Electro-optic metal-insulator-semiconductor-insulator-metal Mach-Zehnder plasmonic modulator

► The performance of an electro-optic metal-insulator-semiconductor-insulator-metal Mach-Zehnder plasmonic modulator on a buried oxide layer was investigated using electromagnetic and carrier transport simulations. ► The subject of research is both timely and important because sub-wavelength confinement of light in plasmonic structures provides the opportunity to integrate photonic devices with silicon electronics on the same platform, with considerably reduced device lengths and power consumption. ► A strongly confined plasmon mode exists in the thin oxide layer between the metal and the semiconductor layer. Electron densities near the oxide/silicon interface were calculated taking account of size-quantisation effects, their presence leads to a large change in the effective plasmon mode index within the MISIM structure for an applied bias. ► Our design exhibits a large change in effective plasmon mode index leading to considerably reduced device length with an acceptable insertion loss.