Ge-on-Si light-emitting materials and devices for silicon photonics

[摘要] (cont.) We have observed an optical bleaching effect, the reduction of absorption under pumping and the prelude of optical gain, above the direct band gap energy from the engineered Ge. The population inversion factor increases with the n-type doping concentration in Ge, as predicted by the theory. By increasing the injection level using a Ge micro-mesa structure carrier confinement, we have successfully demonstrated the net gain, i.e. population inversion. A peak gain of 50 ± 25 cm-1 at 1605 nm has been obtained from the experiment. It is the first report of observing net gain from germanium.

[发布机构] Massachusetts Institute of Technology