Passive long-range surface plasmon-polariton devices in Cytop.

Passive elements operating with long-range surface plasmon polaritons and constructed as Au stripes embedded in Cytop were investigated theoretically and experimentally at wavelengths near 1310 nm. The elements investigated consist of straight waveguides, S-bends, Y-junctions, couplers, and Mach-Zehnder interferometers. The measured performance of these devices is close to theoretical expectations, although uniformity issues were noted, likely because of fabrication imperfections. Cytop is a low-index polymer suitable for biosensing applications involving aqueous buffers. The elements demonstrated thus could form the basis of integrated biosensing devices operating with long-range surface plasmons.