In the relentless pursuit of moving more data, faster and farther, the optical communications industry has undergone a quiet revolution. The shift from simple on-off keying to sophisticated coherent transmission has been the single most significant factor in unlocking the terabit-scale capacities of modern fiber optic networks. And at the very heart of every coherent system lies a critical component: the narrow linewidth laser. https://www.cq-smart.com/narrow-linewidth-laser