Electromagnetically induced transparency: Optics in coherent media

Abstract

Coherent preparation by laser light of quantum states of atoms and molecules can lead to quantum interference in the amplitudes of optical transitions. In this way the optical properties of a medium can be dramatically modified, leading to electromagnetically induced transparency and related effects, which have placed gas-phase systems at the center of recent advances in the development of media with radically new optical properties. This article reviews these advances and the new possibilities they offer for nonlinear optics and quantum information science. As a basis for the theory of electromagnetically induced transparency the authors consider the atomic dynamics and the optical response of the medium to a continuous-wave laser. They then discuss pulse propagation and the adiabatic evolution of field-coupled states and show how coherently prepared media can be used to improve frequency conversion in nonlinear optical mixing experiments. The extension of these concepts to very weak optical fields in the few-photon limit is then examined. The review concludes with a discussion of future prospects and potential new applications. CONTENTS

Metamaterials: a new frontier of science and technology

“…Another appealing topic associated with meta-atom interactions is electromagnetically induced transparency (EIT), 71 recently investigated by several groups. [72][73][74][75][76][77][78][79][80] EIT was first discovered in atomic systems.…”

“…[72][73][74][75][76][77][78][79][80] EIT was first discovered in atomic systems. In a three-level atomic EIT system, 71 the coupling between the excited energy level |2i with a dipole-allowed transition to the ground state |1i and a metastable level |3i by a control beam leads to a destructive interference ( Fig. 8(a)).…”

Quantum nonlinear optics with single photons enabled by strongly interacting atoms

“…Here we demonstrate a medium that is nonlinear at the level of individual quanta, exhibiting strong absorption of photon pairs while remaining transparent to single photons. The quantum nonlinearity is obtained by coherently coupling slowly propagating photons [3][4][5] to strongly interacting atomic Rydberg states [6][7][8][9][10][11][12] in a cold, dense atomic gas 13 . Our approach opens the door for quantum-byquantum control of light fields, including single-photon switching 14 , all-optical deterministic 1 quantum logic 15 , and the realization of strongly correlated many-body states of light 16 .…”

“…For a single incident probe photon, the control field induces a transparency window in the otherwise opaque medium via Electromagnetically Induced Transparency (EIT), and the probe photon travels at much reduced speed in the form of a coupled excitation of light and matter (Rydberg polariton). However, in stark contrast to conventional EIT 5 , if two probe photons are incident onto the Rydberg EIT medium, the strong interaction between two Rydberg atoms tunes the EIT transition out of resonance, thereby destroying the EIT and leading to absorption 14,22,23,25,26 . The experimental demonstration of an extraordinary optical material exhibiting strong two-photon attenuation in combination with single-photon transmission is the central result of this work.…”

Steady-state solution for dark states using a three-level system in coupled quantum dots

“…CPT is a typical phenomena of quantum coherence in three-level system and has been intensively studied in optics [12][13][14][15][16] . By adjusting two laser fields, the electron population between the lowest two energylevels are coherently transferred.…”