Thermo-optic mode extinction modulator based on graphene plasmonic waveguide

We developed a thermo-optic (TO) mode extinction modulator based on graphene plasmonic waveguide. For compact device design and fabrication, the graphene plasmonic waveguide and heating element are configured all-in-one. Thermally induced inhomogeneous refractive-index distribution of the polymer near the microribbon cut off the long-range surface plasmon polariton (LRSPP) stripe mode propagating along a graphene microribbon. Numerical modeling are conducted on the time-dependent temperature (and hence the refractive-index) distribution by resistive heating element inside the graphene TO modulator. Experimental results demonstrate 30 dB attenuation with 12 mW electrical power injection at a telecom wavelength and exhibit a good agreement with the thermal modeling.