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激光远场分布测量一直存在两方面的困难:一方面是由于波面畸变具有不确定性,使得焦平面位置不易确定;另一方面是焦斑“主瓣”和“旁瓣”光能密度相差悬殊,无如此大动态范围的探测器。此文针对现有的激光远场测试的3种常用方法(长焦距透镜法、列阵相机法、Rame Pair法)进行了实验研究。首先需要建立一个实验平台,3种激光远场测试方法在相同的测试条件下对激光束的相同位置进行测试,以减少比对误差。光路排布如图1所示。图1中虚线所包围的部分即3种测试方法的光路排布,由这3种方法分别测得的焦斑和焦斑列阵并通过一定的算法重构焦斑,所得结果比对如图2。 相似文献
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为了评估万焦耳级激光装置不同打靶透镜构型的远场光束质量,采用弱光取样、分束放大成像的探测方法,在横向放大系数相同而光强衰减系数不同的条件下,通过两台16位科学CCD在主瓣光路和旁瓣光路对3ω激光束的焦斑进行采集;基于纹影测量激光焦斑数学模型,获得了动态范围为1 151.7:1的远场焦斑重构图像;并对CCD动态范围、分束光路相对放大系数、系统噪声等因素对焦斑诊断的影响进行了分析.实验表明,该方法能够实现高动态范围远场焦斑的精确测量,对于重构图像的拼接边缘误差小于1 pixel,满足打靶要求. 相似文献
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整体X光透镜性能实验研究 总被引:6,自引:2,他引:4
利用高计数率探测器和低功率光源,在大的能量范围内,同时测量了整体X光透镜的传输效率和焦斑直径与能量的关系。实验结果表明:透镜的焦斑直径随着能量的升高而减小;对04-5-10-5透镜而言,在高于5.8keV的能量范围内,透镜的传输效率随着能量的升高而降低,在低于5.8keV的能量范围内,透镜的传输效率随着能量的升高而增加。通过测量不同能量的X射线在透镜会聚光束中的空间分布,研究了短出口焦距透镜的光晕现象,光晕会导致透镜焦斑直径增大和传输效率测量值的增加。利用轴向扫描法研究了整体X光透镜出口焦距和能量的关系,实验结果表明:会聚透镜的出口焦距随着X射线能量的升高而增加。 相似文献
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像面干涉高光谱成像技术主要应用于遥感成像领域,为了实现不同距离目标的光谱成像探测,提出了一种基于二次成像的像面干涉高光谱成像方法。通过在无限远成像系统中加入前端成像物镜、中继准直物镜和横向剪切分束器,构建一个二次成像的干涉系统。通过采用分离式的前端成像物镜方案,选用变焦镜头或不同焦距的定焦镜头,有效地兼顾远、近距离目标的成像光谱探测。对该方法的成像系统、光谱分辨率和推扫方式等方面进行了分析,进一步搭建了实验装置,对室内近场目标和室外远场目标进行了成像实验,并对生物组织进行了显微光谱干涉成像实验。实验结果表明,该成像方法能够有效用于不同距离目标的高光谱成像探测。 相似文献
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采用Strehl比、桶中功率、β参数和束宽描述远场光束质量,研究了光束控制系统热效应和球差对远场激光光束质量的影响.用四维仿真程序作了详细计算,给出了数值计算结果并进行了物理分析.研究表明,传输通道的热效应和正球差会使远场光强分布扩展,可聚焦能力下降,光束质量变差.有意义的是,当激光发射功率达到一定值时,合适选取负球差会在几何焦面得到比无球差时更高的峰值光强和更好的可聚焦能力.但在以前的工作中,由于焦移,类似的结论是在实际焦面上得出的.非线性热晕的存在是其物理原因,对此用数值计算例子作了说明.
