Electromagnetically Induced Transparency

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Electromagnetically Induced Transparency(EIT)

• Presenter
• B. Younessi
• Bonab University

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Overview

• Introduction
• The history of EIT
• The Physics of EIT
• Some EIT-related phenomena

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Introduction
Electromagnetically induced transparency is a
technique for eliminating the effect of medium on
a propagating beam of electromagnetic radiation.
A weak probe normally experiences absorption
shown in blue. A second coupling beam induces EIT
and creates a "window" in the absorption region
(red).
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The history of EIT

• The Physical effect that is the essence of EIT is
  called coherent population trapping which was
  discovered in 1976 by Gerardo Alzetta and his
  coworkers at University of Pisa in Italy
• Population trapping introduced and shown by Olga
  Kocharovskaya and Yakov Khanin at the Kalinin
  Leningrad Polytechnic institute in 1986
• EIT introduced in 1990 and experimentally
  observed in 1991 by Steve Harris
• (Atac Imamoglu, K. Boller, Marlan Scully, have
  also played important roles in developing EIT)

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The Physics of EIT
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The Physics of EIT(Physical and Optical
Properties of Rubidium 87 )
From Quantum mechanics we have J LS L orbital
angular momentum S spin angular momentum The
hyperfine structure is a result of the coupling
of J with the total nuclear angular momentum I.
The total atomic angular momentum F is then given
by FJI
I total nuclear angular momentum The magnitude
of F can take the values
For the ground state in 87Rb, L 0 and S 1/2,
so J 1/2 for the first excited state, L 1,
so J 1/2 or J 3/2 the L0
L1 (D line) transition is split into two
components the D1 line
and the D2 line
For the 87Rb ground state, J 1/2 and I 3/2,
so F 1 or F 2.
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The Physics of EIT(Physical and Optical
Properties of Rubidium 87 )
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The Physics of EIT(Static description of EIT)
The total Hamiltonian can be written as
After having introduced the dipole approximation
as well as the rotating wave approximation, the
interaction Hamiltonian can be represented in a
rotating frame by
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The Physics of EIT(Static description of EIT)
The eigenvalues of the interaction Hamiltonian
can be calculated to
It is straightforward to verify that the
corresponding eigenstates of the interaction
Hamiltonian are
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The Physics of EIT(Static description of EIT)
If
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The Physics of EIT(The origin of EIT)
The ground state becomes identical to the dark
state from which excitation cannot occur
This results in EIT
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The Physics of EIT(Dynamic description of EIT)
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The Physics of EIT(Dynamic description of EIT)
Master Equation
Polarization
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The Physics of EIT(Density matrix solution)
By applying perturbation theory
Off-diagonal density-matrix elements
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The Physics of EIT(The linear susceptibility)
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The Physics of EIT(EIT)
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EIT-related phenomena (Slow light)
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EIT-related phenomena (Light storage)
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EIT-related phenomena (Experimental setup)
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Thanks for your attention and patience! Any
questions?