Fabrication of surface plasmon waveguides and integrated components on Cytop

The fabrication and physical characterisation of waveguides and integrated components on Cytop are described. The waveguides consist of a thin narrow Au stripe, on an optically infinite layer of Cytop. The integrated components implemented with this waveguide consist of Y-junctions, Mach–Zehnder interferometers and couplers. The waveguides and components are dimensioned such that they propagate long-range surface plasmon-polariton waves when cladded with an index-matched fluid. The fabrication process flow and individual process steps are described in detail. Physical characterisation was conducted on structures having undergone intermediate process steps and on finished structures. The attenuation of waveguides measured through cut-back is in good agreement with theoretical expectations, and mode outputs observed via an infra-red camera are of very good quality. The waveguides and components are useful for (bio)chemical sensing in aqueous solutions.