Liu Yaoran, Lin Linhan, Bangalore Rajeeva Bharath, Jarrett Jeremy W, Li Xintong, Peng Xiaolei, Kollipara Pavana, Yao Kan, Akinwande Deji, Dunn Andrew K, Zheng Yuebing
ACS Nano. 2018 Oct 23;12(10):10383-10392. doi: 10.1021/acsnano.8b05824. Epub 2018 Sep 27.
Optical manipulation of colloidal nanoparticles and molecules is significant in numerous fields. Opto-thermoelectric nanotweezers exploiting multiple coupling among light, heat, and electric fields enables the low-power optical trapping of nanoparticles on a plasmonic substrate. However, the management of light-to-heat conversion for the versatile and precise manipulation of nanoparticles is still elusive. Herein, we explore the opto-thermoelectric trapping at plasmonic antennas that serve as optothermal nanoradiators to achieve the low-power (∼0.08 mW/μm) and deterministic manipulation of nanoparticles. Specifically, precise optical manipulation of nanoparticles is achieved via optical control of the subwavelength thermal hot spots. We employ a femtosecond laser beam to further improve the heat localization and the precise trapping of single ∼30 nm semiconductor quantum dots at the antennas where the plasmon-exciton coupling can be tuned. With its low-power, precise, and versatile particle control, the opto-thermoelectric manipulation can have applications in photonics, life sciences, and colloidal sciences.
胶体纳米颗粒和分子的光学操控在众多领域都具有重要意义。利用光、热和电场之间多重耦合的光热电纳米镊子能够在等离子体基底上实现对纳米颗粒的低功率光学捕获。然而，对于纳米颗粒进行通用且精确操控的光热转换管理仍难以实现。在此，我们探索在用作光热纳米辐射器的等离子体天线处进行光热电捕获，以实现对纳米颗粒的低功率（约0.08 mW/μm）和确定性操控。具体而言，通过对亚波长热热点的光学控制实现对纳米颗粒的精确光学操控。我们采用飞秒激光束进一步改善热局域化，并在可调节等离子体 - 激子耦合的天线处精确捕获单个约30 nm的半导体量子点。凭借其低功率、精确且通用的粒子操控能力，光热电操控可应用于光子学、生命科学和胶体科学领域。
