(Invited) Band-Engineered Ge-On-Si Lasers for Integrated Photonics

Abstract

Electronic-photonic synergy has become an increasingly clear solution to enhance the bandwidth and improve the energy efficiency of information systems. Monolithic lasers on silicon are ideal for large scale electronic-photonic integration. Germanium is a particularly interesting candidate for this application due to its pseudo-direct gap behavior in the near infrared regime for optical communications and compatibility with advanced silicon complementary metal oxide semiconductor (CMOS) technology. In this paper, we review theoretical modeling and experimental studies on optical gain and lasing from monolithic epitaxial Ge-on-Si devices band-engineered by tensile strain and n-type doping to compensate the energy difference between the direct and indirect conduction valleys. Demonstrations of optical gain and lasing at room temperature indicate that the Ge-on-Si laser is a promising candidate for monolithic electronic-photonic integrated circuits.