Selective nanomanipulation using optical forces

纳米光纤倏逝场中纳米颗粒的手性选择性光传输

Chirality-selective optical transport of nanoparticles in the evanescent field of a nanofiber

本文利用纳米光纤倏逝场的圆偏振手性基模，实现了对具有扭转表面的金纳米立方体的手性选择性光传输，并通过反向传播模式配置消除非手性光力，在100纳米尺度上验证了手性对映体的光学分离。

Electromagnetic forces for an arbitrary optical trapping of a spherical dielectric

Analytical solution for optical trapping force on a spherical dielectric particle for an arbitrary positioned focused beam is presented in a generalized Lorenz-Mie and vectorial diffraction theory. In this case the exact electromagnetic field is considered in the focal region. A double tweezers setup was employed to perform ultra sensitive force spectroscopy and observe the forces, demonstrating the selectively couple of the transverse electric (TE), transverse magnetic (TM) modes by means of the beam polarization and positioning, and to observe correspondent morphology-dependent resonances (M…

Size-Selective Optical Printing of Silicon Nanoparticles through Their Dipolar Magnetic Resonance

Silicon nanoparticles possess unique size-dependent optical properties due to their strong electric and magnetic resonances in the visible range. However, their widespread application has been limited, in comparison to other (e.g. metallic) nanoparticles, because their preparation on monodisperse colloids remains challenging. Exploiting the unique properties of Si nanoparticles in nano- and micro-devices calls for methods able to sort and organize them from a colloidal suspension onto specific positions of solid substrates with nanometric precision. Here, we demonstrate that surfactant-free Si…

Chiral standing waves and its trapping force on chiral particles

Up to now, in the literature of optical manipulation, optical force due to chirality usually coexists with the non-chiral force and the chiral force usually takes a very small portion of the total force. In this work, we investigate a case where the optical force exerted on an object is purely due to the chirality while there is zero force on non-chiral object. We find that a trapping force arises on chiral particles when it is placed in a field consisted of two orthogonally polarized counter-propagating plane waves. We have revealed the underlying physics of this force by modeling the particl…

通过硅纳米盘的纵向Mie共振增强的光学手性分离

Enhanced Enantioselective Optical Trapping enabled by Longitudinal Mie Resonances in Silicon Nanodisks

利用硅纳米盘的纵向Mie共振实现高选择性的光学手性分离与捕获

Optical Trapping and Manipulation of Nano-objects with an Apertureless Probe

We propose a novel way to trap and manipulate nano-objects above a dielectric substrate using an apertureless near-field probe. A combination of evanescent illumination and light scattering at the probe apex is used to shape the optical field into a localized, three dimensional optical trap. We use the coupled-dipole method and the Maxwell stress tensor to provide a self-consistent description of the optical force, including retardation and the influence of the substrate. We show that small objects can be selectively captured and manipulated under realistic conditions.

散射力的波前整形增强悬浮纳米颗粒的光学捕获

Wavefront Shaping of Scattering Forces Enhances Optical Trapping of Levitated Nanoparticles

研究提出通过波前整形光场来增强悬浮纳米颗粒的光学陷阱刚度，在不增加光强的情况下选择性降低非保守力并保留保守恢复力，从而提升低压稳定性，为减少量子反作用和热退相干提供了新方法。

Part2: Ultra-short pulse laser patterning of very thin indium tin oxide on glass substrates

We investigate selective patterning of ultra-thin 20 nm Indium Tin Oxide (ITO) thin films on glass substrates, using 343, 515, and 1030 nm femtosecond (fs), and 1030 nm picoseconds (ps) laser pulses. An ablative removal mechanism is observed for all wavelengths at both femtosecond and picoseconds time-scales. The absorbed threshold fluence values were determined to be 12.5 mJ/cm2 at 343 nm, 9.68 mJ/cm2 at 515 nm, and 7.50 mJ/cm2 at 1030 nm for femtosecond and 9.14 mJ/cm2 at 1030 nm for picosecond laser exposure. Surface analysis of ablated craters using atomic force microscopy confirms that th…

用于纳米颗粒光捕获的拓扑优化等离激元超表面

Topology optimized plasmonic metasurfaces for optical trapping of nanoparticles

提出基于密度的拓扑优化框架，通过最大化梯度力优化等离激元超表面，实现对不同尺寸和材料纳米颗粒的高效光捕获，并引入制造约束以简化设计。