Integrated silicon photonics has sparked a significant ramp-up of investment in both academia and industry as a
scalable, power-efficient, and eco-friendly solution. At the heart of this platform is the light source, which in itself, has
been the focus of research and development extensively. This paper sheds light and conveys our perspective on the
current state-of-the-art in different aspects of application-driven on-chip silicon lasers. We tackle this from two perspectives:
device-level and system-wide points of view. In the former, the different routes taken in integrating on-chip
lasers are explored from different material systems to the chosen integration methodologies. Then, the discussion
focus is shifted towards system-wide applications that show great prospects in incorporating photonic integrated circuits
(PIC) with on-chip lasers and active devices, namely, optical communications and interconnects, optical phased
array-based LiDAR, sensors for chemical and biological analysis, integrated quantum technologies, and finally, optical
computing. By leveraging the myriad inherent attractive features of integrated silicon photonics, this paper 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.