey state-of-the-art near-IR high reflectors. The requirements of the coatings were a minimum reflection of 99.5% at 0 degrees incidence angle light at 1064-nm. The choice of coating materials, design, and deposition method were left to the participants. Laser damage testing was performed at a single testing facility using the ISO standard protocol with a 3-ns pulse length laser system operating at 5 Hz in a multi-longitudinal mode. A double blind test assured sample and submitter anonymity. The damage performance results (LIDT) and sample rankings are compared to last year’s competition results where raster scanning test protocol was involved. In addition, details of the deposition processes, coating materials and substrate cleaning method are also shared. We found that hafnia/silica multilayer coatings deposited by e-beam are the most damage resistant under the test conditions. LIDT differences between testing protocols were up to 38 J/cm2, with ISO-reported LIDT results generally higher than those determined by raster scanning.
{"title":"1064-nm, nanosecond laser mirror thin film damage competition","authors":"R. Negres, C. Stolz, Michael D. Thomas, M. Caputo","doi":"10.1117/12.2531861","DOIUrl":"https://doi.org/10.1117/12.2531861","url":null,"abstract":"This year’s competition aimed to survey state-of-the-art near-IR high reflectors. The requirements of the coatings were a minimum reflection of 99.5% at 0 degrees incidence angle light at 1064-nm. The choice of coating materials, design, and deposition method were left to the participants. Laser damage testing was performed at a single testing facility using the ISO standard protocol with a 3-ns pulse length laser system operating at 5 Hz in a multi-longitudinal mode. A double blind test assured sample and submitter anonymity. The damage performance results (LIDT) and sample rankings are compared to last year’s competition results where raster scanning test protocol was involved. In addition, details of the deposition processes, coating materials and substrate cleaning method are also shared. We found that hafnia/silica multilayer coatings deposited by e-beam are the most damage resistant under the test conditions. LIDT differences between testing protocols were up to 38 J/cm2, with ISO-reported LIDT results generally higher than those determined by raster scanning.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126974143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Bartels, P. Allenspacher, W. Riede, H. Schröder, D. Wernham
The ESA satellite Aeolus was successfully launched into space in August 2018 and measures global wind profiles using the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN features a high-power UV laser source emitting nanosecond pulses at a wavelength of 355 nm. A crucial step in the development of ALADIN was the mitigation of laser-induced contamination (LIC). In this work we assess the opportunity of removing LIC deposits using UV/ozone cleaning with a mercury lamp. We find that UV/ozone cleaning is a very effective tool for removing laser-induced molecular contamination induced by the volatile components of a material mix representative of the ALADIN laser. Furthermore, we show that optical surfaces on which a contamination is removed via UV/ozone cleaning behave similar to pristine optical surfaces with respect to their susceptibility to subsequent LIC as well as laser-induced damage. These results demonstrate that UV/ozone cleaning is a useful and safe way of cleaning optical surfaces after ground-based thermal vacuum/lifetime testing.
{"title":"Removal of laser-induced contamination on ALADIN laser optics by UV/ozone cleaning","authors":"N. Bartels, P. Allenspacher, W. Riede, H. Schröder, D. Wernham","doi":"10.1117/12.2535772","DOIUrl":"https://doi.org/10.1117/12.2535772","url":null,"abstract":"The ESA satellite Aeolus was successfully launched into space in August 2018 and measures global wind profiles using the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN features a high-power UV laser source emitting nanosecond pulses at a wavelength of 355 nm. A crucial step in the development of ALADIN was the mitigation of laser-induced contamination (LIC). In this work we assess the opportunity of removing LIC deposits using UV/ozone cleaning with a mercury lamp. We find that UV/ozone cleaning is a very effective tool for removing laser-induced molecular contamination induced by the volatile components of a material mix representative of the ALADIN laser. Furthermore, we show that optical surfaces on which a contamination is removed via UV/ozone cleaning behave similar to pristine optical surfaces with respect to their susceptibility to subsequent LIC as well as laser-induced damage. These results demonstrate that UV/ozone cleaning is a useful and safe way of cleaning optical surfaces after ground-based thermal vacuum/lifetime testing.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114253969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaofeng Liu, Liping Peng, Xi Wang, Xiaoshuang Wang, Da-wei Li, Yuanan Zhao, J. Shao
The damage characteristics of the indium-tin-oxide (ITO) layer and the polyimide (PI) layer, which are two constituent components of a LCD, induced by a high-peak-power laser and a high-average-power laser are investigated. The PI alignment layer is pinned on the ITO film to imitate the structure of the LCD as much as possible in our study. Under the irradiation of the high-peak-power laser, the damage process of the PI/ITO/SUB sample involves thermally induced plastic deformation, followed by cooling when the irradiation fluence is near the LIDT, and rupture when the irradiation fluence is higher. High-average-power laser irradiation results in damaged morphologies of the bulge for the PI/ITO/SUB sample. The temperature distributions induced by the pulsed laser and the high-repetition-rate laser are investigated. The damage is attributed to the intrinsic heat absorption of the ITO films. Under the irritation of the high-peak-power laser, the temperature rises rapidly to a high degree at very short time because of the instant strong absorption in ITO layer, and resulted in vaporization of ITO layer consequently. Subsequently, the vaporized ITO breaks through the surface PI and develops the visible damage. However, under the irritation of high-average-power laser, ITO layer absorbs laser energy, resulting in a slow temperature rise and a small temperature gradient.
{"title":"Laser damage characteristics of indium-tin-oxide film and polyimide film irradiated by 1064nm high power lasers","authors":"Xiaofeng Liu, Liping Peng, Xi Wang, Xiaoshuang Wang, Da-wei Li, Yuanan Zhao, J. Shao","doi":"10.1117/12.2536330","DOIUrl":"https://doi.org/10.1117/12.2536330","url":null,"abstract":"The damage characteristics of the indium-tin-oxide (ITO) layer and the polyimide (PI) layer, which are two constituent components of a LCD, induced by a high-peak-power laser and a high-average-power laser are investigated. The PI alignment layer is pinned on the ITO film to imitate the structure of the LCD as much as possible in our study. Under the irradiation of the high-peak-power laser, the damage process of the PI/ITO/SUB sample involves thermally induced plastic deformation, followed by cooling when the irradiation fluence is near the LIDT, and rupture when the irradiation fluence is higher. High-average-power laser irradiation results in damaged morphologies of the bulge for the PI/ITO/SUB sample. The temperature distributions induced by the pulsed laser and the high-repetition-rate laser are investigated. The damage is attributed to the intrinsic heat absorption of the ITO films. Under the irritation of the high-peak-power laser, the temperature rises rapidly to a high degree at very short time because of the instant strong absorption in ITO layer, and resulted in vaporization of ITO layer consequently. Subsequently, the vaporized ITO breaks through the surface PI and develops the visible damage. However, under the irritation of high-average-power laser, ITO layer absorbs laser energy, resulting in a slow temperature rise and a small temperature gradient.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114659983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：