Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review

Radiation Damping and the Polarization of Fluorescence Radiation

GREGORY A. BREIT, Irving S. Lowen

Published Oct 1, 1934• 17 citations
Publisher

Abstract

If the distance between two or more energy levels is comparable to their natural breadth, the levels cease to act independently. The coupling between the levels is then describable by means of a "damping constant matrix." The usual discussions concern themselves with a diagonal damping constant. Below a systematic treatment of emission, absorption and fluorescence is given without this restriction and it is shown how in general the frequencies of emission lines are affected by this radiation coupling. The theory is applied to the calculation of the polarization of fluorescence radiation. It is shown that the coupling state of the lower group of levels of the fluorescence line does not influence the polarization. Results of detailed calculations are given for the polarization of $\mathrm{H}\ensuremath{\alpha}$ excited by absorption of the second line of the Lyman series.

DOI
10.1103/physrev.46.590

Related papers

THEORY OF COHERENT RESONANT ABSORPTION AND EMISSION AT INFRARED AND OPTICAL FREQUENCIES

Helen S. Freedhoff, Jan Van Kranendonk

The theory of the line shape in coherent resonant absorption and emission in the infrared and optical region is developed. The Dicke spin model and the Lorentz oscillator model of a radiating molecule are discussed in detail, and the complications arising for degenerate levels are analyzed. The absorption and emission spectra are expressed in terms of the damped normal modes of the system of equivalent oscillators interacting via the retarded dipole–dipole interaction, and the results are shown to be identical with those derived using Heitler's quantum theory of radiation damping. The theory is applied to small clusters and linear chains of molecules. For a chain that is small compared with the wavelength, the natural line width is proportional to the total number of molecules, whereas for a long chain the width approaches a constant value. The discussion of three-dimensional systems, and the application to the zero-phonon lines in the infrared spectrum of solid hydrogen will be given in a separate paper.

Canadian Journal of Physics•May 1, 1967•41 citations

A General Solution for the Equations of Natural Line Breadth

Lyman Spitzer

A rigorous solution is given to the Dirac radiation equations for a single radiative transition between two atomic states. The resultant formulas are valid for any appropriate variation with frequency both of the density of light quanta and of the matrix component for the transition. The usual infinity at high frequencies is eliminated naturally. Applications of the formulas are made for the case of an absorption or an emission line.

Physical Review•Feb 15, 1939•14 citations

Resonance Fluorescence in Gases and Molecular Crystals

Hendrik F. Hameka

A general theoretical description is derived for the resonance fluorescence of dilute gases and molecular single crystals with special emphasis on optical rotation spectra. The validity of previous theoretical work on dilute gases is confirmed by proving that the damping constants connecting excited states on different molecules are zero. It is shown that the intensities of optical rotation spectra of molecular crystals are much larger than the corresponding quantities for gases. An important theoretical prediction is that the natural line breadth of a resonance fluorescence emission band belonging to an exciton state in a molecular crystal should be larger than the width of the corresponding optical absorption line. The dependence of the intensity of the optical rotation spectrum on the relative orientation of the crystal with respect to the incident beam of light is discussed.

The Journal of Chemical Physics•May 1, 1963•14 citations

Inelastic collisions and fluorescence in gases

Haider R. Zaidi

The fluorescence spectrum from a multilevel system, in the presence of inelastic collisions which couple the upper states, is calculated in the impact limit. The results are expressed in terms of the collision rates (elastic and inelastic), the collision broadening rates, and the natural damping rates. The integrated intensities are also calculated, and the results are compared with the rate equation results. It is shown that the standard rate equation analysis of the experimental data is not valid when the lower state interaction is significant. The Doppler effect is also included in the general theory of the fluorescent line shapes, and the modification of the profile because of the velocity dependence of the collision rates is discussed.

Canadian Journal of Physics•Sep 1, 1979•3 citations

Self-Coupling of a Two-Level System by a Mirror

Hans Morawitz

We discuss, from a classical as well as a quantum-mechanical point of view, the effect of the coupling of an excited two-level system with itself due to emission and absorption of electric-dipole radiation, the emitted radiation being reflected by a nearby mirror. Expressions familiar from resonance-scattering theory are found for the shift of the transition frequency and linewidth from their values in the absence of the mirror. This renormalization effect leads to spatial modulation in the transition frequency and width of the excited state due to its resonant interaction with itself via the radiation field reflected from the mirror. This formalism is applied to some recent experiments with monomolecular dye layers. The experimental values of the fluorescence lifetime are in good agreement with the theory for distances from 500 to 6000 \AA{}.

