期刊
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
卷 175, 期 -, 页码 46-53出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jqsrt.2016.01.012
关键词
Circularly polarized light; Gold nanoparticle; Optical torque; Rotation; Surface plasmon resonance; Maxwell's stress tensor; Absorption; Scattering; Surface traction; Mie theory; MMP; Axis of revolution
资金
- Ministry of Science and Technology, Taiwan [MOST 102-2221-E-002-056-MY3, 103-2221-E-182-033-MY2, 104-2221-E-182-053]
- Chang Gung Memorial Hospital [CIRPD2E0031]
This study theoretically examines a spinning gold nanoparticle (GNP) driven by circularly polarized (CP) plane waves. The wavelength-dependent optical torques which were exerted on three different shapes of GNPs (spherical, prolate and oblate spheroids) were analyzed by utilizing Mie theory for the former and the multiple multipole method for the latter two, respectively. Numerical results show that both the absorbed and scattered photons contribute to optical torques in most cases. For the case that the CP wave is incident along the long axis of an oblate spheroid or the short axis of a prolate one, the scattering effect in optical torque is more pronounced than the absorption one. This phenomenon is significant especially when the wavelength of the CP wave is close to the longitudinal surface plasmon resonance band of the GNP. In contrast, when the CP wave is incident along the axes of revolution of these shapes of GNPs, the ratio of optical torque to absorption power is directly proportional to the wavelength. Moreover, this ratio is independent of the size and even the aspect ratio of GNPs. This result suggests that only the absorbed photons contribute to optical torques, but not the scattered ones, due to the conservation of angular momentum for cases of rotational symmetry. (C) 2016 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据