講演情報
[11p-C310-3]Optical trapping dynamics of gold nanoparticles with phase-modulated dual co-propagating laser beams
〇(D)Mu-En Li1, Jim Jui-Kai Chen2, Xin-Xiu Wang1, Boris Louis2, Roger Bresoli-Obach3, Johan Hofkens2, Yung-Fu Chen1, Teruki Sugiyama1, Hiroshi Masuhara1 (1.National Yang Ming Chiao Tung Univ., Taiwan, 2.Katholieke Univ. Leuven, Belgium, 3.Universitat Ramon Llull, Spain)
キーワード：
optical trapping、gold nanoparticle、optical binding
Our group has reported a dynamic optical matter based on the optical binding among non-irradiated and irradiated gold (Au) nanoparticles (NPs) by tightly focusing a linearly polarized 1064 nm laser at the glass/solution interface. At the initial stage of this assembly of Au NPs, three Au NPs are aligned perpendicularly to the linear polarization. In the 2024 JSAP Autumn meeting, we reported that two co-propagating linearly polarized laser beams were introduced to study the far-field interactions.3 When the non-irradiated Au NP arrived at the gap between two traps, its localization showed an arc-like distribution, indicating stable trapped positions were constructed outside the focal spot. In this report, we introduce the spatial light modulator that enables the precise phase modulation of the trapping lasers to study the positional correlations among Au NPs. The dynamics of the irradiated Au NPs are investigated using principal component analysis. The extracted collective motions exhibit a similar pattern to the molecular vibrations, including the in-phase (center-of-mass-like) or out-of-phase (stretching-like) motions. The relative contributions of these collective modes vary with the separation distance between the laser beams. Interestingly, when a non-irradiated seventh Au NP is located within the gap between the two laser beams, the collective dynamics of the irradiated Au NPs transition to a predominantly in-phase motion pattern. These observations highlight the role of optical binding in mediating and reshaping collective NP dynamics beyond the irradiation area.