Exploring unconventional optical matter: from within to beyond the photon beam

Optical binding enables the light-induced assembly of multiple body systems, even outside the laser focus. By trapping gold nanoparticles at an interface, a dynamic optical binding network forms through back-scattered light and multi-channel scattering. Optical matter, composed of hybrid metal-dielectric particles, shows even more intriguing dynamics. Silica shell thickness influences optical binding properties, transitioning from linear to hexagonal arrangements. The dynamics of optically bonded particles involve optical forces, electrostatic interactions, and fluid dynamics. Combination of experiments and simulations reveal that reducing electrostatic repulsion promotes near-field bonding, while higher repulsion induces far-field configurations. This highlights the importance of electrostatic interactions in optical binding, demonstrating the potential for tuning properties for various applications. These findings underscore the complex dynamics of optical matter and its potential for creating responsive, highly tunable materials for controlling and manipulating light and matter.