Four-wave mixing enhanced white-light cavity

We discuss bandwidth enhancement of a cavity without reducing its maximum intensity buildup in a regime where the light propagation dynamics is crucial. The enhancement relies on a frequency-dependent phase compensation via negative dispersion provided by a coherently prepared atomic medium in the cavity. We analyze the spatiotemporal dynamics in such a white-light cavity with a full simulation of the field propagation. We find that the probe field dispersion is in addition changed by a coherent field which is generated within the medium via four-wave mixing. Counterintuitively, this in-medium dynamics leads to a further enhancement of the cavity bandwidth.