A crucial yet unavailable component in high-performance photonic integrated circuits (ICs) and other chip-scale photonic systems is an on-chip light source that is efficient, functional, IC-compatible, and electronically addressable. In this talk, I will cover several types of on-chip sources, including perovskite microlasers and luminescent hyperbolic metamaterials, topologically protected microlasers on the III-V platform, as well as spintronic THz emitters on the III-N platform.