按照国标的光学薄膜损伤阈值测试装置

按照ＩＳＯ／ＤＩＳ１１２５４ 光学表面激光损伤阈值测量标准和等价国标的要求,建立了薄膜的１μｍ ＹＡＧ脉冲激光损伤阈值定量测试装置,对脉冲能量、脉冲持续时间、光束分布及相应的不确定度均进行了测试。     

激光量热法测量红外光学薄膜吸收

建立了一种评价波长为1.319μm光学薄膜的吸收损耗的吸收测量系统。采用激光量热计方法的原因在于:它已被广泛用来测量光学薄膜吸收,并且有很高的可靠性。描述了激光量热计法测量吸收装置的设计和建立,并给出基底—薄膜整体吸收的测量结果和记录的温度曲线,最后提出了在研究激光量热计测量方法中几个要考虑的问题。     

Weak absorption test and defect analysis of optical coatings

1Introduction Inmodernoptics,especiallylasertechnolo gy,absorptionisoneofthemostimportant characterswhichmustbeconsidered,notonly foropticalproperties,butalsoforlaser induced damagethreshold(LIDT).Forexample,ab sorptiondefecthasplayedagreatroleinfluen cinglaserinduceddamagebehaviorsofthedie lectricopticalcoatings.Inmanyapplications,veryweakabsorption,1×10-6orless,should bemeasuredandcontrolled.However,thesensitivityofthebestregular spectrometerisonlylowto0.1%.Solutionshad beenfoundtoresolve…     

Investigation of high power laser coatings

1Introduction Opticalthinfilmcoatingisoneofthewea kestopticsinICFlasersystems.Totally,there aretwoaspectswhichinfluencethedevelopment ofthelasersystems.Thefirstaspectislaser damageresistanceofthecoatings,whichpuzzled coatingengineersformanyyears[1].Although muchgreatprogresshasbeenmadeintheoretical analysisofdamagemechanismsandoptimization ofdepositionprocedures,therewerestillmany sealedproblemsrestrictingthefurtherimprove mentofthelaserinduceddamagethreshold(LIDT)[27].Thelaser induceddama…     

几种新颖的光学镀膜材料

当前光学镀膜技术和应用光学的进展迅速,新的各种形式光学镀膜材料不断涌现。介绍了"预熔化"光学镀膜材料、高阈值激光膜材料、用于树脂基片的冷镀材料和光学镀膜用靶材,并对这几种新型材料的应用情况及国内外的现状进行了简要介绍。     

An accurate, repeatable, and well characterized measurement of laser damage density of optical materials

Known for more than 40 years, laser damage phenomena have not been measured reproducibly up to now. Laser resistance of optical components is decreased by the presence of material defects, the distribution of which can initiate a distribution of damage sites. A raster scan test procedure has been used for several years in order to determine laser damage density of large aperture UV fused silica optics. This procedure was improved in terms of accuracy and repeatability. We describe the equipment, test procedure, and data analysis to perform this damage test of large aperture optics with small beams. The originality of the refined procedure is that a shot to shot correlation is performed between the damage occurrence and the corresponding fluence by recording beam parameters of hundreds of thousands of shots during the test at 10 Hz. We characterize the distribution of damaging defects by the fluence at which they cause damage. Because tests are realized with small Gaussian beams (about 1 mm at 1e), beam overlap and beam shape are two key parameters which have to be taken into account in order to determine damage density. After complete data analysis and treatment, we reached a repeatable metrology of laser damage performance. The measurement is destructive for the sample. However, the consideration of error bars on defect distributions in a series of parts allows us to compare data with other installations. This will permit to look for reproducibility, a necessary condition in order to test theoretical predictions.     

光学系统中杂光分析

光学系统的杂散光极易在系统内形成多个鬼像 ,这不仅严重影响光束质量和传输特性 ,并可能对系统光学元件造成永久性损伤。提出了一种基于光线追迹基础的分析光学系统杂光影响的有效方法 ,建立适合各类光学系统杂散光及鬼像分析的数理模型。编制了专门的杂散光分析软件 ,通过计算机光路模拟 ,对光学系统中的鬼光束进行全面、系统分析 ,可得出系统鬼像及关键元件处的能量密度 ,从而在光学系统设计阶段排除鬼像的潜在危害     

Experimental study of new laser-based alignment system at the KEK B-factory injector linear accelerator

A new laser-based alignment system for the precise alignment of accelerator components along an ideal straight line at the KEK B-factory injector linear accelerator (linac) is under development. This system is strongly required in the next generation of B-factories for the stable acceleration of high-brightness electron and positron beams with high bunch charges and also for maintaining the stability of injection beams with high quality. A new laser optics for the generation of a so-called Airy beam has been developed for the laser-based alignment system. The laser propagation characteristics both in vacuum and at atmospheric pressure have been systematically investigated in an 82-m-long straight section of the injector linac. The laser-based alignment measurements based on the new laser optics have been carried out with a measurement resolution of ±0.1 mm level by using an existing laser detection electronics. The horizontal and vertical displacements from a reference laser line measured using this system are in good agreement with those measured using a standard telescope-based optical alignment technique. In this report, we describe the experimental study in detail along with the basic designs and the recent developments in the new laser-based alignment system.     

