Autler-Townes Splitting and chi-2 Turing-Rolls in Microresonators

We demonstrate that the generation of the sparse, i.e., Turing-pattern-like, frequency combs in chi-2 microresonators is explained by the four distinct signal-idler- pump photon energy conservation laws. The transformation of the usually unique three- photon energy conservation to the four conditions happens due to the effect analogous to the Autler-Townes splitting known in the strong photon-atom interaction.