Near-field polarization analysis for an optical nanofiber

光纤纳米纤维的近场偏振分析

• 批准号: 18F18367
• 负责人: NICCHORMAIC SILE
• 金额: $ 1.41万
• 依托单位: Okinawa Institute of Science and Technology Graduate University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2018
• 资助国家: 日本
• 起止时间: 2018-11-09 至 2021-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18F18367/
• 关键词: nanofiber; polarization; spin-orbit coupling; chiral; optical nanofiber; polarization control; directional coupling; whispering gallery mode; optomechanical probe; two-photon atomic spectroscopy; nanofibre; control

During the year, the polarization control in optical nanofibres has been further improved enabling studies on spin-orbit coupling for optically trapped chiral particles adjacent to an optical nanofibre. Spin angular momentum in electromagnetic waves is caused not only by field rotations associated with elliptical polarization, but also by spatial modulations of the field. Consequently, the spin carried by light does not have to be parallel to the energy transfer. Transverse components can be significant in strongly confined light, such as evanescent fields. Here, the transverse spin was revealed through its direct action on a probe particle held and spun by optical tweezers in the evanescent field at the surface of a nanofiber. The work has benefitted from a theoretical model developed by colleagues in ITMO, Russia. This work has been presented at several conferences (including OPIC 2021) and is being prepared for publication.A second work has also been conducted building on the polarization control. Composite material objects such as Janus particles can exhibit interesting dynamics, such as propulsion in response to an external gradient field or collective assembly due to a generated localized thermal gradient around each particle. In this study, we demonstrated light-induced dynamics of metallo-dielectric Janus microspheres with a thin layer of gold that are trapped and propelled in the evanescent field of a nanofiber. We found that Janus particles with a 10 nm or 20 nm gold coating exhibit propulsion speed enhancements compared with uncoated silica microspheres.

年内，光学纳米纤维的偏振控制得到进一步改善，从而能够研究光学捕获的与纳米光纤相邻的手性粒子的自旋-轨道耦合。电磁波中的自旋角动量不仅是由与椭圆极化相关的场旋转引起的，而且是由场的空间调制引起的。因此，光携带的自旋不必与能量传递平行。横向分量在强受限光中可能很重要，例如瞬逝光场。在这里，横向自旋是通过它在纳米纤维表面的逝去场中直接作用于被光学镊子抓住并自旋的探针粒子来揭示的。这项工作得益于俄罗斯ITMO的同事开发的一个理论模型。这项工作已经在几次会议(包括OPIC 2021)上提出，并正在准备出版。第二项工作也在偏振控制的基础上进行。像Janus粒子这样的复合材料物体可以表现出有趣的动力学，例如响应外部梯度场的推进或由于每个粒子周围产生的局部热梯度而形成的集体组装。在这项研究中，我们展示了金属介电Janus微球的光诱导动力学，这种微球带有一层薄薄的金层，被捕获并推动在纳米纤维的消失场中。我们发现，与未包覆的二氧化硅微球相比，包覆了10 nm或20 nm金的Janus粒子表现出了推进速度的提高。

项目成果

Observation of the 87Rb 5S1/2 to 4D3/2 electric quadrupole transition at 516.6 nm mediated via an optical nanofibre

通过光学纳米纤维介导的 516.6 nm 处 87Rb 5S1/2 到 4D3/2 电四极跃迁的观察

• DOI: 10.1103/physrevresearch.2.033341
• 发表时间: 2020
• 期刊: New Journal of Physics
• 影响因子: 3.3
• 作者: Tridib Ray;Ratnesh K Gupta;Vandna Gokhroo;Jesse L Everett;Thomas Nieddu;Krishnapriya S Rajasree;Sile Nic Chormaic
• 通讯作者: Sile Nic Chormaic

Optomechanics with single-mode optical nanofibers

单模光纤纳米纤维的光力学

• 发表时间: 2020
• 作者: G Tkachenko;I Toftul;VG Truong;MI Petrov and S Nic Chormaic
• 通讯作者: MI Petrov and S Nic Chormaic

Using optical fibers for particle trapping and manipulation

使用光纤进行粒子捕获和操纵

• 发表时间: 2021
• 作者: K. Asada;T. Miyamoto;H. Yamakawa;J. Hirata;N. Takamura;T. Morimoto;K. Suzuki;T. Otaki;N. Kida;T. Nakamura;and H. Okamoto;S Nic Chormaic
• 通讯作者: S Nic Chormaic

Polarization control for single-mode optical nanofibers: fundamentals and applications

单模光纤纳米光纤的偏振控制：基础知识和应用

• 发表时间: 2020
• 作者: G Tkachenko;I Toftul;VG Truong;MI Petrov and S Nic Chormaic;Georgiy Tkachenko
• 通讯作者: Georgiy Tkachenko

Controlling Polarization in Optical Nanofibers Using Directional Coupling of Light

利用光的定向耦合控制光学纳米纤维的偏振

• 发表时间: 2019
• 作者: G Tkachenko;I Toftul;VG Truong;MI Petrov and S Nic Chormaic;Georgiy Tkachenko;Georgiy Tkachenko
• 通讯作者: Georgiy Tkachenko