Luca O. Trinchão, Luiz Peres, Eduardo Gonçalves, Miguel Nienstedt, Lais Fujii dos Santos, Paulo F. Jarschel, Thiago Alegre, Nathália B. Tomazio, Gustavo S. Wiederhecker
We present a method for resolving spatial mode overlaps in coupled microresonators based on Kerr and thermal cross-phase modulation. Through a pump-probe setup, we measure the experimental overlap in a three-ring resonator with good agreement with analytical theory. Our technique can be generalized for describing nonlinear interactions in more complex multi- and coupled-mode systems.