Effect of high odrer dispersion on soliton interaction in coupled Kerr cavities

Abstract

We investigate the interaction of dissipative Kerr solitons in two nearly identical coherently driven, coupled microresonators in the presence of third-order dispersion (TOD). Using an asymptotic reduction of the coupled Lugiato--Lefever equations, we derive effective interaction equations governing the soliton separation and collective drift for weak intercavity coupling. TOD breaks the parity symmetry of the soliton profile and qualitatively modifies the effective interaction, leading to asymmetric interaction forces and multiple stable and unstable soliton clusters. The existence and stability of these clusters are controlled by the relative phase of the driving fields and the group-velocity mismatch between the resonators. In particular, an appropriate value of the group-velocity mismatch can give rise to multiple stable bound states, whereas deviations from this value trigger successive saddle-node bifurcations, ultimately leading to periodic soliton collisions. The analytical predictions are confirmed by numerical simulations of the full coupled system.