Two-phase stratified flow of liquid and air in pdms microfluidic channels for optofluidic waveguides

Abstract

We prepared fluorescent liquid-core/air-cladding (LA) waveguide using twophase stratified flow of liquid and air in microfluidic channels. The high refractive index liquid core stream with fluorescent dye is confined by the low refractive index air flow driven by the vacuum suction. Isotropically emitted light from the dye molecules is efficiently captured and guided in the LA waveguide due to the large refractive index contrast. Moreover, the size of LA waveguide could be tuned reversibly and diffusional mixing between core and cladding were prohibited effectively.