Modeling of edge-emitting lasers based on tensile strained germanium microstrips

In this paper, we present a thorough modeling of an edge-emitting laser based on strained germanium (Ge) microstrips. The full-band structure of the tensile strained Ge layer enters the calculation of optical properties. Material gain for strained Ge is used in the 2D simulation of the carrier transport and of the optical field within a cross section of the microstrips orthogonal to the optical cavity. We study optoelectronic properties of the device for two different designs. The simulation results are very promising as they show feasible ways toward Ge emitter devices with lower threshold currents and higher efficiency as published insofar. © 2009-2012 IEEE.