[摘要]:Micro-ring lasers that exhibit a quality factor (Q) larger than 5.2 x 10(6) with a direct-illumination, non-resonant pump are demonstrated (a,b). The micro-rings are coated with three organic dyes forming a cascaded energy-transfer (c,d), which reduces material-losses by a factor larger than 10(4) (e), transforming incoherent light to coherent light with high quantum-efficiency. The operating principle is general and can enable fully integrated on-chip, high-Q micro-lasers.