Abstract
In this Letter, a simple structure formed by a metallic thin layer covering a high-index substrate is used to design an optical tweezer. Owing to the interaction between the field scattered by the particle with an incident plane wave and the proposed structure, a pulling or attractive component of the optical force emerges. This component results in enhancement thanks to the surface plasmons (SPs) excitation arising from the elliptical polarization of the induced dipole moment on the particle. To further exploit the versatility of the proposed approach, we analyze two basic configurations: the reflection scheme, for which the plane wave impinges from the side where the particle is placed; and the transmission scheme, for which the incidence is made from the substrate side. Our results show that the intensity of the pulling force in the reflection scheme and for finite thickness metal layer reaches values exceeding more than twice those provided by a single metallic interface. We also demonstrate that the transmission scheme is more favorable than the reflection scheme for enhancing pulling force intensities. Our contribution can be valuable for realizing simple plasmonic schemes for improving the pulling force via interactions between the nano-particle and SP fields.
Subject
Atomic and Molecular Physics, and Optics
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献