关键词:
高功率激光
热效应
光束控制系统
球差 相似文献
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Light profile microscopy is a new method of thin film imaging in which a microscope forms an image of a laser beam intersecting a thin layer along its depth axis. Emission (luminescence or scatter) from the beam volume is transmitted through a cross sectional view surface and used by a microscope to form an image of the beam propagating through the sample. Fresnel diffraction theory is used in this work to derive a point spread model for a microscope operating in this configuration, assuming that the emission from the source beam is completely incoherent. This theory illustrates the dependence of the image resolution on the laser beam radius, which determines the effective thickness of the system object seen by the microscope. The effect of relative displacement of the source beam center from the object plane of the microscope is evaluated. The present theory shows that radial resolution may be evaluated by means of an object focus envelope and a focal energy distribution computed for the objective lens. PACS 42.25Fx; 07.60Pb 相似文献
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Da-ping Wan Xi-chang Liang Fan-ming Meng De-jin Hu Yu-ming Wang Bing-kui Chen Yi-min Shao 《Optics & Laser Technology》2009,41(4):499-503
Flying optics technologies are used for a range of applications such as a large workpiece processing and laser texturing. It is essential to compensate the variations of laser beam focus parameters while the focus head is moving. A flying optics automatic compensation approach is proposed to achieve invariable laser focal size, focus depth and focus position through computer controlled objective lens and focus lens position. A simple mechanical control method is also presented for the realization of constant beam parameters for flying optics. Numerical simulation is illustrated for a CO2 laser texturing application. The flying optics parameters compensation is simple and easy to control. 相似文献
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A liquid pressure varifocus lens that consists of a thin polymer film and liquid is described. The lens can be continuously
changed from a concave to a convex shape by driving the liquid pressure in the lens. The dynamic range of the focal length
of the convex lens is from 50 to 250 mm. A beam spot verifies the variable focal function on a photographic film exposed by
a He-Ne laser. In addition, the application of the laser for processing is demonstrated to manufacture Fe compressed powder
sheets by normal pulse YAG laser. Its melting marks along a focus change are formed with a minimum width of 0.1 mm. 相似文献
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大口径投影光学系统采用低成本、大口径菲涅耳透镜制作,可将远场散斑强度分布投影到CCD成像探测器上。通过CCD图像处理,能够对给定孔径上的接收功率、闪烁指数进行量化评估;在接收孔径足够大、保障散斑不会因为光束漂移效应而脱离菲涅耳透镜的条件下,该系统还可以对光束漂移和特征半径进行量化评估。同时讨论了CCD像元响应非均匀性误差及其影响、CCD辐照响应函数和图像几何投影系数的定标方法。实验表明,系统能够对激光大气传输过程中的远场散斑特征参数进行监测。特别对自由空间激光通信系统而言,可以为大气衰减和多种大气湍流效应综合作用下的中值电平慢衰落研究和检测阈值优化设计提供实验数据支撑。 相似文献
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线激光束均匀化整形方法研究 总被引:4,自引:0,他引:4
为解决核物理工程、表面热处理、激光加工、激光通信中传输激光束的均匀性问题,提出采用三角楔柱透镜改善线激光均匀性的新方法,并在ZEMAX开发环境下建立了整形光路系统的理论模型。利用所建立的模型,分析了整形柱透镜在不同半径、斜面夹角、透镜介质折射率等参数下光束的均匀性。研究表明:在远场条件下,通过改变整形柱透镜的参数,能够得到能量分布均匀的线激光。在实际应用中,可以采用1个半圆柱和2个相同三角楔胶合成型的简单工艺。进一步模拟发现,两种整形系统所得到的均匀度和线宽一致。 相似文献
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A laser collimator is necessary for testing and verification of the pointing, acquisition and tracking (PAT) performance of inter-satellite laser communication terminals on the ground. The laser collimator must have a large clear aperture to fit the PAT performance testing system. The PAT subsystem has a large field of view for the acquisition and a high angular accuracy for the fine tracking. To resolve the conflict between large field of view and fine angular resolution, a large-aperture double-focus laser collimator is proposed and its optical design and mechanical structure are described. The collimator mainly consists of a primary lens, a reflector, a beam-splitting plate, a secondary lens, two compensating lenses, two imaging sensors and a laser. The primary lens directly forms the long focal length arm of the collimator. The combination of the primary lens and the secondary lens form the short focal length arm of the collimator. The collimator has an angular resolution <0.75 μrad and a 10 mrad field of view. For the collimator, the incident beam is focused on the two imaging sensors by its two arms, and the beam emitted from the laser is collimated and transmitted. The collimator is combined with an optical scanner and a fine beam deflector to test and verify the PAT performance of the inter-satellite laser communication terminal in a full physical manner. 相似文献
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光场多光谱成像技术具有能够同时获取目标二维空间信息和光谱信息的能力,利用光谱信息可以实现目标的分类和识别。为了快速、便捷地获取空间目标的完整光谱信息,实现目标表面光谱信息的真实记录,基于光场多光谱成像原理,采用光谱分光滤光片阵列分光实现主透镜系统入瞳孔径的分割,设计了一款应用于光场多光谱相机的像方远心镜头光学系统。光学系统具有宽波段400 nm~1 000 nm,焦距为240 mm,F数为4,全视场15.52°。像质评价与系统公差分析结果表明:设计的光场多光谱相机的像方远心镜头可以满足实际加工以及正常使用要求。 相似文献