Optics and Photonics Society of Iran

In this paper the performance of a plasmonic modulator, in which the phase of surface plasmon polaritons with a DC or RF bias can be changed, is analyzed and simulated. In such a device, first the light propagating in a silicon waveguide enters a converter section and is converted from photonic mode to plasmonic mode. The surface plasmon polaritons propagate in a metal-insulator-metal structure and are highly confined to metal-insulator interface with high overlapping with bias electric field, experiences a phase change and afterwards is converted again to photonic mode in output converter. The electro-optic “Pockels” effect is responsible for changing the phase of the plasmons in the polymer insulator with a large electro-optic coefficient and consequently a change in refractive index proportional to the bias electric field. It is shown that in this structure the parameter of multiplication of voltage and length, necessary for inducing a phase shift of π is reduced to 1.63 V-mm. Using this phase modulator in a Mach-Zehnder structure, an intensity modulation can be achieved.