Dynamic generation and manipulaition of electromagnetically induced 2D phtonic band-gaps

Abstract

We study the steady optical responses of a four-level Tripod cold 87Rb atomic system, which is driven by two mutually perpendicular strong standing-wave laser fields. It is found that satisfying the condition of a proper detuning between two strong fields, one nearly perfect structure of double photonic band-gap, where reflectivity can reach 95%, can be generated along each direction, respectively. Shifting a strong field (two strong fields) to a travelling-wave field (two travelling-wave fields), we can achieve a reflectivity platform and a transmissivity window (two transmissivity windows). Our new findings are beneficial to a novel all-optical switching and routing, which may have applications in complex all-optical information networks.

Dynamically controlled optical nonreciprocity of a double-ladder system with spontaneously generated coherence in moving atomic optical lattice

“…So, people have proposed the use of electromagnetically induced transparency (EIT) [4] to obtain tunable PBG in cold atoms driven by a standing-wave field. [5][6][7][8] It is important to note that the spatially periodic coherent effect can be generated in cold atoms confined in an optical lattice. [9][10][11][12][13][14] In a theoretical paper, Petrosyan showed that such a system could induce a new PBG under the condition of EIT.…”