Design and simulation of a germanium multiple quantum well metal strip nanocavity plasmon laser

Abstract

In order to achieve electrically pumped plasmon nano lasers, several structures, materials and methods, have been proposed recently. However, there is still a long way to find out a reliable appropriate on-chip plasmon source for commercial plasmonic integrated circuits. In this paper, a new integrated nanocavity plasmon laser is proposed, analyzed and simulated for 1550 nm free-space wavelength. Due to its significant field confinement resulted by the metal strip structure and strong interaction of plasmonic modes with the germanium quantum wells this structure has a remarkable output performance. Purcell factor of this nanocavity is about 291. Using semi-classical rate equations in combination with finite difference time domain (FDTD) cavity mode analysis, the output performance measures are estimated and confirmed with respect to various physical models and simulation tools. Simulation results for this structure which has 0.073 µm2 area show a 2.8 µW output power with 10 µA injection current and about 4.16 mW output power with the threshold pump current of 27 mA, while maintaining its performance in a wide spectral bandwidth about 1.46 THz. It also can be electrically modulated by the pump current up to 5.7 GHz.