Thermo-optic characterization of long-range surface-plasmon devices in Cytop

Thermo-optic modulation experiments were conducted on devices constructed as Au stripes cladded with Cytop designed for a working wavelength of 1310 nm by injecting electric current through metal probes to heat the active region and to change the refractive index of the claddings. Electromigration failure was prevented by controlling the current density below a safety limit. Straight waveguides and single-output Mach-Zehnder interferometers were thermally modulated, in which mode extinction was reached by antiguiding and by destructive interference, respectively. Polymeric memory effects were observed in the operation of the devices.