Physics Open (Nov 2021)
Efficient atomic memory using electromagnetically induced absorption
Abstract
We report on a detailed theoretical investigation of optical information storage in an atomic ensemble modeled by a four-level N-type system, in a nonlinear regime of interaction, where one of the writing fields is large enough to saturate the optical transition. We study the optical pulse generated from a medium in condition of electromagnetically induced absorption (EIA) or electromagnetically induced transparency (EIT). We show that in the EIA condition the energy and the maximum intensity of the pulse extracted are much larger than in the EIT condition. When the information is stored in the EIA condition the full width at half maximum (FWHM) of the optical pulse generated is larger than when extracted in the EIT condition. The energy and maximum intensity of the optical pulse generated are found to have the same decay time whether the information was stored in EIA or EIT conditions. Our work demonstrates a higher efficiency in extracting energy in the saturated regime from an atomic memory based on EIA than from one in EIT condition.
