Light is fundamental in physics. Seeking the possibility of controlling the light has great importance for the modern science and engineering. In this talk, I will discuss two major mechanisms for manipulating the light, from quantum optics, nonlinear optics, as well as nanophotonics aspects. I will first talk the effect of quantum coherence from atomic transitions in the light-matter interaction, during the process of novel light source generations. It has been found that there exists the similarity between the atomic level transition and the photonic transition. I will then show the possibility of achieving synthetic photonic gauge potential, in which the photonic transition is dynamically modulated in photonic structured media. Light therefore can be guided following the topologically-protected one-way edge mode. I will end my talk with discussing a previously unexplored route towards creating the synthetic gauge potential by using quantum coherence in nonlinear materials, which highlights an important connection between topological photonics and nonlinear optics. The capability for manipulating the light from quantum coherence to synthetic gauge potential may provide novel insights towards interdisciplinary researches between topological photonics, quantum optics, and nonlinear optics.