共查询到17条相似文献,搜索用时 78 毫秒
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提出了一种校正鱼眼镜头图像畸变的新方法。通过追迹光学系统的主光线,获得它在投影平面上的径向位置与它在像平面上位置之间的关系曲线;然后用傅立叶级数拟合该关系曲线;并求出该级数的逆函数,结果就可以根据畸变图像复原没有畸变的图像。用该方法数值模拟两个鱼眼镜头系统的图像畸变校正;并用其中一个鱼眼镜头(尼康16 mm/F2.8)拍摄的两张图像进行了畸变校正实验。结果表明,当设置投影平面和物平面重合时,恢复的图像相对于物体的残余径向高度误差非常小(小于0.25%)。实验证明了该方法是可行的。 相似文献
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介绍了获取超大空域物体热像信息的红外鱼眼镜头的光学系统设计,设计采用非制冷长波焦平面阵列探测器,视场为170°,像质得到了很好的矫正。 相似文献
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为了获得光束质量较好、光斑尺寸较小、功率密度较高的、适合于在选区激光熔化快速成型技术中应用的激光束,对应用于选区激光熔化快速成型技术中的高斯光束进行传输与变换。对其传输变换及聚焦特性进行了理论分析与实验验证,实验结果与理论分析的结果相符。取得了功率密度达106W/cm2以上的、光斑尺寸较小的、满足于在选取激光熔化技术中应用的光斑。将其应用于镍基合金(Ni25)和铜磷合金粉末的三维选区激光熔化快速成型。结果表明,这种传输变换及聚焦特性是可行有效的,得到了满足要求的光斑尺寸和功率密度。 相似文献
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利用简易装置搭建“测量线”系统,采用驻波法测量了点聚焦透镜天线焦斑附近轴线上不同位置处的波长λF,与自由空间中的波长λ0相比,找出λF随轴向距离变化而变化的关系,并对该变化进行定性分析。通过对2种点聚焦透镜天线的测量,发现焦斑附近的波长λF较之自由空间中的波长λ0有0~5%的延长,且延长量随离焦点距离的增大而减小。最后对测试系统的精确度和误差源进行了分析。 相似文献
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A grating-coupled surface-emitting semiconductor laser has been integrated with a focusing diffractive beamforming element. A hyperbolic unstable resonator is used to introduce mode discrimination and suppress filamentation in a broad geometry, resulting in a 200-μm-wide coherent output. The light is focused 500 μm above the laser surface to a spot size of 5×7 μm. A remarkable beam stability is observed with very small spot size variation and beam-steering up to three times the threshold current under continuous operation 相似文献
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在激光显示等领域常常需要光强均匀分布的激光光束,为此,深入分析了一种非球面透镜组激光光束整形系统的设计方法,该方法可以将入射光束为准直的单模高斯激光光束整形为光强均匀分布的准直平顶激光光束;给出了该非球面透镜组设计的基本过程,主要包括输出光束函数的选择、光线映射函数的确定和非球面参数的确定;最后选择光线映射函数具有解析解形式的匀化洛伦兹函数作为输出光束分布函数,分别确定了伽利略型和开普勒型的非球面透镜组激光光束整形系统的参数。 相似文献
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Three new applications of a focused laser beam to VLSI interconnect diagnosis have been reported, in which interconnect heating by a laser beam and current change measurement are used. One is a void and Si nodule detection method that monitors current changes caused by resistance changes induced by the laser beam heating, through temperature dependence of resistance. Another is a current measurement method that monitors current changes caused by resistance changes induced by the laser beam heating, through temperature dependence of resistance. The last is a void and other types of anomalies detection method that monitors current changes caused by the laser beam heating through the thermoelectric effect. In this paper, we present new results on these three methods, and discuss the advantages and disadvantages of these methods over other methods. 相似文献
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Theoretical reduction in intensity fluctuations of a focused laser beam propagating through a randomly inhomogeneous medium was qualitatively examined in an experiment in which intensity fluctuations were observed near the focus of the optical system used. A wind tunnel was used to produce the randomly inhomogeneous medium. 相似文献
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高斯光束通过光阑——透镜分离系统的焦移 总被引:4,自引:0,他引:4
本文根据Collins衍射积分公式分析了高斯光束通过光阑--透镜分离系统后的焦移情况,得到在不同的分离状况下,其焦移可能反向或被消除,对它的两种极限情况也做了分析。 相似文献
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《Semiconductor Manufacturing, IEEE Transactions on》2002,15(1):2-8
An edge-emitting laser diode (LD) integrated with a microlens on its emitting surface for the purpose of collimating and fiber coupling is introduced in detail in this paper. A micro-elliptical lens is adopted for the integration in terms of divergence angle in both parallel and transverse directions. The lens with dimensions of 50 μm×30 μm×4 μm is microfabricated on the emitting surface of the laser diode with operating wavelength of 635 nm directly by focused ion beam (FIB) deposition function. The SiO2 deposition is realized by programming of the FIB machine. It is shown by test results that the focused spot size in the parallel and transverse propagation directions are 7.9 and 9.1 μm (at site of 1/e2), respectively, and the coupling efficiency of the compact and miniaturized system can reach as high as 71%. Measured far-field angles (full angle) with the microlens in both parallel and transverse directions are 2.2° and 1.2°, respectively. Compared with the original divergence angles of 31° and 14° without the micro-elliptical lens, they were greatly reduced by this method 相似文献
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