Heterogeneously integrated III-V-on-silicon microspiral disk lasers for optical interconnects

Electrically pumped and directly modulated microlasers comprising a III-V semiconductor multi-quantum well (MQW) heterogeneously integrated on a silicon photonic chip are potentially a key building block for datacenter optical interconnects. We adopt a microspiral disk cavity in the silicon photonic layer, with a seamlessly coupled silicon waveguide at the microspiral notch, for unidirectional laser output-coupling characteristics. We integrate a ring-shaped electrode on top of the III-V gain layer in order to preferentially inject into a group of whispering-gallery-like modes for improved energy efficiency and mode selection. In this paper, we report multi-mode lasing under both pulsed and continuous injection at room temperature. The threshold current density is typically a few kA/cm2.