Collection optics design for KSTAR Thomson scattering system

The collection optics designs are described for the Thomson scattering diagnostic of the Korea superconducting tokamak advanced research (KSTAR) device. The optical systems collecting the light emission induced through the interaction between the plasma electrons and a laser beam are key components for the Thomson scattering system. A duo-lens system was examined, and the final optical designs were derived for Thomson scattering diagnostic of KSTAR.     

光学三维测量技术与应用

光学三维测量技术是一种可视化的测量技术,能完成复杂形体的点、面、形的三维测量,能实现非接触测量,在制造业和航空航天领域得到广泛应用。航空三维激光扫描与摄影测量技术利用激光测距原理和航空摄影测量原理,与基于全球定位系统(GPS)和惯性测量装置(IMU)的机载定位定向系统(POS)联接,可以快速获取大面积地球表面三维数据。本文对光学三维测量技术和航空三维激光扫描技术做一简单介绍,给出三维激光扫描技术在航空航天领域的几个应用。     

Optical coatings for fiber lasers

1Introduction HighPowerFiberLasers(HPFLs)and HighPowerFiberAmplifers(HPFAs)promise anumberofbenefitsintermsoftheirhighopti calefficiency,degreeofintegration,beamquali ty,reliability,spatialcompactnessandthermal management.Thesebenefitsaredrivingtherap idadoptionofHPFLsinanincreasinglywide rangeofapplicationsandpowerlevelsranging fromafewWatts,forexampleinanalyticalap plications,tohigh power>1kWmaterialpro cessing(machiningandwelding)applications.Insilica,neodymium(Nd3+),ytterbium(Yb3+…     

中红外激光薄膜的研究与特性分析

介绍了高能中红外固体激光器中光学薄膜的用途、设计与制备方法。以2μm泵浦和1.06μm泵浦方案为例,针对核心部件光参量振荡器的激光晶体与耦合腔镜,讨论了减反射、部分透过和截止滤光等薄膜在研究过程中的主要技术问题,并在不同情况下对此波段内薄膜的吸收、内应力与损伤阈值完成了特性的对比测试分析,相关薄膜应用在中红外激光器中已取得了5kHz下10W的输出效果。     

用透射光栅谱仪测量多层膜的反射特性

软X射线多层膜是当前应用光学和工程光学的研究热点之一,反射率是其性能和膜层质量最直观的参数,它的测量对了解多层膜性能和改进多层膜制备工艺具有重要意义。本文介绍采用带有前置光学系统的大面积透射光栅光谱仪分光,让软X射线多层膜反射+1级或-1级软X射线,用国产的SIOFM型X射线胶片接受软X射线,通过测量可定性地判断多层膜制备质量,为改进多层膜制备工艺提供重要的参考依据。     

Multi-degree-of-freedom motion error measurement in an ultraprecision machine using laser encoder — Review

Recently, in accordance with the increasing market demand for ultraprecision technology, a high precision multi-degree-of-freedom displacement measurement technology has become important for industrial applications such as the field of manufacturing and inspection because those physical quantities, linear and angular displacements, are key parameters for keeping and improving quality control of a production system. A number of instruments capable of precise multi-degree-of-freedom measurements have been built and some novel techniques have been introduced. The current state-of-art techniques for multi-degree-of-freedom motion error measurement in a linear stage using laser encoder-implemented system are reviewed. First, we summarize the basic principles behind the measurement technology of the motion error in a stage and simple encoder system. Next, the basic design principles of practical laser encoder system are discussed using the experience of past and existing cases to refer to the important points and the major scientific results. The current trends in the field are significantly discussed, including the novel techniques under construction and advanced technologies. Lastly, the future of multi-functional laser encoder-implemented system, highlighting the kinds of new science upcoming in the next few years, is discussed.     

