Asymmetric Frequency Shift in a Single Time-Modulated Cavity

We investigate the unconventional transmission properties of a single cavity experiencing concurrent index and amplitude modulation. Such a device can yield complete asymmetric frequency conversion without additional insertion loss, which remains elusive in a single cavity. Under optimal modulation parameters, the frequency conversion efficiency is enhanced through the redistribution of sideband energy. The phase difference between the two modulations plays a crucial role in realizing this unique behavior. Furthermore, it also achieves tunable carrier suppression, making it a promising candidate for efficient frequency shifters. We derive an exact solution of the time-rate equation governing the dynamics of the modulator and elaborate on the conditions for optimal asymmetric conversion.