Lee Eungkyu, Luo Tengfei
Department of Electronic Engineering, Kyung Hee University, Yongin-si 17104, Gyeonggi-do, Republic of Korea.
Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame 46556, IN, USA.
Nanophotonics. 2021 Nov 10;11(1):79-86. doi: 10.1515/nanoph-2021-0503. eCollection 2022 Jan.
A pulling motion of supercavitating plasmonic nanoparticle (NP) by a single plane wave has received attention for the fundamental physics and potential applications in various fields (, bio-applications, nanofabrication, and nanorobotics). Here, the supercavitating NP depicts a state where a nanobubble encapsulates the NP, which can be formed via the photo-thermal heating process in a liquid. In this letter, we theoretically study the optical force on a supercavitating titanium nitride (TiN) NP by a single plane wave at near-infrared wavelengths to explore optical conditions that can potentially initiate the backward motion of the NP against the wave-propagating direction. An analysis with vector spherical harmonics is used to quantify the optical force on the NP efficiently. Next, the vector field line of the optical force is introduced to visualize the light-driven motion of the NP in a nanobubble. Finally, we characterize the vector field lines at various optical conditions (, various sizes of NP and nanobubble, and wavelength), and we find a suitable window of the optical state which can potentially activate the backward motion of the supercavitating TiN NP.
超空化等离子体纳米粒子（NP）在单平面波作用下的牵引运动因其基础物理特性以及在各个领域（生物应用、纳米制造和纳米机器人技术）的潜在应用而受到关注。在此，超空化NP描述的是纳米气泡包裹NP的一种状态，这种状态可通过液体中的光热加热过程形成。在这封信中，我们从理论上研究了近红外波长下单平面波作用于超空化氮化钛（TiN）NP上的光力，以探索可能引发NP逆着波传播方向向后运动的光学条件。利用矢量球谐函数分析来有效量化作用于NP上的光力。接下来，引入光力的矢量场线以可视化NP在纳米气泡中的光驱动运动。最后，我们对各种光学条件（NP和纳米气泡的各种尺寸以及波长）下的矢量场线进行了表征，并找到了一个合适的光学状态窗口，该窗口有可能激活超空化TiN NP的向后运动。
