A practical guide to electromagnetically induced transparency in atomic vapor

Abstract

This tutorial introduces the theoretical and experimental basics of Electromagnetically Induced Transparency (EIT) in thermal alkali vapors. We first give a brief phenomenological description of EIT in simple three-level systems of stationary atoms and derive analytical expressions for optical absorption and dispersion under EIT conditions. Then we focus on how the thermal motion of atoms affects various parameters of the EIT system. Specifically, we analyze the Doppler broadening of optical transitions, ballistic versus diffusive atomic motion in a limited-volume interaction region, and collisional depopulation and decoherence. Finally, we discuss the common trade-offs important for optimizing an EIT experiment and give a brief "walk-through" of a typical EIT experimental setup. We conclude with a brief overview of current and potential EIT applications.

Effect of phase fluctuations on atomic Talbot images in three-level ladder-type atomic system

“…Therefore, D is of the order of a fraction of MHz. The typical microwave sources used in EIT experiments have linewidth in the range between a few hundred kHz to 2 MHz [36], which is of the same order as D. In such a situation, one may consider using an indirect pump to improve the Talbot peak intensities. Similarly, the Rabi frequency of the control field must also be optimized to obtain maximum peak intensities.…”

Effect of laser detuning and Rabi frequency on rubidium Rydberg electromagnetically-induced transparency for atom-based electric field sensing

“…In order to establish a connection between simulations and experimental observations, the absorption of the quantum system is analyzed using Beer's law. In the case of Rydberg EIT for electric field sensing, this phenomenon is typically observed in a glass cell containing atoms of interest [4,5]. By introducing EIT beams into the cell and measuring the transmission of the probe beam, the resulting signal can be expressed as…”

Simple Python tools for modelling few-level atom-light interactions

“…As noted earlier, often the parameter of interest is the probe coherence ρ 21 as this is proportional to the absorption of the probe laser through the medium. Since ρ 21 = ρ * 12 , we will usually extract ρ 12 from the vector of the solution as this is always at the same index within the vector ρ vect ( [1]) whereas the position of ρ 21 will vary depending on the number of levels. The probe absorption is then α 12 ∝ Im[ρ 12 ].…”

“…Up until this point we have not considered the effects of temperature on the atomic ensemble. These effects arise due to the motion of the atoms and can include collisional effects and modifications due to interactions with a laser beam of finite size [1]. In this tutorial we will only consider the firstorder Doppler effects due to the velocity of the atoms within the ensemble, and we will neglect any collisional or time-offlight effects.…”

“…The simplest way to describe atom-light interactions is to consider a classical picture, such as Einstein's rate equations. However classical descriptions do not give rise to many phenomena of interest in atomlight systems such as electromagnetically induced transparency (EIT) [1]. In order to see how these effects emerge, a semi-classical approach must be used that takes into account Original Content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.…”