Here we demonstrate CMOS-compatible, monolithically-integrated group-IV lasers on silicon as the important on-chip lasers for Si photonics. Using low-temperature growthGe buffer layer techniques, we successfully grew direct-bandgap GeSn layers on Si substrates. By processing the GeSn sample into laser cavities, we achieved lasing action under optical pumping with a low threshold. This technology could be used as the on-chip laser sources for SiPh, enabling a wide range of applications.

Si-based laser is the missing piece of silicon photonics due to the limitation of indirect-bandgap of group-IV semiconductors, leading to extremely low luminescent efficiency. Here we brek this limitation by developing direct-bandgap GeSn lasers on Si using low-temperature growthGe buffer techniques to achieve direct-bandgap GeSn layers. Optical-pumped lasing action was achieved with a narrow linewidth of just ~3 nma low threshold of 50 kW/cm2, which is superior than other groups.

Our technology can be used as the on-chip laser source of silicon photonic chips to enable high-densityfunctional silicon photonic chips. The applications could include optical communications, bio-medical detection, LIDAR, quantum computing. As the market of silicon photonics is tens billion USD dollarsevery silicon chip requires several on-chip light source, our on-chip GeSn laser technology has a great needthus huge market value.