NONLINEAR OPTICS OF ATOMS AND ELECTROMAGNETICALLY INDUCED TRANSPARENCY Dark resonance based optical switching

Abstract

An optical switching method based on dark resonance is proposed for ultrafast/ultrawide fibre-optic communications. The proposed switching method is based on dark-resonance induced refractive index changes in a three-level system interacting with two-colour laser lights. Two different mechanisms in the proposed optical switching method are discussed for the use of electromagnetically induced transparency and two-photon coherence induction. They are also compared for suitable applications in fibre-optic communications. Finally, a hyper-THz optical modulator is proposed, limited by current technologies due to carrier lifetime or population relaxation decay time.