Wang Lin, Cao Yongyin, Zhu Tongtong, Feng Rei, Sun Fangkui, Ding Weiqiang
Opt Express. 2017 Nov 27;25(24):29761-29768. doi: 10.1364/OE.25.029761.
Optical trapping of nano-objects (i.e., the nano-tweezers) has been investigated intensively. Most of those nano-tweezers, however, were focused on the trapping of a single nanoparticle, while the interactions between them were seldom considered. In this work, we propose a nano-tweezers in a slot photonic crystal cavity supporting multiple modes, where the relative positions of two trapped nanoparticles can be tuned by selective excitation of different resonant mode. Results show that both the nanoparticles are trapped at the center of the cavity when the first order mode is excited. When the incident source is tuned to the second order mode, however, these two nanoparticles push each other and are trapped stably at two separated positions. Also, the inter-distance between them can be tuned precisely by changing the relative power of the two modes. This provides a potential method to control the interactions between two nano-objects via optically tuning the separation between them, and may have applications in various related disciplinary.
纳米物体的光镊技术（即纳米镊子）已得到深入研究。然而，大多数此类纳米镊子主要聚焦于单个纳米粒子的捕获，而很少考虑它们之间的相互作用。在这项工作中，我们提出了一种位于支持多种模式的狭缝光子晶体腔中的纳米镊子，其中两个被捕获纳米粒子的相对位置可通过不同共振模式的选择性激发来调节。结果表明，当激发一阶模式时，两个纳米粒子都被捕获在腔的中心。然而，当入射源调谐到二阶模式时，这两个纳米粒子会相互推开并稳定地捕获在两个分离的位置。此外，通过改变两种模式的相对功率，可以精确调节它们之间的间距。这提供了一种通过光学调节两个纳米物体之间的间距来控制它们之间相互作用的潜在方法，并且可能在各种相关学科中具有应用。
