Wednesday 2 November 2016

Paper published in Optics Letters

Our paper on optical binding in two-dimensions has been published as Xiang Han, Hui Luo, Guangzong Xiao and P. H. Jones.  'Optically bound colloidal lattices in evanescent optical fields', Optics Letters 41 4935 (2016).

From the abstract: In this Letter, we demonstrate the formation of a stable two-dimensional lattice of colloidal particles in the interference pattern formed by four evanescent optical fields at a dielectric interface. The microspheres are observed to form a two-dimensional square lattice with lattice vectors inclined relative to the beam propagation directions. We use digital video microscopy and particle tracking to measure the Brownian motion of particles bound in the lattice, and use this to characterize fluctuations in the local ordering of particles using the bond orientational order parameter, the probability distribution of which is shown to be a chi-squared distribution. An explanation for the form of this distribution is presented in terms of fluctuations of the modes of a ring of particles connected by springs.