From the system-level, we develop photonic integrated circuits with on-chip lasers for applications of optical communications and interconnects, optical phased array-based LiDAR, sensors for chemical and biological analysis, integrated quantum technologies, optical computing, etc. By leveraging the myriad inherent attractive features of integrated silicon photonics, we aims to inspire further development in incorporating PICs with on-chip lasers in, but not limited to, these applications for substantial performance gains, green solutions, and mass-production.