Coupled atomic coherences induced by a standing wave

A. I. Alekseev, Ashat M. Basharov

Haitao Zhou, Yu-Peng Dai, Ruifeng Li +3 more

We report an experimental scheme of three-channel all-optical switching based on the conversion between single and double dark states in an atom-ring-cavity system driven by a coherent standing-wave coupling field. By turning on and off the counter-propagating part of the coupling field, the switching for the probe field at three different frequencies is simultaneously achieved. We give a theoretical interpretation to the experimental results via the intracavity susceptibility for thermal atoms at different velocities. The switching performance is experimentally analyzed by introducing an additional coherent pumping light.

Chang Su

Jianchun Wu, Bao-quan Ai

We propose a scheme for high-precision two-dimensional (2D) sub-wavelength atom localization in a tripod-type atomic system. The position information of a moving atom can be obtained by measuring the probe field absorption when the atom interacts with a weak probe field and two orthogonal standing-wave fields. It is found that sub-wavelength atom localization can be obtained under the condition of two-photon resonance. Remarkably, the localization precision can be significantly improved by changing the strength of the coherent coupling fields in the presence of superposition of coherent coupling field and standing-wave field.

Zhaoyang Zhang, Jingliang Feng, Xing Liu +4 more

With two sets of standing-wave fields built in a thermal rubidium vapor cell, we have established a controllable photonic crystal with periodic gain in a coherently prepared N-type four-level atomic configuration. First, the photonic lattice constructed by a resonant standing-wave coupling field results in a spatially modulated susceptibility and makes the signal field diffract in a discrete manner under the condition of electromagnetically induced transparency. Then, with the addition of the standing-wave pump field, the N-type atomic medium can induce a periodic Raman gain on the signal field, which can be effectively controlled by tuning the pertinent atomic parameters. The experimental demonstration of such a real-time reconfigurable photonic crystal structure with periodic Raman gain can pave the way for realizing desired applications predicted in the gain-modulated periodic optical systems.

Subhadeep Gupta, A. E. Leanhardt, Alexander D. Cronin +1 more