Optofluidic light routing via analytically configuring streamlines of micro-flow

Transformation optics (TO) is a new method to design metamaterials that can manipulate electromagnetic fields. Inspired by the traditional TO techniques which is mostly based on the solid metamaterials with a limited range of tunability, a novel streamline tracing-based transformation optofluidics (STTOF) method is proposed to manipulate the light path by analytically designating the light-carrying streamlines of the flow in a two-dimensional circular bounded domain. A dipole flow model is built to analytically calculate the streamlines of the flow field inside the domain which allocates the optical/fluidic source and sink pairs at arbitrary positions. Liquid core/liquid cladding (L2) configuration is used in the experiment to trace the light via a specific streamline. Experimental results verify that the light paths agree well with the theoretical predictions, and demonstrate that a good range of tunability can be achieved by adjusting the flow rates and the source-sink positions of optical/fluidic source and sink pairs.