Physical Review•Nov 25, 1969•229 citations

Effects of coupled atomic states on the resonance scattering of radiation

Rajat Srivastava, Peter R. Fontana

The excitation and decay probabilities for resonance scattering of radiation from an atom with two coupled excited states in an external static field are calculated as a function of time and frequency. Various oscillatory terms are found in the probabilities. These oscillations depend on the frequency of radiation, the external coupling and the energy difference between the excited states. Two special cases are investigated in detail. In the first case where one of the excited states does not decay a 'hole' appears in the emission line at a frequency equal to the frequency difference between the ground state and the unperturbed non-decaying excited state. In the second case where the two excited states decay with the same rate, one of the two lines in the emission spectrum is suppressed and the other is enhanced.

Journal of Physics B Atomic and Molecular Physics•Jun 1, 1974•3 citations
If the distance between two or more energy levels is comparable to their natural breadth, the levels cease to act independently. The coupling between the levels is then describable by means of a "damping constant matrix." The usual discussions concern themselves with a diagonal damping constant. Below a systematic treatment of emission, absorption and fluorescence is given without this restriction and it is shown how in general the frequencies of emission lines are affected by this radiation coupling. The theory is applied to the calculation of the polarization of fluorescence radiation. It is shown that the coupling state of the lower group of levels of the fluorescence line does not influence the polarization. Results of detailed calculations are given for the polarization of H\ensuremathα\mathrm{H}\ensuremath{\alpha}H\ensuremathα excited by absorption of the second line of the Lyman series.
The theory of the line shape in coherent resonant absorption and emission in the infrared and optical region is developed. The Dicke spin model and the Lorentz oscillator model of a radiating molecule are discussed in detail, and the complications arising for degenerate levels are analyzed. The absorption and emission spectra are expressed in terms of the damped normal modes of the system of equivalent oscillators interacting via the retarded dipole–dipole interaction, and the results are shown to be identical with those derived using Heitler's quantum theory of radiation damping. The theory is applied to small clusters and linear chains of molecules. For a chain that is small compared with the wavelength, the natural line width is proportional to the total number of molecules, whereas for a long chain the width approaches a constant value. The discussion of three-dimensional systems, and the application to the zero-phonon lines in the infrared spectrum of solid hydrogen will be given in a separate paper.
A general theoretical description is derived for the resonance fluorescence of dilute gases and molecular single crystals with special emphasis on optical rotation spectra. The validity of previous theoretical work on dilute gases is confirmed by proving that the damping constants connecting excited states on different molecules are zero. It is shown that the intensities of optical rotation spectra of molecular crystals are much larger than the corresponding quantities for gases. An important theoretical prediction is that the natural line breadth of a resonance fluorescence emission band belonging to an exciton state in a molecular crystal should be larger than the width of the corresponding optical absorption line. The dependence of the intensity of the optical rotation spectrum on the relative orientation of the crystal with respect to the incident beam of light is discussed.
The fluorescence spectrum from a multilevel system, in the presence of inelastic collisions which couple the upper states, is calculated in the impact limit. The results are expressed in terms of the collision rates (elastic and inelastic), the collision broadening rates, and the natural damping rates. The integrated intensities are also calculated, and the results are compared with the rate equation results. It is shown that the standard rate equation analysis of the experimental data is not valid when the lower state interaction is significant. The Doppler effect is also included in the general theory of the fluorescent line shapes, and the modification of the profile because of the velocity dependence of the collision rates is discussed.
We discuss, from a classical as well as a quantum-mechanical point of view, the effect of the coupling of an excited two-level system with itself due to emission and absorption of electric-dipole radiation, the emitted radiation being reflected by a nearby mirror. Expressions familiar from resonance-scattering theory are found for the shift of the transition frequency and linewidth from their values in the absence of the mirror. This renormalization effect leads to spatial modulation in the transition frequency and width of the excited state due to its resonant interaction with itself via the radiation field reflected from the mirror. This formalism is applied to some recent experiments with monomolecular dye layers. The experimental values of the fluorescence lifetime are in good agreement with the theory for distances from 500 to 6000 \AA{}.
The excitation and decay probabilities for resonance scattering of radiation from an atom with two coupled excited states in an external static field are calculated as a function of time and frequency. Various oscillatory terms are found in the probabilities. These oscillations depend on the frequency of radiation, the external coupling and the energy difference between the excited states. Two special cases are investigated in detail. In the first case where one of the excited states does not decay a 'hole' appears in the emission line at a frequency equal to the frequency difference between the ground state and the unperturbed non-decaying excited state. In the second case where the two excited states decay with the same rate, one of the two lines in the emission spectrum is suppressed and the other is enhanced.