Microcavity dispersion engineering for the visible optical frequency comb generation

Large normal material dispersion acts as an obstacle in the generation of visible optical frequency combs (OFCs) in microcavities. The trajectory separation of light propagation aggravates the dispersion unbalance in the visible region. Dispersion engineering devoted to compressing the separation reaches a bottleneck due to manufacturing difficulties. In this article, we demonstrated that the separation of the light trajectory can be used to manipulate the cavity dispersion. In a bilayer concentric spherical microcavity (CSM), the visible anomalous dispersion was achieved numerically by precisely matching the separated trajectory with the appropriate materials. Furthermore, we simulated the generation of an optical soliton in the visible region based on the proposed microcavity. Our work provides a clue for the visible dispersion control, and the proposed BK7/silica CSM will be an interesting platform for the visible OFC generation. Published under license by AIP Publishing.