排序方式: 共有42条查询结果,搜索用时 13 毫秒
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激光引信接收光学组件的研究与测试 总被引:1,自引:0,他引:1
根据大气激光通信传输方程和黑体辐射理论提出了计算激光引信中接收光学系统接收视场的方法,通过接收视场确定了接收光学系统的初始结构参数,设计了焦距为15 mm,视场角为2ω≮±7°的柱透镜光学系统.采用倒置法,将线阵CCD探测器置于准直物镜的焦面上接收信号,解决了接收光学系统后截距过短无法安置线阵CCD的问题,扩大了测量范围,又保证了精度,测量误差为1%.针对激光引信的结构特点,设计了测量激光引信接收光学系统视场角的自动测试系统.实验测试结果表明该引信的视场角都在合格范围内,重复精度≤5%,满足设计的要求. 相似文献
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基于小波变换的最小二乘相位解缠算法 总被引:1,自引:2,他引:1
最小二乘法是求解二维相位解缠问题最稳健的方法之一,其本质是在最小二乘意义下使缠绕相位的离散偏导数与解缠相位的偏导数整体偏差最小,并等效为可求解一大型的稀疏线性方程系统。由于系统矩阵结构的稀疏性,在采用迭代法求解时收敛速度非常慢。为了改善收敛特性,提出一种基于多分辨率表示的离散小波变换相位解缠算法。利用小波变换将原线性系统转化成具有较好收敛条件的等价新系统。仿真实验表明,该方法能够很好的恢复真实相位,其解缠效果优于Gauss-Seidel松弛迭代和多重网格法。 相似文献
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光学记录系统的组成,有光源为单一模式的半导体激光器、准直物镜、柱面扩束物镜、旋转多面体、fθ透镜及光敏介质。在不修正半导体激光器象散值Δs时,准直物镜的焦点基本上位于半导体激光器的垂直平面光束原始发散点位置上;柱面扩束物镜仅在激光器的平行平面上具有光焦度,其倍率Γ应满足于关系式;光敏介质应位于fθ透镜后焦点附近。 相似文献
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Attenuation characteristics of a light attenuator combined by polarizers with different extinction ratios 下载免费PDF全文
This paper deals with a systematical analysis and an algorithm of attenuation characteristics of a light attenuator combined by n pieces of polarizers (n-LACP) whose extinction ratios are different from each other.The attenuation ratio expression of a two-LACP is deduced.We find that the monotonic attenuation interval depends on the first polarizer and that the attenuation range depends on the second one.For the three-LACP,a method for obtaining a monotonic attenuation interval is proposed.Moreover,the attenuation ratio expression is demonstrated.Analysis and experiment show that when the initial status of the three-LACP is at the maximum output,if the second or third polarizer rotates alone,the minimum attenuation ratios can reach K-1 2 and K-1 3,respectively,and if the first polarizer rotates,a minimum attenuation ratio of K-1 2 K-1 3 can be obtained (K 1,K 2 and K 3 represent the extinction ratios of the three polarizers in turn).Furthermore,the attenuation ratio expression of n-LACP and the relevant attenuation characteristics are proposed.The minimum attenuation ratio of an n-LACP is (K 2 K 3 ··· K n)-1. 相似文献
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