All-optical filter design: Electromagnetically induced transparency and ring resonator

In this paper, we present a novel method based on Electromagnetically Induced Transparency (EIT) and ring resonator for description of all-optical controllable filters that is so necessary for development of all-optical networks and systems. Impurities including 4-level atoms or nanocrystals added to ring resonator for control of the absorption and the index of refraction. Parameters of the control electromagnetic field or fields are used to manipulate the absorption and the index of refraction of the ring resonator. Also, optical filtering behavior of the ring resonator is studied. It is shown that using the control field, optical filtering properties of the proposed structure can be controlled.