Quantum Optics Laboratory

Beyond the adiabatic approximation, quantum theory of optical pulse interacting with Λ-type configuration atomic media under electromagnetically induced transparency (EIT) condition has been investigated. We consider general situations including ground state and excited state decoherences which introduces extra quantum noises into probe field, studying the slow light as well as storage and retrieval for output squeezed pulse. With the controllable physical quantities, coupling field strength and optical depth of EIT media, we study the output quadrature variance of probe field and demonstrate that the quantum squeezing could be preserved with stronger coupling strength.