Electrically pumped lasing from Ge Fabry-Perot resonators on Si

Abstract

Room temperature lasing from electrically pumped n-type doped Ge edge emitting devices has been observed. The edge emitter is formed by cleaving Si-Ge waveguide heterodiodes, providing optical feedback through a Fabry-Perot resonator. The electroluminescence spectra of the devices showed optical bleaching and intensity gain for wavelengths between 1660 nm and 1700 nm. This fits the theoretically predicted behavior for the n-type Ge material system. With further pulsed electrical injection of 500 kA/cm² it was possible to reach the lasing threshold for such edge emitters. Different lengths and widths of devices have been investigated in order to maintain best gain-absorption ratios.

Analysis of homogeneous broadening in n-type doped Ge layers on Si for laser application

“…A summary of all samples investigated in this work is shown in Table 1. Their doping level is similar to that of the electrically pumped Ge laser demonstrated in [8,9]. An undoped layer of 0.6 µm Ge was used as a reference.…”

Extended Defect Propagation in Highly Tensile-Strained Ge Waveguides

“…Enhanced direct-bandgap photoluminescence has similarly been demonstrated [20][21][22]. Although electrically-pumped pulsed Ge lasers have been demonstrated, the reported threshold currents were very large and operating lifetimes short [23,24]. Efforts to increase efficiency and optical gain by inducing higher strain are often faced with higher dislocation density and nonradiative recombination, which increases the laser threshold.…”

(Si)GeSn nanostructures for light emitters

“…While room temperature electroluminescence at low current densities from homojunction light emitting diodes (LEDs), relying on the direct band gap, has already been demonstrated [6][7][8][9] , optically-pumped lasers still suffer from low maximum operating temperatures 3 . Those may be overcome by decreasing the residual compressive strain in the device by more elaborate geometries, like under-etched micro-disk resonators, or by using quantum effects in heterostructures, where charge carriers are confined in a quantum well or a quantum dot 10,11,12 .…”