Optical matter is a unique class of materials formed by pure electrodynamic interactions of colloidal particles in an optical field, yet previous research on optical matter was almost limited to microparticle systems. Some recent experimental studies, including ours, have extended the boundary of optical matter into nanometer regime, but it remains a significant challenge to build large-scale optical matter with even more than 10 nanoparticles. Here we report our ongoing work on light-driven self-organization of plasmonic nanoparticles into mesoscale clusters and arrays. We use advanced laser beam shaping techniques and the significant electrodynamic interactions among strongly scattering Ag nanoparticles to stabilize the self-organization. By simultaneously controlling the intensity, phase and polarization of light, we can design and tailor the optical field to assemble stable optical matter with more nanoparticles, and reveal new structures arising from optical binding interactions.
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