Observations of Optically Bound Colloidal Assemblies

In recent years there has been growing interest in assembling complex structures from colloidal suspensions for use in both fundamental and applied studies. We are exploring a relatively new and highly tunable inter-particle colloidal force known as the optical binding force. The optical binding force is mediated by light scattering between two or more particles in an intense optical field which can be externally modified. We use experimental methods to impose this optical binding force onto clusters of dielectric colloidal particles. We will discuss unique behaviors that arise from this force, including the formation of multiple extended particle chains and formation of planar arrays.