BS PD ISO/TR 20811:2017描述了测量数据的设置、测试程序和分析，以调查 空间和真空应用中的激光诱导分子污染（LIMC）。LIMC是由于强光辐射与光学表面的相互作用而在光学表面形成的沉积 排出气体，尤其是从有机材料中排出分子。这是一种分子污染现象 它与颗粒污染不同，颗粒污染可能发生在制造、组装和生产过程中， 光学元件的集成或测试。 激光诱导沉积的形成会导致光学元件性能的恶化 系统LIMC可以增加相位畸变、散射和吸收。LIMC尤其重要 如果激光系统在真空中以短波长和短脉冲持续时间运行。这样 一种情况下，即使污染物质的分压很小，在10？5 hPa可能会产生强烈的 对光学性能的负面影响。研究还表明，激光损伤阈值 如果使用激光，可以减少10倍甚至更多- 涉及诱发沉积。激光诱导的分子污染和激光诱导的损伤都是一种现象 激光辐射与光学表面的相互作用在LIMC中起主要作用，而LIMC具有额外的 分子污染。因此，本文件根据ISO 21254（所有部分）进行处理 规定了测定激光损伤阈值的试验方法。该方法用于定性评估被调查材料是否导致 在光学表面上的低浓度沉积- 高能纳秒存在下的压力环境 波长为355nm的脉冲激光照射。由于光化学表面反应的性质， 这一结果不能直接转移到辐射特性改变的情况 （尤其是波长、重复频率、脉冲持续时间等）。由于激光器的非线性增长 污染及其检测方法，该技术不提供定量手段 评估矿床，因此，应将其视为一种将材料与 关于它们的激光污染行为。此外，选择具有代表性的污染量不在本方法的范围之内 材料——代表材料附近存在的材料分压 真实激光系统中的光学表面。这是通过其他方法仔细推导出来的，是强制性的 在应用此方法之前要固定的参数。交叉引用:ISO 21254（所有部分）ISO 11145:2016ISO 14644-8:2013 ED2ASTM E1559-09ISO 11146-1:2005 Ed 1ISO 15388: 2012ASTM E595-07ECSS-Q-ST-70-02购买时可用的当前修订版包含在本文件的购买中。

BS PD ISO/TR 20811:2017 describes the setup, test procedure and analysis of measured data for investigation of laser-induced molecular contamination (LIMC) for space and vacuum applications.LIMC is the formation of depositions on optical surfaces due to interaction of intense light radiation with outgassing molecules especially from organic materials. It is a phenomenon of molecular contamination and it is distinguished from particle contamination, which can occur during manufacturing, assembly, integration or test of the optical components.Formation of laser-induced depositions can lead to deterioration of the performance of an optical system. Phase distortion, scattering and absorption can be increased by LIMC. LIMC is of particular relevance, if a laser system is operated in vacuum at short wavelength and short pulse duration. In such a case, even small partial pressure of contamination material in the range of 10?5 hPa could have strong negative impact on optical performance. It was also shown that the laser-induced damage threshold could be reduced by a factor of 10 and more if laser-induced depositions are involved.Laser-induced molecular contamination and laser-induced damage are both phenomena, for which the interaction of laser radiation with optical surfaces plays a major role, in case of LIMC with additional molecular contamination. Therefore, this document is treated in relation to ISO 21254 (all parts) which specifies the test methods for the determination of laser-induced damage thresholds.This method was derived to evaluate qualitatively, whether the material under investigation causes deposits on optical surfaces in a low-pressure environment in the presence of high-energy nanosecond pulsed laser irradiation at a wavelength of 355 nm. Due to the nature of photochemical surface reactions, this result cannot be directly transferred to scenarios where the properties of the irradiation are altered (especially wavelength, repetition rate, pulse duration, etc.). Due to the non-linear growth of the laserinduced contamination and its detection methods, this technique does not provide quantitative means to evaluate the deposit and, therefore, it should be seen as a means to compare materials relatively with respect to their laser-induced contamination behaviour.Furthermore, it is out of the scope of this method to select representative quantities of contamination materials - representative with respect to the material partial pressure present in the vicinity of the optical surface in a real laser system. This is carefully derived with other methods and is a mandatory parameter to be fixed before applying this method.Cross References:ISO 21254 (all parts)ISO 11145:2016ISO 14644-8:2013 ED2ASTM E1559 - 09ISO 11146-1:2005 Ed 1ISO 15388:2012ASTM E595 - 07ECSS-Q-ST-70-02CAll current amendments available at time of purchase are included with the purchase of this document.