Dynamics of a stored Zeeman coherence grating in an external magnetic field

Abstract

We investigate the evolution of a Zeeman coherence grating induced in a cold atomic cesium sample in the presence of an external magnetic field. The gratings are created in a three-beam light storage configuration using two quasi-collinear writing laser pulses and reading with a counterpropagating pulse after a variable time delay. The phase conjugated pulse arising from the atomic sample is monitored. Collapses and revivals of the retrieved pulse are observed for different polarizations of the laser beams and for different directions of the applied magnetic field. While magnetic field inhomogeneities are responsible for the decay of the coherent atomic response, a fivefold increase in the coherence decay time, with respect to no applied magnetic field, is obtained for an appropriate choice of the direction of the applied magnetic field. A simplified theoretical model illustrates the role of the magnetic field mean and its inhomogeneity on the collective atomic response.

Polarization characteristics of radiation of atomic ensemble under coherent excitation in the presence of a strong magnetic field

“…Continuing interest in these phenomena is related not so much to the phenomena themselves, but rather their applications -lasing without inversion [1], laser cooling [2] and stored light [3]. If the system under consideration is not in the CPT state, the polarization characteristics of its radiation can be used for the diagnostics of the anisotropy of the processes occurring in that system.…”

Electromagnetically induced blazed grating at low light levels

“…Several applications have been proposed and demonstrated experimentally for such atomic gratings: all-optical switching and routing [1], tunable photonic band gaps [2], light storage [3,4], and beam splitting and fanning [5], among others. Many of the different schemes that have been proposed for creating an atomic grating use electromagnetically induced transparency (EIT) [6].…”

Theoretical investigation of electromagnetically induced phase grating in RF-driven cascade-type atomic systems

“…EIG initially was proposed in a Λ-type threelevel atomic system [1], then experimentally demonstrated in cold and hot atomic media [2][3][4]. The great attention to EIG is due to its potential applications in significant fields such as all-optical switching and routing [2], probing material optical properties [4], atomic/molecular velocimetry [5], light storage [6,7], optical bistability realization [8], beam splitting and fanning [9], shaping a biphoton spectrum [10], developing novel photonic devices in semiconductor QW systems [11], and controlling multi-wave mixing signals via photonic band gap of electromagnetically induced absorption grating in atomic media [12]. It is shown that the intensity of higher-order diffractions could be enhanced in a three-level ladder type system [13].…”