Laser Damage最新文献_第6页

Ultra-sensitive laser-based contamination detection for space applications 用于空间应用的超灵敏激光污染检测

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2602232

D. Raiser, J. Holburg, K. Mann, Ricardo Martins, A. Tighe

{"title":"Ultra-sensitive laser-based contamination detection for space applications","authors":"D. Raiser, J. Holburg, K. Mann, Ricardo Martins, A. Tighe","doi":"10.1117/12.2602232","DOIUrl":"https://doi.org/10.1117/12.2602232","url":null,"abstract":"Molecular contamination due to outgassing of organic materials in vacuum can be a source of significant degradation for space equipment, especially for sensitive optical instruments. Thus, on-ground contamination measurements in vacuum are essential to ensure the flight hardware cleanliness and for making in-flight performance predictions. A suitable detection technique shall work in-situ and in real-time, i.e. it shall be possible to measure the real-time build-up of contamination layers of a few nanometers and less on surfaces in vacuum in the presence of an outgassing source. In this paper we address a new experimental setup for controlled contamination and high-sensitivity spectroscopic analysis of the contaminants on representative material for typical space optics. The central method of choice for the detection of organic contaminants incorporated in this setup is laser-induced fluorescence (LIF), which provides the demanded distinguishability of the applied contamination species. Different excitation wavelengths in the UV spectral range are used. LIF measurements are accompanied by in operando verification of amount and species of the contaminants by a thermoelectric quartz crystal microbalance (TQCM) and a mass spectrometer (MS). This parameter study aims for exploring the laser parameter dependent detection limits and the temperature-dependent condensation process with respect to various substrate-contaminant combinations, in order to reveal strategies to prevent contamination for space applications.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116098301","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}

引用次数: 0

Bulk LIDT variances of fused silica: a material developer's perspective 熔融二氧化硅的体LIDT差异:材料开发人员的观点

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2599501

F. Nürnberg, B. Kühn

{"title":"Bulk LIDT variances of fused silica: a material developer's perspective","authors":"F. Nürnberg, B. Kühn","doi":"10.1117/12.2599501","DOIUrl":"https://doi.org/10.1117/12.2599501","url":null,"abstract":"Fused silica an optical material of choice for high energy laser applications offers a wide range of advantages in the UV and NIR wavelength range. Increasing laser performance (especially with critical fluences) require detailed information on laser induced damage threshold of the optical material itself, and not just the coating. Therefore, S-on-1 measurements according to ISO 21254-2 were commissioned from two different, experienced, and well-respected laboratories. The resulting LIDT (laser induced damage threshold) values are discussed in the context of current publications and differences are worked out. The measurements focus on the ns-pulse regime at 1064 and 355nm. The results differ up to a factor of 10 between different laboratories. In comparison to the literature study, we noticed a spread of measured values around a factor of 20. Non-binding recommendations of the standard as well as the optical setup have significant influence on the obtained LIDT values. However, depending on the optical design of the application, one or the other optical setup with the corresponding LIDT value can be relevant. In this respect there is no such thing as a single, generally applicable value. Nevertheless, a standard should enable material comparisons under sufficiently standardized conditions.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114521734","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}

引用次数: 0

Spatio-temporal evolution of femtosecond laser pulses in dielectric multi-layers controlling the damage behavior 飞秒激光脉冲在介质多层中的时空演化控制损伤行为

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2600528

M. Lenzner, Amir Khabbazi Oskouei, L. Emmert, M. Jupé, T. Willemsen, M. Steinecke, D. Ristau, W. Rudolph

引用次数: 0

Degradation of optical coatings induced by high-intensity, 515 nm, sub-picosecond burst-mode laser beam 高强度、515 nm、亚皮秒爆发模式激光束对光学涂层的影响

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2598668

U. Wegner, J. Meier, D. Rompotis, R. Secareanu, M. Emons, B. Monoszlai, M. Lederer

{"title":"Degradation of optical coatings induced by high-intensity, 515 nm, sub-picosecond burst-mode laser beam","authors":"U. Wegner, J. Meier, D. Rompotis, R. Secareanu, M. Emons, B. Monoszlai, M. Lederer","doi":"10.1117/12.2598668","DOIUrl":"https://doi.org/10.1117/12.2598668","url":null,"abstract":"We are presenting our observations regarding laser induced degradation of coated optics exposed to the burst-mode pulsetrain of the optical pump-probe laser systems (PP-laser) at the European X-ray Free Electron Laser (EuXFEL). Degradation happens on HR and AR coatings from various suppliers during the course of prolonged exposure to the 515 nm, 800 fs burst-mode radiation. Since the lasers typically operate 24/7, coatings degrade within a few weeks to several months, depending on the requested burst lengths and number of pulses and hence integrated burst energies. Reduced performance of pointing- and pulse energy-stability and a drop of average power of the non-collinear optical parametric amplifiers (NOPAs) result. As user facility, the EuXFEL strives to maximize up-time and to reliably provide high quality x-ray and optical laser beam lines for user experiments, which is compromised to some extent by the observed coating degradation. In this report we show our investigations into the effect so far. In collaboration with the coating manufacturer Layertec GmbH, an improved mirror coating was found, which prolongs optics life time by nearly a factor of 3.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132578544","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}

