Fabrication of surface plasmon waveguides and devices in Cytop with integrated microfluidic channels

Abstract

Long range surface plasmon-polariton waveguides and devices suitable for biosensing were fabricated and characterized physically and optically. The structures consist of thin (∼35 nm) patterned Au stripes embedded in thick Cytop claddings (∼8 μm each). Portions of Au stripes were exposed by patterning and etching though the top Cytop cladding using an O2 plasma etch. The etched Cytop cavities act as microfluidic channels to contain and direct the sensing fluid. Intermediate process steps were verified through physical characterization as were fully fabricated structures. Optical testing was performed on Cytop-embedded structures and on channel-filled (with sensing fluid) structures. The structures were excited through end-fire coupling to optical fibers.