A novel optofluidic evanescent waveguide sensor system for fluorescence spectroscopy fabricated by micro-stereolithography

In this contribution we present the design, fabrication and measurement results of an evanescent liquid-core/ liquid-cladding (L2) waveguide sensor system for on-chip fluorescence spectroscopy. To efficiently excite the sample (fluorescent particles or solutions) in the laminar flow regime a novel hydrodynamic focusing design is realized which positions the analyte in the evanescent field region at the core/cladding interface. The fiber-chip-coupled laser light is guided by the L2 waveguide and ensures a relatively uniform fluorescence excitation along the analysis channel. The chip is fabricated by rapid prototyping (micro-stereolithography) in less than 1.5 hours.