Gradual edge enhancement in spiral phase contrast imaging with fractional vortex filters.
Gradual edge enhancement in spiral phase contrast imaging with fractional vortex filters.
复制标题
使用分数涡旋滤波器的螺旋相衬成像的逐渐边缘增强
DOI：
10.1038/srep15826
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发表时间：
2015-10-29
影响因子：
4.6
通讯作者：
Chen L
中科院分区：
文献类型：
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作者：
Wang J;Zhang W;Qi Q;Zheng S;Chen L
在螺旋相位衬度成像中，通常采用整数螺旋相位板（SPP）对物体进行径向希尔伯特变换。在这里，我们引入分数SPP滤波器，而不是整数的，研究纯相位对象的边缘增强的逐渐形成。在我们的实验配置中使用了两个空间光调制器。其中一个用于显示五角星星星的纯相位物体，另一个用于显示分数拓扑电荷Q的动态滤波器。感兴趣的是通过逐渐改变分数涡旋从Q = 0到1的边缘和背景亮度的完全反转的观察。基于分数阶SPP的OAM谱对实验结果进行了很好的解释，表明滤波后的输出图像可以看作是整数阶OAM滤波后所有可能图像的相干叠加。此外，我们还证明了旋转的三叶三叶草在真实的时间内仍然可以观察到螺旋相衬效应。我们的研究结果可能在光学显微成像中找到潜在的应用。
In the spiral phase contrast imaging, the integer spiral phase plate (SPP) are generally employed to perform the radial Hilbert transform on the object. Here we introduce fractional SPP filters, instead of the integer ones, to investigate the gradual formation of edge enhancement for pure phase objects. Two spatial light modulators are used in our experimental configuration. One is addressed to display the pure phase object of a five-pointed star, while the other serves as a dynamic filter of fractional topological chargeQ. Of interest is the observation of the complete reversal of the edge and background brightness by gradually changing the fractional vortices fromQ= 0 to 1. The experimental results were well interpreted based on the OAM spectra of fractional SPP, which indicates that the filtered output image can be considered as a coherent superposition of all possible images that are individually resulted from the integer OAM filtering. Besides, we show that the spiral phase contrast effect can still be observed in real time for a rotating three-leaf clover. Our results may find potential applications in the optical microscopic imaging.