Electrically Tunable Plasmonic Absorber Based On Cu-ITO Subwavelength Grating On SOI At Telecom Wavelength

Abstract

An electrically controlled optical absorption is numerically proposed in a plasmonic waveguide on silicon-oninsulator (SOI) consisting of copper-Indium tin oxide (ITO) based subwavelength grating at 1.55 µm wavelength. The Cu-ITO subwavelength grating in form of a discontinuous Cu layer filled with ITO together with electrically tunable permittivity of ITO provides us with a tunable absorption and efficient guidance of plasmonic mode. An n-type ITO is used which exhibits a significant change in the carrier concentration with the applied voltage resulting in a change in optical absorption at a telecom wavelength of 1.55 µm. We numerically observe maximum tuning in absorption at a grating period of 600 nm and a duty cycle of 50%. The proposed device shows a smaller effective mode area of Am= 0.01421 /µm2 and a plasmonic confinement factor of 34.67%. The device is reported to have an extinction ratio of 10.28 dB for a 100 µm long device at a low voltage of 6V.

Optically Triggered AlGaN/GaN Semiconductor Power Transistor with Bi-layer Anti-reflecting Structure

“…The electrical characteristic of the device is numerically calculated by Lumerical DEVICE simulation tool [17]- [19]. The CHARGER solver is run in steady state mode and transient state mode to calculate device current and switching characteristics respectively.…”