We study electromagnetically induced transparency (EIT) and nonlinear pulse propagation in a resonant atomic gas confined in a microwaveguide. We find that the quantum-interference effect in this system can be greatly enhanced due to the reduction of the mode volume of the optical field. In particular, compared with atomic gases in free space, the EIT transparency window in the present confined system can be much wider and deeper, the group velocity of the probe field can be much slower, and the Kerr nonlinearity of the system can be much stronger. We show that a more efficient production of ultraslow optical solitons in the present system may be achieved with much slower propagating velocity and lower generation power. Features of EIT and pulse propagation in the present system are very promising for practical applications in optical information processing and transmission.
We propose a scheme to obtain stable nonlinear optical pulses and realize their storage and retrieval in an ultracold ladder-type three-level atomic gas via electromagnetically induced transparency. Based on Maxwell-Bloch equations we derive a nonlinear equation governing the evolution of probe field envelope, and show that optical solitons with ultraslow propagating velocity and extremely low generation power can be created in the system. Furthermore, we demonstrate that such ultraslow optical solitons can be stored and retrieved by switching off and on a control field. Due to the balance between dispersion and nonlinearity, the ultraslow optical solitons are robust during propagation, and hence their storage and retrieval are more desirable than that of linear optical pulses. This raises the possibility of realizing the storage and retrieval of light and quantum information by using solitonic pulses.
We investigate the formation and propagation of ultraslow weak-light solitons and their memory in the atomic gas filled in a kagome-structured hollow-core photonic crystal fiber (HC-PCF) via electromagnetically induced transparency (EIT). We show that, due to the strong light-atom coupling contributed by the transverse confinement of the HC-PCF, the EIT and hence the optical Kerr nonlinearity of the system can be largely enhanced, and hence optical solitons with very short formation distance, ultraslow propagation velocity, and extremely low generation power can be realized. We also show that the optical solitons obtained can not only be robust during propagation, but also be stored and retrieved with high efficiency through the switching off and on of a control laser field. The results reported herein are promising for practical applications of all-optical information processing and transmission via the ultraslow weak-light solitons and the kagome-structured HC-PCF.
X waves are a special type of wave packet that can maintain their transverse profile of
X shape during propagation, and they are of much interest for the study of fundamental physics and practical applications. Here we present a scheme to generate nonlinear
X waves and realize their active control by using a cold gas of Rydberg atoms via electromagnetically induced transparency (EIT). We show that, due to the EIT effect contributed by a control laser field and the strong, nonlocal Kerr nonlinearity contributed by Rydberg-Rydberg interaction between atoms, the system supports high-dimensional, nonlocal, and nonlinear optical
X waves, which have low propagation loss, ultraslow propagation velocity, and ultralow generation power. We also show that the stability domain of such
X waves can be greatly enlarged by increasing the nonlocality degree of the Kerr nonlinearity, and their motion trajectory can be manipulated by using an external magnetic field. Our study opens a route for generating and controlling nonlocal ultraslow nonlinear optical
X waves, which may have promising applications in optical information processing and transmission.
We propose a scheme to realize the storage and retrieval of optical Peregrine solitons in a coherent atomic gas via electromagnetically induced transparency (EIT). We show that optical Peregrine solitons with very small propagation loss, ultraslow motional velocity, and extremely low generation power can be created in the system via EIT. We also show that such solitons can be stored, retrieved, split, and routed with high efficiency and fidelity through the manipulation of control laser fields. The results reported here are useful for the active control of optical Peregrine solitons and promising for applications in optical information processing and transmission.