引用次数: 0

Analysis of cumulative probability of growth of damage sites at the National Ignition Facility 国家点火装置损伤点增长的累积概率分析

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2598943

Zhi-min Liao, C. Miller, D. Cross, C. Carr

引用次数: 0

515-nm, femtosecond laser mirror thin film damage competition 515nm，飞秒激光反射薄膜损伤竞赛

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2597206

R. Negres, C. Stolz, G. Batavičiūtė, A. Melninkaitis

{"title":"515-nm, femtosecond laser mirror thin film damage competition","authors":"R. Negres, C. Stolz, G. Batavičiūtė, A. Melninkaitis","doi":"10.1117/12.2597206","DOIUrl":"https://doi.org/10.1117/12.2597206","url":null,"abstract":"This year’s competition is a continuation of the 2020 thin film damage competition conducted with nanosecond (ns) laser pulses and aimed to survey state-of-the-art visible high reflectors in the femtosecond (fs) pulse length regime. The requirements for the coatings were a minimum reflection of 99.5% at 0 degrees incidence angle at 532 nm. The fs-laser source available for testing in 2021 delivered pulses at 515 nm; as a result, to accommodate both ns- and fs-damage tests on the same samples, the latter tests were conducted at an incidence angle of 25 degrees to re-center the reflection spectral band of the coatings, i.e., a blue shift from 532 nm to 515 nm. The choice of coating materials, design, and deposition method were left to the participants. Laser damage testing of samples received in 2020 and new sample submissions in 2021 was per- formed at a single testing facility using the S-on-1 standardized test protocol with a 200-fs pulse length laser system operating at 5 kHz in a single-longitudinal mode. A double-blind test assured sample and submitter anonymity. The damage performance results (LIDT), sample rankings, details of the deposition processes, coating materials and substrate cleaning methods are shared. These experiments enabled not only direct comparison among the participants but also the performance contrast in two different pulse length regimes. We found that different deposition methods and coating materials yield comparably high laser resistance in the fs-pulse regime. Namely, hafnia/silica, hafnia/alumina/silica or tantala/alumina/silica multilayer coatings were the most damage resistant under exposure to fs-laser pulses within the coating deposition groups. In contrast, hafnia/silica coatings by e-beam were identified as best performers in the ns-pulse regime.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115884804","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}

引用次数: 0

Detection of contamination of protective windows in Laser Powder Bed Fusion by means of a line scan camera 用线扫描相机检测激光熔床防护窗的污染

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2598589

Niklas Praetzsch, Hermann Sturzebecher, N. Pirch, F. Fischer, C. Haefner

引用次数: 0

The effect of chirp and wavelength for ultrafast bulk modification of solids with tightly focused laser pulses 啁啾和波长对紧密聚焦激光脉冲固体超快体改性的影响

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2603492

E. Mareev, E. Migal, F. Potemkin

引用次数: 0

In-situ cleaning organic contaminants on SiO2 sol-gel antireflection film by low-pressure air plasma 低压空气等离子体原位清洗SiO2溶胶-凝胶增透膜上的有机污染物

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2599668

Yuhai Li, Q. Bai, R. Shen, Peng Zhang, L. Lu, Xiao-Qing Yuan, X. Miao, W. Han, Hao Liu, Lin Huang, Caizhen Yao

{"title":"In-situ cleaning organic contaminants on SiO2 sol-gel antireflection film by low-pressure air plasma","authors":"Yuhai Li, Q. Bai, R. Shen, Peng Zhang, L. Lu, Xiao-Qing Yuan, X. Miao, W. Han, Hao Liu, Lin Huang, Caizhen Yao","doi":"10.1117/12.2599668","DOIUrl":"https://doi.org/10.1117/12.2599668","url":null,"abstract":"Organic contaminants on optical components can degrade optical properties, thus limiting the energy enhancement of highpeak- power laser systems. It is still challenging to remove organic contaminants on the SiO2 sol-gel antireflection film and avoid damage. In this work, a low-pressure air plasma in-situ cleaning technique and a chemical reaction model of plasma cleaning were proposed to study the removal of organic contaminants. The optical properties of sol-gel AR films suffered from organic contaminants were evaluated by transmittance and laser-induced damage threshold, which recovered completely after 5 minutes of plasma cleaning without damage. Meanwhile, the hydrophilicity of the surface and the surface free energy were significantly increased after plasma treating. Surface composition analysis indicated that the CH and C-C bonds were reduced considerably, while abundant C=C and C=O bonds were produced after plasma cleaning. Optical emission spectrum analyzed the reactive species and its concentration in the air plasma as a reference for simulation. The chemical interaction process of oxygen radicals with organic contaminants was simulated by reactive molecular dynamics. The results can provide a guide for optical components in-situ cleaning.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130999429","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}

引用次数: 0

Evaluation of alumina and silica coating materials for the NIF final turning mirrors NIF最终转向镜用氧化铝和二氧化硅涂层材料的评价

Laser Damage Pub Date : 2021-10-12 DOI: 10.1117/12.2598577

C. Stolz, J. Weng, Tsion Teklemarim, M. Brophy, P. Kupinski

引用次数: 1