The perfect photon absorption is studied in a cavity quantum electrodynamics (CQED) system, in which an optical parameter amplifier (OPA) is coupled to the cavity mode. This makes it possible to control the optical phase to realize the perfect photon absorption. It is found that in the presence of one and two injected fields, the perfect photon absorption is present in these two cases and can be controlled by adjusting the parametric phase. Moreover, different from the previous predictions of perfect photon absorption in atomic CQED systems, the perfect photon absorption can be changed significantly by the relative phase. Our work provides a new platform to use the parametric processes to make an available way to control the behaviors of photons and to take advantage of the optical phase to achieve the perfect photon absorption.

See in Ref. [Yang Zhang, Yu-Bo Ma, Xin-Ping Li, Yu Guo, and Chang-Shui Yu. Perfect photon absorption based on the optical parametric process. Chin. Phys. B 30 (6): 064203 (2021).] for more detail.​