Frequency comb generation in a resonantly pumped exciton-polariton microring resonator

We develop a scheme for generation of a regular sequence of narrow spectral lines (optical frequency comb) in semiconductor micro-ring resonators operating in the strong-coupling regime. A strong optical nonlinearity of exciton-polaritons, forming as mixed states between the microcavity photons and quantum-well excitons, allows for a low-threshold operation. This work demonstrates visibility of using the exciton-polaritons for the purposes of generation of GHz combs and trains of picoseconds pulses for future all-polariton information processing schemes.