Wu Jun, Tang Xinquan, Xia Jun
Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096, China.
Nanoscale Res Lett. 2019 Mar 5;14(1):82. doi: 10.1186/s11671-019-2895-0.
A tractor beam, which has the ability to attract objects, is a class of special optical beams. Currently, people are using the holographic technology to shape complex optical tractor beams for both fundamental research and practical applications. However, most of the work reported is focusing on generating two-dimensional (2D) tractor beams and simple three-dimensional (3D) tractor beams, which has limitations in the further development on mechanism and application of beam shaping. In the present work, we are introducing our study in designing multiple 3D tractor beams with spatial location regulated independently. Meanwhile, each individual beam could be prescribed along arbitrary geometric curve and twisted at arbitrary angles as desired. In our method, the computer-generated hologram (CGH) of each curve is calculated, and all the CGHs are multiplexed and encoded into one phase-only hologram by adding respective linear phase grating such that different 3D curves appeared in the different positions of the focal regions. We experimentally prove that the generation of optical tractor beams at 3D configuration can be readily achieved. The generated beams in the present study are especially useful for applications such as multiple micro-machining optical trapping and complex 3D manipulation.
牵引光束是一类特殊的光束，具有吸引物体的能力。目前，人们正在利用全息技术来塑造复杂的光学牵引光束，用于基础研究和实际应用。然而，大多数已报道的工作都集中在生成二维（2D）牵引光束和简单的三维（3D）牵引光束上，这在光束整形的机理和应用的进一步发展方面存在局限性。在本工作中，我们介绍了我们在设计多个空间位置独立调节的3D牵引光束方面的研究。同时，每个单独的光束可以沿着任意几何曲线规定，并根据需要以任意角度扭曲。在我们的方法中，计算每条曲线的计算机生成全息图（CGH），并且通过添加各自的线性相位光栅将所有的CGH复用并编码成一个纯相位全息图，使得不同的3D曲线出现在焦区的不同位置。我们通过实验证明，可以很容易地实现3D构型的光学牵引光束的生成。本研究中生成的光束对于诸如多重微加工光学捕获和复杂3D操纵等应用特别有用。
