共查询到19条相似文献,搜索用时 140 毫秒
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基于液晶空间光调制器的空间滤波实验 总被引:1,自引:0,他引:1
空间滤波实验可以实现对输入物体的频谱分析及图像的边缘增强、噪声消除等各种图像处理。液晶空间光调制器可以作为衍射波面变换器件来使用。在空间滤波实验系统的滤波面上放置了液晶空间光调制器,并用CCD数码相机进行输出图像的观察和记录,分别给出了低通滤波、高通滤波、方向滤波等的仿真实验结果。该实验实现了输入数字物体的实时改变,并能够实时观察采用不同空间滤波器对输出像的影响。 相似文献
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光学空间滤波过程的计算机仿真 总被引:20,自引:2,他引:18
提出了一种利用MATLAB软件并通过计算机仿真光学空间滤波实验过程的新方法.其特点是:既可以随意改变所设计滤波器的参量,又可以对输入图象进行振幅、相位或复合滤波,并且可实现傅里叶变换频谱中相位信息的提取、存储和利用,因而能够完成一般光学实验中往往难以实现的某些操作.并分别给出了网格滤波、低通、高通及相位滤波等仿真实验结果.这种仿真实验给光学滤波器的设计和图象处理带来很大方便,同时也为相关器件的设计提供了一条新的途径. 相似文献
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当电磁波的传输轴和各向异性超常介质的光轴成任意夹角时,发现在界面处可以产生反常全向全反射和反常负折射现象.导出了电磁波的入射角和能流折射角之间的函数关系,根据此关系可方便地选择合适的介电张量和磁导率张量,使特定入射角所对应的折射是正或是负.此外,发现当入射角小于某一角度时,尤其在垂直入射附近时,透射率最小甚至为零;基于这一特性,提出了一种新型的薄片型高通空间滤波器的构想,和传统的空间滤波系统相比,可以大大减少滤波系统的体积;这一特性也可用于构造空间低频反射器件.
关键词:
超常介质
各向异性
反常传播
空间滤波 相似文献
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Simultaneous spatial and spectral filtering by an optical resonant filter has been characterized experimentally to furnish additional insight into the operation and applications of optical resonant filters. Our experimental study can be useful for applications that depend on spatial filtering, spectral filtering, spatial-spectral filtering, and polarization selectivity. One significant application is the integration of an optical resonant filter with semiconductor lasers to control the spatial-spectral radiation for optimum performance. 相似文献
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Coherent combining of two fiber lasers has been experimentally demonstrated by using a ring coupled cavity and single-mode
fiber filtering technique. Their phases are primarily synchronized due to mutual injection coupling introduced by a common
ring coupled cavity, and efficient phase locking is realized by utilizing a single-mode feedback fiber to filter the far-field
pattern. The detailed experimental investigations indicate that the stability of phase locking can be improved significantly
by this spatial filtering technique, and the far-field intensity distribution can be manipulated by controlling the position
of the filtering fiber. 相似文献
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S.-Y. Huang T.-C. Wung A. Y.-G. Fuh H.-C. Yeh C.-Y. Huang C.-M. Ma S.-C. Huang T.-S. Mo C.-R. Lee 《Applied physics. B, Lasers and optics》2009,97(4):749-752
This work presents an electro- and photo-controllable spatial filter that is based on a liquid crystal (LC) film with a photoconductive
layer. The controllable spatial filter can be formed because of the controllability of the photoelectro-induced screen effect
of the space charge in the LC cell. An applied dc voltage or incident pumped intensity can be controlled to enable different spatial distributions of the diffraction pattern
of the target object to be selected for filtering by the LC cell, such that various reconstructed images can be obtained.
A simulation using Fourier analysis is developed, and its results agree closely with experimental results. Additionally, the
LC spatial filter has the extra advantage of controllable low or high filtering functions: they are controlled by switching
the configuration between normally black and normally white modes. 相似文献
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《中国光学快报(英文版)》2016,(12)
A setup for the generation of arbitrary vector beams is proposed. The setup mainly consists of a spatial light modulator(SLM), an angle-adjustable polarization beam splitter modulator, and a spatial filtering imaging system. Compared with the system using a birefringent beam splitter with a non-adjustable splitting angle,the polarization splitting angle of the improved setup can be adjusted by slightly rotating the related mirrors,which will bring more convenience when different wavelengths and different pixel sizes of SLMs are involved.The experimental results also demonstrate that the setup possesses a good polarization-selective imaging ability, which reveals that the setup may also be useful in polarization-selective spatial filtering imaging and polarization-encoded encryption. 相似文献
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The spatial filtering method is a useful technique for the dynamic and automatic analysis in digital holographic microscopy. It has been shown that the proper selection of the spatial filter would improve the quality of the reconstructed image. However different results would be obtained by employing the spatial filter with different parameter threshold decided at different standard. This paper, according to the histogram analysis of the distribution of the +1 term spectrum of each hologram, gropes for the uniform standard for the decision of the threshold of the adaptive filter. It helps the adaptive spatial filtering method to be more advantageous for the dynamic and automatic analysis. 相似文献
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Phase retrieval in two-wavelength DSSI (digital speckle shearing interferometry) using a combined filtering method is proposed for small deformation derivative measurement. A simultaneous two-wavelength illumination and 3-CCD camera are employed in the experimental setup. The proposed method, which uses a two-wavelength technique does not require the conventional spatial phase unwrapping and has the advantage of good noise suppression for phase retrieval. Experimental results obtained show that using the proposed combined filtering method sensitivity similar to the single wavelength technique can be achieved. 相似文献
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A. N. Bogaturov A. S. Gurvich V. A. Myakinin J. C. Dainty C. J. Solomon N. J. Wooder 《Waves in Random and Complex Media》1993,3(1):9-16
It has been predicted theoretically that the combination of spatial filtering together with double-passage illumination and viewing of a deterministic object leads to an improvement in image quality. The results of experimental investigations of this effect are presented. 相似文献
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In the present communication, an application of coherent gradient sensing (CGS) for collimation testing of an optical beam has been proposed. In the path of the beam to be tested, a set of two identical linear Ronchi gratings is introduced. The diffracted orders from the two gratings traveling in the same direction are isolated using spatial filtering arrangement. The resulting laterally sheared wavefronts carry information regarding the defocusing errors. The grating rotation mechanism has been incorporated for collimation setting. The results of experimental investigation are presented. Improved accuracy and precision has been achieved because the requirement of maintaining the grating separation to be equal to self-imaging distance as in Talbot interferometry has been alleviated. 相似文献
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A coherent optical information system has been analysed using the Fresnel diffraction theory. Considering the spherical wave
illumination, the same system is used for spatial filtering and subsequent reimaging. The conditions for locating the spatial
frequency plane and the image plane have been pointed out. The scale of the Fourier transform can be controlled by three degrees
of freedom. The final image formed is inverted and magnified with respect to the input signal. The present analysis has been
compared with those of Pernick and Moharir. Aberrations involved have also been discussed. 相似文献