Optical Binding of Nano-structures

14.06.2017, 14:00

Dr Stephen Simpson, Institute of Scientific Instruments of the CAS, v. v. i., Brno, Czech Republic

Optical binding occurs when scattered light induces structured interactions between nanoparticles. In a symmetrical system, action and reaction are balanced and stable particle arrays occur. However, breaking the symmetry can unbalance the optical forces and result in non-conservative motion. While optically bound spheres have been extensively studied, little has been reported on lower symmetry systems. This presentation theoretically investigates the self-organisation of nanostructures, driven by coupled optical interaction forces. These systems display various forms of configuration dependent behaviour. In particular, ensembles of nanowires can form stationary, ladder-like structures as well as assymetric, arrow shaped, assemblies that move spontaneously. Introducing chirality, either in the geometry of the nanoparticles, or in the incident optical field, gives rise to coordinated rotational states that combining spin and orbital motion. In a sense, these are self-organising nano-machines. Whilst the examples presented are quite basic, the capacity of similar systems to sustain complex, emergent effects and functional behaviour is evident.

Some of this work has just been accepted for publication in Nano Letters: pubs.acs.org/doi/abs/10.1021/acs.nanolett.7b00494