Ultrafast all-optical modulation in a silicon nanoplasmonic resonator

Ultrafast all-optical modulation in silicon-based metal-insulator-semiconductor-insulator-metal nanoring resonators through photogeneration of free-carriers using two-photon absorption is presented 3-D through finite difference time domain simulations. In a compact device footprint of only 1.4 µm(2), a 13.1 dB modulation amplitude was obtained with a switching time of only 2 ps using a modest pump pulse energy of 16.0 pJ. The larger bandwidth associated with more compact nanorings is shown to result in increased modulation amplitude.