A nano-optofluidic waveguide coupler with super-resolution via concurrent dean flows

This paper presents a nano-optofluidic waveguide coupler realized by a pair of concurrent dean flows. Distinctively different from solid waveguide coupler, this nano-optofluidic waveguides consists of a laminar liquid flow, which exhibits spatially varying bidirectional refractive index profile that support novel evanescent coupling phenomenon. The nanogap and the refractive index contrast of the nano-optofluidic waveguides can be measured with super-resolution in nm by analyzing its resulted evanescent coupling pattern. The nano-optofluidic waveguides can be used for biomolecular manipulation and detection in near future.