Three-dimensional shape-controllable focal spot array created by focusing vortex beams modulated by multi-value pure-phase grating.
Three-dimensional shape-controllable focal spot array created by focusing vortex beams modulated by multi-value pure-phase grating.
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DOI：
10.1364/oe.22.021354
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发表时间：
2014-09
期刊：
影响因子：
3.8
通讯作者：
Linwei Zhu;Meiyu Sun;Mengjun Zhu;Jiannong Chen;Xiumin Gao;Wangzi Ma;Dawei Zhang
中科院分区：
文献类型：
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作者：
Linwei Zhu;Meiyu Sun;Mengjun Zhu;Jiannong Chen;Xiumin Gao;Wangzi Ma;Dawei Zhang
提出了一种在高数值孔径（NA）物镜的后孔径处利用二维（2D）纯相位调制光栅和由四象限相位分布单元构成的轴向平移纯相位调制相结合的方法来产生三维（3D）形状可控的焦斑阵列。结果表明，采用优化算法设计的一维光栅在一个周期内可以产生任意数目的等间距衍射光斑，且衍射光斑的强度相同。用该方法设计的二维纯相位光栅可以产生二维衍射光斑阵列。阵列中沿两个维度中的每一个沿着的点的数量仅取决于具有维度的不同相位值的划分区域的数量。我们还表明，通过结合后孔径处的轴向平移相位调制，我们可以在高NA物镜的焦体积处创建3D焦斑阵列。此外，通过引入空间移位的多束涡旋光束作为入射光束，可以控制三维焦面阵列中每个焦斑的形状或强度分布。这种形状可控的三维焦斑阵列可用于人工超材料的制备、并行光学微操作和多焦多光子显微成像。
We propose a method for creating a three-dimensional (3D) shape-controllable focal spot array by combination of a two-dimensional (2D) pure-phase modulation grating and an additional axial shifting pure-phase modulation composed of four-quadrant phase distribution unit at the back aperture of a high numerical aperture (NA) objective. It is demonstrated that the one-dimensional (1D) grating designed by optimized algorithm of selected number of equally spaced arbitrary phase value in a single period could produce desired number of equally spaced diffraction spot with identical intensity. It is also shown that the 2D pure-phase grating designed with this method could generate 2D diffraction spot array. The number of the spots in the array along each of two dimensions depends solely on the number of divided area with different phase values of the dimension. We also show that, by combining the axial translation phase modulation at the back aperture, we can create 3D focal spot array at the focal volume of the high NA objective. Furthermore, the shape or intensity distribution of each focal spot in the 3D focal array can be manipulated by introducing spatially shifted multi vortex beams as the incident beam. These kinds of 3D shape-controllable focal spot array could be utilized in the fabrication of artificial metamaterials, in parallel optical micromanipulation and multifocal multiphoton microscopic imaging.