Response Times of Degenerately Doped Semiconductor Based Plasmonic Modulator

Abstract

Abstract We present a transient response study of a semiconductor-based plasmonic switch. The proposed device operates through active control and modulation of localized electron density waves i.e., Surface Plasmon Polaritons (SPPs) at degenerately doped In0.53Ga0.47As based PN++ junctions. A set of devices are designed and fabricated, and their optical and electronic behaviors are studied both experimentally and theoretically. Optical characterization shows far-field reflectivity modulation, a result of electrical tuning of the SPPs at the PN++ junctions for mid-IR wavelengths with significant 3dB bandwidths. Numerical studies using a self-consistent electro-optic multi-physics model are performed to uncover the temporal response of the devices’ electromagnetic and kinetic mechanisms facilitating the SPP switching at the PN++ junctions. The numerical simulations show strong synergy with the experimental results, validating the claim of possible electrical tunability of the device with a 3dB bandwidth as high as 2GHz. Thus, this study confirms that the presented SPPD architecture can be implemented for high-speed control of SPPs through electrical means, potentially providing a pathway toward fast all-semiconductor plasmonic devices.