熔石英光学元件加工亚表面缺陷检测及抑制技术研究进展

熔石英材料因具有硬度大、热膨胀系数低、透射光谱范围广等良好的机械性能和热学、光学特性,广泛应用于国防、航天等领域中关键光学元件的制造。作为一种典型的硬脆材料,在传统的研磨抛光加工中,不可避免地会引入亚表面层的微裂纹、划痕等结构性缺陷,这些缺陷会严重降低熔石英元件在高功率激光使用环境下的激光损伤阈值,并影响其在高冲击载荷使用环境下的抗断裂损伤能力。从硬脆材料的磨削机理出发,对熔石英光学元件亚表面缺陷的产生机制、亚表面缺陷的检测技术、熔石英亚表面缺陷抑制技术的研究现状进行综述,重点对比针对加工亚表面缺陷的有损检测和无损检测技术的优缺点,探讨多种先进表面加工技术在抑制熔石英光学元件亚表面缺陷中的应用。希望为优化大口径、高精度、高质量熔石英光学元件加工工艺,并提升其在高功率激光、高冲击载荷等极端服役环境下使用性能、延缓其使用寿命提供有益参考。     

A high accuracy femto-/picosecond laser damage test facility dedicated to the study of optical thin films

A laser damage test facility delivering pulses from 100 fs to 3 ps and designed to operate at 1030 nm is presented. The different details of its implementation and performances are given. The originality of this system relies the online damage detection system based on Nomarski microscopy and the use of a non-conventional energy detection method based on the utilization of a cooled CCD that offers the possibility to obtain the laser induced damage threshold (LIDT) with high accuracy. Applications of this instrument to study thin films under laser irradiation are presented. Particularly the deterministic behavior of the sub-picosecond damage is investigated in the case of fused silica and oxide films. It is demonstrated that the transition of 0-1 damage probability is very sharp and the LIDT is perfectly deterministic at few hundreds of femtoseconds. The damage process in dielectric materials being the results of electronic processes, specific information such as the material bandgap is needed for the interpretation of results and applications of scaling laws. A review of the different approaches for the estimation of the absorption gap of optical dielectric coatings is conducted and the results given by the different methods are compared and discussed. The LIDT and gap of several oxide materials are then measured with the presented instrument: Al(2)O(3), Nb(2)O(5), HfO(2), SiO(2), Ta(2)O(5), and ZrO(2). The obtained relation between the LIDT and gap at 1030 nm confirms the linear evolution of the threshold with the bandgap that exists at 800 nm, and our work expands the number of tested materials.     

顾客满意度测评方法及其应用

国际标准化组织（ISO）发布的ISO/TS16949-2009《质量体系汽车供方关于应用ISO9001-2008的特殊要求》提出了＂以顾客为关注焦点＂等8项质量管理原则,把顾客满意作为对质量管理体系业绩的一种测量方法。标准明确要求要监视和测量顾客满意,借助于数据分析提供所需的顾客满意的信息,进一步通过纠正和预防措施,达到持续改进的目的。＂满足顾客的要求和期望＂即始于顾客要求,止于顾客满意,将取代追求质量合格或服务的达标而成为企业的最高目标。     

High laser damage threshold coatings and damage testing technology

1Introduction Thelaser induceddamagethreshold(LIDT)ofopticalcoatingsisalimitedfactorfordevelop mentofahighpeakpowerlaser.Theoutput fluencesthatcanbeattainedontheNationalIg nitionFacility(NIF)whichcontains192beam linesbuiltbytheUniteStatesareultimatlylim itedbyopticalcoatingswithinthechain.These opticalcoatingsneedtosatisfythefluencere quest,22J/cm2forreflectivemirrorsand11J/cm2forpolarizers(1064nm,3nspulselength).Becausethedamagemechanismofthecoatings understronglaserirradiationisverycom…     

Simultaneous multi-dimensional spatial frequency modulation imaging

Abstract

One of the primary challenges in advanced manufacturing (AM) is the lack of efficient optical metrics for ensuring quality control over the manufacturing process. Many current imaging techniques have excessive data requirements and require computationally intensive post-processing to effectively characterize various AM environments. Spatial frequency modulated imaging (SPIFI) addresses many of these issues with the following benefits: it is compatible with long working distance optics, provides a large field-of-view, features single element detection, and can provide enhanced resolution. Here, we demonstrate SPIFI with enhanced resolution in multiple dimensions for the first time. This is achieved by incorporating multiple linear extended excitation sources oriented with axes at arbitrary angles with respect to each other. The system utilizes a single modulation mask enabling facile implementation within existing imaging systems such as those found in laser AM systems.     

Calibration of a planar laser induced fluorescence technique for use in large scale water facilities

A calibration process for planar laser induced fluorescence (PLIF) is presented and employed to investigate the mixing field of a co-flowing jet in a water channel flow. The calibration technique uses individual calibration curves for each pixel in the image array that correct for the non-uniformities of the laser sheet, optics and digital sensor and account for parameters that affect fluorescence efficiency of the dye. A unique commercial optic is introduced into the optical train to generate a thin laser sheet with an approximately uniform laser intensity distribution. The performance of the calibration procedure is investigated by analysis of the calibration data and through the investigation of a co-flowing jet. The results compare well with the results documented in the literature for this flow field. The work shows that the simple approach designed specifically for application in large-scale facilities is suitable for calibration of PLIF style techniques.