We report the soliton frequency comb generation in microring optical parametric oscillators operating in the downconversion regime and with the simultaneous presence of the χ2 and Kerr nonlinearities. The combs are studied considering a typical geometry of a bulk LiNbO3 toroidal resonator with the normal group velocity dispersion spanning an interval between the pump and the down-converted signal. We have identified critical power signaling a transition between the relatively low pump power predominantly χ2 combs and the high pump power ones shaped by the competition between the χ2 and Kerr nonlinearities.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics